Circulating Anti-Immunoglobulin Antibodies in Recent-Onset Type I Diabetic Patients

Abstract

Human sera from 51 recent-onset insulin-dependent (type I) diabetic patients and 47 unrelated control subjects were screened for the possible presence of circulating factors reacting with several anti-pancreatic islet monoclonal antibodies (MoAb.ISL) in solid-phase radioimmunoassay methods (the original goal being the detection of anti-idiotypic islet cell antibodies and/or specific islet cell antigen-bearing immune complexes). MoAbs from the parental myeloma cell line and purified immunoglobulins (Igs) from different animal species were controls. Type I diabetic sera showed significantly increased binding to MoAb.ISL-coated wells compared with normal subjects (P less than .001). However, the same sera also tended to show a higher binding to the control (non-islet-related) MoAb. Sera from type I diabetic patients also reacted with horse, bovine, pig, rabbit, and goat IgG. Displacement of the binding has been obtained by F(ab')2 and/or Fc fragments of IgG. Evidence has been obtained regarding a similar reaction with human IgM. All the sera were negative when tested for rheumatoid factor by nephelometry. The circulating antibodies described have been proven to be different from islet cell autoantibodies. An anti-Ig antibody is thus present in the sera of recent-onset diabetic patients and represents an additional immunological phenomenon with possible physiopathological and clinical significance.

T‐lymphocytes and the pathogenesis of type 1 (insulin‐dependent) diabetes mellitus

“…Over the years, a number of autoantigens have been reported to be recognized by autoantibodies in type 1 diabetes patients, including 64K/GAD and 38 kDa [44,48], insulin [36], tubulin [88], gangliosides [3 I], albumin [89], IgG [90], hsp-65 [51]. Antibody responses to some of these molecules only occur in a minority of patients.…”

Multiple Target Antigens in Pre-Type I Diabetes: Implications for Prediction

“…antithyroid microsomal [42,43], antiadrenal medullary [44,45], antisympathetic ganglion [46], antigastric parietal cell [42,43] and anticarcinoid tumor [47] antibodies. Fur thermore, autoantibodies against proinsulin [48], insulin receptors [49,50] and immunoglobulins of different spe cies [51] have been demonstrated in new-onset diabetic patients.…”

Anti-goat immunoglobulin antibodies in diabetic children at diagnosis and follow-up: comparison with islet cell antibodies and other autoantibodies

“…During the search for anti-idiotypic anti¬ bodies, an immunoglobulin reacting with antihuman islet cell monoclonal antibodies as well as with non-islet specific imunoglobulins from differ¬ ent animal species, including humans, has been re¬ cently found in the early stages of Type I diabetes mellitus (Di Mario et al 1988). …”