Serum IgA/C3 ratio and glomerular C3 staining predict progression of IgA nephropathy in children

Abstract

Background: This retrospective study aimed to evaluate the significance of serum immunoglobulin A/ complement 3 (IgA/C3) ratio and glomerular C3 staining at the onset of disease for predicting progression of IgA nephropathy in children. Methods: A total of 41 children with IgA nephropathy were allocated to two groups according to proteinuria (proteinuria <50 mg/kg/day group and proteinuria ≥50 mg/kg/day group) to compare their clinical data. Receiver operating characteristic (ROC) curves were used to evaluate the optimal cutoff value of serum IgA/C3 ratio in two groups. According to the optimal cutoff value of serum IgA/C3 ratio and glomerular C3 staining, the children were divided into four groups: Group A (serum IgA/C3 ratio <2.025 and glomerular C3 staining <2.0); Group B (serum IgA/C3 ratio ≥2.025 and glomerular C3 staining <2.0); Group C (serum IgA/C3 ratio <2.025 and glomerular C3 staining ≥2.0); and Group D (serum IgA/C3 ratio ≥2.025 and glomerular C3 staining ≥2.0). Then, the risk factors [including proteinuria and glomerular filtration rate (GFR) and pathological findings] were compared in these 4 groups at onset of IgA nephropathy. Results: Serum IgA/C3 ratio in the proteinuria <50 mg/kg/day group was significantly higher compared to the proteinuria ≥50 mg/kg/day group (P<0.01). According to ROC curves, the optimal cutoff value for the IgA/C3 ratio was 2.025 in two groups. At onset of IgA nephropathy, patients with IgA/C3 ratio <2.025 were predicted with nephrotic range proteinuria. When glomerular C3 staining was at the same level (glomerular C3 staining <2.0), GFR was significantly lower in group B (serum IgA/C3 ratio ≥2.025) compared with group A (serum IgA/C3 ratio <2.025). When serum IgA/C3 ratio was at the same level (serum IgA/C3 ratio <2.025), GFR was significantly lower in group C (glomerular C3 staining ≥2.0) compared with group A (glomerular C3 staining <2.0). Pathological findings and MEST (Oxford classification of IgA nephropathy) scores did not differ among the 4 groups at onset of the disease. Conclusions: Serum IgA/C3 ratio and glomerular C3 staining may be useful markers of the progression of IgA nephropathy in children, but not good markers for pathological findings at the onset of disease.

Systematic Review of the Link Between Oxford MEST-C Classification and Complement Activation in IgA Nephropathy

“…, 17 2021 C3 Poland Pediatric 148 IF; plasma, turbidmetric 11.6 67 95.8 ± 33.5 1.4 (0.02–9.6) Lang et al. , 18 2021 C3; IgA/C3 ratio China Pediatric 41 IF:C3;IgA/C3: turbidmetric 9.3 63 118.8 ± 41.2 NA Wu et al. , 38 2021 C3 China Pediatric 98 IF; plasma, turbidmetric 9.7 67 108.5 ± 37.1 2.7 (1.1–8.3) Xie et al.…”

“…Some studies have suggested that complement activation is associated with more severe MEST-C scores, 11 , 12 , 13 , 14 , 15 whereas others have reported no significant correlation between the 2. 16 , 17 , 18 , 19 …”

Urinary epidermal growth factor predicts complete remission of proteinuria in Chinese children with IgA nephropathy

“…These serum immunological parameters were reported to be associated with kidney histological lesions or kidney outcomes of IgAN. [44][45][46][47][48][49][50] Our study had several strengths. On the analytical aspects, the method of ELISA was used in our study, which is considered the gold standard for measuring EGF because of its better sensitivity and specificity compared with other methods (such as radioimmunoassays, radioreceptor assays, enzyme immunoassays, and ultramicroELISA assay) for detection of EGF in urine.…”

Development and Validation of a Nomogram for the Early Prediction of Iga Nephropathy in Primary Glomerulonephritis

“…Since then, several researchers have reported serum IgA as diagnostic and prognostic markers of IgAN [19,20] . Recently, studies have found that serum IgA/C3 ratio had better diagnostic and prognostic value for IgAN [8,21,22] . At the beginning of the model building, we also considered including serum IgA/C3 ratio in the nomogram model, but unfortunately it did not improve the diagnostic value of the model.…”