Unconventional T cells in chronic hepatitis B patients on long-term suppressive therapy with tenofovir followed by a Peg-IFN add-on strategy: A randomized study.

HBV eradication in chronic hepatitis B (CHB) subjects is rarely achieved with either nucleos(t)ide analogues (NA) or pegylated interferon (Peg-IFN), which both have a limited effect in restoring immune responses. Thirty CHB subjects on long-term treatment with tenofovir (TDF) and HBV suppression were enrolled and randomized 1:2 to either receive Peg-IFN-α-2a add-on therapy or continue TDF alone. We studied γδ T and iNKT frequency and function (by flow cytometry) at baseline, at 12 weeks and 12 weeks after the end of treatment. A higher reduction in qHBsAg occurred in the add-on group compared with the NA group at W12 (P = .016) and at W24 (P = .012). A decline of qHBsAg ≥0.5 log10 at week 24 occurred in 4 of 10 patients in the add-on arm and 1 of 20 in the NA arm, respectively (P = .03). HBsAg loss was seen in 20% of subjects in the add-on group and in none of the NA group. Compared to HBV negative, CHB on TDF showed lower frequency of iNKT (P = .03) and γδ T cells (P = .03) as well as fewer γδ T cells expressing Vδ2 T-cell receptors (P = .005). No changes in unconventional T-cell frequency and function were shown in both add-on and NA patients nor were differences detected between the two treatment groups. We report persistent impairment of unconventional T cells in CHB. Despite a greater qHBsAg decline of add-on patients, our data failed to detect any effect of Peg-IFN treatment on unconventional T cells.