Evans syndrome in a patient with Langerhans cell histiocytosis: possible pathogenesis of autoimmunity in LCH.

We report a 1-year-old girl with Evans syndrome coexisting with histologically confirmed Langerhans cell histiocytosis (LCH) affecting the cervical lymph nodes, liver, and spleen. Anti-cardiolipin antibody, anti-SS-A antibody, and anti-SS-B antibody as well as a direct antiglobulin test and platelet-associated IgG were all positive at the onset, and these autoantibodies became negative with the resolution of LCH by chemotherapy. Serum T-helper-2 (Th2) cytokine levels such as those of interleukin (IL)-6 and IL-10 were high whereas those of Th1 cytokines such as IL-2 and interferon-gamma were low at the onset, and this cytokine imbalance was normalized during the resolution of LCH. These results suggest that cytokine imbalance due to LCH led to multiple autoimmune phenomena in the present patient.