The Occurrence of Serum 7S IgM in Diseases Associated with Immunoglobulin Abnormalities

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).…”

“…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-…”

Monomeric (7S) IgM found in the serum of rheumatoid arthritis patients share idiotypes with pentameric (19S) monoclonal rheumatoid factors.

“…Previous reports document the occurrence of polyclonal, low molecular weight IgM (7S, IgM) in various patients with autoimmune diseases (1)(2)(3)(4)(5)(6)(7)(8) and occasionally in apparently normal individuals (9,10). In rheumatoid arthritis (RA)' patients, seropositive for rheumatoid factor (RF+), the occurrence of 7S IgM is associated with disease severity and frequently with vasculitis, (11,12).…”

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).…”