Molecular evidence for repertoire skewing of T large granular lymphocyte proliferation after allogeneic hematopoietic SCT: Report of two cases

摘要

Large granular lymphocyte (LGL) expansion in patients after allo-HCT (poiy- or monoclonal) can be either asymptomatic1 or accompanied by cytopenias and autoimmune manifestations.2 Strong association with viral infections in many cases implicates pathogenetically a chronic antigenic stimulation.We here present the results from a comprehensive evaluation, including detailed immunogenetic analysis, of two cases with benign oligoclonal expansion of CD3+ LGLs causing transient myelosuppression in the context of successive episodes of herpesvirus reactivation after allo-HSCT. Interestingly, both cases developed a highly restricted T-cell receptor beta-chain (TRB) gene repertoire with common gene usage in the predominant clonotypes, strongly implicating Ag involvement in their development.