Abstract
Post transplant Hemophagocytic lymphohistiocytosis (HLH) is a form of secondary HLH, which can be either early onset or late onset and is associated with significant morbidity and mortality. With the increasing popularity of post transplant cyclophosphamide based haploidentical stem cell transplantation (SCT), post transplant HLH is becoming a significant complication especially in benign hematological disorders. Methods: We present 4 cases of post transplant HLH occurring in 2 cases of severe aplastic anemia (post haploidentical SCT) and 2 cases of thalassemia major (post matched sibling SCT). All 4 cases had early onset variety with dismal prognosis. Conclusion: Post-transplant HLH is an important entity in benign hematological disorders, which needs to be identified early and treated promptly with steroids, monoclonal agents or immunosuppressive therapy. Serum ferritin levels are an important biomarker and help in monitoring response.