title: Severe insulin resistance due to anti-insulin antibodies: response to plasma exchange and immunosuppressive therapy.
abstract: Anti-insulin antibodies have been described in two contexts: in insulin-naive individuals (so-called 'insulin autoimmune syndrome') and in patients with insulin-treated diabetes, in whom antibodies are rarely of clinical significance. We report the case of an 68-year-old woman who exhibited a local allergic reaction to subcutaneous insulin followed by severe insulin resistance, evidenced by poor glycaemic control despite treatment with > 3.5 U/kg of insulin per day. She was found to have circulating polyclonal anti-insulin antibodies of the IgG subtype and responded clinically to a course of plasma exchange and immunosuppression with mycophenolate mofetil and, subsequently, intravenous immunoglobulin. Falling titres of antibodies on this regimen correlated with improved glycaemic control. This case suggests that clinicians should be alert to the possibility of insulin resistance due to anti-insulin antibodies and that immunosuppression in this situation may be a valuable therapeutic option.
authors.affiliation: Institute of Metabolic Science and Department of Clinical Biochemistry, Addenbrooke's Hospital, Cambridge, UK.
authors.forename: J R
authors.initials: JR
authors.lastname: Greenfield
authors.forename: A
authors.initials: A
authors.lastname: Tuthill
authors.forename: M A
authors.initials: MA
authors.lastname: Soos
authors.forename: R K
authors.initials: RK
authors.lastname: Semple
authors.forename: D J
authors.initials: DJ
authors.lastname: Halsall
authors.forename: A
authors.initials: A
authors.lastname: Chaudhry
authors.forename: S
authors.initials: S
authors.lastname: O'Rahilly
mesh_terms: D000368:Aged; D000937:Antigen-Antibody Reactions / Q000276:immunology; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy* / Q000276:immunology; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D007279:Injections, Subcutaneous / Q000379:methods; D007328:Insulin / Q000097:blood / Q000276:immunology*; D007330:Insulin Antibodies / Q000097:blood / Q000276:immunology*; D007333:Insulin Resistance / Q000276:immunology*; D009173:Mycophenolic Acid / Q000031:analogs & derivatives* / Q000627:therapeutic use; D010951:Plasma Exchange / Q000379:methods
chemical_list: D007166:Immunosuppressive Agents; D007328:Insulin; D007330:Insulin Antibodies; D009173:Mycophenolic Acid