AimTo analyze whether different hepatitis B virus (HBV) infection status influenced the prognosis of patients with lupus nephritis (LN) under immunosuppressive therapy. MethodsA retrospective study enrolled 177 adults with active LN (Classes III, IV, V or mixed), and divided them into three groups: (i) HBV-free group (n=93), antibodies to hepatitis B surface antigen positive only or all items negative; (ii) occult HBV infection group (n=68), hepatitis B surface antigen (HBsAg) negative and antibody to hepatitis B core antigen positive with undetectable HBV DNA; and (iii) HBV infection group (n=16), HBsAg-positive. The composite renal outcome was defined as a composite of progression to end-stage renal disease, 50% estimated glomerular filtration rate decrease, or death. ResultsThe HBV infection rate was 9.04% in active LN. In the HBV infection group, a greater proportion of patients delayed immunosuppressive therapy, reduced prednisone dose, used mycophenolate mofetil in the first induction phase, received immunoglobulin pulse therapy, as well as avoided methylprednisolone pulse treatment (P<0.05). The composite renal outcome was significantly different among the three groups: 4/93 (4.30%) of the HBV-free group, 7/68 (10.29%) of the occult HBV infection group, and 4/16 (25.00%) of HBV infection group (P=0.018). Univariate and multivariate analyses identified three independent risk factors of composite renal outcome: active HBV carrier (odds ratio [OR] 10.342, 95% CI 2.151-66.053, P=0.017), cycle of immunosuppression>1 (OR 3.345, 95% CI 1.201-9.983, P=0.025), and delayed immunosuppressive therapy (OR 3.118, 95% CI 1.207-10.662, P=0.031). ConclusionsAll these results suggested that HBV infection status might confer a worse prognosis for patients with active LN.