ANALYSIS OF ANTIBODY REACTIVITIES TOWARD SELF-ANTIGENS OF IGM OF PATIENTS WITH WALDENSTROMS MACROGLOBULINEMIA

By using a quantitative immunoblotting technique, we have analyzed the repertoires of antibody reactivities of IgM directed toward self anti gens in the serum of patients with Waldenstrom's macroglobulinemia (WM ) and in the serum of healthy adults, Monoclonal IgM of patients with WM expressed Various degrees of polyreactivity and a high degree of he terogeneity with regard to the number and the nature of the protein ba nds that were recognized in homologous tissue extracts. Heterogeneous patterns of reactivity of WM IgM contrasted with the conserved profile s of reactivity of IgM in the serum of healthy blood donors, Protein b ands that were recognized by WM IgM belonged to the restricted set of self antigens recognized in homologous tissues by normal polyclonal Ig M, indicating the absence of a disease-specific reactivity profile of monoclonal WM IgM. Thus, monoclonal IgM that is present in large amoun ts in WM distorts the homogeneous pattern of reactivity of natural ant ibodies with self antigens which characterizes the natural antibody re pertoire of healthy individuals.