Long-term outcome and predictors of long-term outcome in patients with lupus nephritis managed at a tertiary hospital in Mumbai

Aim Study the long-term outcome of the patients with LN and identify the baseline factors that can predict the long-term outcome of these patients Methods All biopsy-proven LN patients who attended our regular 'lupus nephritis' clinic from 2013 to 2021 were studied. Data of these patients were collected from the hospital patient records. Standard therapy was given as per the KDIGO guidelines, and the renal response was evaluated according to KDIGO outcome criteria. Cox' regression analysis was used to determine predictors of chronic kidney disease (persistent doubling of serum creatinine with creatinine >= 1.5 mg%). Kaplan-Meier analysis was used for renal survival. Results Eighty patients with at least 1 year of follow-up were included. Median age of onset was 24 years (IQR18-35). Median follow up was 6.5 years (IQR 3-10). World Health Organisation renal biopsy profile was Class I 1(1.2 %), Class II 6(7.5 %), Class III 9(11.2 %), Class IV 36(45 %), Class V 18(22.5 %) and Mixed Class IV + V 10 (12%). Complete remission was achieved in 63.75%, 70 % and 66.6% patients at 1, 2 and 5 years, respectively. Survival with normal renal function was 88.5 %, 85.8% and 60 % at 5, 10 and 15 years, respectively. Risk factors for poor outcome on univariate analysis were presence of Raynaud's phenomena-hazard ratio(HR) 7.78 (CI 1.944-31.207; p < .004), baseline hypertension-HR 5.356 (CI 1.479-19.403; p < .011), tubulointerstitial involvement-HR 1.076 (CI 1.032-1.222; p < .001), time to complete response-HR 1.036 (CI 1.036-1.067; p < .02 ), serum creatinine at 6 months HR 10.51 (CI 2.19-50.39; p < .003), failure to achieve complete response at 2 years HR 6.271 (CI 1.567-25.092; p < .009) and the number of nephritic flares HR 1.868(CI 1.103-3.164 ; p < .02). Renal relapses were quite common, with 1.8 flares per 10 patient-years of follow up. Infection was the most common cause of death, with bacterial lower respiratory infections and pulmonary tuberculosis being the most common. Conclusions Apart from conventional risk factors, other predictive factors like the presence of Raynaud's phenomenon, tubulointerstitial fibrosis and tubular atrophy on kidney biopsy, and initial response to induction therapy by 6 months have a significant impact on the long-term outcome in patients with LN.