title: Therapeutic plasma exchange normalizes insulin-mediated response in a child with type 1 diabetes and insulin autoimmune syndrome.
abstract: Insulin autoimmune syndrome (IAS), characterized by glycemic dysregulation and life-threatening hypoglycemia, can occur in patients with type 1 diabetes (T1D). Diagnostic confirmation is complex but important in order to ensure timely initiation of definitive therapy.
  
  
  
  We aimed to quantitate the degree of immunoglobulin-insulin complex (IIC) formation and its effects on glycemic control in a patient with T1D and IAS compared with T1D and non-T1D controls and before and after therapeutic plasma exchange (TPE).
  
  
  
  The prospective descriptive study was conducted between June 2015 and December 2015 in a quaternary children's hospital in Brisbane, Australia. Percent Free "Immunoreactive" Insulin (%FII) as assessed by polyethylene glycol precipitation studies and its relationship to plasma glucose and serum insulin concentration.
  
  
  
  Samples from the patient with T1D and IAS demonstrated lower mean %FII compared to T1D (23.8 ± 2.0 vs 52.0 ± 6.7; P < .0001) and non-T1D (23.8 ± 2.0 vs 102.9 ± 2.7; P < .0001) controls. This was associated with loss of glycemic predictability and frequent severe hypoglycemia. TPE increased %FII (23.8 ± 2.0 before TPE vs 83.6 ± 2.5 after TPE, P < .0001) and reestablished plasma glucose responsiveness to exogenous insulin.
  
  
  
  IAS should be considered in T1D patients with unexplained glycemic instability and hypoglycemia. The laboratory plays an integral diagnostic role.
  
  
  
  TPE is an effective method for removing IICs and normalizing insulin-mediated glucose responses.
authors.affiliation: Department of Endocrinology & Diabetes, Lady Cilento Children's Hospital, South Brisbane, Queensland, Australia.|School of Medicine, University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Erin F
authors.initials: EF
authors.lastname: Sharwood
authors.affiliation: Mater Research-University of Queensland Institute, South Brisbane, Queensland, Australia.
authors.forename: Ian P
authors.initials: IP
authors.lastname: Hughes
authors.affiliation: School of Medicine, University of Queensland, Brisbane, Queensland, Australia.|Department of Chemical Pathology, Pathology Queensland, The Royal Brisbane and Women's Hospital, Herston, Queensland, Australia.
authors.forename: Carel J
authors.initials: CJ
authors.lastname: Pretorius
authors.affiliation: School of Medicine, University of Queensland, Brisbane, Queensland, Australia.|Department of Nephrology, Lady Cilento Children's Hospital, South Brisbane, Queensland, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Trnka
authors.affiliation: School of Medicine, University of Queensland, Brisbane, Queensland, Australia.|Department of Immunology, Lady Cilento Children's Hospital, South Brisbane, Queensland, Australia.
authors.forename: Jane
authors.initials: J
authors.lastname: Peake
authors.affiliation: Department of Endocrinology & Diabetes, Lady Cilento Children's Hospital, South Brisbane, Queensland, Australia.|School of Medicine, University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Tony
authors.identifier: 0000-0002-7909-3670
authors.initials: T
authors.lastname: Huynh
mesh_terms: D001327:Autoimmune Diseases / Q000175:diagnosis / Q000209:etiology / Q000628:therapy*; D002648:Child; D003922:Diabetes Mellitus, Type 1 / Q000150:complications* / Q000276:immunology; D006801:Humans; D007003:Hypoglycemia / Q000276:immunology*; D007328:Insulin / Q000276:immunology*; D008297:Male; D010951:Plasma Exchange; D011446:Prospective Studies
chemical_list: D007328:Insulin
keywords: hypoglycemia; insulin autoimmune syndrome; therapeutic plasma exchange; type 1 diabetes