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Acquired lipodystrophy is often characterized as an idiopathic subtype of lipodystrophy. Despite suspicion of an immune-mediated pathology, biomarkers such as autoantibodies are generally lacking. Here, we used an unbiased proteome-wide screening approach to identify autoantibodies to the adipocyte-specific lipid droplet protein perilipin 1 (PLIN1) in a murine model of autoimmune polyendocrine syndrome type 1 (APS1). We then tested for PLIN1 autoantibodies in human subjects with acquired lipodystrophy with two independent severe breaks in immune tolerance (including APS1) along with control subjects using a specific radioligand binding assay and indirect immunofluorescence on fat tissue. We identified autoantibodies to PLIN1 in these two cases, including the first reported case of APS1 with acquired lipodystrophy and a second patient who acquired lipodystrophy as an immune-related adverse event following cancer immunotherapy. Lastly, we also found PLIN1 autoantibodies to be specifically enriched in a subset of patients with acquired generalized lipodystrophy (17 of 46 [37%]), particularly those with panniculitis and other features of autoimmunity. These data lend additional support to new literature that suggests that PLIN1 autoantibodies represent a marker of acquired autoimmune lipodystrophies and further link them to a break in immune tolerance.

Patients with biallelic loss-of-function variants of AIRE suffer from autoimmune polyendocrine syndrome type-1 (APS-1) and produce a broad range of autoantibodies (auto-Abs), including circulating auto-Abs neutralizing most type I interferons (IFNs). These auto-Abs were recently reported to account for at least 10% of cases of life-threatening COVID-19 pneumonia in the general population. We report 22 APS-1 patients from 21 kindreds in seven countries, aged between 8 and 48 yr and infected with SARS-CoV-2 since February 2020. The 21 patients tested had auto-Abs neutralizing IFN-α subtypes and/or IFN-ω; one had anti-IFN-β and another anti-IFN-ε, but none had anti-IFN-κ. Strikingly, 19 patients (86%) were hospitalized for COVID-19 pneumonia, including 15 (68%) admitted to an intensive care unit, 11 (50%) who required mechanical ventilation, and four (18%) who died. Ambulatory disease in three patients (14%) was possibly accounted for by prior or early specific interventions. Preexisting auto-Abs neutralizing type I IFNs in APS-1 patients confer a very high risk of life-threatening COVID-19 pneumonia at any age.

Objective Previous studies indicate a possible bidirectional stimulatory relationship between parathyroid hormone (PTH) and adrenocortical hormones, but the pattern of adrenocortical secretion in hypoparathyroidism is unknown. We aimed to characterize the adrenocortical secretion in patients with postsurgical hypoparathyroidism, and whether continuous subcutaneous PTH (1-34) infusion alters secretion patterns. Design Crossover interventional study. Methods We recruited 10 patients with postsurgical hypoparathyroidism with very low PTH levels on stable treatment with active vitamin D and calcium. Cortisol, cortisone, and aldosterone levels were measured in microdialysate from subcutaneous tissue over 24 h, before and during continuous subcutaneous PTH (1-34) infusion. Cortisol was also assayed in serum, saliva, and urine, and aldosterone and ACTH in serum and plasma, respectively. Ten patients with primary hyperparathyroidism and 10 healthy volunteers matched for sex and age served as controls. Results Hypoparathyroid patients displayed both ultradian and circadian rhythmicity for tissue cortisol, cortisone, and aldosterone. Tissue aldosterone and cortisone levels were significantly lower in hypoparathyroid patients than in healthy controls, with no difference in tissue cortisol, but a higher cortisol to cortisone ratio. Treatment with PTH (1-34) increased tissue levels of aldosterone, cortisol, and cortisone and reduced the ratio of cortisol to cortisone. Conclusion Adrenocortical hormone levels are reduced in postsurgical hypoparathyroidism, and partly restored by short-term continuous subcutaneous PTH (1-34) therapy. Clinical trial registration number NCT02986607 [ABSTRACT FROM AUTHOR]

Autoimmune polyendocrine syndrome type 1 (APS1) is a monogenic disorder that features multiple autoimmune disease manifestations. It is caused by mutations in the Autoimmune regulator (AIRE) gene, which promote thymic display of thousands of peripheral tissue antigens in a process critical for establishing central immune tolerance. We here used proteome arrays to perform a comprehensive study of autoimmune targets in APS1. Interrogation of established autoantigens revealed highly reliable detection of autoantibodies, and by exploring the full panel of more than 9000 proteins we further identified MAGEB2 and PDILT as novel major autoantigens in APS1. Our proteome-wide assessment revealed a marked enrichment for tissue-specific immune targets, mirroring AIRE's selectiveness for this category of genes. Our findings also suggest that only a very limited portion of the proteome becomes targeted by the immune system in APS1, which contrasts the broad defect of thymic presentation associated with AIRE-deficiency and raises novel questions what other factors are needed for break of tolerance.

Glucocorticoids are widely prescribed as anti-inflammatory and immunosuppressive agents. This results in at least 1% of the population using chronic glucocorticoid therapy, being at risk for glucocorticoid-induced adrenal insufficiency. This risk is dependent on the dose, duration and potency of the glucocorticoid, route of administration, and individual susceptibility. Once glucocorticoid-induced adrenal insufficiency develops or is suspected, it necessitates careful education and management of affected patients. Tapering glucocorticoids can be challenging when symptoms of glucocorticoid withdrawal develop, which overlap with those of adrenal insufficiency. In general, tapering of glucocorticoids can be more rapidly within a supraphysiological range, followed by a slower taper when on physiological glucocorticoid dosing. The degree and persistence of HPA axis suppression after cessation of glucocorticoid therapy are dependent on overall exposure and recovery of adrenal function varies greatly amongst individuals. This first European Society of Endocrinology/Endocrine Society joint clinical practice guideline provides guidance on this clinically relevant condition to aid clinicians involved in the care of patients on chronic glucocorticoid therapy. [ABSTRACT FROM AUTHOR]

Interstitial lung disease (ILD) is a complex and heterogeneous disorder that is often associated with autoimmune syndromes. Despite the connection between ILD and autoimmunity, it remains unclear whether ILD can develop from an autoimmune response that specifically targets the lung parenchyma. We examined a severe form of autoimmune disease, autoimmune polyglandular syndrome type 1 (APS1), and established a strong link between an autoimmune response to the lung-specific protein BPIFB1 (bactericidal/permeability-increasing fold-containing B1) and clinical ILD. Screening of a large cohort of APS1 patients revealed autoantibodies to BPIFB1 in 9.6% of APS1 subjects overall and in 100% of APS1 subjects with ILD. Further investigation of ILD outside the APS1 disorder revealed BPIFB1 autoantibodies present in 14.6% of patients with connective tissue disease-associated ILD and in 12.0% of patients with idiopathic ILD. The animal model for APS1, Aire⁻/⁻ mice, harbors autoantibodies to a similar lung antigen (BPIFB9); these autoantibodies are a marker for ILD. We found that a defect in thymic tolerance was responsible for the production of BPIFB9 autoantibodies and the development of ILD. We also found that immunoreactivity targeting BPIFB1 independent of a defect in Aire also led to ILD, consistent with our discovery of BPIFB1 autoantibodies in non-APS1 patients. Overall, our results demonstrate that autoimmunity targeting the lung-specific antigen BPIFB1 may contribute to the pathogenesis of ILD in patients with APS1 and in subsets of patients with non-APS1 ILD, demonstrating the role of lung-specific autoimmunity in the genesis of ILD.

Objective Atypical Graves disease (GD) is a common complication in multiple sclerosis (MS) patients treated with alemtuzumab. We present epidemiological, clinical, and biochemical characteristics of alemtuzumab-induced GD. Methods Retrospective follow-up study of MS patients treated with alemtuzumab from 2014 to 2020, including clinical course of GD, pregnancy outcome, and thyroid eye disease (TED). Results We enrolled 183 of 203 patients (90%, 68% women) treated with alemtuzumab at 4 hospitals in Norway. Seventy-five (41%) developed thyroid dysfunction, of whom 58 (77%) had GD. Median time from the first dose of alemtuzumab to GD diagnosis was 25 months (range, 0-64). Twenty-four of 58 GD patients (41%) had alternating phases of hyper- and hypothyroidism. Thyrotropin receptor antibodies became undetectable in 23 of 58 (40%) and they could discontinue antithyroid drug treatment after a median of 22 (range, 2-58) months. Conversely, 26 (44%) had active disease during a median follow-up of 39 months (range, 11-72). Two patients (3%) received definitive treatment with radioiodine, 6 (10%) with thyroidectomy. Nine developed TED (16%), 7 had mild and 2 moderate to severe disease. Four patients completed pregnancy, all without maternal or fetal complications. Patients who developed GD had a lower frequency of new MS relapses and MRI lesions than those without. Conclusion GD is a very common complication of alemtuzumab treatment and is characterized by alternating hyper- and hypothyroidism. Both remission rates and the prevalence of TED were lower than those reported for conventional GD. Pregnancies were uncomplicated and GD was associated with a lower risk of subsequent MS activity. [ABSTRACT FROM AUTHOR]

Primary adrenal insufficiency (PAI) is most often caused by an autoimmune destruction of the adrenal cortex resulting in failure to produce cortisol and aldosterone. The aetiology is thought to be a combination of genetic and environmental risk factors, leading to breakdown of immunological tolerance. Regulatory T cells (Tregs) are deficient in many autoimmune disorders, but it is not known whether they contribute to development of PAI. We aimed to investigate the frequency and function of naive and expanded Tregs in patients with PAI and polyendocrine syndromes compared to age- and gender-matched healthy controls. Flow cytometry was used to assess the frequency and characterize functional markers of blood Tregs in PAI (N = 15). Expanded Treg suppressive abilities were assessed with a flow cytometry based suppression assay (N = 20), while bulk RNA-sequencing was used to examine transcriptomic differences (N = 16) and oxygen consumption rate was measured by a Seahorse cell metabolic assay (N = 11). Our results showed that Treg frequency and suppressive capacity were similar between patients and controls. An increased expression of killer-cell leptin-like receptors and mitochondrial genes was revealed in PAI patients, but their expanded Tregs did not display signs of mitochondrial dysfunction. Our findings do not support a clear role for Tregs in the contribution of PAI development. Regulatory T cells (Tregs) are involved in the initiation or progress of many autoimmune disorders. Here, we describe number and function of Tregs in the endocrine autoimmune disorder primary adrenal insufficiency (PAI). Tregs from PAI patients were adequate in number and in functional cell assays, but had an increase in mitochondria and killer receptors in transcriptomic assays, and showed a higher proliferation capacity, which might point to a higher turnover of these suppressive cells. Graphical Abstract [ABSTRACT FROM AUTHOR]