A chest x-ray taken by her family physician 1 year previously showed bilateral infiltrates. At that time she was diagnosed with pneumonia and treated with several courses of oral antibiotics, including amoxicillin, with no clinical improvement.
Her symptoms continued to worsen, as did her pulmonary infiltrates, as shown on a more recent chest x-ray. (See p. 2 for a more comprehensive history.)
SHORT DIFFERENTIAL DIAGNOSIS:
* HIV infection.
* Antibody deficiency secondary to drug complications, infectious disease, malignancy, or systemic disorder.
* Hyper-IgM syndrome.
* Common variable immune deficiency.
WORK-UP: The patient's past medical history revealed numerous infectious and immunologic problems, including mild varicella as a preschooler, follicular hyperplasia, adenoidal hypertrophy, splenomegaly, a goiter and hypothyroidism associated with Hashimoto's thyroiditis, multiple episodes of otitis media necessitating several myringotomies, and infectious mononucleosis. She was not sexually active and had no known contact with anyone with tuberculosis.
She was 5 feet 4 inches tall and weighed 142 pounds, putting her at the 85th weight percentile. Her blood pressure was 100/85 mm Hg, her heart rate was 96 beats/min, and her respiratory rate was 18 per minute. She had enlarged tonsils.
Her laboratory tests and pulmonary function tests all were within normal limits. She underwent another chest x-ray, which showed bilateral opacities and infiltrates as well as hilar enlargement.
Relatives on her father's and mother's sides suffered from a variety of infectious and immune disorders, including leukemia, viral pleural pericarditis, asthma, emphysema, and inflammatory bowel disease, among others.
The patient had an IgG level of 0.62 g/L, well below the normal range of 5.49 to 15.84 g/L. Specifically, she was low in IgG subtypes 1-3 and at the low-normal end of subtype 4. Her IgA level, at less than 0.07 g/L, also was below the normal range of 0.61-3.48 g/L. Her IgM level was within normal limits.
Her antibody titers to measles, mumps, rubella, and varicella zoster virus IgG all were negative. Her tetanus antibody was undetectable, and her diphtheria antibody was 0.02[micro]g/mL. She also tested negative for Epstein-Barr virus DNA on polymerase chain reaction, and she was negative for antibodies to cytomegalovirus.
She tested negative for HIV and any other condition associated with secondary immune deficiency.
Agammaglobulinemia is characterized by a complete absence or marked deficiency of immunoglobulins and lymphoid hypoplasia.
It was ruled out because this patient did have measurable IgG and IgA titers and a normal level of IgM as well as lymphoid hyperplasia.
Lymphoid hyperplasia and tonsillar hy pertrophy, plus elevated levels of IgM, characterize hyper-IgM. However, this patient had a normal IgM level. What's more, the syndrome usually occurs in boys.
Common variable immune deficiency (CVID) is the most prevalent primary immune deficiency and results when B cells fail to differentiate into plasma cells, leading to defective antibody formation. Reduced titers of IgG and IgA are the hallmarks of the disorder; about 50% of patients also have low IgM. T-cell function also is deficient in about 50% of cases.
CVID is characterized by recurrent, pyogenic infections, including otitis media, chronic sinusitis, and pneumonia that sometimes progresses to bronchiectasis. Some patients also develop malabsorption syndromes.
Severe, recurrent herpes simplex virus infections also are common with CVID. The disease is associated with an increased risk of non-Hodgkin's lymphoma, malignant lymphoma, and gastrointestinal carcinoma as patients enter their fifth and sixth decades of life.
Autoimmune diseases, including lymphoid interstitial pneumonia and autoimmune endocrinopathies such as thyroiditis, occur in approximately 22% of patients.
Twenty-year survival after diagnosis is about 67% in women and 64% in men. Lymphoma is the most frequent cause of death.
FINAL DIAGNOSIS: Common variable immune deficiency.
TREATMENT: The patient was treated with IV immune globulin 300-500 mg/kg every 2-4 weeks, with the goal of accumulating a trough IgG level greater than 500 mg/dL. Her symptoms improved, she experienced less shortness of breath, and she has been contracting fewer infections.
This case was presented by Dr. Kirsten Miller, a pediatric resident at the University of British Columbia, Vancouver, at a conference sponsored by the North Pacific Pediatric Society.
To comment on this case or offer an unusual case for publication, write to PEDIATRIC News, 12230 Wilkins Ave., Rockville, MD 20852;fax 301-816-8738; or e-mail firstname.lastname@example.org.
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|Title Annotation:||common variable immune deficiency|
|Date:||Nov 1, 2003|
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