Role of omalizumab in insulin hypersensitivity: a case report and review of the literature.

BACKGROUND: Insulin allergy is a rare yet severe side effect of exogenous insulin use. Management typically involves use of alternative antihyperglycaemic agents, symptom control with antihistamines, use of different insulin formulations, and induction of tolerance with incremental doses of insulin. This treatment regimen is not always successful, and the use of omalizumab, an anti-IgE monoclonal antibody, has been used to induce tolerance to insulin. CASE REPORT: G.M. is a 62-year-old man with Type 2 diabetes mellitus. His condition was not optimized on oral agents, and insulin therapy was required. G.M. had anaphylaxis to insulin NPH, and subsequent skin-prick testing was positive to insulin aspart, insulin NPH, insulin glulisine, insulin detemir, regular insulin, insulin glargine 100 units/ml and insulin glargine 300 units/ml. He received incremental doses of several insulin formulations; however, he experienced diffuse urticaria preventing optimal glycaemic control. Three successful cases have been described in the literature of omalizumab inducing tolerance to exogenous insulin; therefore, G.M. was started on omalizumab. He subsequently tolerated treatment doses of insulin glulisine and insulin detemir with no allergic reactions and with improvement in glycaemic control. CONCLUSION: To our knowledge, this is the first described case of allergy to insulin glargine 300 units/ml and reiterates the potential use of omalizumab in insulin allergy. Further research is warranted to determine if omalizumab should be considered standard of care in difficult-to-treat insulin hypersensitivity.

Recovery of adrenal function after chronic secondary adrenal insufficiency in patients with hypopituitarism.

OBJECTIVE: Previous studies have reported recovery of secondary adrenal insufficiency (SAI) in patients with pituitary disorders, generally immediately after pituitary surgery; however, data regarding recovery of long-term SAI are lacking. We conducted a study to assess the longer term recovery rate of SAI in patients with pituitary disorders. METHODS: We identified all SAI patients in the Halifax Neuropituitary Database from 1 November 2005 to 30 September 2014, who had required glucocorticoid therapy for ≥3 months, and had a minimum follow-up of 6 months. Patients with ACTH-secreting adenomas, those receiving glucocorticoids only in the routine peri-operative period for pituitary surgery and those on glucocorticoids for nonpituitary conditions were excluded. SAI was defined as either basal serum cortisol < 130 nm and/or a subnormal cortisol response to ACTH-(1-24) stimulation test or insulin tolerance test response. RESULTS: Fifty-one patients fulfilled the criteria. Nine (17·6%) patients had complete recovery of SAI over a median of 20 months (range: 8-51) after initiating glucocorticoid replacement. Patients with smaller tumour size had increased likelihood of hypothalamic-pituitary-adrenal (HPA) axis recovery, whereas those with secondary hypogonadism or growth hormone deficiency were less likely to recover. Those with initial cortisol >175 nm had an almost one in two chance of recovery. CONCLUSION: Results from our study show that approximately one in six patients with SAI recover adrenal function, even up to 5 years after diagnosis. We recommend that patients with SAI undergo regular testing to assess recovery in order to prevent unnecessary glucocorticoid therapy.