title: Latent mesangial immunoglobulin A deposition in long-term functioning kidney does not correlate with disease progression and may exhibit fluctuating patterns.
abstract: BACKGROUND
  Latent mesangial immunoglobulin (Ig)A deposition in long-term functioning kidney does not correlate with disease progression and may exhibit fluctuating patterns Mesangial IgA deposition without urinary abnormalities (latent mesangial IgA deposition) is occasionally observed in non-episode biopsies of kidney allografts. However, the histologic features of latent IgA deposition have not been fully characterized.
  
  
  METHODS
  To better identify the clinicopathologic background of subclinical mesangial IgA deposition, we compared the clinical and histologic characteristics of long-term functioning kidney allografts with and without latent IgA deposition.
  
  
  RESULTS
  Among 29 patients with a posttransplant duration of >10 years, 37.9% exhibited latent mesangial IgA deposition. Biopsies indicated that renal function at the time of and 5 years before subclinical mesangial IgA deposition was generally similar. HLA-DR4 and HLA-Bw51 showed a nonsignificant trend to be more frequent in the IgA-positive group. Histologic investigation demonstrated no changes in disease scores based on the Banff 2009 classification between groups. Immunofluorescence revealed co-deposition of C3 at >1+ intensity in 72% IgA-positive patients. Immunohistochemical analysis revealed that IgA deposition per se did not cause notable increases in intraglomerular α-smooth muscle actin (SMA)-positive cells. One patient with subclinical IgA deposition demonstrated a waxing and waning pattern in the amount of IgA deposition.
  
  
  CONCLUSIONS
  This study suggests that subclinical IgA deposition in long-term functioning kidney allografts is not associated with progressive course in clinical and pathologic findings. Furthermore, the amount of subclinical IgA deposition may exhibit fluctuating patterns in some cases.
authors: Division of Diagnostic Pathology, Kobe University Graduate School of Medicine, Kobe, Japan. Electronic address: shara@med.kobe-u.ac.jp.
authors: S
authors: S
authors: Hara
authors: Department of Advanced Technology for Transplantation, Osaka University Graduate School of Medicine, Osaka, Japan.
authors: N
authors: N
authors: Ichimaru
authors: Sakurabashi Circulate Organ Clinic, Osaka, Japan.
authors: M
authors: M
authors: Kyo
authors: Yamaguchi's Pathology Laboratory, Matsudo, Chiba, Japan.
authors: Y
authors: Y
authors: Yamaguchi
authors: Inoue Hospital, Osaka, Japan.
authors: Y
authors: Y
authors: Kojima
authors: Department of Advanced Technology for Transplantation, Osaka University Graduate School of Medicine, Osaka, Japan.
authors: S
authors: S
authors: Takahara
authors: Division of Diagnostic Pathology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors: T
authors: T
authors: Itoh
mesh_terms: D001706:Biopsy; D018450:Disease Progression; D005260:Female; D005922:Glomerulonephritis, IGA / Q000276:immunology* / Q000473:pathology; D006801:Humans; D007070:Immunoglobulin A / Q000276:immunology*; D007150:Immunohistochemistry; D007668:Kidney / Q000276:immunology* / Q000378:metabolism; D007674:Kidney Diseases / Q000473:pathology* / Q000601:surgery; D007678:Kidney Glomerulus / Q000276:immunology / Q000378:metabolism; D016030:Kidney Transplantation; D008297:Male; D050527:Mesangial Cells / Q000276:immunology*; D008856:Microscopy, Fluorescence; D008875:Middle Aged; D010641:Phenotype; D051437:Renal Insufficiency / Q000473:pathology / Q000601:surgery; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D007070:Immunoglobulin A