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Approach to the patient with neutropenia in childhood.

Abstract

Neutrophils have an important role in host defense and acute inflammation. It is well known that susceptibility to infection increases when the neutrophil count is low. Neutropenia were classified as mild, moderate and severe according to the neutrophil counts, or acute and chronic depending on the duration of neutropenia, or congenital and acquired according to the mechanism. The patients with neutropenia are clinically different due to underlying mechanism, they have life- threatening infections or no infection may be observed. The most common cause of acquired neutropenia is viral infection, followed by drugs and autoimmune neutropenia. Congenital neutropenia are usually diagnosed by acute and life- threatening invasive bacterial and fungal infections. Immune system disorders and other systemic abnormalities may be accompanied or not. Recent years, novel single gen defects causing congenital neutropenia were defined through advanced genetic techniques. Molecular diagnosis is useful for risk stratification, choice of therapy and prognosis on follow- up. This review was prepared for pediatricians as a guide focused on approach neutropenia, which tests should be performed and when should be referred to a specialist. (Turk Pediatri Ars 2015; 50: 136-44)

Keywords: Children, congenital neutropenia, acquired neutropenia, neutropenia

Introduction

Neutrophils or polymorphonuclear leukocytes develop from the stem cells in the blood marrow. These cells are involved in acute inflammation and host defense against bacterial infections and phagocytosis occurs in these cells.

1-1.5X[10.sup.9]/kg neutrophils are produced daily in the human body and they are found in the storage pool in the bone marrow. Only 2-5% enter the circulation. A portion of these cells are located on the vascular wall (1).

The average lifespan of neutrophils is 7-10 days. Maturation stages in the bone marrow are as follows: stem cell, myeloblast, promyelocyte, myelocyte, metamyelocyte, band and neutrophil. The cells do not divide after the stage of myelocyte. Generally, half of the cells in the bone marrow are composed of white blood cells. The majority of these cells include metamyelocytes and the following mature cells. The band cells and neutrophils in the bone marrow constitute 50% of the granulocyte series. Mature nautrophils are trasferred to the tissues after staying in the circulation for 3-12 hours and live there for 2-3 days (1, 2).

For neutrophils to function adequately, they should primarily be produced in adequate numbers in the bone marrow, should be transferred to the peripheral circulation in adequate numbers, migrate rapidly to the area of infection and engulf and kill microorganisms. One of the most important one among these necessary features is adequate number of neutrophils (1-3).

An absolute neutrophil count (ANC) below the normal level by age and race is defined as neutropenia.

The lower limit of neutropenia in newborns is 6 000/m[m.sup.3]. As the baby grows up, this limit reduces to 1 000/m[m.sup.3] by the second week and this level is accepted to be normal up to the age of one year. After the age of one year the lower limit is 1 500/m[m.sup.3]. In the black race, this limit is accepted to be 1200/m[m.sup.3] (3, 4).

The absolute/total neutrophil count can be calculated simply using the following formula:

Absolute neutrophil count (ANC)=white blood cell count X (neutrophil % + band cell %)/100

Neutropenias are classified by absolute neutrophil count as follows:

1 000-1 500/m[m.sup.3]: mild neutropenia

500 - 1 000/m[m.sup.3]: moderate neutropenia

<500/m[m.sup.3]: severe neutropenia

<100/m[m.sup.3]: very severe neutropenia (3, 4).

Predisposition to infection is increased in neutropenia. This relation has been known well since 1960s. However, the main determinant in the relation of neutropenia and infection is not always the neutrophil count. In clinical pratice, there are patients who have never had infection or severe infection, though their neutrophil counts are below 500/m[m.sup.3]. In this case, the determinant is not the count of circulating neutrophils, but the neutrophil storage in the bone marrow. If the storage is enough, no infection occurs. The severity of neutropenia and the frequency and severity of infection are inversely proportional.

If cell production in the myeloid series is decreased or the storage is reduced in the bone marrow, the risk of infection is high. In neutropenia caused by increased destruction in the peripheral blood, the risk of infection is lower. If neutropenia is not alone and is accompanied by neutrophil dysfunction, hypogammaglobulinemia or malnutrition and the patient's age is young, the risk of infection increases further (3, 4).

The agent in neutropenic patients is usually the endogenous flora. The gingiva, nail beds and anal region should be examined carefully in all neutropenic patients. The signs of infection may be supressed in these patients, but fever is almost always observed as a finding of inflammation. If a neutropenic patient has no fever, though he/she looks ill, the picture is very severe and the patient is usually lost in a short time.

In the period of neutropenia, the neutrophil count is attempted to be increased by using growth factors. Granulocyte colony stimulating factor (G-CSF) is one of these growth factors which enables maturation of the neutrophil precursors by stimulating them and lets them be transferred to the peripheral blood earlier (1, 3, 5).

Causes of neutropenia

1. Decreased production

2. Inability to be transferred from the bone marrow to the peripheral blood (ineffective production)

3. Increased margination-sequestration (pseudoneu-tropenia)

4. Increased destruction

Neutropenia may also be classified as acute or chronic and acquired or congenital.

If a finding persists longer than 14 days, it is generally considered to have become chronic in medicine. For neutropenia this period is stated to be two months in some books and six months in some others. It has been stated that correction of neutropenia even following a simple event may last for up to 8-12 months. Therefore, it is thought that calling neutropenia "chronic" before 6 months is not very appropriate (1, 3-5).

There are two more neutropenia types with unclear etiology which are difficult to classify as acquired or congenital and which are observed in the childhood: chronic benign neutropenia and familial neutropenia.

Chronic benign neutropenia

Chronic benign neutropenia is the most common cause of neutropenia in children below the age of four years in cases where an infection cannot be demonstrated. There is no underlying infectious, inflammatory or malign disease in these patients. There is no history of similar disease in the family. The absolute neutrophil count ranges between 200 and 500/m[m.sup.3]. The disease has a benign course independent of the severity of neutropenia. In these patients, the bone marrow is either normal or an increase in the myeloid precursors is observed and maturation is observed to be paused in the late stage. Rarely, anti-neutrophil antibodies are found in the sera of the patients. However, the etiology is still not clear. In the beginning, corticosteroids, splenectomy and cytotoxic agents were being used in treatment targeting the antibodies, but adequate response could not be obtained. Currently, the risk of infection is successfully reduced with G-CSF. However, G-CSF is recommended to be used in cases of repetetive infection complications because of the benign character of the disease (1, 3-6).

Benign familial neutropenia

Neutropenia is observed more commonly in some ethnic groups. Neutropenia is mild and therefore, there is no predisposition to infections. It has an autosomal dominant inheritance and examination of the bone marrow is normal. Therefore, blood counts of the parents and siblings should also be examined even if there are no complaints in neutropenic patients (3).

Acquired neutropenias

The cause of neutropenia in acquired neutropenias is shortening of the neutrophil lifespan because of destruction or increased consumption of the neutrophils in the peripheral blood. The bone marrow is normal or there is pausing in late maturation in the metamyelocyte/band stage. The risk of development of infection in acquired neutropenias is substantially lower compared to the other neutropenias (7-9).

1. Infection-related neutropenia

Since infections are observed commonly in children, the most common cause of neutropenias observed in this period is also infections. Acute transient neutropenias most commonly occur after viral infections. Acute transient neutropenia starts in a few days before the onset of infection and continues until viremia ends. Viral infections including varicella, measels, rubella, hepatitis A and B, influenza, cytomegalovirus, Ebstein-Barr virus, parvovirus B19, adenovirus and coxsackie lead to neutropenia by causing to a reduction in production and increase in destruction. In "human immunodeficiency virus infection", immune mechanisms in which anti-neutrophil antibodies and hypersplenism are involved are also effective. Neutropenia may also be observed in bacterial infections including S. aureus, brucella, rickettsia and tubeculosis. Use of G-CSF may be beneficial in patients with neutropenia caused by depletion of storage pools in the bone marrow and inadequate production in severe sepsis (1, 4, 6-8).

2. Neutropenia related with medications

Currently, many different medications may lead to neutropenia. Dose-dependent bone marrow supression is observed most commonly with chemotherapy drugs, phenothiazines, semi-synthetic penicillins, non-steroid anti-inflammatory drugs, aminopyrine derivatives, barbiturates, gold compounds, sulfonamides and antithyroid drugs. Neutropenia develops in 2-3 months with use of medications and it is expected to improve in approximately 10 days with discontinuation of the drug, but this period may sometimes be longer. Rarely, neutropenia may occur as a result of idiosyncratic supression of myeloid production with antibiotics, anti-diabetics, antihistaminics and antihypertensive drugs, destruction of neutrophils related with differences in drug metabolism (phenothiazine, thiouracil) and leukocyte destruction due to antibodies developing against the leukocyte-drug complex (phenylbutasone, chlorpropamide) (3, 4, 7, 8).

3. Autoimmune neutropenia

This is a chronic neutropenia which occurs because of destruction of neutrophils by neutrophil specific IgM and IgG antibodies produced against NA1, NA2, ND1, ND2 and NB1 antigens in neutrophils. Autoimmune neutropenias may be related with secondary causes or may occur primarily without being related with any disease (10, 11).

a) Primary autoimmune neutropenia

This occurs rarely and is observed mostly in girls and in children below the age of two years. Recurrent mild cutaneous and upper respiratory tract infections are found commonly. The gold standard in the diagnosis is demonstration of neutrophil specific autoantibodies, but negative autoantibodies do not exclude the diagnosis. The bone marrow is normal. The disease has a good prognosis and neutropenia generally improves spontaneously. The total neutrophil count ranges between 0 and 150/m[m.sup.3], but infections are mild. Most patients are given prophylactic antibiotic (trimethoprim-sulfa-methoxazole), whereas immunosupressive drugs are not used. If there is a severe infection, high dose intravenous immunoglobulin and G-CSF may be used in addition to antibiotics.

b) Secondary autoimmune neutropenia

This is usually observed in adults. It constitutes a part of autoimmune diseases. It occurs less commonly compared to autoimmune anemia and thrombocytopenia. Cytotoxic drugs including cyclosporin and methotrexate directed to antibody are used in treatment. G-CSF may be used to reduce the risk of development of infection especially when the neutrophil count reduces below 1000/m[m.sup.3]. When secondary autoimmune neutropenia is considered in children, autoimmune lymph-oproliferative syndrome (ALPS) and Evans syndrome should be considered primarily, if rheumatic disease is not considered. Both diseases are characterized with lymphadenopathy, splenomegaly and autoimmunity. When autoimmune neutropenia is associated with hemolytic anemia and thrombocytopenia, Evans syndrome should be considered. Increased apoptosis as a result of Fas mutations is the cause of the disease (1, 3, 4, 7-11).

4. Isoimmune neonatal neutropenia

This is similar to Rh hemolytic disease of the newborn. It occurs as a result of destruction of neutrophils by way of placental transfer of the antibodies produced in the sensitized mother against HNA1, HNA2, HNA3, HNB1 and HNC1 antigens in the baby's neutrophils. In brief, it may be described as Rh disease which occurs against neutrophils rather than red blood cells. The disease which is characterized with moderate of severe neutropenia occurs in 2 of 1000 live births. Although it does not generally cause to too many problems, bone marrow examination should be performed in neutropenic newborns who have severe infections including recurrent bacterial infection or sepsis and granulocyte transfusion or G-CSF should be administered, if pause in early maturation is found (4, 7, 8).

Neutropenia starting immediately after delivery and lasting for up to 30 days may occur in approximately 50% of the babies of hypertensive mothers. Thrombocytopenia frequently accompanies neutropenia. Bone marrow supression is found in these babies (1, 3).

In addition, complement is activated, margination of neutrophils increases and pseudoneutropenia may occur in burns and acute respiratory distress syndrome.

Similarly, neutropenia may develop with neutrophil destruction as a result of activation of complement in paroxysmal nocturnal hemoglobinuria. In folic acid, cupper and vitamin B12 deficiency, neutropenia may occur because of ineffective myelopoesis in addition to megaloblastic anemia (1, 3, 8).

Neutropenias due to hereditary causes

These neutropenias develop in relation with disruption in any stage of growth or maturation of neutrophils. They occur rarely, but are important because they lead to recurrent infections and have a chronic course.

After 2000s, congenital severe neutropenias have been started to be resolved genetically. Early apoptosis is the cause of neutropenia in most of these neutropenias (12-18).

1. Kostmann syndrome

Kostmann syndrome was described by Swedish Kostmann for the first time in 1956. The most important finding of the disease is severe bacterial infections observed in the early childhood which start from the delivery. There is severe neutropenia; the neutrophil count is below 200/m[m.sup.3]. The incidence is 12/1 000 000 and the female/male ratio is equal. Although it generally has an autosomal recessive inheritance, it may also occur as a result of autosomal dominant inheritance or spontaneous mutations (1, 3). Mutations in the neutrophil elastase gene are responsible of this syndrome. These mutations stop maturation in the promyelocyte/myelocyte stage in the bone marrow. Clinically, severe bacterial infections including omphalitis, otitis, pneumonia, sepsis and cutaneous and hepatic abscesses are found. If these infections are not treated, they threaten life and the most commonly found agents include staphylococci, streptococci, gram negative bacilli and fungi. The disease becomes symptomatic in the first month in 50% of the cases and in the first six months in 100% of the cases (12-14). More than 95% of the patients give response to low dose (3-10 [micro]g/kg) G-CSF.

Granulocyte colony stimulating factor increases the number of neutrophils and decreases the frequency of infections by correcting the pause in maturation of myelocytes. The patients are not lost because of infection. If they survive, G-CSF receptor mutations occur in 12% and cytogenetic changes including monosomia 7 occur in 50%. In presence of cytogenetic changes, these patients carry a risk of malignant transformation (myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML)). Bone marrow trasnplantation should be performed in the patients who are unresponsive to granulocyte colony stimulating factor. If bone marrow transplantation is to be performed, it should be performed in the neutropenic period. It is emphasized that the success rate is very low, when it is performed after malignant disease develops. It is known that the risk of development of MDS and AML is high in patients who receive a daily G-CSF dose above 8 g/kg. Although a relation between malignant transformation and use of G-CSF is suspected, it is rather interpreted such that it is related with a decrease in losses due to infection and occurence in this group of patients who can live up to advanced ages (15-17).

2. Cyclic neutropenia

Cyclic neutropenia is characterized with fever, painful oral ulcers, lymphadenopathy and recurrent infections which develop in relation with recurrent severe neutropenia. It has an autosomal dominant inheritance and the mutations in the neutrophil elastase gene are responsible of this disease similar to Kostman syndrome. These mutations cause to neutropenia by accelerating apoptosis in neutrophil presursors (18). Cyclic neutropenia generally occurs below the age of one year. Fever, oral ulcers, lymphadenopathy and severe neutropenia occur every 21 days (14-42 days) as regular attacks. The attacks generally last for 3-6 days and patients are asymptomatic during the intervals and the neutrophil counts are normal (6, 12-14). Most patients can be followed up by reducing the problems using low dose G-CSF. The interval between the attacks prolongs and the period of neutropenia shortens with granulocyte colony stimulating factor (1, 6).

3. Shwachman-Diamond syndrome

This syndrome which generally becomes symptomatic during infancy is characterized with autosomal recessive exocrine pancreatic failure, short stature, developmental retardation, immune disorder, hepatic disease, skeletal abnormalities and hematological involvement. Its incidence ranges between 1/100 000 and 1/200 000. It is more common in males. Pancreatic failure (steatorrhea, malabsorption) is observed in addition to neutropenia which is specific for the syndrome. In addition, growth and developmental retardation and skeletal abnormalities in the form of metaphysiel dysplasia may be found. Anemia, increased HbF level, thrombocytopenia, disrupted neutrophil chemotaxis may be observed in addition to neutropenia. These patients should be monitored closely. Malign diseases may be found in the follow-up. Oral pancreatic enzymes are used for pancreatic failure, cyclosporin A is used for bone marrow failure and G-CSF is used for deep neutropenia. Bone marrow transplantation should be performed as soon as possible (1, 3, 19).

4. Myelokathexis

This is a rare cause of severe neutropenia which has an autosomal dominant inheritance. Disruption occurs in neutrophils in the bone marrow as a result of decreased expression of Bclx which is an antiapoptotic protein and release of these cells into the peripheral blood is disrupted (ineffective myelopoesis). Use of granulocyte colony stimulating factor may increase the neutrophil count. It has a form which is abbreviated as WHIM (Warts, Hypogammaglobulinemia, Infections, Myelokathexis). Extensive warts, hypogammaglobulinemia, infections and myelokathexis are found in this syndrome (1, 12, 18).

5. Reticular dysgenesis

Reticular dysgenesis is disruption in undifferentiated stem cells; none of the myeloid cells can be produced. Erythrocyte and platelet production is normal. Agranulocytosis and lymphoid hypoplasia are present. Abnormal T cells and a marked reduction in IgA and IgM levels are observed. The bone marrow is hypoplasic. The patients are lost in early infancy because of severe bacterial infections. The only treatment method is bone marrow transplantation in the early stage (1, 3, 12, 18).

6. Dyskeratosis congenita

This is a X-linked disease characterized with bone marrow hypoplasia, mild neutropenia, nail dystrophy and cutaneous reticular hyperpigmentation. Neutropenia is mild and infections are rare (1, 3, 12, 18).

7. Neutropenia related with immunological disorders

Neutropenia may accompany many immune deficiencies (gammaglobulin abnormalities, T cell defects, natural killer cell abnormalities). These patients generally present with recurrent bacterial infections, hepatosplenomegaly and developmental retardation in childhood. Since consanguineous marriages are common in Turkey, there is a history of similar disease in the family. Neutropenia is observed with a rate of of 25% in X-linked agammaglobulinemia and with a rate of 50% in X-linked hyperimmune M syndrome.

The cause of neutropenia in immune deficiency syndromes has not been elucidated fully. Mostly, decreased production and autoimmune mehanisms are blamed. In hyperimmune M syndrome, it is thought that G-CSF production is not triggerred bcause of disrupted CD40 ligand on the surface of B lymphocytes and this leads to neutropenia. Treatment should be directed to the primary disease rather than neutropenia (1, 3, 10).

8. Neutropenia related with metabolic diseases

Neutropenia is observed in congenital metabolic diseases including hyperglycinuria, orotic aciduria, metylmalonic aciduria, hyperglycinemia and more commonly glucogen storage disease (GSD) type 1b patients. In glucogen storage disease, hypoglycemia, convulsions and hepatosplenomegaly are observed in relation with disruption in glucose-6-phosphate translocase enzyme. In glucogen storage disease type 1b, neutropenia and neutrophil dysfunction are present in contrast to the other types. Although the cause of neutropenia and neutrophil dysfunction is not known clearly, maturation pause in the myelocyte stage in the bone marrow may be observed. In some patients, there is problem in release of neutrophils into the peripheral blood. G-CSF is used in treatment, but it should be kept in mind that hypersplenism requiring splenectomy may occur in long-term use (1, 3, 4, 7, 9).

9. Other causes

Rarely, isolated neutropenia may be observed in the initial phase of bone marrow failure syndromes involving the whole bone marrow. Afterwards, other series may be affected (3).

Evaluation of neutropenic patients

In evaluation of the patients, neutropenia should be confirmed primarily. When a neutropenic blood count is found, blood count is repeated on the blood sample which is ensured to have been obtained under appropriate conditions and not kept waiting, using a qualified automation device. Examination should be performed after neutropenia is confirmed with peripheral smear. In addition, findings directed to specific diagnoses should be evaluated with peripheral smear. For example, presence of blasts suggests leukemia, nucleated erythrocytes suggest hemolytic anemia or blood loss, hypersegmented neutrophils suggest vitamin [B.sub.12] or folic acid deficiency and neutrophils with pycnotic nuclei suggest myelokathexis. The tables which show standard neutrophil counts by age should be referred to in order to confirm neutropenia. Generally, repetetive blood counts are performed to exclude transient neutropenia observed in viral infections in young children.

[FIGURE 1 OMITTED]

Neutropenia may also rarely be found as a result of relative reduction in the peripheral blood because of adhesion of neutrophils onto the vascular wall or hiding in the spleen and bone marrow. Two different tests are performed to demonstrate these situations (1, 3):

1. Neutrophil reserve in the vascular wall

Epinephrine (adrenaline) test (0.1 mL 1: 1 000 sc): the absolute neutrophil count is measured at the 5th, 10th, 15th and 30th minutes.

Normal: increase of the figure by two-fold.

2. Bone marrow neutrophil reserve

a. Cortisone stimulation test (5 mg/kg IV): The absolute neutrophil count is measured every hour for 6 hours. Normal: An increase of 2 000/m[m.sup.3] in the neutrophil count.

b. Typhoid stimulation test (0.5 mL vaccine s.c) (currently not performed frequently): The absolute neutrophil count is measured at the 3rd, 6th, 12th and 24th hours. Normal: A 3-4-fold increase is expected in the absolute neutrophil count.

If the patient is considered neutropenic, a diagnosis is attempted to be made using the flowchart in Figure 1 according to history, findings, physical examination and presence of old blood counts.

A detailed history including the time of onset of neutropenia, the severity and frequency of infection, presence of recurrent infections, medications used and unexplained infant deaths in the family should be taken. On physical examination, growth and development retardation, phenotypical abnormalities and findings of infection should be noted. The mucous membranes, gingiva, teeth, skin, tympanic membranes, perianal region, liver, spleen and lymph nodes and nail bed and surroundings should specifically be examined carefully and the family should be taught to regularly check these regions. In presence of petechiae and purpura, thrombocytopenia should be suspected and systemic diseases should be considered. Presence of rheumatic findings should be investigated.

The severity and duration of neutropenia determine the extent of laboratory studies. If the patient is found to be neutropenic during viral infection or a short time after viral infection, complete blood count should be repeated 2-4 weeks later. Generally, neutropenia improves during this period and examination of bone marrow is not needed. However, neutropenias which develop secondary to infection rarely last for longer than eight weeks and may persist for up to one year. Patients with a history of recurrent severe infections secondary to neutropenia should be investigated in detail. In the early phase, it is sometimes difficult to understand if neutropenia has caused to infection or infection has caused to neutropenia (1, 3).

Complete blood count is performed 2-3 times a week for six weeks to differentiate cyclic neutropenia from severe chronic neutropenia. Bone marrow aspiration and cytogenetic examination are needed both for identification of myeloid cell maturation and for the diagnosis of myelodysplastic syndrome and leukemia. Patients who have diarrhea or malabsorption together with neutropenia should be examined in terms of Shwachman-Diamond syndrome. Growth and development should be closely monitored in children with recurrent infections caused by chronic severe neutropenia. ANA should be tested in patients with findings of rheumatic disease and vitamin [B.sub.12] and folic acid levels should be measured in patients with malnutrition. Neutropenic patients with recurrent infections and a familal history of sibling death should definitely be evaluated in terms of immune deficiency.

If the cause of neutropenia is HAX gene mutation, neurological problems are present in 30% of the cases (epileptic seizures, learning difficulty, developmental disorder) (15, 16).

Tests to be ordered in neutropenic patients: one should not hurry to order tests for neutropenic patients. The clinical picture should always be directive for investigations. In case of severe, recurrent infections, acting quickly can sometimes save the patient's life. It should be kept in mind that the majority of neutropenias in the childhood are secondary to infection and the tests are expensive and not availabe everywhere. History of drug use should be taken carefully in neutropenic patients and patients should be followed up for at least two months after discontinuing all drugs, if possible. Follow-up should not be discontinued quickly in neutropenic patients. One should be careful in terms of MDS and leukemia, but this should not be shared much with the family. Otherwise, we can create a hypochondriac patient group who have their complete blood counts performed almost every day in outpatient clinics (1, 3).

Laboratory tests:

1. Complete blood count, absolute neutrophil count and reticulocyte count

2. A 6-8 week chart, three times a week to exclude cyclic neutropenia

3. Maturation stages and pausing in the granulocyte series should be noted on bone marrow examination and erythrocyte and platelet series should also be examined

4. Karyotype and FISH should be studied on bone marrow samples in terms of the risk of development of MDS and leukemia (especially monosomia 7 and 5q)

5. Electron microscopic examination

6. Identification of antineutrophil antibody

a. Granulocyte immunoflourescence test (GIFT)

b. Granulocyte indirect immunoflourescence test (GIIFT)

c. Granulocyte agglutination test (GAT)

d. Enzyme-linked immunoassasy (ELISA)

e. Monoclonal Antibody Immobilization of Granulocyte Antigens (MAIGA)

7. Immunological tests

a. Immunoglobulins (IgA, IgG, IgM, IgE)

b. Cellular immunity (lymphocyte subgroups T cell proliferation, T cell subgroup examination, NK counts and function skin tests, purified protein derivative (PPD) test)

c. Antinuclear antibodies, C3, C4, CH50

8. Screening for metabolic diseases

a. Amino acid screening in plasma and urine

b. Serum vitamin [B.sub.12], folic acid and copper levels

9. Findings of pancreatic disease

a. Findings of exocrine pancreatic failure: fecal fat, pancreatic enzyme, serum tripsinogen and isoamilase levels

b. Evaluation of the pancreas in terms of lipomatosis with computarized tomography

10. Identification of chromosome breakage (specifies Fanconi anemia)

11. Bone graphies (cartilage-hair hypoplasia, Shwachman-Diomand syndrome, Fanconi anemia)

12. Serum muramidase level (indicates ineffective myelopoesis)

13. Flow cytometry examination CD55 and CD59 (PNH disease)

14. Bone density measurement (osteoporosis and osteopenia are present in 14% of neutropenic patients)

15. Gene mutation examinations (ELA2, GFI-1, WAS, SBDS (Shwachman-Diomand syndrome), HAX1, TAZ (Barth syndrome), Fanconi genes, LYST (Chediak Higashi syndrome), G6PC3 deficiency)

Treatment and use of G-CSF in chronic neutropenias

Satisfactory outcomes could be obtained after introduction of G-CSF in chronic neutropenias. Only antibiotics and lithium derivatives had been used previosly and a good clinical response could not be observed. The results of international severe chronic neutropenia records found that the neutrophil count became normal, infections could be prevented and the symptoms of inflammation decreased in more than 90% of the patients using G-CSF. In congenital neutropenia, a good response was obtained with a higher dose. In the idiopathic group, response could be obtained with lower doses. Unresponsive patients constitute a small group of the patients with congenital neutropenia and they are lost, if early bone marrow transplantation (BMT) is not performed. These drugs which stimulate neutrophil production in the bone marrow are administered subcutaneously at an appropriate dose with appropriate intervals. They may cause to side effects including fever, shivering and muscle and bone pain. Since these side effects are observed only in the beginning of treatment, they do not cause to problems in treatment compliance. As emphasized in the part of Kostmann syndrome, the claims that G-CSF treatment causes to malignant transformation especially in patients with congenital neutropenia constitute the side effect which is discussed to the greatest extent. The survival times of patients with chronic neutropenia have prolonged with granulocyte colony stimulating factor. As a result, the thought that G-CSF saves time for development of malignancy predominates. In this patient group, G-CSF also improves the quality of life by markedly decreasing infections in addition to increased surivival time. The risk of MDS/leukemia was found to be 11.8% in patients (50/422) with severe neutropenia who had been followed up between 1987 and 2005. Again, the annual risk of development of MDS/leukemia was found to be 2% in 374 patients who had been using G-CSF for at least ten years in another study. In these patients, the risk of development of MDS/leukemia was found to be 22% 15 years later. The risk is higher in patients with a ANC of <2.1X109/L despite use of a dose of >8[micro]g/kg/day (1, 3, 12-14, 18).

When you have a neutropenic patient;

- Hospitalize the patient if he/she looks toxic and has a body temperature persisting above 37.5 [degrees]C.

- Obtain cultures immediately (especially hemoculture, urine culture, throat culture and culture of infected area, if present).

- Initiate a wide spectrum antibiotic by the intravenous or intramuscular route (should have strong gram negative efficiceny).

- If microorganism is grown in culture, antibiotic treatment is continued for 10-14 days by the intravenous route.

- If no microorganism is grown in culture, continue antibiotic treatment until fever subsides and neutropenia improves (this condition may not be valid for patients who are known to have neutropenia previously).

- Put the patient in a single room, if possible or in accompaniment with another patient who is known to have no infection for sure.

- Limit entry of guests and other healthcare workers.

- Be sure that people entering the room have washed their hands.

- Clean the skin surface with povidone or chlorhexidine solution before each intervention.

- Avoid interventions by way of oral mucosa, perineum and rectum (rectal temperature measurement, enema and rectal palpation should be avoided).

- Administer antibiotic to prevent development of secondary bacterial infections in presence of oral ulcers and gingivitis, make the patient rinse his/her mouth with 3% hydrogen peroxide and make him/her use a soft toothbrush.

- If the patient has a diagnosis (especially Kostmann, Shwachman-Diomand or severe neutropenia), initiate G-CSF at a dose of 5 [micro]g/kg and increase the dose rapidly by the neutrophil count.

Innovations in neutropenia

Genetics is gradually gaining importance to a greater extent in neutropenic patients. Many patients with neutropenia who can not be diagnosed and classified are diagnosed and treatment approach and follow-up for these patients are pursued in a qualified way. Newly defined genetic mutations and clinical findings were explained in the symposium related with congenital neutropenias held in March 2015 in Europe. Until the present time, a total of 19 gene defects including 7 gene mutations leading to congenital neutropenia (ELANE; CXCR4, SBDS, PT14, HAX1, G6PC3, RUNX1) and different genetic diseases accompanied by neutropenias have been identified (12). JAGN-1 deficiency which has been very recently identified is also one of the causes of severe neutropenia. It has autosomal recessive inheritance and adequate increase in the neutrophil count is not found with G-CSF treatment (20). Since RUNX1 and CSF3R mutations among congenital neutropenias carry a potential for leukemia, G-CSF should be used carefully in patients with these mutations (21). In addition, patients who have ELANE, SDS or GATA2 mutation also carry a risk for development of leukemia (12, 22). ELANE gene mutation may present with a picture of both cyclic neutropenia and congenital neutropenia. AML/MDS does not develop in patients with a clinical picture of cyclic neutropenia, whereas AML/MDS is found with a rate of 15% in patients with a picture of congenital neutropenia (6). In congenital neutropenia, the factors which determine the risk of leukemia include the neutrophil count, mutation type and intensity of G-CSF treatment. It is showed that, use of vitamin B3 (niacin) and G-CSF in treatment of severe congenital neutropenia as a novelty increased neutrophil count significantly at the end of four weeks (23). New immune deficiency syndromes have been found in recent years while elucidating the etiology of neutropenia in the light of genetic examinations. In DOCK2 and DOCK8 deficiencies, invasive bacterial and viral infections are observed starting from early ages. Increased IgE, allergy and fungal infections are more frequent especially in DOCK-8 deficiency, while lymphopenia, disrupted antibody response, natural killer cell and neutrophil dysfunction are more prominent in DOCK2 deficiency. This disease can be healed completely with bone marrow transplantation (24).

Peer-review: Externally peer-reviewed.

Author Contributions: Concept - T.C.; Design - T.C., B.K.; Supervision - T.C.; Funding - T.C., B.K.; Materials - T.C., B.K.; Collection and/or Processing - T.C., B.K.; Analysis and/or Interpretation - T.C., B.K.; Literature Review - T.C., B.K.; Writer - T.C., B.K.; Critical Review - T.C., B.K.; Other - T.C., B.K.

Conflict of Interest: No conflict of interest was declared by the authors.

Financial Disclosure: The authors declared that this study has received no financial support.

References

(1.) Boxer L, Dale DC. Neutropenia: causes and consequences. Semin Hematol 2002; 39: 75-81. [CrossRef]

(2.) Kruger P, Saffarzadeh M, Weber AN, et al. Neutrophils: between host defence, immune modulation, and tissue injury. PLoS Pathog 2015; 11: e1004651. [CrossRef]

(3.) Lanzkowsky P. Manual of pediatric hematology and oncology. 5th ed. New York: Churchill Livingstone Inc, 2011. p. 275-95.

(4.) Walkovich K, Boxer LA. How to approach neutropenia in childhood. Pediatr Rev 2013; 34: 173-84. [CrossRef]

(5.) Welte K, Zeidler C. Severe congenital neutropenia. Hematol Oncol Clin North Am 2009; 23: 307-20. [CrossRef]

(6.) Dale DC, Welte K. Cyclic and chronic neutropenia. Cancer Treat Res 2011; 157: 97-8. [CrossRef]

(7.) Boxer LA. How to approach neutropenia. Hematology Am Soc Hematol Educ Program 2012; 2012: 174-82.

(8.) Berliner N, Horwitz M, Loughran TP Jr. Acquired neutropenia. Hematology Am Soc Hematol Educ Program 2004; 63-79. [CrossRef]

(9.) Fioredda F, Calvillo M, Bonanomi S, et al. Congenital and acquired neutropenia consensus guidelines on diagnosis from the Neutropenia Committee of the Marrow Failure Syndrome Group of the AIEOP (Associazione Italiana Emato-Oncologia Pediatrica). Pediatr Blood Cancer 2011; 57: 10-7. [CrossRef]

(10.) Starkebaum G. Chronic neutropenia associated with autoimmune disease. Semin Hematol 2002; 39: 121-7. [CrossRef]

(11.) Farruggia P, Dufour C. Diagnosis and management of primary autoimmune neutropenia in children: insights for clinicians. Ther Adv Hematol 2015; 6: 15-24. [CrossRef]

(12.) Hauck F, Klein C. Pathogenic mechanisms and clinical implications of congenital neutropenia syndromes. Curr Opin Allergy Clin Immunol 2013; 13: 596-606. [CrossRef]

(13.) Ozbek N. Konjenital notropenilere genetik bakis. TJH 2009; 26: 1-8.

(14.) Zeidler C, Germeshausen M, Klein C, Welte K. Clinical implications of ELA2-, HAX1-, and G-CSF-receptor (CSF3R) mutations in severe congenital neutropenia. Br J Haematol 2009; 144: 459-67. [CrossRef]

(15.) Roques G, Munzer M, Barthez MA, et al. Neurological findings and genetic alterations in patients with Kostmann syndrome and HAX1 mutations. Pediatr Blood Cancer 2014; 61: 1041-8. [CrossRef]

(16.) Freedman MH, Alter BP. Risk of myelodysplastic syndrome and acute myeloid leukemia in congenital neutropenias. Semin Hematol 2002; 39: 128-33. [CrossRef]

(17.) Rosenberg PS, Zeidler C, Bolyard AA, et al. Stable longterm risk of leukaemia in patients with severe congenital neutropenia maintained on G-CSF therapy. Br J Haematol 2010; 150: 196-9. [CrossRef]

(18.) Klein C. Congenital neutropenia. Hematology Am Soc Hematol Educ Program 2009; 1: 344-50. [CrossRef]

(19.) Dror Y. Shwachman-Diamond syndrome. Pediatr Blood Cancer. 2005; 45: 892-901. [CrossRef]

(20.) Boztug K, Jarvinen PM, Salzer E, et al. JAGN1 deficiency causes aberrant myeloid cell homeostasis and congenital neutropenia. Nat Genet 2014; 46: 1021-7. [CrossRef]

(21.) Skokowa J, Steinemann D, Katsman-Kuipers JE, et al. Cooperativity of RUNX1 and CSF3R mutations in severe congenital neutropenia: a unique pathway in myeloid leukemogenesis. Blood 2014; 123: 2229-37. [CrossRef]

(22.) Collin M, Dickinson R, Bigley V. Haematopoietic and immune defects associated with GATA2 mutation. Br J Haematol 2015; 169: 173-87. [CrossRef]

(23.) Khanna-Gupta A, Berliner N. Vitamin B3 boosts neutrophil counts. Nat Med 2009; 15: 139-41. [CrossRef]

(24.) Aydin SE, Kilic SS, Aytekin C, et al. DOCK8 deficiency: clinical and immunological phenotype and treatment options - a review of 136 patients. J Clin Immunol 2015; 35: 189-98. [CrossRef]

Tiraje Celkan, Begum Cirin Koc

Division of Pediatric Hematology-Oncology, Istanbul University Cerrahpasa Faculty of Medicine, Istanbul, Turkey

This study was presented at the 11th Uludag Pediatrics Winter Congress, 15-18 March 2015, Bursa.

Address for Correspondence: Begum Sirin Koc, Istanbul Universitesi Cerrahpasa Tip Fakultesi, Cocuk Hematoloji-Onkoloji Bilim Dali, Istanbul, Turkiye. E-mail: begumsirins@hotmail.com

Received: 23.03.2015

Accepted: 30.03.2015
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Title Annotation:Review
Author:Celkan, Tiraje; Koc, Begum Sirin
Publication:Turkish Pediatrics Archive
Article Type:Report
Date:Sep 1, 2015
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