Fatal reactive hemophagocytosis related to disseminated histoplasmosis with endocarditis: an unusual case diagnosed at autopsy.

Abstract: Reactive hemophagocytic syndrome (RHS) is an uncommon life-threatening disorder. It is believed to be caused by widespread non-neoplastic proliferation and inappropriate activation of mature macrophages, resulting in excessive cytokine activation which leads to hematophagocytosis by cells of the macrophage-monocyte lineage and multiorgan dysfunction. RHS may be associated with infections caused by bacterial, viral and fungal organisms as well as lymphoproliferative disorders, nonhematopoietic malignancies, autoimmune diseases and some therapeutic drugs. Immunosuppression is a frequent underlying condition in RHS. The following case presentation describes a patient with a history of chronic hepatitis C, cryoglobulinemia, renal failure and Staphylococcus aureus perinephric abscess and bacteremia, who, at autopsy, was found to have disseminated histoplasmosis with fungal endocarditis and RHS.

Key Words: autopsy, fungal endocarditis, disseminated histoplasmosis, reactive hemophagocytic syndrome

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Reactive hemophagocytic syndrome (RHS) is a potentially fatal disorder characterized by marked activation of the monocyte-macrophage cell line leading to excessive hemophagocytosis. (1) It is commonly associated with immunosuppression and postulated to be caused by hyperactivation of T lymphocytes resulting in excessive cytokine secretion and macrophage activation. (1-3) Hypercytokinemia leads to fever and multiorgan dysfunction including pancytopenia, disseminated intravascular coagulation (DIC), diffuse alveolar damage, hepatosplenomegaly, elevation of serum ferritin, triglycerides and liver enzymes and neurologic disorders. (2,3) RHS can be triggered by non-neoplastic and neoplastic conditions including systemic bacterial, viral and fungal infections, lymphoproliferative disorders, malignancies, autoimmune diseases and therapeutic agents.

RHS has been reported in association with disseminated histoplasmosis in AIDS patients and, less frequently, in immunosuppressed, non-AIDS patients. (4-11) To our knowledge, there have been no autopsy descriptions of Histoplasma-associated RHS and few well-illustrated autopsy descriptions of Histoplasma endocarditis. The following is a case report of Histoplasma-associated RHS, diagnosed at autopsy, in an HIV-negative patient treated with corticosteroids for hepatitis C virus-associated cryoglobulinemia.

Case Report

A 52-year-old male with a history of chronic hepatitis C and hypertension was brought to the emergency department because of confusion, lethargy and poor oral intake of two weeks' duration.

Six months before final admission, he had been diagnosed with chronic hepatitis C and mixed cryoglobulinemia. A liver biopsy obtained during this evaluation revealed grade 3 lobular activity, stage II portal fibrosis, steatosis and multiple granulomas of undetermined significance. Findings were interpreted as consistent with chronic hepatitis C. Subsequently, chronic hepatitis C and cryoglobulinemia were treated with prednisone 40 mg/d, ribavirin and interferon for several months. No valvular abnormalities were detected on echocardiography (echo). Four months before final admission, the patient developed renal failure and underwent a kidney biopsy interpreted as mesangial proliferative glomerulonephritis with no evidence of cryoglobulin deposition. The biopsy procedure was complicated by formation of an infected perinephric hematoma, accompanied by four successive blood cultures positive for methicillin-susceptible Staphylococcus aureus. Repeat echo revealed a thickened aortic valve with a mobile mass on the right coronary cusp, and he was treated for six weeks with nafcillin and received hemodialysis. Two months before final admission, after completion of the antibiotic regimen for presumed bacterial endocarditis, the patient developed intermittent fever, chills, nausea, vomiting and confusion, was again hospitalized and received a six-week course of antibiotics for methicillin-sensitive S aureus, based on a positive perinephric fluid aspirate. On final admission, the patient was febrile, delirious, had diffuse abdominal tenderness and a painful right parotid gland. Culture of parotid gland aspiration grew 4+ methicillin-resistant Staphylococcus aureus, 4+ enterococcus and 3+ Candida tropicalis. He had a white blood cell count of 1.5 X [10.sup.3]/[micro]L with a predominance of granulocytes. Electrolytes were within normal limits, and neither pulmonary infiltrates nor lymphadenopathy were seen on chest x-ray. Blood cultures were obtained and were reported as negative for bacterial organisms. A mobile vegetation, unchanged compared with the study performed 8 weeks previously, was noted on echo. Again, antibiotics were initiated for treatment of suspected S aureus bacteremia and persistent infective endocarditis; however, over the ensuing seven days the patient developed bilateral pulmonary infiltrates, pancytopenia, coagulopathy, metabolic acidosis, and hypotension. Nadir values for white blood cell, red blood cell and platelet counts were 0.7 X [10.sup.3]/[micro]L, 2.74 X [10.sup.6]/[micro]L and 17 X [10.sup.3]/[micro]L, respectively. On his final day of life, the patient's activated partial thromboplastin time was 105 seconds, prothrombin time was 23.7 seconds and fibrinogen was 97 mg/dL. Serum lactate dehydrogenase was 2723 mg/dL, BUN was 61 mg/dL and creatinine was 4.8 mg/dL. A bone marrow biopsy was planned, but was deferred owing to hemodynamic instability and the family's request to limit diagnostic procedures. The patient expired eight days after admission. HIV screening test (enzyme immunoassay), performed retrospectively on blood drawn antemortem, was negative.

Autopsy Findings

A swelling in the region of the right parotid gland was noted, and a fine needle aspirate (FNA) was performed for cytologic evaluation. The lungs were heavy (right: 1050 g, left: 1100 g), firm and subcrepitant; however, no focal lesions were seen grossly. The heart weighed 490 g. The aortic valve was tricuspid, and there were vegetations present on the ventricular aspects of all three cusps. The largest vegetation measured 2.0 X 1.5 X 1.2 cm and was located on the right coronary cusp. Those on the noncoronary and left coronary cusps measured 1.0 X 0.7 X 0.2 cm and 0.5 X 0.5 X 0.2 cm, respectively. The vegetations firmly adhered to the valves and were not friable. No purulent exudate was noted. The cusps were fairly moveable, and the valves appeared to be architecturally intact. No perforations were found. (Fig. 1) The largest vegetation was sectioned, scraped with a scalpel blade, and slide preparations were made. Moderate to severe atherosclerosis of the coronary arteries was noted in the left anterior descending artery and left circumflex artery. There was marked hepatosplenomegaly. The spleen weighed 1610 g, and the liver weighed 3700 g. Two firm, tan, wedge-shaped subcapsular infarcts were seen in the spleen. A 9.5 X 5.5 X 2.8 cm, maroon mass containing bright yellow, hematoidin-like pigment was found adjacent to and adherent to the capsule of the right kidney. This finding was consistent with an organizing hematoma.

Postmortem Cytology Findings

Fine needle aspiration of the right parotid gland showed neutrophilic and histiocytic exudate, necrotic debris and Gram positive cocci. Romanowsky-stained scrape preparation of the cardiac vegetation contained very scanty mononuclear cells and the presence of abundant extracellular, oval, yeast-like cells, 2 to 4 [micro]m in length with pale blue endoplasm, a magenta-colored cap at one pole and a thin, clear zone surrounding the yeast endoplasm. Occasional budding forms were seen. Yeast morphology was typical of Histoplasma capsulatum (Fig. 1). Romanowsky-stained scrape preparation of the perinephric hematoma contained old blood, rhomboid and cocklebur-shaped golden pigment typical of hematoidin and few mononuclear cells. Neither bacteria nor neutrophilic exudates were seen.

Histopathology

The aortic valve vegetations all had similar histology. The superficial portions of the vegetations were composed largely of fibrin with focal calcifications and abundant yeastlike cells entrapped within the fibrin. Inflammatory cells were absent within the superficial and mid portions of the vegetations. At the bases of the vegetations, there were fibroblasts, Anitschkow cells and macrophages. Neutrophils were not seen, and the underlying valve tissue was intact. No yeast was found within the myocardium. There were hyaline membranes and edema, indicative of diffuse alveolar damage, and the presence of focal hemorrhage in both lungs. A solitary, microscopic granuloma containing His-toplasma-like yeast was found within the right lung. Scanty yeast forms were seen within mononuclear phagocytes of the liver, spleen and kidneys. There was moderate hepatic steatosis and grade 2 fibrosis. Methenamine silver (GMS) stains were performed, retrospectively, on antemortem liver biopsy, and no fungi were identified. A striking finding was the presence of numerous benign-appearing, hemophagocytic macrophages within the bone marrow, spleen and liver. At least 20% of the bone marrow cells were macrophages (Fig. 2). No fungi were identified on GMS-stained rib bone marrow sections.

Postmortem Culture Results

After review of scrape preparation of valvular vegetation, a sample of unfixed spleen was submitted for microbial cultures. Also, a not yet discarded blood culture bottle was retrieved, and a request was made to hold the bottle for an additional three weeks to evaluate for fungal growth. Three weeks later, both blood and spleen cultures were positive for Histoplasma capsulatum.

Discussion

This complex case might be thought of as a labyrinthine journey to the heart of Darling, Histoplasma capsulatum having been described by Darling in 1906. The presence of multiple comorbid conditions hindered diagnostic efforts. The past history of S aureus-infected hematoma following kidney biopsy made the clinical assumption of bacterial endocarditis reasonable. Routine blood cultures had been held only one week for bacterial growth, insufficient time for growth of H capsulatum. Histoplasma capsulatum endocarditis is an uncommon complication of disseminated histoplasmosis that may occur in patients with no underlying valvular disease. (12) We do not believe that this case represents histoplasmosis superimposed upon S aureus endocarditis on the basis of the absence of neutrophils and the absence of destruction of the valve cusp that one would expect in the case of S aureus endocarditis. Neutrophils were present within the parotid gland aspirate, making neutropenia an unlikely explanation for the complete absence of polymorphonuclear leukocytes within the heart valve. It is our opinion that the patient was successfully treated for S aureus bacteremia and that his parotiditis was a separate, unrelated disease entity. The large, nondestructive vegetations, composed predominantly of fibrin and extracellular yeast, are consistent with published descriptions of Histoplasma endocarditis. (13,14) Although hyphal forms have been described in some reports of H capsulatum endocarditis, (15) only yeast-like forms were seen in this case. The heart valve lesion had been presumed at autopsy to be bacterial endocarditis; and, therefore, only a scrape preparation was done before placement of heart into fixative. Use of postmortem cytologic scraping preparations allowed for early recognition of the etiologic agent of endocarditis and appropriate culture protocols.

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The presence of pancytopenia, diffuse alveolar damage, severe coagulopathy and neurologic status changes can all be explained on the basis of the hypercytokinemia found in reactive hemophagocytic syndrome. (1-3) In this case, coagulopathy and progressive multiorgan failure were thought to be caused by sepsis-associated DIC. Bone marrow biopsy and fungal culture could have established the diagnosis antemortem; however, the patient expired before bone marrow could be sampled. The presence of multiple splenic infarcts in this case is consistent with a reported high rate of systemic embolization (58%) associated with Histoplasma capsulatum endocarditis. (16)

This patient's disease fits the clinical criteria for RHS. (1) Review of the literature revealed 16 cases of histoplasmosis-associated RHS. (4-11) Ten of these reported cases were in AIDS patients. One had unknown HIV status. Of the remaining five non-AIDS patients, four were being treated with immunosuppressive drugs because of leukemia (1 case), Crohn disease (1 case) or solid organ transplantation (2 cases). The fifth patient had chronic mucocutaneous candidiasis, a primary immunodeficiency disorder characterized by selective defect of cell-mediated immunity. All five reported cases recovered after receiving antifungal therapy. This case represents the first detailed autopsy report and the 6th case of disseminated histoplasmosis and RHS in an HIV-negative patient. We speculate that steroid-associated immunosuppression predisposed the patient to disseminated histoplasmosis, fungal endocarditis and RHS.

Hemophagocytic syndrome occurs in association with a wide variety of infections, neoplasms, collagen vascular diseases, and acquired and inherited immunodeficiency states. The association with infectious disease is particularly important because life-threatening RHS can obscure the clinical features of the underlying infection and negatively affect outcome. A high index of suspicion is required for early recognition of RHS as the cause of unexplained pancytopenia. Successful management depends on the early identification and treatment of a causative infectious agent. This case illustrates the diagnostic challenge imposed by Histoplasma endocarditis and the numerous deleterious effects of hemophagocytosis on organ function.

References

1. Tsuda H. Hemophagocytic syndrome (HPS) in children and adults. Int J Hematol 1997;65:215-226.

2. Fujiwara F, Hibi S, Imashuku S. Hypercytokinemia and hemophagocytic syndrome. Am J Pediatr Hematol Oncol 1993;15:92-98.

3. Ohga S, Maatsuzaki A, Nishizaki M, et al. Inflammatory cytokines in virus-associated hemophagocytic syndrome: interferon gamma as a sensitive indicator of disease activity. Am J Pediatr Hematol Oncol 1993;15:291-298.

4. Koduri PR, Chundi V, DeMarais P, et al. Reactive hemophagocytic syndrome: a new presentation of disseminated histoplasmosis in patients with AIDS. Clin Infect Dis 1995;21:1463-1465.

5. Chemlal K, Andrieu-Bautru V, Couvelard A. Hemophagocytic syndrome during Histoplasma capsulatum infection. Haematologia 1997;82:726.

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9. Rao RD, Morice WG, Phyliky RL. Hemophagocytosis in a patient with chronic lymphocytic leukemia and histoplasmosis. Mayo Clin Proc 2002;77:287-290.

10. Reiner AP, Spivak JL. Hematophagic histiocytosis: a report of 23 new patients and a review of the literature. Medicine (Baltimore) 1988;67:369-388.

11. Majluf-Cruz AS, Hurtado-Monroy R, Souto-Meirino C, et al. Hemopaghocytic syndrome associated with histoplasmosis in the acquired immunodeficiency syndrome: description of 3 cases and review of the literature. Sangre (Bare) 1993;38:51-55.

12. Blair TP, Waugh RA, Pollack M, et al. Histoplasma endocarditis. Am Heart J 1980;99:783-788.

13. Berman B. Histoplasmosis endocarditis. Sinai Hospital J (Balt) 1960;9:4-8.

14. Goodwin RA Jr, Shapiro JL, Thurman GH. Disseminated histoplasmosis: clinical and pathologic correlations. Medicine (Baltimore) 1980;59:1-33.

15. Svirbely JR, Ayers LW, Buesching WJ. Filamentous Histoplasma caspulatum endocarditis involving mitral and aortic valve porcine bioprostheses. Arch Pathol Lab Med 1985;109:273-276.

16. Bhatti S, Vilenski L, Tight R, et al. Histoplasma endocarditis: clinical and mycologic features and outcomes. J Infect 2005;51:2-9.

Zhiqin Wang, MD, Alexander G. Duarte, MD, and Vicki J. Schnadig, MD

From the Departments of Pathology and Internal Medicine, University of Texas Medical Branch, Galveston, TX.

Reprint request: Vicki J. Schnadig, MD, Department of Pathology, Division of Cytopathology, John Sealy Annex, Room 9.300, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555-0548. Email: [e-mail]

Accepted July 27, 2006.

RELATED ARTICLE: Key Points

* Disseminated histoplasmosis-associated reactive hemophagocytosis usually occurs in patients with acquired immunodeficiency syndrome (AIDS), but it can also be seen in HIV-negative, immunosuppressed patients.

* Reactive hemophagocytic syndrome (RHS) is believed to represent systemic activation of cytokines leading to pancytopenia, hepatosplenomegaly and multiorgan failure. All of these clinical findings can be also seen in bacterial sepsis without RHS.

* Histoplasma endocarditis is characterized by slow progression of a nondestructive vegetation.

* This report illustrates the diagnostic challenge imposed by disseminated fungal infection and reactive hemophagocytic syndrome, especially when complicated by a history of Staphylococcus aureus infection.