Early renal response and baseline serum albumin in childhood proliferative lupus nephritis managed with a mycophenolate mofetil-first, response-guided strategy.

backgroundMycophenolate mofetil (MMF) is a recommended first-line treatment option for proliferative lupus nephritis (LN), but evidence from pediatric real-world cohorts remains limited. We evaluated short-term renal response and baseline factors associated with time to first complete renal response (CRR) in Vietnamese children managed with an MMF-first, response-guided strategy.

methodsWe retrospectively studied children aged ≤16 years with biopsy-proven proliferative LN selected for an institutional MMF-first, response-guided strategy. The primary outcome was time to first CRR within 6 months. Kaplan-Meier and Cox analyses were performed; baseline serum albumin was modeled with a time-varying coefficient because the proportional hazards assumption was not met.

resultsAmong 66 children, 61 (92.4%) achieved a first CRR within 6 months (median, 3 months), and 56 (84.8%) were in CRR at month 6. Higher baseline serum albumin was associated with earlier first CRR after adjustment for baseline proteinuria and estimated glomerular filtration rate, although this association attenuated over time (time-varying effect, P = 0.008). In exploratory analyses, children with baseline serum albumin ≤2.5 g/dL achieved first CRR later than those with higher albumin.

conclusionsChildren selected for an MMF-first, response-guided strategy had favorable short-term renal response. Higher baseline serum albumin was associated with earlier CRR, particularly during the early treatment period, but should be interpreted as a marker of response kinetics rather than a validated independent predictor. These findings should not be generalized to children with severe proliferative LN requiring an alternative initial treatment strategy.