Abstract Summary
Introduction: T-large granular lymphocyte leukemia (T-LGLL) accounts for an important portion of secondary pure red cell aplasia (PRCA) patients. For CsA-resistant or relapsed patients, outcomes of sequential regimen consisting of cyclophosphamide combined with prednisone (CP) have been less reported. Methods: 65 patients with T-LGLL-asssociated PRCA were enrolled, and initially treated with CsA in our study. CP regimen was administrated in patients who failed to CsA. The clinical features and treating outcomes were investigated. Results: An overall response rate (ORR) to CsA was 43% (28/65) and a complete response rate (CRR) was 23% (15/65). The median time to initial response was 3 months (1-9 months), and the median time to complete response (CR) was 4 months (1-10 months). 24 cases were administrated with CP regeimen after failed to CsA, with an ORR being 79% and CRR 63%. The ORR of CsA was not markedly different between STAT3/5b mutant and wild-type patients (43% vs 46%, P=0.850). In STAT3/5b mutant cases, CP regimen responded better than CsA (89% vs 43%, P=0.040). TCR sequencing demonstrated that the highest frequency of V-gene acquisition belonged to family, which was related to poor response to CsA. Conclusion: Sequential CP regimen is effective for CsA-resistant and relapsed cases, particularly in patients with STAT3/5b mutations and TRBV06 gene rearrangements.
