Extracellular NAD+ levels are associated with CD203a expression on Th17 cells and predict long-term recurrence-free survival in hepatocellular carcinoma.

Abstract

Background and aims: Mortality rates for hepatocellular carcinoma (HCC) remain high, while multimodal treatment approaches offer new perspectives. Here, we investigated the association 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 25 patients with HCC and 24 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 predominant in HCC patients, a significant reduction in plasma eNAD⁺ concentrations was measured (p < 0.05). Further, a significant correlation was found between HCC patients 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 sixfold 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 fivefold 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 indicates that eNAD⁺ levels are decreased in patients with liver fibrosis or cirrhosis. Strikingly, patients with high CD203a expression on Th17 cells had a significantly increased likelihood of recurrence, highlighting its potential as a valuable prognostic marker and a possible therapeutic target.