RESUMEN
Abstract Background: Lupus nephritis (LN) is a major source of morbidity and mortality in patients with systemic lupus erythematosus (SLE), with 10-25% of patients progressing to end-stage renal disease (ESRD). Objective: This study aims to elucidate the predictive capabilities of 24-h proteinuria (24PTU) and serum creatinine (sCr) after 12 months of treatment with respect to long-term renal outcomes in LN in a single-center cohort of LN patients. Methods: A retrospective analysis was performed on 214 patients diagnosed with LN followed in our center. Values of 24PTU and sCr were assessed at baseline and after 3, 6 and 12 months, and after 5 years and/or the last evaluation. Chronic kidney disease (CKD) was defined as an estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2 for 3 months or longer. End-stage renal disease (ESRD) was defined as the need for permanent dialysis. Receiver operating characteristics curves (ROC) were used to test the best cut-off value of 24PTU and sCr at 12 months who predict bad long-term renal outcomes. Results: The mean follow-up period was 11.2 ± 7.2 years. The best cut-off values for 24PTU and sCr as predictor of CKD were, respectively, 0.9 g/24 h and 0.9 mg/dL. ROC curve for 24PTU had a slightly lower performance than ROC curve for sCr as predictor for CKD (PTU AUC = 0.68; sCr AUC = 0.70), but sensitivity and specificity were better for 24PTU (24PTU: sensitivity = 63.5%, specificity = 71.2%; sCr: sensitivity = 54.8%, specificity = 75.3%). When the outcome was ESRD the best cut-off points were 0.9 g/24hs and 1.3 mg/dL for 24PTU and sCr, respectively, and the curve performance was better for 24PTU (PTU AUC = 0.72; sCr AUC = 0.61). Conclusions: In this ethnically diverse population with LN followed for a long time (> 10 years), levels of 24PTU > 0.9/day at 12 months was a good predictor of bad long-term renal outcome. The serum creatinine > 0.9 mg/dL and > 1.3 mg/dL at 12 months were also good predictors of CKD and ESRD, respectively. Patients with 24PTU < 0.9 g/day and sCr < 1.3 mg/dL at 12 months are not likely to develop ESRD because of the high negative predictive values (NPV) (93.2% and 82%). 24PTU and sCr are relevant as components for a treat-to-target strategy for LN treatment, since their high NPV corroborates their importance as good predictors of long-term renal outcome.
RESUMEN
Os autores relatam o caso de um paciente do sexo masculino, 71 anos de idade, com diagnóstico de doença de Paget óssea sacral. Foi realizado estudo com radiografia, cintilografia, tomografia computadorizada e ressonância magnética, e o diagnóstico foi confirmado por análise histopatológica. O paciente evoluiu com boa resposta ao uso de ibandronato 150 mg, mensalmente, com redução significativa dos marcadores bioquímicos da doença.
The authors report a case of a 71-year-old male patient diagnosed with Paget's disease of sacrum. Imaging study was performed with radiography, scintigraphy, computed tomography and magnetic resonance imaging, and the diagnosis was confirmed by biopsy. The patient progressed with a good response to monthly treatment with ibandronate 150 mg, presenting a significant reduction in biochemical markers of disease.