Therapeutic plasma exchange normalizes insulin-mediated response in a child with type 1 diabetes and insulin autoimmune syndrome

Abstract

Background: 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. Aims: 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). Materials & Methods: 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. Results: 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. Discussion: IAS should be considered in T1D patients with unexplained glycemic instability and hypoglycemia. The laboratory plays an integral diagnostic role. Conclusion: TPE is an effective method for removing IICs and normalizing insulin-mediated glucose responses.L6151485772017-04-07 <br />2021-08-18 <br />