Infection Associated Hemophagocytic Histiocytosis and Its Effect on Hematological Parameters

Infection associated hemophagocytosis may result from immunologic activation of mononuclear phagocyte system. The phenomenon of HP may affect various organ functions and hematological parameters. Exaggerated HP can lead to HPS which is a fatal condition. Recognizing and treating this disorder (anticytokine therapy) and underlying infection may save the life of the patient. The aim of the present study was to determine the etiology and grading of hemophagocytosis (HP) associated with infection and its effect on haematological parameters, and, to correlate it with the clinicopathological effects of hemophagocytic syndrome (HPS). A total of sixty two patients suffering from infection of varied etiology were included in this study. Bone marrow aspiration was done in all the cases along with complete blood counts. Bone marrow smears were examined for HP and its intensity and effect on hematological parameters was recorded. Among the sixty two patients included in this study, 27% (17/62) had viral infection followed by enteric fever (21%; 13/62), tuberculosis and visceral leishmaniasis (14% each; 9/62 each), malaria (13%; 8/62), brucellosis and others (5% each; 3/62). Most patients showed either moderate (grade II, 50%; 31/62) or severe degree (grade III, 34%; 21/62) of HP. Hemophagocytic syndrome was present in 34% patients. Patients with increased intensity of HP in the bone marrow had profound effect on hematological parameters; particularly hemoglobin and platelet count, resulting in the depression of these formed elements. Viral, bacterial and parasitic infections play an important role in the causation of histiocytic hyperplasia with HP. It may present as HPS with multisystem disorder which could be fatal if improperly diagnosed and left untreated. Severe intensity of HP has a profound effect on hematology parameters of patients particularly on hemoglobin level, total leukocyte count) and platelet count with a drastic decrease in all of the parameters during the severe disease course.