Renal protective effect of antiplatelet therapy in antiphospholipid antibody-positive lupus nephritis patients without antiphospholipid syndrome

OBJECTIVE: We sought to evaluate the effect of antiplatelet therapy in addition to conventional immunosuppressive therapy for lupus nephritis (LN) patients positive for antiphospholipid antibodies (aPL) without definite antiphospholipid syndrome (APS). METHODS: Patients with biopsy-proven LN class III or IV were retrospectively evaluated. We selected patients positive for anticardiolipin antibody (aCL) or lupus anticoagulant (LA) who did not meet the criteria for a diagnosis of APS. The patients were divided into two subgroups according to whether antiplatelet therapy was received. The cumulative complete renal response (CR) rate, relapse-free rate, and change in estimated glomerular filtration rate (eGFR) over 3 years after induction therapy were calculated. RESULTS: We identified 17 patients who received antiplatelet therapy and 21 who did not. Baseline clinicopathological characteristics and immunosuppressive therapy did not show a significant difference between the two groups except for a higher incidence of LN class IV in the treatment group (p = 0.03). There was no difference in cumulative CR rate, relapse-free rate, or eGFR change between these subgroups. However, when data on LA-positive patients were assessed, an improvement in eGFR was found (p = 0.04) in patients receiving antiplatelet treatment. CONCLUSION: Addition of anti-platelet therapy was associated with an improvement of eGFR in LA-positive patients with LN class III or IV.