Citations

ABSTRACT Inactivating mutations of the ENPP1 gene are associated with generalized arterial calcification of infancy (GACI) and less often autosomal-recessive hypophosphatemic rickets type 2 (ARHR2). We aimed to investigate the spectrum of phenotypes in a family with monoallelic and biallelic mutations of ENPP1 after identification through whole exome sequencing of a 54-year-old female with biallelic mutation of ENPP1, c.323G > T; p.Cys108Phe and c.1441C > T; p.Arg481Trp. Including the proband, 2 subjects had biallelic mutations, 5 had monoallelic mutations, and 2 had no mutation of ENPP1. The maternal mutation, a known pathogenic variant associated with GACI, was found in 3 subjects with monoallelic mutations, while the paternal mutation, which was not previously reported, was present in 2 subjects with monoallelic mutations. Both subjects with biallelic mutations had bowing of bilateral femurs, periarticular mineral deposition, normocalcemic primary hyperparathyroidism with multigland parathyroidectomy, increased carotid intima-media thickness, and enthesopathy was also noted in one subject. Intact FGF23 was elevated in both subjects with biallelic mutations, while C-terminal FGF23 was only elevated in one and PPi was reduced in one. Subjects with monoallelic mutations did not have periarticular calcifications or bone deformities. To conclude, patients with biallelic GACI causing mutations can survive well into adulthood, and despite the same biallelic ENPP1 pathogenic variants, clinical and biochemical manifestations can significantly differ, and include enthesopathy and primary hyperparathyroidism, which have not been previously described. Although carriers of monoallelic ENPP1 variants appear unaffected by classic disease manifestations, there may be subtle biochemical and clinical findings that warrant further investigation. © 2019 American Society for Bone and Mineral Research.

Background: Thyroid immune-related adverse events (IRAEs) have been reported more frequently with programmed cell death protein-1 (PD-1) inhibitors than cytotoxic T lymphocyte antigen 4 (CTLA-4) inhibitors, but there is limited data describing endocrinopathies from programmed cell death protein–ligand 1 (PD-L1) inhibitors. This study characterizes thyroid IRAEs in cancer patients treated with PD-L1 inhibitors and examines the impact on overall survival. Methods: This is a retrospective cohort study of cancer patients treated with atezolizumab and avelumab at the Mayo Clinic, Rochester, Minnesota, from June 1, 2016 to January 30, 2018, and followed for a median of 10.1 months. Thyroid IRAEs were characterized as new onset hypothyroidism, thyrotoxicosis, and worsening of pre-existing hypothyroidism. Results: Of 91 patients treated with a PD-L1 inhibitor, 19 (21%) developed new onset thyroid dysfunction, of whom 14 presented with hypothyroidism and 5 with thyrotoxicosis (3 progressed to hypothyroidism and 2 returned to euthyroidism), and 4 (4%) had worsening of pre-existing hypothyroidism. Thyroid IRAEs occurred after a median of two doses (6 weeks), 48% required thyroid hormone replacement, and none required steroids or discontinuation of immunotherapy. Two out of four patients with thyroid peroxidase (TPO) antibody >9 IU/mL at baseline developed thyroid IRAEs. Median TPO antibody titer was not different between those with and without thyroid IRAEs but was higher in those with overt than those with subclinical hypothyroidism (5 vs. 0.3 IU/mL, p = 0.003) and those prescribed thyroid hormone replacement as compared with observation (5.5 vs. 0.3, p = 0.008). Diffusely increased thyroid 18-fluorodeoxyglucose ( 18 FDG) uptake on positron emission tomography (PET) scan occurred in 71% with thyroid IRAE as compared with 6% without thyroid IRAEs ( p = 0.001). Patients who developed thyroid IRAEs had longer overall survival ( p = 0.027) and lower mortality (hazard ratio 0.49 [95% CI 0.25–0.99], p = 0.034) after adjusting for potential confounders. Conclusions: PD-L1 inhibitors lead to immune-mediated thyroiditis, the most frequent endocrine IRAE. In most cases, management is supportive without requiring steroids or discontinuation of immunotherapy. Diffusely increased thyroid 18 FDG uptake on PET scan may predict the occurrence of thyroiditis, whereas TPO antibodies may help identify its severity. Thyroiditis may be a biomarker for antitumor immune response, highlighting the need to further characterize its underlying mechanism.

AbstractObjectivesLong-term follow-up is important for determining performance characteristics of thyroid fine-needle aspiration (FNA).MethodsHistologic or 3 or more years of clinical follow-up was used to calculate performance characteristics of thyroid FNA before and after implementation of The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC). The impact of noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) classification was also investigated.ResultsFollow-up was obtained for 1,277/1,134 and 1,616/1,393 aspirates/patients (median clinical follow-up, 9.9 and 4.4 years, pre- and post-TBSRTC, respectively). Nondiagnostic, suspicious for follicular neoplasm, and suspicious for malignancy (SFM) diagnoses decreased and benign diagnoses increased post-TBSRTC, while atypical rate remained less than 1%. Negative predictive value for benign nodules and positive predictive value (PPV) for SFM increased significantly. Eleven nodules were reclassified as NIFTP, slightly decreasing PPV/risk of malignancy (ROM).ConclusionsAppropriate ROM for thyroid FNA can be achieved through application of TBSRTC terminology with minimal use of atypical category.

Background: Severe pretibial myxedema (PTM) can be difficult to manage, highlighting the need to investigate newer therapies. Rituximab (RTX) and intravenous immunoglobulin (IVIg) have been tried in Graves' orbitopathy. Since PTM and orbitopathy share a similar underlying pathophysiology, this study aimed to explore these therapies for progressive PTM. Methods: The electronic database was screened for PTM patients evaluated at the Mayo Clinic, Rochester, from 2002 to 2016, and three patients who received IVIg and five who received RTX are reported. PTM pattern was classified as non-pitting edema, plaque and induration, nodular/nummular, and elephantiasis. PTM was confirmed by biopsy in six patients. Results: The patients' median age was 53.8 years, 75% were female, and all but one patient were either active or former smokers. All patients were euthyroid and had progressed despite various therapies prior to starting these agents. Six patients had a plaque and induration pattern, and two had a nodular pattern with elephantiasis. After therapy, six (75%) patients had PTM stability or improvement both subjectively and objectively (80% with RTX and 66% with IVIg). The three patients (one in the IVIg group and two in the RTX group) who had subjective improvement had a plaque pattern. One patient with elephantiasis had a transient response to IVIg and another had stability after RTX. Thyrotropin receptor antibody values and orbitopathy also improved in patients who demonstrated PTM improvement. No serious adverse events were reported, but one patient each had transient hypertension and injection-site thrombophlebitis after IVIg. Conclusions: Immunomodulation therapy was followed by PTM improvement or stability in most patients, with a slightly better response after RTX compared to IVIg. A validated response assessment instrument and larger series of patients are required to determine if the underlying disease process could be curtailed with these agents.

Objective Insulin-dependent diabetes can occur with immune checkpoint inhibitor (ICI) therapy. We aimed to characterize the frequency, natural history and potential predictors of ICI-induced diabetes. Research design and methods We reviewed 1444 patients treated with ICIs over 6 years at our cancer center, and from the 1163 patients who received programmed cell death protein 1 (PD-1) inhibitors, we identified 21 such cases, 12 of which developed new-onset insulin-dependent diabetes and 9 experienced worsening of pre-existing type 2 diabetes. Results ICI-induced diabetes occurred most frequently with pembrolizumab (2.2%) compared with nivolumab (1%) and ipilimumab (0%). The median age was 61 years, and body mass index was 31 kg/m2, which are both higher than expected for spontaneous type 1 diabetes. Other immune-related adverse events occurred in 62%, the most common being immune mediated thyroid disease. New-onset insulin-dependent diabetes developed after a median of four cycles or 5 months; 67% presented with diabetic ketoacidosis and 83% with low or undetectable C-peptide. Autoantibodies were elevated in 5/7 (71%) at the time of new-onset diabetes. Diabetes did not resolve during a median follow-up of 1 year. Conclusions PD-1 inhibitors can lead to insulin deficiency presenting as new-onset diabetes or worsening of pre-existing type 2 diabetes, with a frequency of 1.8 %. The underlying mechanism appears similar to spontaneous type 1 diabetes but there is a faster progression to severe insulin deficiency. Better characterization of ICI-induced diabetes will improve patient care and enhance our understanding of immune-mediated diabetes.

AbstractThe course and pathogenesis of Graves’ disease and Graves’ ophthalmopathy are interdependent, influencing each other’s therapeutic choices. Multiple factors including geographic location, access to medical services, patient and physician preferences influence the management of these conditions. Graves’ disease is classically managed with one of three treatment options – antithyroid drugs, radioactive iodine, and thyroidectomy. In recent years, there has been a shift towards antithyroid drugs, including long term therapy with these agents, given the advantage of avoiding hypothyroidism and the apparent safety of this approach. In addition, new therapies are (slowly) emerging, focusing on immunomodulation. Technological advances are opening doors to non-pharmaceutical interventions that aim to deal with both structural thyroid abnormalities as well as biochemical abnormalities of hyperthyroidism. Graves’ ophthalmopathy management is guided by its activity and severity status, with treatment options including smoking cessation, control of hyperthyroidism, local eye measures, glucocorticoids, selenium, orbital radiotherapy, and surgery. In addition to these established treatment choices, new immunotherapy-based approaches are being tested. Some of them (tocilizumab and teprotumumab) are very promising but further evaluation is needed before we can establish their role in clinical care. Agents identified as beneficial in Graves’ disease management will likely be tested in Graves’ ophthalmopathy as well. In the coming years, our main clinical responsibility will be to find the proper balance between the benefits and potential risks of these incoming therapies, and to identify the subgroups of patients where this ratio is most likely to favor a safe and successful therapeutic outcome.

Purpose: Thyroid autoimmunity affects approximately 5% of the population, and its investigation relies heavily on the use of autoantibodies. Thyroid stimulating hormone receptor (TSHR) autoantibodies (TRAb) play a central role in the evaluation of Graves disease (GD), Graves ophthalmopathy (GO) and pretibial myxedema (PTM). However, there is still controversy regarding overall TRAb assay diagnostic accuracy and their prognostic utility. Methods: We reviewed and analyzed the literature reporting TRAb assays and their clinical utility. Results: Current assays measure the overall TRAb titer in a competitive manner (TSH binding inhibiting immunoglobulin assay) or biologic activity of the stimulating TSHR autoantibodies (thyroid stimulating immunoglobulin assay). Both types of assays have improved over time with advances in sensitivity and specificity. TRAb are particularly relevant in hyperthyroidism cases where use of iodinated contrast is not an option (e.g., pregnancy or recent use of iodinated contrast) or in cases of euthyroid eye disease, suspicious for GO. Third generation TRAb assays are useful for therapy selection in GD, prognostic predictions in GO and risk prediction for fetal and neonatal thyrotoxicosis. Discussion: Given the pathogenic role of TRAb, we expect that the future will bring useful evidence regarding their predictive role with respect to efficacy of therapeutic modalities for GO and PTM. We also hope to better understand the role of blocking and neutral antibodies against TSHR, and harness that ability for modulation of thyroid function or therapy of differentiated thyroid carcinoma managed with TSH suppression. Conclusions: Thyroid autoimmune diseases have seen tremendous gains in understanding their pathophysiology, largely antibody mediated. Better TRAb testing is becoming a springboard for providing individualized patient care.

Aims. Hypoglycemia is a limiting factor for achieving stringent glycemic control in diabetes. This study analyzes the frequency and predictors of hypoglycemia in insulin-treated diabetes in an ambulatory setting. Methods. A retrospective chart review was performed to study self-monitored blood glucose (SMBG) data for 3 months prior to a patient’s HbA1c test. Results. Hypoglycemia occurred more frequently in type 1 than in type 2 diabetes; however, 19% of type 2 diabetes patients did experience at least one episode of severe hypoglycemia. For type 1 diabetes, hypoglycemia had a positive association with glycemic variability and duration of diabetes and a negative association with HbA1c and lowest blood glucose (BG). For type 2 diabetes, a positive association was noted with glycemic variability and a negative association with age and lowest BG. Conclusions. Delineating factors predisposing to hypoglycemia in type 2 diabetes is difficult. Lower HbA1c is a potential predictor of hypoglycemia in type 1 but not in type 2 diabetes. Longer duration of diabetes for type 1 and younger age for type 2 are associated with more hypoglycemia. Glycemic variability portends increased risk for hypoglycemia and should be a focus of further research.