A specific and sensitive assay for blood levels of glycated CD59: a novel biomarker for diabetes

Am J Hematol. 2013 Aug;88(8):670-6. doi: 10.1002/ajh.23478. Epub 2013 Jun 20.


Increasing evidence links the complement system with complications of human diabetes. The complement regulatory protein CD59, an inhibitor of formation of membrane attack complex (MAC), is inhibited by hyperglycemia-induced glycation fostering increased deposition of MAC, a major effector of complement-mediated tissue damage. CD59, an ubiquitous GPI-anchored membrane protein, is shed from cell membranes by phospholipases generating a soluble form present in blood and urine. We established an enzyme-linked immunosorbent assay (ELISA) to measure serum/plasma glycated human CD59 (hCD59) (GCD59) and evaluated its potential as a diabetes biomarker. We used a synthetic peptide strategy to generate (a) a mouse monoclonal antibody to capture hCD59, (b) a rabbit monoclonal antibody to detect GCD59, and (c) a GCD59 surrogate for assay standardization. ELISA conditions were optimized for precision, reproducibility, and clinical sensitivity. The clinical utility of the assay was initially evaluated in 24 subjects with or without diabetes and further validated in a study that included 100 subjects with and 90 subjects without a diagnosis of diabetes. GCD59 (a) was significantly higher in individuals with than in individual without diabetes, (b) was independently associated with HbA1c, and (c) identified individuals with diabetes with high specificity and sensitivity. We report the development and standardization of a novel, sensitive, and specific ELISA for measuring GCD59 in blood. The assay distinguished individuals with diabetes from those without, and showed strong correlation between GCD59 and HbA1c. Because GCD59 likely contributes to the pathogenesis of diabetes complications, measurement of blood levels of GCD59 may be useful in the diagnosis and management of diabetes.

Publication types

  • Clinical Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adolescent
  • Adult
  • Animals
  • Antibodies, Monoclonal, Murine-Derived / chemistry
  • Antibodies, Monoclonal, Murine-Derived / immunology
  • Biomarkers / blood
  • Biomarkers / chemistry
  • CD59 Antigens / blood*
  • CD59 Antigens / chemistry
  • CD59 Antigens / immunology
  • Diabetes Mellitus, Type 2 / blood*
  • Diabetes Mellitus, Type 2 / diagnosis
  • Diabetes Mellitus, Type 2 / immunology
  • Enzyme-Linked Immunosorbent Assay / methods
  • Female
  • Glycated Hemoglobin A / immunology
  • Glycated Hemoglobin A / metabolism
  • Glycosylation
  • Humans
  • Male
  • Mice
  • Middle Aged
  • Rats
  • Sensitivity and Specificity


  • Antibodies, Monoclonal, Murine-Derived
  • Biomarkers
  • CD59 Antigens
  • Glycated Hemoglobin A
  • hemoglobin A1c protein, human
  • CD59 protein, human