Urinary sediments could differentiate the endocapillary proliferative lupus nephritis and endocapillary proliferative IgA nephrology

Abstract Background: The role of manual urine sediment examination in the diagnosis and prognostication of endocapillary proliferative glomerulonephritis remains to be elucidated. This study aims to investigated the differences of urinary sediment findings between lupus nephritis and IgA nephropathy with endocapillary proliferative glomerulonephritis and further evaluated associations of leukocyturia with disease activity, pathological features and prognosis.Methods: The urinary sediment of 126 patients, including 92 patients with lupus nephritis and 34 patients with IgA nephropathy, with a renal biopsy-proven endocapillary proliferative glomerulonephritis were examined in the morning before renal biopsy according to a standardized method. The urinary elements investigated including various cells, casts and crystals. The associations of the level of leukocyturia and disease activity, pathological features and prognosis were further analyzed.Results: In the patients with endocapillary proliferative glomerulonephritis, normal to mild leukocyturia (≤12/HPF), and moderate to severe leukocyturia (>12/HPF) were found in 52(41.27%) and 74 (58.73%) patients, respectively. The proportion of moderate to severe leukocyturia, the frequency of urinary white blood cells casts and waxy casts were significantly higher in endocapillary proliferative lupus nephritis patients compared with endocapillary proliferative IgA nephropathy patients (P<0.001, P=0.020, P=0.010, respectively). In the proliferative lupus nephritis group, the levels of leukocyturia was significantly correlated with serum creatinine (r=0.288, P=0.005), eGFR (r=-0.284, P= 0.006), serum C3 (r=-0.275, P= 0.009) , SLEDAI scores (r=0.383, P=＜0.001) and glomerular leukocyte infiltration (r=0.285, P= 0.002). A multivariate analysis showed that leukocyturia was identified as an independent risk factor for renal outcome in proliferative lupus nephritis (HR: 1.456, 95% CI: 1.083-1.957, P=0.013) but not in IgA nephropathy (HR: 1.069, 95% CI: 0.494-2.312, P=0.866).Conclusions: Urinary sediments of the endocapillary proliferative lupus nephritis and endocapillary proliferative IgA nephrology differed in many aspects. Leukocyturia could reflect the disease activity and prognosis of endocapillary proliferative glomerulonephritis, especially in lupus nephritis.