Germline HAVCR2 mutations and their relation to the clinical spectrum of subcutaneous panniculitis-like T-cell lymphoma and hemophagocytic lymphohistiocytosis: results from a multicenter study and meta-analysis

Germline HAVCR2 mutations are frequently detected in subcutaneous panniculitis-like T-cell lymphoma (SPTCL) patients with/without hemophagocytic lymphohistiocytosis (HLH) but factors associated with variable manifestations remain undetermined. To evaluate clinical variations and associated factors in SPTCL and/or HLH with/without HAVCR2 mutations, we performed direct sequencing of HAVCR2 exon 2 using DNA from patients with SPTCL or idiopathic HLH/HLH-like systemic illnesses, defined by HLH alone without secondary causes. The systematic review and individual patient data (IPD) level meta-analysis which included the present and previously published studies reporting HAVCR2 mutations in SPTCL with/without HLH populations was subsequently conducted using random-effects meta-analysis and multivariate logistic regression. Among 34 patients enrolled, ten of 28 SPTCL patients developed HLH/HLH-like systemic illnesses. Six cases with HAVCR2Y82C mutation manifested with HLH without panniculitis. Male sex (P=0.03) and age