Extracellular NAD + Modulates CD203a Expression on Th17 Cells and Predicts Long-Term Recurrence-Free Survival in Hepatocellular Carcinoma

Background and Aims: Mortality rates for hepatocellular carcinoma (HCC) remain high, while multimodal treatment approaches offer new perspectives. Here, we investigated the influence of extracellular nicotinamide adenine dinucleotide (eNAD +) on ecto-nucleotide pyrophosphatase/phosphodiesterase 1 (CD203a, ENPP1 or PC-1) on Th17 cells in relation to the likelihood of HCC recurrence following liver resection. Method: The study compared heparinized blood plasma samples from 95 patients who underwent liver resection, including 20 patients with HCC and 10 control patients without liver disease. Plasma eNAD + concentrations were determined using a heat-based dichotomous pH extraction method, followed by enzymatic cycling and a colorimetric assay for quantification. Fibrosis was graded histologically using the Desmet score (F0-F4). Surface expression analysis was performed using flow cytometry. Results: With increasing grades of liver fibrosis grade a significant reduction in plasma eNAD + concentrations was measured (p < 0.05). Further, a significant correlation was found between eNAD + levels and CD203a expression on CD4 + , CCR4 + as well as CCR6 + T cells (p < 0.05). Patients who exhibited high proportions of CD203a expressing Th17 cells (CD4 + , CCR6 + CCR4 +) post surgery were found to be at a 6-fold increased risk (HR 6.38, 95% Cl 1,51-27.00) of HCC recurrence and had a median recurrence-free survival of 233 days (p < 0.05), compared to patients with low CD203a expressing Th17 cells (CD4 + CCR6 + CCR4 +). Similarly, patients who had a high proportion of CD203a expressing Th17 cells (CD4 + CCR6 +) following surgery had a 5-fold increased risk (HR 5.56, 95% Cl 1.58-19.59) of HCC recurrence and a median recurrence-free survival of 334 days (p < 0.05) compared to those with low CD203a expressing Th17 cells (CCR6 +). Conclusion: The data indicate that eNAD + levels are decreased in patients with liver fibrosis or cirrhosis, and are correlated with the expression of ectoenzyme CD203a on Th17 cells. Consequently, patients with high expression of CD203a on Th17 cells had a significantly increased likelihood of recurrence, indicating their potential as valuable prognostic markers and a possible therapeutic target.