Immunoglobulins in Chronic Cold Haemagglutinin Disease

Abstract
Summary.: Total serum IgM levels in 32 patients with chronic cold haemagglutinin disease ranged from 100 to 2400 mg/100 ml; follow‐up in nine patients showed slowly progressive increases.The excess IgM was mostly cold agglutinin and although there was considerable variation in serologic activity on a molecular basis, specific lytic activity against enzyme‐treated red cells was very similar. The cold agglutinin IgM seemed well produced and closely parallel to normal IgM; few 7S units and little Bence‐Jones proteinuria were detected. Non cold‐agglutinin IgM levels were mostly normal, but 31% of patients showed subnormal levels of IgA or IgG especially when the IgM level was greater than 1000 mg/100 ml.