A pilot study on tacrolimus treatment in membranous or quiescent lupus nephritis with proteinuria resistant to angiotensin inhibition or blockade.

Persistent proteinuria in patients with quiescent lupus can result from membranous lupus nephritis and/or glomerular scarring following previous flares. This pilot study examined the effects of tacrolimus over two years in six patients with membranous/inactive lupus nephritis and persistent proteinuria despite angiotensin inhibition/blockade. Tacrolimus treatment reduced proteinuria and increased serum albumin (time effect, P = 0.047 and 0.032 respectively). Compared with baseline levels, proteinuria improved by more than 50% in five patients (83.3%) and hypoalbuminaemia was corrected in four patients. The efficacy was most prominent in four patients with biopsy-proven membranous lupus nephritis, whose protienuria improved by over 80%. One patient developed biopsy-proven chronic nephrotoxicity after 10 months of tacrolimus treatment, despite non-excessive blood levels. These data suggest that tacrolimus is an effective treatment for proteinuria due to membranous lupus nephritis, but should probably be reserved for patients who are refractory to other non-nephrotoxic treatments, in view of the potential risk of subclinical nephrotoxicity.