Introduction: Diabetic retinopathy (DR) remains the leading cause of preventable vision loss in developed countries. Adverse activation of the complement system plays an essential role in development of complications in diabetes and has been demonstrated in eyes from patients with DR. We hypothesized that complement proteins of lectin pathway can predict severe DR, defined as proliferative DR and macular edema, in newly diagnosed type 1 diabetes.

Methods: In this explorative study, incidence of severe DR was monitored in a cohort of newly diagnosed type 1 diabetes patients (n=270) with median follow-up time of 18 years (range 1-22 years). Baseline complement proteins MBL, M-ficolin, H-ficolin, MASP-1, MASP-2, MASP-3, MAp44, and MAp19 were quantified using immunoassays. A cox proportional hazards regression model was applied to test for difference between quantile groups and adjusted for age and HbA1c.

Results: During follow-up, 28 patients developed severe DR. A tendency arose when testing association between MAp44 levels and severe DR in an unadjusted model (HR, 4th quartile vs. the remaining, 1.3; 95% CI 0.99, 1.6), p = 0.06), which became significant in the adjusted model (HR, 1.33; 95% CI 1.0, 1.7), p = 0.04), Fig. 1.

Conclusion: MAp44 was significantly associated with development of severe DR, whereas other complement factors were not. Further analysis in a larger cohort is warranted.


C.B. Holt: None. I.T. Hoffmann-Petersen: None. J.A. østergaard: None. H.D. Parving: None. S. Thiel: None. P. Hovind: None. L. Tarnow: Stock/Shareholder; Self; Novo Nordisk A/S. Other Relationship; Self; Novo Nordisk Foundation. P. Rossing: Advisory Panel; Self; AstraZeneca, Bayer AG, Boehringer Ingelheim Pharmaceuticals, Inc. Speaker’s Bureau; Self; Eli Lilly and Company, Merck Sharp & Dohme Corp. Other Relationship; Self; Novartis AG, Novo Nordisk A/S. T.K. Hansen: None.


Aarhus University; Foundation of Skibsredder Per Henriksen

Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered. More information is available at