Glycated immunoglobulin M in diabetic patients.
Measurement of glycation levels on isolated immunoglobulin M (IgM), a short half-life protein, could be an index of glycaemic control. We determined glycated IgM levels in a diabetic patients population as compared to control non-diabetic subjects in a cross-sectional and longitudinal study. For that purpose we developed a precipitation method for IgM purification, measured glycation on the purified protein by a nitroblue tetrazolium assay and correlated glycated IgM, glycated haemoglobin (HbA1c) and fructosamine rates. The purification method we developed comprises dextran sulfate-CaCl2, ammonium sulfate and polyethylene glycol precipitations and it allows extraction of IgM free of contaminants as shown by immunoelectrophoresis. Glycated IgM levels were 8.65 +/- 0.15 nmol deoxymorpholinofructose (DOMF) equivalents/mg protein for non-diabetic subjects (n = 30) and 12.08 +/- 0.60 nmol DOMF equivalents/mg protein (n = 67) for diabetic patients. Diabetic patients had then a 40% rise in glycated IgM (p < 0.0005). In a longitudinal study with patients undergoing treatment aimed at improving their metabolic control, glycated IgM levels decreased significantly (p < 0.001) between the day of admission and the fifth day. Average rate of fall was 13% with a range of 3.0 to 22.0% (n = 28). Glycated IgM clearly responds more rapidly than fructosamines which fell by 7.0% and than HbA1c, which showed a rate of fall of 3.9% in the same period. A significant positive correlation was found between these parameters, being stronger between glycated IgM and fructosamines. This method could provide an alternative approach as a short-term marker of glycaemic control for clinical trials.
Menini
T
T
Département d'immunopharmacologie, faculté de pharmacie, université Louis-Pasteur, Illkirch, France.
Gugliucci
A
A
Sodahlon
Y K
YK
Stahl
A J
AJ
Blickle
J F
JF
Brogard
J M
JM
D003922:Diabetes Mellitus, Type 1 / Q000097:blood*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D005260:Female; D019270:Fructosamine; D006442:Glycated Hemoglobin / Q000032:analysis; D017127:Glycation End Products, Advanced / Q000097:blood*; D006595:Hexosamines / Q000097:blood; D006801:Humans; D007075:Immunoglobulin M / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D012016:Reference Values
D019270:Fructosamine; D006442:Glycated Hemoglobin; D017127:Glycation End Products, Advanced; D006595:Hexosamines; D007075:Immunoglobulin M