Determinants of renal functional outcome in lupus nephritis: a single centre retrospective study

Background: Lupus nephritis (LN) is a rare disease but is thestrongest predictor of poor outcome in patients with SystemicLupus Erythematosis (SLE). It is associated with significantmorbidity, with 10–20% of patients developing end stagerenal failure. As there is a paucity of randomized clinicaltrial data in LN, and no consistent literature regarding baselinefactors that predict renal outcome, we were prompted to analyseour centre's complete experience of managing LN. Methods: A retrospective analysis was undertaken of all patientspresenting to our renal centre with biopsy proven LN from 1979–2003.Patients were divided into two categories, those with stableor deteriorating renal function over time. Baseline parameterswere correlated with renal outcome. Results: Complete clinical records were available for 45 (40female) patients. Mean (SD) age of onset of SLE was 32 ±14 years, and mean age onset of LN was 36 ± 13 years.Patients were followed up for an average of 74 ± 56 months.Four patients (9%) had WHO Class II LN, 11 (24%) WHO Class IIIand there were 15 (33%) each in Class IV and V, respectivelyon renal biopsy. Five (11%) patients presented with acute renalfailure and all had proliferative changes on biopsy. The chiefarbiters of renal functional deterioration over follow up werelonger time to development of LN (P = 0.04), a high plateletcount and worse baseline renal function (both P = 0.05). Therewas a trend relating low haemoglobin or membranous histologyto poor renal outcome, and Class IV histology to better outcome. Conclusion: The study has identified that longer time to developmentof LN, high platelet count and poorer renal function at baselinesuggest a worse renal outcome in LN. The study was small butLN is a rare condition. A combination of factors is likely toinfluence renal outcome in LN and larger prospective trialsare required to ascertain consistent baseline prognostic markers.