IgA Nephropathy in Japanese Children and Adults: A Comparative Study of Clinicopathological Features

Abstract

A comparative clinicopathological study was retroscpectively performed in 61 children and 51 adults with IgA nephropathy. Hematuria and/or proteinuria as a chance finding was the most common initial clinical sign, being observed in 82.0% of the children and in 52.9% of the adults. At renal biopsy, hypertension and severe proteinuria were found in 9.8 and 33.3% of the adults and in 0 and 14.8% of the children (both p < 0.05), respectively. Elevations of blood urea nitrogen and serum creatinine were found at this time of biopsy in 21.6 and 9.8% of the adults, but in none of the children (p < 0.001 and p < 0.05, respectively). Histologically, focal glomerulosclerosis and tubular atrophy were found in 52.9% of the adults and in 32.8% of the children (p < 0.05). However, some features of the disease seen in both groups were similar, including the incidences of IgA nephropathy, sex ratio, the mode of onset, incidences of gross hematuria, and high IgA levels in the sera. Furthermore, the relationships between the severity of proteinuria and renal lesions were similar: mesangial proliferation, glomerulosclerosis, and tubular atrophy increased with the degree of the severity of proteinuria. These results suggest that IgA nephropathy is essentially identical in children and adults, although adult patients tend to be further advanced in their disease course at the time of diagnosis, and that focal glomerulosclerosis with tubular atrophy is correlated with deterioration of renal function.

Absence of Mesangial C1q Deposition Is Associated with Resolution of Proteinuria and Hematuria after Tonsillectomy Plus Steroid Pulse Therapy for Immunoglobulin A Nephropathy

“…The majority of authors believe that complement activation by the alternative or lectin pathway is important in the pathogenesis of IgAN [1]. However, many studies have shown that a certain proportion of IgAN patients demonstrate the mesangial deposition of C1q [17,18,19,20,21,22,23,25]. This C1q deposition may simply be incidental, and not pathogenic.…”

“…C1q deposition is found in 0 to 45% of patients with IgAN [17,18,19,20,21,22,23,24]. Some studies have found that mesangial C1q deposition is associated with a decrease in eGFR in patients with IgAN [25].…”

Nefropatia por IgA: análise histológica e correlação clínico-morfológica em pacientes do Estado de Minas Gerais

“…A porcentagem de casos com deposição de C3 confirma a literatura prévia que evidencia tal fração do complemento em mais de 90% das biópsias. 6,40 A porcentagem de deposição de C1q se aproxima de dados dos trabalhos. 41,42 Vale ressaltar que, assim como as lesões histopatológicas, o padrão de deposição à imunofluorescência também é bastante variável ao redor do mundo e que nossos resultados expressam características das biópsias de pacientes do Estado de Minas Gerais.…”

Henoch-SchÖlein Purpura Nephritis in Children: A Severe IgA Mediated Glomerulonephritis

“…Thus, although HSPN patients exhibited more active glomerular lesions in mesangial and endocapillary proliferation, the scoring system suggested by classification was not sufficient to distinguish HSPN from IgAN. Previous studies have shown that IgAN presents with more mesangial proliferation in adult [26][27][28][29][30]. Because a majority of pediatric HSPN and IgAN patients belonged in the highest M score group in present study (Table 4), the M score defined by the Oxford Classification may underscore pediatric IgAN as well as HSPN.…”

“…The reason for failure of the MEST scheme to differentiate activity of glomerular lesions in HSPN and IgAN may probably relate to the differences in the morphological findings between children and adult with IgAN [26][27][28][29][30]. Younger patients present with significantly more mesangial and endocapillary proliferation.…”