Factors influencing outcome and incidence of late complications in children who underwent allogeneic hematopoietic stem cell transplantation for hemoglobinopathy.

BACKGROUND: Hematopoietic stem cell transplantation (HSCT) remains the only potentially curative treatment for severe hemoglobinopathy (HGP). Late complications (LCs) are all events occurring beyond two years post-HSCT. We retrospectively analyzed prevalence, factors influencing occurrence, and prognosis of LCs post-HSCT for HGP. PATIENTS AND METHODS: Between 2000 and 2011, 47 patients (21 males, 26 females; 43 with beta thalassemia major, four with sickle cell disease) who had survived more than two years post-HSCT for HGP were retrospectively reviewed. Mean age at HSCT was 7.7 years (1.1-32 years); mean follow-up was 7.1 years (2-11.6 years); 11 patients were splenectomized; mean ferritin level was 3022 ng/mL (350-10900); and seven patients underwent a second HSCT.
RESULTS: Endocrinological complications were observed with primary gonadal failure in 16/20 mature females and 4/11 mature males, in five patients with primary hypothyroidism and in four with insulin-dependent diabetes mellitus (DM). Skeletal complications were observed in 10 with secondary osteoporosis; 22 patients had elevated transaminase levels; two had hepatitis B reactivation. Neurological, cardiac and ocular manifestations were relatively rare. A higher incidence of LCs was observed in splenectomized than in nonsplenectomized patients: cGVHD -64% versus 13% (P = .003); endocrine abnormalities -91% versus 30.5%, (P = .001); elevated transaminase levels -73% versus 33% (P = .043); mortality -18% versus 2.7% (NS).
CONCLUSIONS: LCs post-HSCT for HGP are common and heterogeneous. Etiology is multifactorial with iron overload (IO), class, splenectomy, age, chronic GVHD, and corticosteroid (CS) treatment. Our data may help build follow-up guidelines to limit, detect, and treat any LCs and improve quality of life.