What We Have Learnt About Hematopoietic Cell Transplantation in Chronic Granulomatous Disease: A Single Pediatric Center Experience

Introduction Hematopoietic cell transplantation (HCT) is a curative treatment for chronic granulomatous disease (CGD). Post-HCT outcomes are poorly reported in Latin America. We describe the outcome of a CGD pediatric cohort. Methods Retrospective analysis from 11 clinical records. 1 patient excluded due to lack of enough information. Results 10 males, 9 X-linked CGD. Median follow-up 3.3 years (0-12), median age at transplant 6.9 years (range: 1-13). Pre-HCT patients had 10 severe infections, 10 growth failure, 9 lung disease, 8 CGD colitis, and 5 BCG complications. Patients received peripheral blood stem cells (n = 6), bone marrow (n = 3), or cord (n = 1) from matched (n = 3) or mismatched (n = 3) unrelated donors, haploidentical (n = 3) or matched sibling donor (n = 1) using (7, 70%) busulfan-fludarabine conditioning, (2, 20%) busulfan-cyclophosphamide, and (1, 10%) fludarabine-melphalan. Tacrolimus and mycophenolate as graft versus host disease (GvHD) prophylaxis in most patients (50%). 2 patients (20%) developed acute, and 2 (20%) chronic GvHD. 5 patients (50%) had CMV, 2 (20%) EBV, and 1 (10%) adenovirus viremia. 1 (10%) developed EBV posttransplant lymphoproliferative disease. At last follow-up, 6 patients were alive, resulting in a 12-year overall survival of 54%. Of the 4 patients that passed away, 2 had graft failure. During the follow-up: 5 patients (83.3%) stabilized lung disease, 5 (83.3%) resolved colitis, 3 (50%) had significant infections, and 3 (50%) improved growth. 4 patients had donor chimerism performed, being 100% with normal dihydrorhodamine (DHR). 6/11 patients had lab follow-up after day 360. 4 patients achieved T cell immune reconstitution (median CD4naive: 30.4%). At day 720, 1/5 showed normal B cell subsets with a median IgA 161 mg/dl and IgM 127 mg/dl (n = 5). Conclusions Most patients had multiple severe pre-HCT complications. Despite high mortality, HCT led to immune T reconstitution with improvement in lung disease and colitis. These results support HCT as a curative option for CGD and highlight the need for earlier referral and better transplant strategies.