Antiproteinuric effect of ARB in lupus nephritis patients with persistent proteinuria despite immunosuppressive therapy

Abstract

Recent immunosuppressive treatments for lupus nephritis have improved renal survival rate, however, there still exists lupus nephritis refractory to these treatments. Angiotensin receptor blockers (ARBs) are known not only to decrease blood pressure but also to have an independent renoprotecting effect by interrupting renin-angiotensin system. The aim of this study was to evaluate whether ARBs have an additive effect on refractory lupus nephritis. Enrolled in this trial were twelve patients with lupus nephritis who were diagnosed by renal biopsy and remained proteinuria despite corticosteroids and/or immunosuppressive treatments. ARB, losartan or candesartan, was administered for six months. Various clinical parameters were compared before and after ARB administration. Proteinuria decreased after ARB treatment in 83% of the patients and the median amount of proteinuria significantly decreased from 2530 mg/g Cr to 459 mg/g Cr (P = 0.03). In addition, serum albumin and cholesterol levels were significantly improved. Systolic blood pressure significantly decreased, but none had symptoms of hypotension. The antiproteinuric effect of ARB did not correlate with the reduction of blood pressure. Interestingly, higher total complement activity levels before ARB treatment were associated with a greater reduction of proteinuria. The addition of ARB would be a safe and effective treatment for lupus nephritis with persistent proteinuria despite corticosteroids and/or immunosuppressive treatments.