Case Report: Insulin hypersensitivity in youth with type 1 diabetes

Objective

Immediate type I, type III, and delayed type IV hypersensitivity reactions to insulin are rare, but potentially serious complications of exogenous insulin administration required for the treatment of type 1 diabetes (T1D).

Methods

We present four cases of insulin hypersensitivity reactions occurring in youth with T1D and a literature review of this topic.

Results

Insulin hypersensitivity reactions included types I, III, and IV with presentations ranging from localized urticaria, erythematous nodules, and eczematous plaques to anaphylaxis with respiratory distress. Reactions occurred in youth with newly diagnosed T1D and in those with long-standing T1D who were using both injection and insulin pump therapy. Multidisciplinary care involving pediatric endocrinology and allergy/immunology utilizing trials of many adjunct therapies yielded minimal improvement. Despite the use of various treatments, including antihistamines, topical therapies, immunosuppressant medications, desensitization trials, and intravenous immune globulin, cutaneous reactions, elevated hemoglobin A1c levels, and negative effects on quality of life remain persistent challenges. One patient became one of the youngest pancreas transplant recipients in the world at age 12 years due to uncontrollable symptoms and intolerable adverse effects of attempted therapies.

Conclusion

Although rare, insulin hypersensitivity reactions negatively affect glycemic control and quality of life. These cases demonstrate the varying severity and presentation of insulin hypersensitivity reactions along with the limited success of various treatment approaches. Given the life-sustaining nature of insulin therapy, further studies are needed to better understand the underlying pathophysiology of insulin hypersensitivity and to develop targeted treatment approaches.

Embryonic vitamin D deficiency programs hematopoietic stem cells to induce type 2 diabetes

Environmental factors may alter the fetal genome to cause metabolic diseases. It is unknown whether embryonic immune cell programming impacts the risk of type 2 diabetes in later life. We demonstrate that transplantation of fetal hematopoietic stem cells (HSCs) made vitamin D deficient in utero induce diabetes in vitamin D-sufficient mice. Vitamin D deficiency epigenetically suppresses Jarid2 expression and activates the Mef2/PGC1a pathway in HSCs, which persists in recipient bone marrow, resulting in adipose macrophage infiltration. These macrophages secrete miR106-5p, which promotes adipose insulin resistance by repressing PIK3 catalytic and regulatory subunits and down-regulating AKT signaling. Vitamin D-deficient monocytes from human cord blood have comparable Jarid2/Mef2/PGC1a expression changes and secrete miR-106b-5p, causing adipocyte insulin resistance. These findings suggest that vitamin D deficiency during development has epigenetic consequences impacting the systemic metabolic milieu.

Steroid Use in the NICU: Treatment and Tapering

The adrenal gland cortex produces life-sustaining steroid hormones that are critical for the development and survival of the fetus and neonate. Antenatal and postnatal administration of steroids has critical therapeutic effects in preterm infants. However, prolonged postnatal steroid therapy for more than 1 to 2 weeks is associated with iatrogenic adrenal insufficiency and should prompt consideration of a steroid taper and stress dose precautions. In this review, we will describe fetal adrenal development and steroidogenesis, the effect of antenatal exogenous steroids, the therapeutic role of postnatal steroids, evaluation and treatment of adrenal insufficiency, and the role of steroid tapers after prolonged steroid treatment.

Rates of adrenal insufficiency using a monoclonal vs. polyclonal cortisol assay

OBJECTIVES

The diagnosis of adrenal insufficiency relies on clear cut-offs and accurate measurement of cortisol levels. Newer monoclonal antibody assays may increase the rate of diagnosis of adrenal insufficiency if traditional cortisol cut-off levels <18 mcg/dL (500 nmol/L) are applied. We aimed to determine if the rate of diagnosis of adrenal insufficiency using a 1 mcg Cosyntropin stimulation test varied with the change in cortisol assay from a polyclonal to a monoclonal antibody assay.

METHODS

Cortisol levels obtained during the 1 mcg Cosyntropin stimulation test performed in the last semester of 2016 using a polyclonal antibody cortisol assay were compared to tests performed using a monoclonal antibody cortisol assay during the first semester of 2017. Cosyntropin tests included cortisol values obtained at baseline, 20 min and 30 min after IV administration of 1 mcg Cosyntropin. Peak cortisol cut-off value <18 mcg/dL was used to diagnose adrenal insufficiency.

RESULTS

Stimulated cortisol values after 1 mcg Cosyntropin using the monoclonal assay in 2017 (n=38) were significantly lower (33%) compared to those obtained with the polyclonal assay in 2016 (n=27) (p-value <0.001). The number of passing tests with a peak cortisol value >18 mcg/dL fell from 74% in 2016 (20 out of 27 tests) to 29% in 2017 (11 out of 38 tests).

CONCLUSIONS

The change in cortisol assay substantially increased the number of patients diagnosed with adrenal insufficiency after 1 mcg Cosyntropin stimulation testing. Standardization of cortisol assays and diagnostic criteria is critical for the accurate diagnosis of adrenal insufficiency.

Immunity and Hypertension

Hypertension is the primary cause of cardiovascular mortality. Despite multiple existing treatments, only half of those with the disease achieve adequate control. Therefore, understanding the mechanisms causing hypertension is essential for the development of novel therapies. Many studies demonstrate that immune cell infiltration of the vessel wall, kidney and central nervous system, as well as their counterparts of oxidative stress, the renal renin-angiotensin system (RAS) and sympathetic tone play a critical role in the development of hypertension. Genetically modified mice lacking components of innate and/or adaptive immunity confirm the importance of chronic inflammation in hypertension and its complications. Depletion of immune cells improves endothelial function, decreases oxidative stress, reduces vascular tone and prevents renal interstitial infiltrates, sodium retention and kidney damage. Moreover, the ablation of microglia or central nervous system perivascular macrophages reduces RAS-induced inflammation and prevents sympathetic nervous system activation and hypertension. Therefore, understanding immune cell functioning and their interactions with tissues that regulate hypertensive responses may be the future of novel antihypertensive therapies.