Haploidentical hematopoietic stem cell transplantation using post-transplant cyclophosphamide in patients with inborn errors of immunity: Experience in a reference center in Colombia.

INTRODUCTION

Inborn errors of immunity is a diverse group of rare diseases caused by over 400 genetic mutations affecting the immune system and increasing infection susceptibility, autoimmunity, and malignancy. Hematopoietic stem cell transplantation offers a curative option for some inborn errors of immunity, with haploidentical donors providing a viable alternative when identical donors are unavailable.

OBJECTIVE

To determine survival, usefulness of weekly chimerism monitoring, immune reconstitution, and complications in patients with inborn errors of immunity who underwent haploidentical hematopoietic stem cell transplantation at a reference center in Colombia.

MATERIALS AND

METHODS

We conducted a retrospective and observational study of a case series of pediatric patients who underwent haploidentical hematopoietic stem cell transplantation with post-transplant cyclophosphamide and follow-up with weekly chimerism. Survival analysis was performed using the Kaplan-Meier method.

RESULTS

Sixteen patients with haploidentical familial donor transplantation were included. The most frequent diagnosis was severe combined immunodeficiency (n=5). Eleven out of seventeen patients received a non-myeloablative conditioning regimen. Twelve out of sixteen patients developed acute graft-versus-host disease. Out of these, 3 corresponded to grades III-IV. Post-transplant infections affected 14 of the subjects, predominating bacterial agents. Median T-cell chimerism was greater than 80% during the follow-up. Reconstitution of B and T lymphocytes was achieved in more than 80%. Overall survival at five years was 81%. Survival at 100 days was 94%.

CONCLUSION

Haploidentical hematopoietic stem cell transplantation using post-transplant cyclophosphamide is a viable alternative for inborn errors of immunity when an identical donor is unavailable. Serial chimerism monitoring is useful for graft follow-up.