Elevated levels of mannan-binding lectin in patients with type 1 diabetes.
The hepatic protein mannan-binding lectin (MBL) activates the complement system on binding to carbohydrate patterns and is involved in first-line defense against invading microorganisms. Emerging evidence indicates that in some situations MBL may cause inexpedient complement activation and tissue injury through binding to endothelial glycosylations. MBL levels are suppressed by insulin treatment in critically ill patients, and, hypothetically, hepatic portal hypoinsulinemia could lead to increased levels of MBL in patients with type 1 diabetes. We measured MBL and C-reactive protein (CRP) levels in 132 normoalbuminuric type 1 diabetic patients and 66 healthy age- and sex-matched controls. The median MBL concentration was higher in diabetic patients than in healthy controls [1290 micro g/liter (interquartile range, IQR 354-2961 micro g/liter) vs. 970 micro g/liter (IQR 277-1607 micro g/liter), P = 0.025], whereas CRP concentrations were similar among patients and controls [1.42 mg/liter (IQR 0.95-2.21) vs. 1.21 mg/l (IQR 0.74-2.13), NS]. In diabetic subjects, CRP levels correlated with poor glycemic control as indicated by hemoglobin A(1c) and daily insulin dose, which was not the case with MBL. MBL concentrations were positively correlated with urinary albumin excretion (r = 0.22; P = 0.013) and increased with increasing urinary albumin excretion tertile (P = 0.036). In conclusion, our data demonstrate that circulating MBL concentrations are significantly elevated in patients with type 1 diabetes and suggest a possible role of MBL in the pathogenesis of renovascular complications in diabetes.
Hansen
Troels Krarup
TK
Medical Department M, Aarhus University Hospital, Aarhus University, DK-8000 Aarhus, Denmark. tkh@dadlnet.dk
Thiel
Steffen
S
Knudsen
Søren Tang
ST
Gravholt
Claus Højbjerg
CH
Christiansen
Jens Sandahl
JS
Mogensen
Carl Erik
CE
Poulsen
Per Løgstrup
PL
D000328:Adult; D002097:C-Reactive Protein / Q000378:metabolism; D003165:Complement System Proteins / Q000378:metabolism; D003922:Diabetes Mellitus, Type 1 / Q000097:blood*; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D008297:Male; D037601:Mannose-Binding Lectin / Q000097:blood*; D008875:Middle Aged
D007328:Insulin; D037601:Mannose-Binding Lectin; D003165:Complement System Proteins; D002097:C-Reactive Protein