Histoplasma capsulatum Infection in an Allogeneic Hematopoietic Stem Cell Transplant Patient Receiving Voriconazole Prophylaxis

Abstract

Histoplasma capsulatum infection is a rare complication in the allogeneic stem cell transplant patients. Minimal guidance exists on how to appropriately manage histoplasmosis in these patients. We report a patient who developed Histoplasma pneumonia while receiving voriconazole prophylaxis at a therapeutic trough level. The patient experienced significant clinical improvement after initiation of itraconazole pharmacotherapy. We recommend a lower threshold for evaluation for histoplasmosis in allogeneic hematopoietic stem cell transplant recipients who live in endemic regions, regardless of their antifungal prophylactic regimen.

A review of endemic mycoses after hematopoietic stem cell transplantation

“…There were 16 published reports on endemic fungal infection after HSCT that met the criteria for inclusion in this review. [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] The majority of these reports were from the United States, and there was one report each from India, 14 from Turkey, 3 and from Hong Kong. 17 These 16 reports described nine cases of histoplasmosis, 2,[5][6][7]9,11,13,14,16 seven cases of coccidioidomycosis, 4,8,10,12,15 and two cases of talaromycosis.…”

“…[2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] The majority of these reports were from the United States, and there was one report each from India, 14 from Turkey, 3 and from Hong Kong. 17 These 16 reports described nine cases of histoplasmosis, 2,[5][6][7]9,11,13,14,16 seven cases of coccidioidomycosis, 4,8,10,12,15 and two cases of talaromycosis. 3,17 There were no published cases of paracoccidioidomycosis and blastomycoses among HSCT recipients.…”

“…16 The diagnosis of histoplasmosis after HSCT was confirmed by a combination of histopathology and culture (n = 2), 7,16 histopathology alone (n = 6), 5,6,9,11,13,14 or serology (n = 1). 2 Notably, serum galactomannan was also positive in two recipients, 5,7 and blastomyces urine antigen was detected in 1. 9 Only two were initially treated with an amphotericin B product, 5,9 while the rest (n = 4) were treated with an azole.…”

“…There were nine cases of histoplasmosis reported among seven allogeneic 2,5,6,11,13,14,16 and two autologous 7,9 HSCT recipients. All were male, with a median age of 45 (range 21-75) years.…”

“…One recipient who lived in an endemic area also raised chickens and worked with heavy machinery. 16 Four patients had a history of aGVHD 2,5,11,16 prior to presentation, but the onset of histoplasmosis in relation to GVHD was only reported in three. 2,5,16 Two recipients 5,16 presented within a month of aGVHD diagnosis and treatment.…”