Low levels of CD3 + and CD8 + T cells in peripheral blood can predict poor efficacy of first-line chemotherapy in patients with angioimmunoblastic T cell lymphoma.

To investigate the prognostic significance of lymphocyte subsets in newly diagnosed angioimmunoblastic T-cell lymphoma (AITL) patients and track the dynamic changes in these subsets during treatment. We retrospectively analyzed the medical records in 56 patients with AITL. Lymphocyte subsets were assessed by flow cytometry at diagnosis. Receiver operating characteristic curves were employed to establish optimal cut-off values for lymphocyte subset assessment. Univariate and multivariate analyses were used to evaluate overall survival (OS) and progression-free survival (PFS). The first-line treatment demonstrated an overall response rate (ORR) of 71.4%. Optimal cut-off values for ORR were determined for CD3 + T cell percentage (61.9%) and CD8 + T cell percentage (28.4%), with corresponding AUC of 0.756 [95% CI (0.611-0.902), p = 0.003] and 0.745 [95% CI (0.596-0.894), p = 0.004]. The ORR for the Low CD3+/CD8 + Group (CD3 + T < 61.9% and CD8 + T < 28.4%) and High CD3+/CD8 + Group (CD3 + T ≥ 61.9% or CD8 + T ≥ 28.4%) was 25.0% and 84.1%, respectively (p < 0.001). With a median follow-up time of 37.4 months, the median PFS were 5.6 and 16.0 months for the both groups. After two cycles of chemotherapy, a significant elevation in the percentage of CD3 + T cells was observed comparing to pre-treatment. Three months post-treatment, the CD4/CD8 ratio reduced significantly, indicating a rebalancing of T cell populations. Reduced levels of CD3 + and CD8 + T lymphocyte may indicate inferior chemotherapy efficacy and poorer PFS in AITL. Monitoring the baseline lymphocyte subsets and their dynamic changes can assist in clinical treatment decision - making.