Linchuang shenzangbing zazhi (Dec 2024)
Predictive value of serum IgG/C3 levels for membranous nephropathy in diabetics with proteinuria and negative phospholipase A2 receptor antibody
Abstract
Objective To detect the level of serum immunoglobulin (Ig)G/C3 in diabetes mellitus (DM) patients with proteinuria and negative serum T-type phospholipase A2 receptor (PLA2R) antibody and explore its non-invasive predictive value for membranous nephropathy (MN). Methods A total of 52 DM patients with negative serum PLA2R antibody undergoing renal biopsy were retrospectively reviewed. The eligible subjects were assigned into two groups of diabetic kidney disease (DKD, n = 22) and MN with/without DKD (MN±DKD, n = 22) according to clinicopathological characteristics. Risk factors for MN were evaluated by multivariate Logistic regression analysis. The optimal predictive value for IgG/C3 was estimated by receiver operator characteristic (ROC) curve. Results Blood urea nitrogen was significantly higher in DKD group than that in MN±DKD group [(9.34±3.48) vs (6.88±2.44) mmol/L] (P<0.05). Blood creatinine became markedly elevated in DKD group than that in MN±DKD group [(159.68±94.08) vs (102.20±53.94) μmol/L] (P<0.05). As compared with MN±DKD group, IgG[(8.45±2.12) vs (5.85±2.65) g/L](P<0.01), IgG/C3[(7.57±2.05) vs (4.66±1.77)](P<0.01), diabetic duration [(7.11±6.02) vs (3.80±4.34) year] (P<0.05) and proportion of DKD (72.73% vs 18.18%)(P<0.01) were all significantly higher in DKD group than that in MN±DKD group. Multivariate Logistic regression indicated that serum IgG/C3 level (OR = 0.411, 95%CI: 0.185-0.910, P = 0.028) was an independent predictor of MN in diabetics. ROC curve indicated that the optimal cutoff value of IgG/C3 for predicting MN was 6.098 with a sensitivity of 77.3% and a specificity of 77.3%. And IgG/C3≤6.098 was an optimal predictor of MN in diabetics. Conclusion Lower IgG/C3 level is an independent indicator of MN in diabetics with isolated proteinuria and negative serum PLA2R antibody. Renal biopsy is recommended for these patients.
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