Clinical diagnostic performance of common laboratory indicators in primary glomerulonephritis

Immunoglobulin A nephropathy (IgAN) and membranous nephropathy (MN) are common types of primary glomerulonephritis (PGD). A lack of specific clinical features makes diagnosis difficult. Kidney function indicators have been used for their diagnosis. However, the diagnostic performance of these indicators is undetermined. The purpose of this paper is to evaluate their diagnostic potential.

101 patients with PGD were enrolled, including 50 with MN and 51 with IgAN. The healthy controls included 110 volunteers. The indicators related to kidney function, including TP, ALB, Cre, CysC, eGFR, C1q, Ure, Anti-PLA2R, complement C3, and complement C4 in serum, ACR in urine, and antinuclear antibody profile, IgG staining, IgA staining, IgM staining, C3 staining and C1q staining in tissue samples were evaluated.

Statistical differences were found in TP, ALB, Ure, CysC, eGFR, C1q, Anti-PLA2R, complement C3, complement C4 and ACR among the three groups of subjects. ROC analysis showed that Anti-PLA2R and ACR had the highest specificity for identifying IgAN and/or MN from the healthy controls, ACR had the highest sensitivity. The Sp and Se of IgA and IgG in tissue samples for the identification of IgAN and MN were both high. Both IgAN and MN were predicted by anti-PLA2R, especially MN. In tissue samples, MN patients were more likely to be IgG positive and IgAN patients were more likely to be IgA positive.

IgAN and MN may be differentiated using serum Anti-PLA2R, tissue IgG, and tissue IgA. Cre is only useful in middle and late stages of GPDs, ACR is an exclusion marker, and CysC and C1q cannot be used to identify MN.