SERUM IMMUNOGLOBULIN G ( IgG ) AS A PREDICTIVE MARKER OF EARLY RENAL AFFECTION IN TYPE 2 DIABETIC PATIENTS.

Background:- Diabetic nephropathy (DN) is one of the most common diabetic microvascular complications. Albuminuria is considered the gold standard of onset or progression of DN. However albuminuria has certain limitations, clinical practice suggested detectable albuminuria is later than the onset of DN. Thus, the request for more reliable highly sensitive and specific biomarkers is needed for early prediction the onset and progression of DN, which is important to slow down or prevent the renal function decline in diabetic patients. Immunoglobulin G (IgG) is a high molecular weight protein that has been proposed to be a marker for DN and is freely filtered by the glomeruli and completely catabolized in the proximal tubules. In this study we aimed to evaluate serum IgG as a marker of early renal affection in type 2 diabetic patients. Subjects and methods:- This study was performed on 52 type 2 diabetic patients and were compared with 26 healthy subjects as a control group, they were classified as the following; Group I: Including 26 healthy subjects ,Group II: Including 26 type 2 diabetic patients without diabetic nephropathy and Group III: Including 26 type 2 diabetic patients with diabetic nephropathy. All studied patients were subjected to complete medical history and detailed clinical examination, routine laboratory tests including fasting blood glucose(FBS),2-h postprandial blood glucose (PPS) and glycosylated hemoglobin (HbA1c %), serum creatinine, urinary creatinine, urinary albumin , urine albumin/creatinine ratio, measurement of creatinine clearance ,blood urea and serum IgG. Results:- Serum IgG increased significantly in diabetic patients without nephropathy compared to control group and diabetic patients with nephropathy and significantly increased in diabetic patients with nephropathy compared to control group ( P <0.001 ).Also there was significant correlation between serum IgG and duration of treatment ,FBS,PPS,HBA1C, serum creatinine, urine albumin , urine creatinine , urine albumin / creatinine ratio and creatinine clearance (P<.001). Conclusion:- Serum IgG may be useful in detecting early renal impairment in type 2 diabetes mellitus (DM).