揭示包涵体肌炎中扩增的 CD8(+) 大颗粒淋巴细胞的意义：对 T 细胞表型和功能改变及疾病严重程度的洞察

We investigated the incidence of a CD8 + T-LGL lymphoproliferative disorder in 85 IBM patients and an aged-matched group of 56 Healthy Controls (HC). Further, we analysed the phenotypical characteristics of the expanded T-LGLs and investigated whether their occurrence was associated with any particular HLA alleles or clinical characteristics.

Blood cell analysis by flow cytometry revealed expansion of T-LGLs in 34 of the 85 (40%) IBM patients. The T cell immunophenotype of T-LGL HIGH patients was characterised by increased expression of surface molecules including CD57 and KLRG1, and to a lesser extent of CD94 and CD56 predominantly in CD8 + T cells, although we also observed modest changes in CD4 + T cells and γδ T cells. Analysis of Ki67 in CD57 + KLRG1 + T cells revealed that only a small proportion of these cells was proliferating. Comparative analysis of CD8 + and CD4 + T cells isolated from matched blood and muscle samples donated by three patients indicated a consistent pattern of more pronounced alterations in muscles, although not significant due to small sample size. In the T-LGL HIGH patient group, we found increased frequencies of perforin-producing CD8 + and CD4 + T cells that were moderately correlated to combined CD57 and KLRG1 expression. Investigation of the HLA haplotypes of 75 IBM patients identified that carriage of the HLA-C*14:02:01 allele was significantly higher in T-LGL HIGH compared to T-LGL LOW individuals. Expansion of T-LGL was not significantly associated with seropositivity patient status for anti-cytosolic 5'-nucleotidase 1A autoantibodies. Clinically, the age at disease onset and disease duration were similar in the T-LGL HIGH and T-LGL LOW patient groups. However, metadata analysis of functional alterations indicated that patients with expanded T-LGL more frequently relied on mobility aids than T-LGL LOW patients indicating greater disease severity.

Altogether, these results suggest that T-LGL expansion occurring in IBM patients is correlated with exacerbated immune dysregulation and increased disease burden.