Activation of complement system by mannan pathway and Mbl2 genotypes in patients with type 2 diabetes and nephropathy

• Main Authors: Tjaša Cerar, Draženka Pongrac Barlovič, Anže Zorin, Nadan Gregorič, Vladimir Kotnik
• Format: Article
• Language: English
• Published: Slovenian Medical Association 2014-11-01
• Series: Zdravniški Vestnik
• Subjects: nephropathy, diabetes, complement, mannan binding lectin
• Online Access: http://vestnik.szd.si/index.php/ZdravVest/article/view/103
• ISSN: 1318-0347; 1581-0224

<p>To add new evidence that complement activation by the mannan (lectin) pathway is involved in the pathogenesis of nephropathy in patients with type 2 diabetes, we collected blood and urine samples from 20 patients with type 2 diabetes and nephropathy and 20 apparently healthy individuals from the general population. We performed tests for complement activation analysis (CH50, APH50, C3, C4, C3d/dg, C4d, SC5b-9, MBL and genotyping of <em>Mbl2</em> gene) in blood and (C3d/dg, C4d,  MBL, and SC5b-9) in urine. We found significant signs of complement activation in patients with type 2 diabetes and nephropathy in blood and in urine. We also observed significant genetic differences between healthy individuals and patients with type 2 diabetes and nephropathy concerning the <em>Mbl2</em> gene. Healthy individuals were apparently more heterogeneous (45 % A0 type) in presentation of the structural <em>Mbl2</em> genotype, giving intermediate and low levels of MBL protein, compared to patients with type 2 diabetes and nephropathy, who had a very homogenous <em>Mbl2</em> genome (75 % AA type) giving a high level of MBL production. From our data we can conclude that patients with type 2 diabetes and nephropathy presents more frequently with <em>Mbl2</em> gene polymorphism giving high production of the MBL protein, what is very likely connected with acquired renal injury.</p>