Reactive hemophagocytic syndrome associated with thrombotic thrombocytopenic purpura during therapeutic plasma exchange.

Hemophagocytic lymphohistiocytosis (HLH) is characterized by fever, cytopenia, splenomegaly, and lymphohistiocytic proliferation with hemophagocytosis. Sporadic, familial, and reactive HLH varieties exist. The latter, also termed the reactive hemophagocytic syndrome (RHS), has been associated with a variety of infectious and noninfectious etiologies. Activation of monocytes in RHS is due to stimulation by high levels of activating cytokines. RHS has not been associated previously with thrombotic thrombocytopenic purpura (TTP). TTP is a multisystem disorder characterized by consumptive thrombocytopenia, microangiopathic hemolytic anemia, neurologic symptoms, renal impairment, and fever. We report on a 33 year old male patient with a classic picture of TTP who initially responded to therapeutic plasma exchange but then became refractory to treatment and developed RHS. It is likely that a specific pathophysiology involving the activation of neutrophils during TPE is present for the development of cytokine-induced hemophagocytosis during TTP treatment. The consequent development of RHS possibly caused early TTP relapse.