Abstract
Adult-onset hemophagocytic lymphohistiocytosis (HLH) has features that are distinct from that of HLH in pediatric patients. The clinical records at the Japanese Red Cross Kumamoto Hospital were reviewed. We retrospectively analyzed 34 patients who fulfilled the diagnostic criteria of HLH-2004. The median age of patients was 60.0 (range 15-86). Underlying diseases were diagnosed in 17 patients. They consisted of malignant lymphoma (n=3), other neoplastic disease (n=3), viral infection (n=4), collagen vascular disease (n=3), Kikuchi's disease (n=3) and drug (n=1). Underlying diseases were not diagnosed in 17 patients despite examination. The treatments were steroids (n=18), dexamethasone + cyclosporine A (CSA) + etoposide (n=4), multidrug chemotherapy (n=2), steroids and CSA (n=3). Eleven patients died during observation. In a multivariate analysis, the significant predictor for death was age at onset (hazard ratio, 1.22; 95%CI, 1.02-1.44; P=0.027). Autopsy was performed in 4 cases, but the underlying disease remained unknown in 3 of those cases. Adult-onset HLH has high diversity and various outcomes. The mechanism of adult-onset HLH is not fully understood and further research is required.