title: A case of slowly progressive type 1 diabetes with unstable glycemic control caused by unusual insulin antibody and successfully treated with steroid therapy.
abstract: A 75-year-old man with type 1 diabetes and history of insulin therapy for previous 3 years using only human recombinant ones was suffering from unstable glycemic control. He had a high level of total insulin and a high titer of insulin antibodies (IA) (bound/total ratio: 89.8%). Low affinity constant (k(1): 0.0312 x 10(8) M(-1)) and high binding capacity (b(1): 51.8 x 10(-8) M) of IA in the patient detected by the Scatchard analysis were not compatible with those of IA associated with exogenous insulin injections in the diabetic patients, but compatible with those of the insulin autoantibodies found in patients with insulin autoimmune syndrome (IAS), although he had DRB1*0405, which may have protection against IAS development. The glucose infusion rate during hyperinsulinemic euglycemic clamp was 2.84 mg/kg/min, suggesting a high level of insulin resistance. Steroid pulse therapy (1000 mg for 3 days) aimed at reducing the possible effect of the IA on his insulin resistance and glycemic instability successfully decreased IA titer (from 89.8 to 58.3%), lowered its binding capacity (51.8-9.8 x 10(-8) M), increased glucose infusion rate (from 2.84 to 5.55 mg/kg/min) and improved glycemic control (HbA(1c): from 10.0 to 7.4%) with reduced blood glucose excursion. In conclusion, the alteration in insulin pharmacokinetics induced by IA seemed to be the cause of the brittle diabetes of the present case. Steroid treatment might be useful for the improvement of glycamic control in such patients with high IA levels and unstable blood glucose.
authors.affiliation: Department of Metabolic Medicine, Faculty of Medical and Pharmaceutical Sciences, Kumamoto University, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Matsuyoshi
authors.forename: Seiya
authors.initials: S
authors.lastname: Shimoda
authors.forename: Kaku
authors.initials: K
authors.lastname: Tsuruzoe
authors.forename: Kayo
authors.initials: K
authors.lastname: Taketa
authors.forename: Takeshi
authors.initials: T
authors.lastname: Chirioka
authors.forename: Fumi
authors.initials: F
authors.lastname: Sakamoto
authors.forename: Michiharu
authors.initials: M
authors.lastname: Sakakida
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Miyamura
authors.forename: Eiichi
authors.initials: E
authors.lastname: Araki
mesh_terms: D000284:Administration, Oral; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism*; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000175:diagnosis / Q000188:drug therapy* / Q000276:immunology; D018450:Disease Progression; D006801:Humans; D007330:Insulin Antibodies / Q000097:blood*; D008297:Male; D011239:Prednisolone / Q000008:administration & dosage / Q000627:therapeutic use*
chemical_list: D001786:Blood Glucose; D007330:Insulin Antibodies; D011239:Prednisolone