Background Corticosteroid therapy is effective for systemic lupus erythematosus (SLE), but many adverse effects have been observed. Tacrolimus (TAC) is an immunosuppressive agent that is used after organ transplantation. TAC is also used for induction therapy in SLE patients, but no investigations of TAC in maintenance therapy have been reported.

Objectives This study examined the efficacy of TAC combination therapy during the maintenance phase of SLE.

Methods Thirty-five patients with SLE (27 females and 8 males) were assessed at baseline and following 6 months of TAC administration (from 1 mg to 5 mg per day) using changes in corticosteroid dose and clinical examination. Proteinuria, serum complement levels (C3c) and anti-double-stranded DNA (dsDNA) titers were assessed. The relapse rate of SLE and adverse effects were assessed.

Results The mean patient age was 42.0±16.4 years at the initiation of therapy, and the mean disease duration was 76±52 months. Other immunosuppressive drugs (azathioprine, 1 patient; and mizoribine, 9 patients) were combined with corticosteroids, but these agents had been discontinued due to ineffectiveness and/or adverse effects. Corticosteroid doses were reduced from 12.3±8.3 at baseline to 10.4±8.5 mg per day following 6 months of TAC administration (p<0.05). Serum complement levels (C3c) increased significantly from 69.3±29.8 to 75.9±33.9 mg/dL (normal range; 86-160 mg/dL) (p<0.05). However, anti-dsDNA titers were not altered (from 30.2±70.8 to 22.8±50.9). Proteinuria decreased in 10 patients but increased in 3 patients. No significant changes in proteinuria were observed in 22patients. No relapse of SLE was observed in this study. Adverse effects were observed in 2 patients, including the muscle cramp in one patient and an elevation of creatinine kinase and lactic dehydrogenase in one patient. These effects were reversed following the cessation of TAC administration.

Conclusions TAC combination therapy during the maintenance phase of SLE was found in this study to be beneficial. TAC reduced corticosteroid doses, elevated serum complement level, and decreased proteinuria. No relapse of SLE or major adverse events was observed.

Disclosure of Interest None Declared