Effective Hematopoietic Stem Cell Transplantation with Reduced Intensity Conditioning for Patients with Chronic Granulomatous Disease.

Abstract 3339

Poster Board III-227

Chronic granulomatous disease (CGD) is the most common inherited disorders of phagocytic function caused by abnormal nicotinamide adenine dinucleotide phosphate (NADPH) oxidase which produces reactive oxygen species. Defects in four of the NADPH components are responsible for CGD: gp91phox, p47phox, p67phox and p22phox. Due to the defects in production of superoxide, patients are highly susceptible to catalase-positive infections including fungi, as well as developing granuloma and autoimmune complications. To date, hematopoietic stem cell transplantation (HSCT) is the only curative treatment for patients with CGD. The HSCT for CGD patients using myeloablative conditioning regimen consisting of busulfan and cyclophosphamide (CY) has been proven to cure the disease. However, HSCT with this myeloablative conditioning regimen has considerable risk of transplantation-related morbidity (TRM) and mortality in patients with life-threatening infection and long-term complications including graft-versus host disease (GVHD), pulmonary late effects, and gonadal failure. To avoid the risk of TRM and long-term complications, we underwent bone marrow transplantation (BMT) with reduced-intensity conditioning (RIC) for 12 patients with CGD from 2002 to 2009 in Hiroshima University. Seven patients were transplanted from related donors and five patients from unrelated donors. Conditioning regimens consisted of fludarabine, CY and TBI (3 Gy) with or without antithymoglobulin or melphalan (L-PAM). Three of twelve patients who had severe life-threatening infections such as multiple brain abscesses, multiple liver abscesses or multiple pulmonary abscesses with high level of CRP (>15 mg/dl) underwent BMT. One of three patients who had suffered from severe fungal infection in both lungs was died from pulmonary hemorrhage due to the engraftment syndrome on day 45 after BMT. No TRM during the conditioning and early period after BMT was observed in the remaining 11 patients, irrespective of the presence of active and intractable infections/inflammation. The patients alive were eliminated from infections and/or inflammation with complete chimerism. Four patients undergoing BMT using fludarabine-based regimen without L-PAM required donor lymphocyte infusion to achieve complete donor chimerism. The addition of L-PAM to fludarabine-based RIC rapidly induced the complete engraftment of donor cells without any toxicity in 7 patients. The frequency and severity of acute or chronic GVHD were not significant and sufficiently tolerable. Karnofsky performance scale of all patients alive has been 100% after BMT. Furthermore, apparent endocrinological problems including gonadal function were not observed during the limited period after BMT. These results suggest HSCT using RIC with L-PAM is effective therapy for CGD patients for successful complete engraftment and minimal toxicity.