Improving Post-Transplant Outcomes Following Allogeneic Hematopoietic Stem Cell Transplant for Sickle Cell Disease in a Low Resource Setting: Experience from a Dedicated Post-Transplant Clinic in Nigeria

Abstract

<h3>Background</h3> Allogeneic hematopoietic stem cell transplantation (Allo-HCT) is potentially curative in eligible patients with sickle cell disease (SCD). Improved transplant technology coupled with low transplant-related mortality has resulted in the development of a cottage industry in most of Africa, where 85% of all SCD births world-wide occurs. Families are seeking curative options primarily outside their country of residence, only to return back to a low-resource setting like Nigeria where long-term programs for the management of patient's post-transplant are lacking. <h3>Methods</h3> To address this perceived care gap, a dedicated post-transplant care clinic was developed. Patients were seen at various time points post-transplant (Days+112- 415). Most patients, (7/8), received haploidentical peripheral blood stem cell transplant from parental donors, while one patient received matched related bone marrow transplant. Three patients received myeloablative conditioning and five received non-myeloablative conditioning as well as preconditioning with hydroxyurea, azathioprine and chronic blood transfusion therapy. All patients who underwent haploidentical HCT received post-transplant Cytoxan as part of their GVHD prophylaxis. <h3>Result</h3> All patients had sickle cell anemia (HbSS), ages ranged from 2-18 years, all were considered asymptomatic (Figure 1). Main life-threatening health complications encountered include EBV reactivation in 38% (3/8), chronic GVHD 63% (5/8), others included febrile illnesses, pseudomembranous colitis, renal tubular acidosis, malnutrition and mixed chimerism (Figure 2). About 50% of the patients self-discontinued immunosuppression therapy without adequate guidance and most had delayed health maintenance measures such as routine immunizations and appropriate antimicrobial prophylaxis (Figure 3). Other logistical challenges encountered include delayed timely reporting of diagnostic tests (Chimerism: 14 to 21 days turnaround time; viral studies: 14 to 21 days turnaround time; drug trough levels: 14 to 21 days turnaround time), unavailability of irradiated blood products and lack of cost-effective medications. <h3>Conclusion</h3> A dedicated comprehensive, long-term care program for children with SCD residing in a low income setting who have undergone Allo-HCT, can improve their post-transplant outcomes. Locally adapted supportive care strategies can address the unique challenges encountered by these patients.