Role of hemophagocytic histiocytosis in the etiology of thrombocytopenia in patients with sepsis syndrome or septic shock.

We conducted a study to assess the incidence and outcome of hemophagocytic histiocytosis (HH) in thrombocytopenic patients with sepsis syndrome or septic shock and to define the possible associations between HH, disseminated intravascular coagulation (DIC), and platelet-associated IgG (PAIgG) in promoting thrombocytopenia. Twenty immunocompetent thrombocytopenic patients were included. Bone marrow aspirates were obtained from each patient to identify hemophagocytic histiocytes. Coagulation parameters, PAIgG levels, and bacterial and viral infections were studied. Twelve patients with HH were identified. The presence of DIC and of PAIgG were often associated with this disease. No herpesvirus infection was demonstrated. Eight of the 12 patients with HH and four of the eight patients without HH died (P = NS). The results of this study suggest that HH could be involved in the development of thrombocytopenia in immunocompetent patients with sepsis syndrome or septic shock. HH does not seem to be associated with increased mortality.