A Low Molecular Weight Immunoglobulin Antigenically Related to 19 S IgM*

IgM rheumatoid factor and low molecular weight IgM. An association with vasculitis

“…Recently a correlation between eosinophilia and vasculitis has been observed in rehumatoid patients and elevated levels of IgGanti-7-globulins have been observed in the sera (60,61 (25) found a relationship between 7s antinuclear factor and disease activity in patients with systemic lupus erythematosus; and Solomon and Kunkel (27) have observed a patient with plasma lymphoid cell malignancy and monoclonal 7s IgM who had severe peripheral neuropathy. However Dammaccco et a1 (22) found 7s IgM in 28% of rheumatoid patients and noted no difference clinically between these patients and those without 7s IgM. 7s IgM has also been described in a variety of other diseases such as systemic lupus erythematosus (24,25). Waldenstrom's macroglobulinemia (22,2426) dysgammaglobulinemia (SO), malignant disease of the plasma cell lymphoid system and lymphoproliferative disorders (27,28), trypanosomiasis (26), and a variety of infectious diseases (31).…”

“…Waldenstrom's macroglobulinemia (22,2426) dysgammaglobulinemia (SO), malignant disease of the plasma cell lymphoid system and lymphoproliferative disorders (27,28), trypanosomiasis (26), and a variety of infectious diseases (31). A variety of antibody specificities for 7s IgM has been observed (19,24,25,(62)(63)(64) …”

“…Sera were tested for 7s IgM by double immunodiffusion against monospecific rabbit antihuman IgM in 4% polyacrylamide gel which permits diffusion of 7s but not 19s IgM, as described by Stobo and Tomasi (24). As a positive control IgM RF purified by gel filtration of a high titer serum on a column of Bio-Gel A5M, reduced to its 7s subunits by M dithiothreitol (Calbiochem, Los Angeles, California) and alkylated with lo-* M iodoacetamide, was utilized.…”

“…Low molecular weight IgM (7s IgM+) has been described in normal serum (19,20), rheumatoid serum and synovial fluid (21)(22)(23), and in sera from patients with a variety of diseases (24)(25)(26)(27)(28)(29)(30)(31). The presence of 7s IgM in sera of rheumatoid patients has been correlated with the Occurrence of vasculitis In the present study an attempt has been made to determine the frequency of occurrence of IgG RF and of 7s IgM in the sera of rheumatoid patients with and without vasculitis and to ascertain the possible clin-…”

Autoantibodies, including antibasement membrane antibody, in patients with selective IgA deficiency.

“…75-IgM in addition to 195-IgM is sometimes found in the sera of the patients with lymphoma, primary macroglobulinemia, IgA deficiency, etc. (Stobo and Tomasi 1967;Bush et al 1969;Dammacco et al 1970;Funakoshi et al 1984). Increased secretion of 75-IgM might provide a compensatory mechanism for protection against foreign antigens in IgA deficient patients (Ammann 1977).…”