Dynamic changes of T-cell subsets and their relation with tumor recurrence after microwave ablation in patients with hepatocellular carcinoma

Thermal ablation can evoke an immune response, which may have effects on the prognosis of patients with hepatocellular carcinoma (HCC). Our aim is to investigate the changes of circulating T-cell subsets after microwave ablation (MWA) and to explore the risk factors of tumor recurrence in patients with hepatitis B virus (HBV)-related HCC.Thirty patients with HBV-related HCC were enrolled in this study. The blood samples were collected both before and after MWA (24 h, 72 h, and 1 month after MWA). The distributions of Th17 cells, regulatory Treg-cells, CD4+ T-cells, CD8+ T-cells, and CD3+ T-cells were determined by flow cytometer. The potential-related factors of tumor recurrence were analyzed by logistic regression.The levels of circulating T-cell subsets, except for Th17 cells, were relatively stable after MWA. The frequency of Th17 cells increased from 3.98% ± 2.40% before treatment to 5.53% ±3.27% 24 h after treatment. Eight of 30 patients had a tumor recurrence. The results of logistic regression suggested that among 11 candidates, only the level of Th17 cells was the risk factor of tumor recurrence. To remove the interference from other factors, seven patients with tumor(s) >3 cm or alpha-fetoprotein >400 ng/mL were excluded in another parallel logistic regression. The results of such regression clearly demonstrated that circulating Th17 cells is indeed a related factor of tumor recurrence.Thermal ablation may evoke a transitional immune response by increasing the frequency of Th17 cells. Patients with high levels of baseline circulating Th17 cells, instead of the transient elevation of Th17 cells induced by MWA, are at the risk of tumor recurrence.