The contemporary adolescent and young adult sickle cell population in Malawi

Abstract Sickle cell disease (SCD) is one of the most common inherited red blood cell disorders worldwide, with the majority of affected births occurring in sub-Saharan Africa (SSA). SCD is a chronic, progressive condition characterized by recurrent vaso-occlusive episodes and cumulative multi-organ damage. While recent studies have confirmed the safety and efficacy of hydroxyurea for children with SCD in SSA, data on long-term outcomes beyond early childhood remain limited. In 2017, the pediatric sickle cell clinic at Kamuzu Central Hospital (KCH) in Lilongwe, Malawi, implemented universal hydroxyurea therapy for all children with SCD. We conducted a follow-up study of adolescents and young adults (AYA) aged ≥16 years who were receiving routine care in this dedicated clinic under real-world conditions. Demographics, clinical outcomes, and laboratory parameters were extracted from the clinic's electronic database. A total of 207 patients aged ≥16 years were identified. Of these, 195 (94%) were alive and actively receiving care, 3 (1%) were confirmed deceased, and 9 (4%) were lost to follow-up. The mean age of patients in active care was 18.0 ± 1.9 years, with a mean age at diagnosis of 5.7 ± 1.1 years. Hydroxyurea use was nearly universal (187 patients, 96%), with an average treatment duration of 6.0 ± 2.7 years. Mean baseline laboratory values included: hemoglobin 8.0 ± 1.3 g/dL, MCV 92 ± 8.4 fL, WBC 14.2 ± 7.0 ×10³/µL, ANC 6.2 ± 4.8 ×10³/µL, and platelets 343 ± 167 ×10³/µL. Overall, 21% of patients had received at least one blood transfusion, and 23% had been hospitalized at least once for SCD-related complications.This study provides the first description of an AYA cohort with SCD in Malawi receiving routine hydroxyurea therapy in a dedicated pediatric clinic outside of a clinical trial. The findings demonstrate the long-term feasibility and effectiveness of hydroxyurea in improving survival into adolescence and young adulthood. With 94% of patients alive and in active follow-up, this real-world experience highlights the impact of universal hydroxyurea combined with supportive care in a resource-limited setting. As childhood survival improves across SSA, the expanding AYA population underscores the urgent need to build capacity for comprehensive adult SCD care. Efforts to address the global burden of SCD must now evolve from a focus on childhood mortality to supporting long-term health and survival into adulthood.