Distribution of total DNA and cccDNA in serum and PBMCs may reflect the HBV immune status in HBsAg+ and HBsAg− patients coinfected or not with HIV or HCV

SummaryBackgroundThe potential reservoir role of serum and peripheral blood mononuclear cells (PBMCs) for total HBV DNA (tDNA) and cccDNA still remains unknown.Material and methodsWe analyzed tDNA and cccDNA with a single sensitive and validated standardized real-time PCR method in serum and PBMCs in two populations of chronic HBV infection coinfected or not with HCV and/or HIV viruses: a retrospective cohort of 130 HBsAg-negative (HBsAg−) patients with “anti-HBc alone” or anti-HBc and anti-HBs antibodies (Ab) and a cohort of 70 HBsAg-positive patients, 16 of them being prospectively followed under treatment.ResultsAmong HBsAg− patients, HBV DNA was detected in serum or PBMCs in about half of the cases with various distributions of tDNA and cccDNA: in HIV-negative patients with an “antiHBc alone” profile, tDNA was mostly detected in PBMCs suggesting a possible active role of PBMCs; although cccDNA was not detected in PBMCs in HIV-positive patients, tDNA and cccDNA were mostly observed in serum, suggesting a specific pattern of more “persistent” than “occult” infection in this population. Patients with anti-HBc and anti-HBs Ab harbored tDNA in serum or in PBMCs, regardless of their HIV or HCV status, raising the question of a viral reactivation risk during immunosupression in these patients. Among HBsAg+ patients, tDNA was detected in serum and PBMCs of 88.5% of the cases and cccDNA in 22%. Levels of tDNA in both compartments were highly correlated during treatment, suggesting a passive reservoir role for PBMCs.ConclusionThe respective distribution of tDNA and cccDNA in serum and PBMCs may reflect the different immune statuses of the host in HBsAg+ and HBsAg− patients. The frequency of HBV DNA in PBMCs from AgHBs− patients suggests a viral reactivation risk during immunodepression in those patients.