Increased serum mannose binding lectin levels are associated with diabetic retinopathy.

Background: Mannose-binding lectin (MBL) may be implicated in the pathogenesis of diabetic retinopathy (DR) complications. We investigated serum MBL levels in type 2 diabetic patients with and without DR.

Methods: Serum MBL levels were determined in 184 type 2 diabetic patients with DR and 189 type 2 diabetic patients without DR matched for age, sex, and duration of diabetes. Multivariate analyses were performed using logistic regression models. The diagnostic value of MBL was compared with the HbA1c, Hs-CRP and with other known markers.

Results: We found that serum MBL levels were significantly higher in diabetes with DR as compared to without-DR [3456 (IQR, 3128-3800) ug/l and 2432 (IQR, 2100-2670) ug/l, respectively; P<0.0001]. In multivariate logistic regression analysis, after adjusting for all other significant factors, MBL remained can be seen as an independent DR marker with an adjusted OR of 1.002 (95% CI, 1.001-1.003; P<0.0001). Based on the ROC curve, the optimal cutoff value of serum MBL levels as an indicator for diagnosis of DR was projected to be 3050 ug/L, which yielded a sensitivity of 82.5% and a specificity of 88.0%, with the area under the curve at 0.907 (95% CI, 0.876-0.938).

Conclusions: In type 2 diabetic patients, evaluated serum levels of MBL can be seen as an independent marker of DR even after correcting for possible confounding factors.