Hemophagocytic syndromes (HPSs) including hemophagocytic lymphohistiocytosis (HLH) in adults: A systematic scoping review

Most knowledge of hemophagocytic syndromes (HPSs) including hemophagocytic lymphohistiocytosis (HLH) is derived from pediatric studies; literature on adult HPS/HLH predominantly consists of small retrospective studies with clinical and methodological heterogeneity. The aims of this systematic scoping review were to provide an overview of existing literature on adult HPS/HLH, describe current practices in diagnosis and treatment, and propose priorities for future research. Articles from Ovid Medline, Embase and Pubmed (1975-2015) describing 10 or more unique adults (age > 15 years) with HPS/HLH were included. 82 publications were eligible: 10 were prospective and 72 were retrospective. Of the six distinct diagnostic criteria, the HLH-2004 criteria were by far the most commonly used. A minority of studies tested for genetic abnormalities (12), soluble interleukin-2 receptor (11), and/or NK function (11) in a subset of patients. Most centers used steroids and either etoposide-based (HLH-94/HLH-2004) or doxorubicin-based (CHOP) initial therapy regimens. Allogeneic hematopoietic cell therapy for treatment of adult HLH has rarely been reported. Mortality in larger treatment focused studies ranged from 20 to 88%. Developing adult-specific diagnostic criteria based on widely evaluable features of secondary HPS/HLH and establishing standard initial therapies are priorities for future research.