Background Early complete remission (within 12 months) is considered an important protective factor against development of chronic kidney disease (CKD) in lupus nephritis (LN). However, a certain proportion of such patients still develop advanced CKD. Our objective was to describe the factors associated with the development of CKD stage IV or worse in LN patients who achieved early complete remission.

Methods Patients with LN based on biopsy or abnormal proteinuria (>0.5g/day) and/or urinary sediment for two consecutive visits in the absence of other plausible explanation were retrieved from the Toronto Lupus Clinic database. Individuals with advanced CKD at baseline (eGFR&x2266;29ml/min/1.73m2) were excluded. All patients achieved complete remission (proteinuria<0.5g/24h, inactive urinary sediment and serum creatinine &x2266;120% of baseline) within 12 months. Patients were followed for at least 5 years after LN diagnosis.

Results Of 273 eligible patients, 21 (7.7%) developed advanced CKD after a median of 5.8 years from the time of remission (range 0.7–31.7 years). At baseline, these patients had higher SCR (124.9±71.9 vs. 80.7±25.8μmol/L, p<0.001); other baseline characteristics were not significantly different. Multivariate survival analysis for predictors of advanced CKD is shown in table 1. The major factors for early CKD were poor compliance or insufficient therapy due to concomitant infections in 7 and moderate-to-severe interstitial fibrosis and tubular atrophy (IFTA) in 4 patients. In late progressors, compliance was poor in 2, moderate-to-severe IFTA in 3, poorly controlled hypertension in 2, thrombotic microangiopathy in one, refractory disease in one while one patient progressed very slowly over 32 years.

Conclusions Patients with impaired kidney function, low complement C3 at baseline and histopathologic features of chronic irreversible damage (interstitial fibrosis/tubular atrophy), are at risk for CKD despite early remission and should be followed closely. The importance of maintenance therapy should be communicated to prevent non-compliance and subsequent flares.