Hematopoietic Stem Cell Transplantation in Paroxysmal Nocturnal Hemoglobinuria

Abstract

BACKGROUND: Paroxysmal nocturnal hemoglobinuria (PNH) is a rare acquired hematological disorder characterized by episodic intravascular hemolysis. Despite newer therapies such as eculizumab, hematopoietic stem cell transplantation (HSCT) remains the only curative therapy. MATERIALS AND METHODS: An observational analytical retrospective study was conducted comprising eight PNH patients who had undergone HSCT at our center. From January 2014 to December 2020, we performed HSCT in 8 PNH patients, 5 female and 3 male, with median age of 32 years (range: 15–38 years). RESULTS: Seven patients had pancytopenia, associated with marrow hypocellularity. One patient presented with a thrombotic episode. Seven had matched sibling donor (MSD) transplant and one underwent haploidentical transplant. The median time from diagnosis to transplant was 7 months (range: 1–38 months). All received reduced intensity conditioning (RIC): Flu-Bu-Cy-A TG for MSD transplants and Flu-A TG-Post Cy in haploidentical transplants. Median CD34+ stem cell dose was 5.5 × 106/kg (range 3.4–5.8 × 106/kg). All had successful engraftment. Acute graft versus host disease (GVHD) Grade I–III occurred in six patients. Chronic GVHD occurred in two patients. One patient succumbed to Grade III liver GVHD. Rest seven patients are alive till date and transfusion independent. The overall survival was 87.5% at a median of 26 months. CONCLUSIONS: HSCT is the only curative therapy for PNH. With the use of RIC, the outcomes of PNH patients can be improved. The incidence of GVHD is high with RIC regimens but can be managed with prompt immunosuppression.