Outcome of participants with nephrotic syndrome in combined clinical trials of lupus nephritis

OBJECTIVE: The outcome of participants with nephrotic syndrome in clinical trials of lupus nephritis has not been studied in detail. METHODS: Collated data from two randomised controlled trials in lupus nephritis, Lupus Nephritis Assessment of Rituximab (LUNAR) and A Study to Evaluate Ocrelizumab in Patients With Nephritis due to Systemic Lupus Erythematosus (BELONG) were analysed. Nephrotic syndrome was defined as albumin <3 g/dL and urine protein/creatinine ratio ≥3.5 g/g at start of trial. Renal response was defined as a first morning urine protein/creatinine ratio ≤0.5 g/g in addition to ≤25% increase in creatinine from trial entry assessed at week 48. Logistic regression was used to evaluate the association of nephrotic syndrome with renal response while adjusting for treatment received and ACE inhibitor or angiotensin receptor blocker use. RESULTS: 28 (26%) participants with nephrotic syndrome achieved renal response as compared with 130 (52.5%) of those without (p<0.001). Having nephrotic syndrome at baseline significantly lowered the likelihood of achieving renal response (OR 0.32, 95 % CI 0.19 to 0.54, p<0.001). 125 (80%) participants achieved resolution of their nephrotic syndrome in a median time of 16 weeks. CONCLUSIONS: Nephrotic syndrome at baseline decreases the likelihood of renal response at 1 year. Longer clinical trials or better short-term predictors of long-term outcomes may better assess the effect of novel therapeutic approaches on subjects with nephrotic syndrome.