Non-histologic factors discriminating proliferative lupus nephritis from membranous lupus nephritis

Background: To investigate non-histologic factors that can discriminate proliferative lupus nephritis (LN) from membranous LN in patients with systemic lupus erythematosus with renal manifestations. Methods: Patients with biopsy-proven proliferative LN (class III ± V and class IV ± V) and membranous LN (class V) were included. Non-histologic factors were compared between the two groups. A logistic regression analysis was performed to identify the factors associated with proliferative LN. To assess the accuracy of these factors in discriminating between proliferative LN and membranous LN, we performed a receiver-operating characteristic analysis. Results: Of the total 168 patients with biopsy-proven LN, 150 patients (89.3%) had proliferative LN, and 18 patients (10.7%) had membranous LN. In the multivariable logistic regression analysis, positive anti-double-stranded DNA (anti-dsDNA) antibody (adjusted OR = 11.200, 95% CI = 2.202-56.957, p = 0.004) was associated with proliferative LN, while positive anti-U1RNP antibody (adjusted OR = 0.176, 95% CI = 0.040-0.769, p = 0.021) and higher glomerular filtration rate (GFR) (adjusted OR = 0.973, 95% CI = 0.951-0.994, p = 0.013) were inversely associated with proliferative LN. Among these covariates, the anti-dsDNA antibody (area under the curve = 0.806, 95% CI = 0.695-0.916) had the highest accuracy in discriminating between proliferative LN and membranous LN. Conclusion: The positivity of anti-dsDNA antibody was associated with proliferative LN, while the positivity of anti-U1RNP antibody and GFR were inversely associated with proliferative LN. The anti-dsDNA antibody had a good accuracy in discriminating proliferative LN from membranous LN.