Related Experiment Videos
Urinary IgG4: an additional parameter in characterizing patients with incipient diabetic nephropathy
S Gambardella1, S Morano, A Cancelli
1Clinica Medica II (Dept. of Endocrinology I), Policlinico Umberto I, University of Rome La Sapienza, Italy.
Diabetes Research (Edinburgh, Scotland)
|April 1, 1989
Summary
Urinary IgG4 levels increase in early diabetic nephropathy, indicating impaired kidney filtration selectivity even before microalbuminuria is severe. This suggests IgG4 may help detect preclinical kidney damage in diabetic patients.
Area of Science:
- Nephrology
- Immunology
- Diabetology
Background:
- Diabetic nephropathy involves progressive kidney filtration impairment.
- Early stages may show increased excretion of anionic proteins due to charge selectivity loss.
- Urinary IgG4, an acidic immunoglobulin, may indicate preclinical charge selectivity impairment.
Purpose of the Study:
- To investigate the hypothesis that urinary IgG4 excretion indicates charge selectivity impairment in preclinical diabetic nephropathy.
- To evaluate IgG4 as a potential biomarker for characterizing microalbuminuric patients.
Main Methods:
- Tested 53 Type 1 diabetic patients (grouped by albumin excretion rate) and 20 controls.
- Measured urinary IgG4 and total IgG using ELISA and RIA.
- Assessed nephrological and metabolic parameters.
Main Results:
- Urinary IgG4 was significantly elevated in patients with moderate and severe albuminuria compared to controls.
- The IgG4/IgG ratio increased in these groups, indicating selective IgG4 excretion.
- IgG4 levels were elevated even when total IgG remained within normal ranges in moderate albuminuria.
Conclusions:
- Elevated urinary IgG4 suggests selective filtration of this acidic protein in diabetic nephropathy.
- Urinary IgG4 may serve as an additional biomarker for early detection and patient subgrouping in microalbuminuria.