Diversity and combinations of infectious agents in 38 adults with an infection-triggered reactive haemophagocytic syndrome: a multicenter study.

Reactive haemophagocytic syndrome (HS) is a rare condition that occurs in patients with infections, haematological malignancies or autoimmune diseases. Although various microorganisms are thought to trigger HS, most of the literature data on this topic have been gathered in single-centre case series. Here, we sought to characterize infectious triggers in a large, multicentre cohort of patients with HS. Patients were included in the present study if HS was solely due to one or more infections. Detailed microbiological data were recorded. Of the 162 patients with HS in the cohort, 40 (25%) had at least one infection and 38 of the latter (including 14 women, 36.8%) were included. The median age was 46 years. Seven patients were presumed to be immunocompetent (18.4%), whereas 19 patients (50%) were infected with human immunodeficiency virus and 12 patients (31.6%) were immunocompromised for other reasons. Twenty-seven patients (71.1%) had a single infection, whereas six (15.8%) and five (13.1%) patients had, respectively, two and three concomitant infections. We observed pyogenic bacterial infections (n = 7), tuberculosis (n = 10), non-tuberculous mycobacteriosis (n = 3), viral infections (n = 17: 11 cytomegalovirus, three Epstein-Barr virus, two human herpesvirus 8, one herpes simplex virus 2), parasitic infections (n = 8: four disseminated toxoplasmosis, one leishmaniasis, three malaria), fungal infections (n = 5: four pulmonary pneumocystosis and one candidaemia). Eighteen patients (47.4%) received corticosteroids and/or etoposide. Twelve patients died (31.6%). All multiple infections and all deaths occurred in immunocompromised patients. When compared with patients suffering from malignancy-associated HS, patients with infection-triggered HS were younger and more likely to be immunocompromised, and had a better outcome.