Gradual Maturation of the B-Cell Receptor Repertoire After Pediatric Hematopoietic Stem Cell Transplantation: Insights into Early Immune Reconstitution

Highlight

– Early reconstitution of a broad and diverse naïve B-cell receptor (BCR) repertoire occurs within 3 months after pediatric hematopoietic stem cell transplantation (HSCT).
– Antigen-experienced B-cell repertoires show delayed somatic hypermutation and junctional diversity, normalizing approximately 24 months post-HSCT.
– Molecular features of affinity maturation, including mutation targeting and replacement-to-silent mutation ratios, remain intact despite delayed maturation.
– Clonal expansions in class-switched B-cell compartments are present but do not compromise overall repertoire diversity.

Study Background