Cold agglutinins specificity

A specific cold agglutinin cross-reacting with anti-N was detected in the sera of 68 (21%) of 325 hemodialysis patients each had used a dialyser that had been sterilized with formaldehyde. The results of transfusion experiments suggested in vivo hemolytic activity of this antibody. The authors postulated that such in vivo exposure to formaldehyde might make the MN-receptor on erythrocytes immunogenic, thus inducing the formation of the anti-N-like antibody. 

A monoclonal band can be found in most cases, but serum must be separated at 37°C. The ESR in the cold is much higher than at 37°C, due to massive agglutination in the cold. The monoclonal IgM is readily measured (C14), averaging 0.4 g/100 ml (range 0.1-2.4). The residual IgM and IgA and IgG are usually normal. In some 30% patients, mostly those with high IgM levels, a subnormal level of IgA is found. The cold agglutinin IgM is mostly well produced, with no Bence Jones proteinuria or 7 S IgM, and, on a molecular basis, specific lytic activity against enzyme-treated red cells was very similar. 

Data are adapted from compilations of Dure et at. (1989). O, high osmoticum (PEG or salt) D, desiccation C, cold W, wounding H, heat , untested or unknown. Sd, seed St, stem Pase, protease ASI, a-amylase/subtilisin inhibitor WGA, wheat germ agglutinin RNP, ribonuclear protein not organ specific. Table updated from Skriver Mundy (1990). 

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