Circulating antibodies to nephrin in patients with type 1 diabetes.

Abstract

BACKGROUND:

Patients with type 1 diabetes typically develop autoantibodies to antigens of the pancreatic islet cells including insulin, glutamic acid decarboxylase and the protein tyrosine phosphatase-related islet antigen 2 protein. Nephrin is a protein shared by the kidney glomeruli, pancreatic beta-cells and islet microendothelia. Since circulating antibodies to nephrin have been shown to cause proteinuria, we wanted to test whether such autoantibodies can be detected in diabetic patients.

METHODS:

We developed a radioimmunoprecipitation assay and analysed samples in a follow-up series of 66 patients with type 1 diabetes.

RESULTS:

A total of 24% of the patients tested positive for nephrin autoantibodies at diagnosis, whereas 23, 14 and 18% had these antibodies at 2, 5 and 10 years, respectively. During the follow-up at 16-19 years after diagnosis, 14 patients had signs of renal injury and 29% of them tested positive for nephrin autoantibodies in at least one sample.

CONCLUSIONS:

We conclude that a subset of patients with type 1 diabetes present with circulating autoantibodies to nephrin. However, the present data do not allow conclusions of a causative role for these antibodies in the pathogenesis of proteinuria in diabetes.

• Authors: Petri Aaltonen, Johanna Rinta-Valkama, Anu Pätäri, Päivi Tossavainen, Tuula Palmén, Petri Kulmala, Mikael Knip, Harry Holthöfer
• Journal: Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association (Nephrol Dial Transplant) Vol. 22 Issue 1 Pg. 146-53 (Jan 2007) ISSN: 0931-0509 [Print] England
• PMID: 16963480 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Autoantibodies
• Membrane Proteins
• nephrin

Topics

• Adolescent
• Autoantibodies (chemistry)
• Child
• Child, Preschool
• Cohort Studies
• Diabetes Mellitus, Type 1 (blood, immunology)
• Female
• Humans
• Immunoprecipitation
• Infant
• Kidney (pathology)
• Male
• Membrane Proteins (blood, chemistry, immunology)
• Microscopy, Fluorescence
• Time Factors