Measurement of serum IgA and C3 may predict the diagnosis of patients with IgA nephropathy prior to renal biopsy

Abstract

The levels of serum IgA and C3 in patients with IgA nephropathy were determined using international standard serum (IFCC/CRM470) in a multicenter trial in Japan. The ratio of serum IgA to C3 (serum IgA/C3 ratio) without any information from renal biopsy was used for the diagnosis of IgA nephropathy. Three hundred and six patients with IgA nephropathy and other glomerular diseases, and 418 healthy adults were examined. The new diagnostic standardized criterion in patients with IgA nephropathy, obtained by nephelometric immune assay based on the international reference preparation CRM470, was 315 mg/dl. The serum IgA/C3 ratio was a more useful marker for distinguishing IgA nephropathy from non-IgA nephropathy together with serum IgA levels. This suggests that the measurement of serum IgA and C3 may predict the diagnosis of patients with IgA nephropathy prior to renal biopsy.

Relationship between serum IgA/C3 ratio and severity of histological lesions using the Oxford classification in children with IgA nephropathy

“…These results are at variance with results reported by Komatsu et al for adult patients evaluated using the four-grade classification of the Special Study Group on Progressive Glomerular Disease. Their study showed significantly higher IgA/C3 ratio values in patients with more severe lesions (grade III-IV) compared with those with milder (grade I-II) lesion, with no significant differences in serum IgA and C3 levels between groups [13]. In our pediatric population, however, MEST score ≥ 3 was found significantly more frequently in patients with WHO grade III-IV lesions compared with those with grade I-II lesions.…”

Relationship between serum IgA/C3 ratio and severity of histological lesions using the Oxford classification in children with IgA nephropathy

“…These results are at variance with results reported by Komatsu et al for adult patients evaluated using the four-grade classification of the Special Study Group on Progressive Glomerular Disease. Their study showed significantly higher IgA/C3 ratio values in patients with more severe lesions (grade III-IV) compared with those with milder (grade I-II) lesion, with no significant differences in serum IgA and C3 levels between groups [13]. In our pediatric population, however, MEST score ≥ 3 was found significantly more frequently in patients with WHO grade III-IV lesions compared with those with grade I-II lesions.…”

Increased Serum IgA in Children with IgA Nephropathy, Severity of Kidney Biopsy Findings and Long-Term Outcomes

“…In the present study we found an elevated IgA in the serum samples from 46 out of the 89 (52 %) children. In adult patients, IgA >315 mg/dL is considered diagnostic of IgAN, although the IgA level has not been identified as a valuable prognostic factor (Tomino et al 2000). Episodes of overt hematuria in the course of IgAN are less frequent in adults compared with children.…”

The role of mucosal immune dysregulation in the pathogenesis of immunoglobulin A nephropathy

“…Elevated blood IgA levels in patients with IgAN compared to those in healthy individuals have been confirmed in both Western and Asian populations ( 121 – 123 ). Furthermore, circulating IgA1 levels are elevated in patients with IgAN ( 123 – 127 ), which is supported by experimental results showing an increase in the proportion of IgA1 plasma cells in the bone marrow ( 123 , 128 ).…”

Relationship between serum IgA/C3 ratio and severity of histological lesions using the Oxford classification in children with IgA nephropathy

“…These results are at variance with results reported by Komatsu et al for adult patients evaluated using the four-grade classification of the Special Study Group on Progressive Glomerular Disease. Their study showed significantly higher IgA/C3 ratio values in patients with more severe lesions (grade III-IV) compared with those with milder (grade I-II) lesion, with no significant differences in serum IgA and C3 levels between groups [13]. In our pediatric population, however, MEST score ≥ 3 was found significantly more frequently in patients with WHO grade III-IV lesions compared with those with grade I-II lesions.…”

Increased Serum IgA in Children with IgA Nephropathy, Severity of Kidney Biopsy Findings and Long-Term Outcomes

“…In the present study we found an elevated IgA in the serum samples from 46 out of the 89 (52 %) children. In adult patients, IgA >315 mg/dL is considered diagnostic of IgAN, although the IgA level has not been identified as a valuable prognostic factor (Tomino et al 2000). Episodes of overt hematuria in the course of IgAN are less frequent in adults compared with children.…”

The role of mucosal immune dysregulation in the pathogenesis of immunoglobulin A nephropathy

“…Elevated blood IgA levels in patients with IgAN compared to those in healthy individuals have been confirmed in both Western and Asian populations ( 121 – 123 ). Furthermore, circulating IgA1 levels are elevated in patients with IgAN ( 123 – 127 ), which is supported by experimental results showing an increase in the proportion of IgA1 plasma cells in the bone marrow ( 123 , 128 ).…”

Relationship between serum IgA/C3 ratio and severity of histological lesions using the Oxford classification in children with IgA nephropathy

“…These results are at variance with results reported by Komatsu et al for adult patients evaluated using the four-grade classification of the Special Study Group on Progressive Glomerular Disease. Their study showed significantly higher IgA/C3 ratio values in patients with more severe lesions (grade III-IV) compared with those with milder (grade I-II) lesion, with no significant differences in serum IgA and C3 levels between groups [13]. In our pediatric population, however, MEST score ≥ 3 was found significantly more frequently in patients with WHO grade III-IV lesions compared with those with grade I-II lesions.…”

Increased Serum IgA in Children with IgA Nephropathy, Severity of Kidney Biopsy Findings and Long-Term Outcomes

“…In the present study we found an elevated IgA in the serum samples from 46 out of the 89 (52 %) children. In adult patients, IgA >315 mg/dL is considered diagnostic of IgAN, although the IgA level has not been identified as a valuable prognostic factor (Tomino et al 2000). Episodes of overt hematuria in the course of IgAN are less frequent in adults compared with children.…”

The role of mucosal immune dysregulation in the pathogenesis of immunoglobulin A nephropathy

“…Elevated blood IgA levels in patients with IgAN compared to those in healthy individuals have been confirmed in both Western and Asian populations ( 121 – 123 ). Furthermore, circulating IgA1 levels are elevated in patients with IgAN ( 123 – 127 ), which is supported by experimental results showing an increase in the proportion of IgA1 plasma cells in the bone marrow ( 123 , 128 ).…”