Serum Levels of Interferon-gamma, Cytotoxic Factor and Soluble Interleukin-2 Receptor in Childhood Hemophagocytic Syndromes.

Serum levels of interferon (IFN)-gamma, cytotoxic factor (CF) and soluble interleukin-2 receptor (sIL2R) were assayed in relation to hyperferritinemia in eleven cases of malignant histiocytosis (MH), seven of virus-associated hemophagocytic syndrome (VAHS) and one of familial erythrophagocytic lymphohistiocytosis (FEL). IFN-gamma was markedly elevated (>10,000 U/ml) in 5 MH cases and only in one case of VAHS. CF was significantly elevated (> 150 U/ml) in 5 MH and 4 VAHS/FEL patients. sIL2R were remarkably elevated (> 10,000 U/ml) in 5 MH and 4 VAHS patients. In individual cases, the patterns of these parameters were quite different, suggesting the existence of a variable pathophysiology in cases with hemophagocytic syndromes. In terms of the patients' outcome, high IFN-gamma or sIL2R levels were associated with a poor prognosis while high CF appeared to be associated with a better prognosis.