Significance of anti-HBc serological status in primary immune thrombocytopenia

The association of previous hepatitis B virus (HBV) exposure [hepatitis B surface antigen (HBsAg) negative, hepatitis B core antibody (anti-HBc/HBcAb) positive] with disease severity and decision on treatment option in primary immune thrombocytopenia (ITP) patients remains unclear. Data from 725 patients diagnosed with ITP were analyzed to elucidate the association between anti-HBc serological status and disease severity. Data from a published prospective study [high-dose dexamethasone (HD-DXM), HD-DXM plus recombinant human thrombopoietin, NCT01734044] and two retrospective studies (standard-dose and low-dose rituximab) were rearranged to evaluate the impact of anti-HBc serological status on the response and outcome to ITP-specific treatments and the risk of HBV reactivation related to these treatments. The prevalence of HBsAg^- HBcAb⁺ and HBsAg^- HBcAb^- in ITP patients was 51·03% and 48·97% respectively. Compared to the HBsAg^- HBcAb^- group, patients in the HBsAg^- HBcAb⁺ group had lower platelet count, higher bleeding score, and longer hospitalization (P = 0·002, 0·033, and 0·008 respectively). Moreover, the initial complete response rate of HBsAg^- HBcAb⁺ patients was lower than that of HBsAg^- HBcAb^- patients (45·2% vs 59·8%, P = 0·027). In conclusion, previous HBV exposure was correlated with disease severity and hospitalization in ITP patients. Anti-HBc positivity may be considered as a predictor for poor response to ITP-specific treatments.