中国 NK 细胞大颗粒淋巴细胞白血病患者的临床表现与基因特征：单中心回顾性分析

Natural killer cell large granular lymphocytic leukemia (NK-LGLL) is a rare and heterogenous lymphoproliferative disorder.

This study retrospectively evaluated 35 consecutive Chinese patients (median age 58 years) to evaluate their unique clinical-biological profiles and treatment responses.

Our Chinese population exhibited a distinct comorbidity spectrum, characterized by a lower prevalence of concurrent arthritis (2. 9%) and secondary malignancies, compared with Western cohorts. At diagnosis, 31. 4% of the cohort had neutropenia, 42. 9% had anemia, and 31. 4% had thrombocytopenia. The median large granular lymphocyte count was 3. 9 10 9 /L (range 0. 11-114. 8 10 9 /L; IQR 1. 9 10 9 /L, 5. 9 10 9 /L). Immunophenotyping consistently identified as a CD3- CD56+ clone.

Notably, genomic profiling via NGS revealed a STAT3 mutation rate of 14. 3%. Regarding therapeutic efficacy, frontline immunosuppressive therapy with cyclophosphamide or cyclosporine was associated with favorable clinical responses (best overall response, complete remission rate 66. 7% for both).

Additionally, sirolimus emerged as a potentially highly effective salvage option, yielding an overall response rate of 85. 7% (95%CI 42. 1-99. 6%) and complete remission rate of 57. 1%. With an estimated 3-year overall survival rate of 85. 6% (95%CI 73. 3%, 99. 8%), our findings suggest a generally indolent clinical course of NK-LGLL in this Chinese cohort and highlight the potential of mTOR inhibition in refractory cases, warranting further prospective investigation.