促肾上腺皮质激素分泌型垂体癌中的优势 T 细胞受体克隆型是有效抗 PD-1 治疗期间外周血 CD4(+) 和 CD8(+) 细胞中频率最高的克隆

To evaluate tumor-infiltrating lymphocytes (TILs) in pituitary carcinoma and to compare T-cell receptor (TCR) clonotypes between the pituitary and peripheral blood.

A 34-year-old woman with Lynch syndrome and adrenocorticotropic hormone-secreting pituitary carcinoma with hepatic metastasis received anti-PD-1 therapy, achieving durable disease control exceeding 1 year. Immunohistochemistry was performed on treatment-naïve surgical tumor samples, and TCR repertoire analyses were conducted on both the tumor sample and peripheral blood mononuclear cells collected during effective anti-PD-1 therapy.

Treatment-naïve pituitary carcinoma tissues exhibited infiltration of CD4 + and CD8 + T cells. Analysis of the TCR repertoire identified 15 clonotypes with a high frequency (> 1% of sequencing reads) in the tumor; among these, four of the five most prevalent clonotypes were co-detected as dominant clones in peripheral blood after treatment, including the most abundant clones found within the CD4 + and CD8 + T cell populations. Despite control of the primary and hepatic lesions, ovarian metastasis developed, which was associated with reduced CD4 + TILs.

The presence of CD4 + and CD8 + TILs may underlie the immunological foundation for PD-1 blockade efficacy in pituitary carcinoma, supported by the detection of tumor-resident TCR clonotypes in peripheral blood during a positive therapeutic response.