Glomerular capillary tenascin staining in renal allografts and its correlation with capillary loop 'double contours', proteinuria and graft outcome.
BACKGROUND
Glomerular capillary injuries result in proteinuria, previously reported to be a risk factor for renal allograft dysfunction. According to the Banff 97 Working Classification of Renal Allograft Pathology, 'double contours' in glomerular capillary loops (GC-DC) were suggested to be most specific for chronic transplant glomerulopathy. Tenascin-C (TN), a component of extracellular matrix, is known to be overexpressed in various conditions.


METHODS
TN immunostaining was performed by the labeled streptavidin biotin method. The correlations between glomerular capillary TN (GC-TN) and proteinuria, and between GC-DC and GC-TN, were studied in 27 biopsies showing chronic allograft nephropathy (CAN) lesions. In 14 patients (serum creatinine <2.0 mg/dl at biopsy), graft outcome was studied. Graft function 3 years after biopsy was classified as stable or deteriorated; the term 'deteriorated' was used if serum creatinine had increased 20% over baseline, or if the patient required dialysis.


RESULTS
In CAN, GC-TN correlated with GC-DC. Proteinuria in patients with intense GC-TN tended to increase during 1 year after biopsy. In graft outcome analysis, GC-TN was significantly lower in stable grafts than in deteriorated ones. Furthermore, all 3 patients demonstrating weak GC-TN without GC-DC returned to dialysis.


CONCLUSIONS
TN immunostaining is a sensitive method to detect glomerular capillary injury with a predictive value for renal allograft dysfunction.
Fukuda
Michio
M
Department of Internal Medicine and Pathophysiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan. m-fukuda@med.nagoya-cu.ac.jp
Morozumi
Kunio
K
Uchida
Kazuharu
K
Oikawa
Tadashi
T
Takeda
Asami
A
Yosida
Atsuhiro
A
Kimura
Genjiro
G
D000328:Adult; D000911:Antibodies, Monoclonal; D015415:Biomarkers / Q000032:analysis; D001706:Biopsy; D002196:Capillaries / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007674:Kidney Diseases / Q000150:complications / Q000175:diagnosis / Q000473:pathology*; D007678:Kidney Glomerulus / Q000098:blood supply / Q000737:chemistry* / Q000473:pathology; D016030:Kidney Transplantation; D008297:Male; D011507:Proteinuria / Q000209:etiology; D019063:Tenascin / Q000032:analysis*; D014184:Transplantation, Homologous; D017211:Treatment Failure
D000911:Antibodies, Monoclonal; D015415:Biomarkers; D019063:Tenascin