Immune response in asymptomatic paraproteinemia. I. Primary and secondary antibody response to Helix pomatia hemocyanin.

In a group of 20 patients with asymptomatic paraproteinemia, as judged after at least 3 years of follow-up, the primary and secondary antibody response to Helix pomatia hemocyanin (HPH) was defective as compared with the response in controls. The class of antibody was assessed by mercaptoethanol (ME) treatment of serum. A lowered response was found not only in the total but also in the ME-resistant (mainly 7S, IgG) antibody titer. Low anti-HPH antibody titers were preferentially found in the patients with high serum paraprotein levels, whereas in half of the patients with low serum paraprotein levels a completely normal antibody response was found. No differences in the total or 7S anti-HPH antibody response were found between patients with IgG, IgM, or IgA paraproteinemia. The polyclonal serum Ig levels were not predictive for the measured anti-HPH response. The anamnestic diphtheria and tetanus antibody response was not different from that of controls.