Outcome criteria for lupus nephritis trials: a critical overview

Lupus nephritis is an important cause of morbidity and mortality in patients with systemic lupus erythematosus. Traditional outcome criteria such as doubling of serum creatinine, end-stage renal disease and death have been used in controlled therapeutic trials, but are limited by their low incidence and the extended period of time required to reach them. More recently, discussions have focused on composite outcome measures, such as remission and relapse, as well as measures of health-related quality of life, general lupus activity and cumulative damage indexes. We review the strengths and weaknesses of several outcome criteria, and we propose criteria for both small pilot studies and large definitive trials.