Autoantibodies to Perilipin-1 Define a Subset of Acquired Generalized Lipodystrophy

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.

Feasibility and performance of the Idylla™ NRAS/BRAF cartridge mutation assay on thyroid liquid-based fine-needle aspiration

BACKGROUND

Thyroid nodules with indeterminate cytology represent up to 30% of cases. Molecular testing is now highly recommended to improve management. This study aimed to evaluate the use of the Idylla™ NRAS/BRAF mutation test, a rapid and automated polymerase chain reaction (PCR) assay validated for fixed paraffin-embedded use, on residual thyroid liquid-based fine-needle aspiration (LB-FNA).

METHODS

Concordance between mutations detected by the Idylla™ assay and the gold-standard qPCR was assessed by splitting in two aliquots 31 BRAF or RAS mutated and 5 non-mutated LB-FNA samples. Samples were obtained either from simulated FNA after thyroidectomy or from FNA obtained during routine care. A third aliquot was used to assess the limit of detection of Idylla™ for five mutated samples.

RESULTS

The Idylla™ assay showed a sensitivity of 97% and a specificity of 83% as results were concordant for 34 out of 36 samples. One discordant sample concerned a BRAF p.K601E-mutation which is not detected by the Idylla™ cartridge. The other showed a false-positive NRAS p.A146T detection and a weak BRAF p.V600E detection. The limit of detection of the Idylla™ assay was not reached by the dilution assay.

CONCLUSION

Idylla™ NRAS/BRAF mutation testing can be performed on residual thyroid LB-FNA, using low DNA quantity input, thus not requiring a dedicated sample. The Idylla™ NRAS/BRAF assay offers a quick and easy first step for analyzing the main molecular alterations in indeterminate thyroid nodules, hence improving diagnostic management.

Graves' Disease during Immune Checkpoint Inhibitor Therapy (A Case Series and Literature Review)

Thyrotoxicosis is an adverse event associated with immune checkpoint inhibitors (ICPis) that occurs in 0.6 to 3.2% of treated patients, depending on ICPi class. Presentation usually consists of a biphasic thyroiditis with transient thyrotoxicosis and secondary hypothyroidism. ICPi-induced Graves' disease (GD), due to the stimulating activity of TSH-receptor autoantibodies (TRAb), is extremely rare. The aim of this retrospective study was to describe the characteristics and evolution of GD during ICPi therapy. Five among 243 patients followed for ICPi-induced thyrotoxicosis showed TRAb positivity (2% of the cohort). GD occurred quickly after initiation of ICPis; its course was typical for two patients, with prolonged requirement for antithyroid drug treatment (ATD). The three other patients experienced biphasic thyroiditis with secondary hypothyroidism requiring long-term substitution. Three other patients had a diagnosis of GD before starting ICPis; they evolved toward hypothyroidism with early cessation of ATD and long-term substitution treatment during ICPi treatment. None developed significant Graves' orbitopathy. ICPi treatment was not interrupted for thyroid dysfunction. In conclusion, GD is a rare, immune-related adverse event of ICPis with an unusual course and frequent evolution to biphasic thyroiditis. In the case of ICPi-induced thyrotoxicosis in the presence of TRAb, observing the spontaneous evolution and performing a scintigraphy are useful before starting ATD treatment. Pre-existing GD is not exacerbated by ICPis and tends to evolve towards hypothyroidism. ICPi treatment can be maintained with adequate biochemical surveillance.

Anti-PD1 and Anti-PDL1-Induced Hypophysitis: A Cohort Study of 17 Patients with Longitudinal Follow-Up

Hypophysitis, secondary to programmed cell death 1 protein (PD1) and programmed cell death 1 ligand 1 (PDL1) inhibitors, were thought to be rare, with only a few studies describing more than one case with long-term follow-up. The aim of the present study was to describe the clinical, laboratory, and morphological characteristics of PD1/PDL1 inhibitor-induced hypophysitis, and its long-term course. This cohort study was conducted at the University Hospital of Lyon, France, with longitudinal follow-up of patients. Seventeen cases of PD1/PDL1 inhibitor-induced hypophysitis were included. The median time to onset of hypophysitis was 28 weeks (range: 10–46). At diagnosis, 16 patients complained of fatigue, 12 of nausea or loss of appetite, while headache was rare. We found no imaging pituitary abnormality. All patients presented adrenocorticotropic hormone (ACTH) deficiency; other pituitary deficiencies were less common (n = 7). At last follow-up (median: 13 months), ACTH deficiency persisted in all but one patient and one patient recovered from gonadotropic deficiency. PD1/PDL1 inhibitor-induced hypophysitis is a clinical entity different from those associated to cytotoxic T-lymphocyte antigen-4 (CTLA4) inhibitors, with less obvious clinical and radiological signs, and probably a different mechanism. The paucity of symptoms demonstrates the need for systematic hormonal follow-up for patients receiving PD1/PDL1 inhibitors.

Poorly differentiated thyroid carcinoma with pleomorphic giant cells-a case report

Poorly differentiated thyroid carcinoma (PDTC) refers to a malignant tumour that displays an intermediate prognosis between well-differentiated carcinomas and anaplastic thyroid carcinomas (ATC). In the thyroid, pleomorphic giant cells are observed in ATC or in some non-neoplastic thyroid diseases. We described the case of a 43-year-old woman with a 34-mm nodule in her thyroid right lobe. Microscopic examination revealed an encapsulated tumour with a main solid growth pattern and extensive capsular invasion. Multiple images of angioinvasion were observed. There was neither necrosis nor inflammation. Most of the tumour cells were medium-sized and intermingled with pleomorphic giant tumour cells with bizarre features. The immunoprofile (keratins +, TTF1+, Pax 8+) proved their thyroid origin. By NGS, no molecular alteration was identified. The patient was treated by surgery and radioiodine therapy and she has no recurrence after a follow-up of 24 months. Our case meets all the histological criteria of the Turin proposal for PDTC but with pleomorphic giant cells and is very different from ATC according to clinical, histological and immunohistochemical features. Pleomorphic tumour giant cells in thyroid carcinomas could be present in PDTC and do not always represent dedifferentiation and more aggressive carcinoma, thyroid neoplasm.

The multifaceted nature of diabetes mellitus induced by checkpoint inhibitors

Immune checkpoint inhibitors (CPI) are increasingly being used in oncology, and many autoimmune side effects have been described. Diabetes mellitus (DM) has been reported in approximately 1% of subjects treated with programmed cell death-1 and programmed death ligand 1 (PD-1/PD-L1) inhibitors, alone or in association with CTLA-4 inhibitors. In the present mini-review, we aimed to describe different clinical pictures and pathophysiology associated with these forms of diabetes. Data on CPI-related DM was gathered from the largest case series in the literature and from our centre dedicated to immunotherapy complications (ImmuCare-Hospices Civils de Lyon). Most cases are acute autoimmune insulin-dependent diabetes which are similar to fulminant diabetes (extremely acute onset with concomitant near-normal HbA1c levels). Other cases, however, have a phenotype close to type 2 diabetes or appear as a decompensation of previously known type 2 diabetes. The occurrence of diabetes can also be a complication of autoimmune pancreatitis induced by CPI use. Finally, two cases of diabetes in a context of autoimmune lipoatrophy have recently been described. Regarding the wide variety of CPI-induced diabetes, the discovery of a glucose disorder under CPI should motivate specialised care for aetiological diagnosis and appropriate treatment.

Acquired Generalized Lipodystrophy: A New Cause of Anti-PD-1 Immune-Related Diabetes

OBJECTIVE

Anti-programmed cell death-1 (anti-PD-1) antibodies have revolutionized advanced cancer therapy. Anti-PD-1 therapy is responsible for immune-related adverse events, with frequent endocrine manifestations, including acute-onset type 1 diabetes. Acquired generalized lipodystrophy (AGL) is a rare disease, believed to be immune mediated, characterized by loss of adipose tissue and insulin resistance-associated complications.

RESEARCH DESIGN AND METHODS

We describe the first reported case of AGL induced by immune checkpoint therapy.

RESULTS

A 62-year-old woman with metastatic melanoma treated with nivolumab was referred for major hyperglycemia, hypertriglyceridemia, and nonalcoholic steatohepatitis. She had presented with a rapidly progressive generalized loss of subcutaneous adipose tissue. Diabetes was associated with severe insulin resistance and undetectable plasma leptin. Subcutaneous biopsy revealed atrophic adipose tissue infiltrated with cytotoxic CD8⁺ T lymphocytes and fibrosis.

CONCLUSIONS

AGL is an additional immune-related adverse event of anti-PD-1 therapy that leads to severe insulin resistance-associated complications.

Diabetes mellitus induced by PD-1 and PD-L1 inhibitors: description of pancreatic endocrine and exocrine phenotype

AIMS

Programmed cell death-1 and programmed death ligand 1 (PD-1/PD-L1) inhibitors restore antitumor immunity, but many autoimmune side-effects have been described. Diabetes mellitus is a rare complication, and little data concerning its pathophysiology and phenotype have been published. This study aimed to describe both pancreatic endocrine and exocrine functions, immunological features and change in pancreas volume in subjects with diabetes mellitus induced by PD-1 and PD-L1 inhibitors.

METHODS

We analyzed the data of six subjects treated with immunotherapy who presented acute diabetes.

RESULTS

There were five men and one woman. Median age was 67 years (range 55-83). Three subjects were treated with nivolumab, two with pembrolizumab and one with durvalumab. Median time to diabetes onset after immunotherapy initiation was 4 months (range 2-13). Four patients presented fulminant diabetes (FD); none of these had type 1 diabetes (T1D)-related autoantibodies, none of them had T1D or FD-very high-risk HLA class II profiles. The bi-hormonal endocrine and exocrine pancreatic failure previously reported for one FD patient was not found in other FD subjects, but glucagon response was blunted in another FD patient. Pancreas volume was decreased at diabetes onset in 2 FD patients, and all patients presented a subsequent decrease of pancreas volume during follow-up.

CONCLUSIONS

In the patients presented herein, immunotherapy-induced diabetes was not associated with T1D-related autoantibodies. The hormonal and morphological analysis of the pancreatic glands of these six cases contributes to the understanding of the underlying and probably heterogeneous mechanisms. There is a need to find biomarkers to identify patients at risk to develop these new forms of diabetes at early stages of the process to prevent ketoacidosis and to evaluate preventive strategies.

Homozygous leptin receptor mutation due to uniparental disomy of chromosome 1: response to bariatric surgery

CONTEXT

Severe early-onset obesity with major hyperphagia associated with hypogonadotropic hypogonadism is recognized as the main clinical presentation of leptin (LEP) or LEP receptor (LEPR) gene complete deficiency. In a few reported cases, homozygous mutations have been found in patients from consanguineous families. Care of LEPR-deficient patients is complicated because they cannot benefit from LEP treatment. Furthermore, gastric surgery may not be recommended in such genetic hypothalamic obesity.

OBJECTIVE

We investigated in a morbidly obese patient the genetic origin of his obesity and evaluated the benefit of bariatric surgery in this case.

SUBJECT AND METHODS

The patient exhibited severe early-onset obesity with hyperphagia and delayed puberty in a nonobese family. He had clinical and hormonal follow-up from 3 to 26 years of age. Gastroplasty procedures were undertaken when he was 16 and 18 years old. LEPR genetic analysis of the patient and his relatives was performed.

RESULTS

A new homozygous LEPR sequence frameshift, predicted to generate a truncated protein from a premature stop codon in exon 14, was identified in the proband inherited from two paternal copies of chromosome 1 (isodisomy). Vertical ring gastroplasty was sufficient to induce and maintain a 40-kg weight loss into adulthood.

CONCLUSION

We described the first case of a patient with chromosome 1 uniparental isodisomy revealed by molecular analysis of LEPR. In this case, gastroplasty may be partially effective for weight control as illustrated.

LDL from obese patients with the metabolic syndrome show increased lipid peroxidation and activate platelets

AIMS/HYPOTHESIS

This study assessed oxidative stress in LDL from obese patients with the metabolic syndrome and compared it with that in LDL from type 2 diabetic patients or control volunteers. It also determined the effect on platelets of LDL from the three groups.

METHODS

The profiles of lipids, fatty acids and fatty acid oxidation products were determined in LDL isolated from plasma of patients with the metabolic syndrome, patients with type 2 diabetes and volunteers (n = 10 per group). The effects of LDL from the participant groups on the platelet arachidonic acid signalling cascade and aggregation were investigated.

RESULTS

Compared with LDL from control volunteers, LDL from obese metabolic syndrome and type 2 diabetic patients had lower cholesteryl ester, higher triacylglycerol and lower ethanolamine plasmalogen levels. Proportions of linoleic acid were decreased in phosphatidylcholine and cholesteryl esters in LDL from both patient groups. Among the markers of lipid peroxidation, oxidation products of linoleic acid (hydroxy-octadecadienoic acids) and malondialdehyde were increased by 59% and twofold, respectively in LDL from metabolic syndrome and type 2 diabetic patients. LDL from metabolic syndrome and type 2 diabetic patients were equally potent in activating the platelet arachidonic acid signalling cascade through increased phosphorylation of p38 mitogen-activated protein kinase and cytosolic phospholipase A(2), and through increased thromboxane B(2) formation. LDL from patients with the metabolic syndrome and type 2 diabetes potentiated platelet aggregation by threefold and 3.5-fold respectively, whereas control LDL had no activating effects on platelets.

CONCLUSIONS/INTERPRETATION

The metabolic syndrome in obese patients, without or with diabetes, is associated with increased oxidative stress in LDL, which triggers platelet activation.

[Hypertriglyceridemia: therapeutic strategy]

Causes of hypertriglyceridemia (HTG) vary according to their severity and to their character pure or mixed. Environmental factors including caloric intake excess, fructose overload, alcohol consumption, metabolic syndrom, diabetes, and drug exposure are mostly involved in pure, mild HTG. In contrast, the main etiology of mixed HTG (combined dyslipidemia) is familial combined hyperlipidemia which is commonly associated with metabolic syndrome. Major HTG (> 10 g/L) results mostly from genetic disorder in lipid metabolism with a variable contribution of environmental factors. The complications of HTG are an increased risk of acute pancreatitis (TG > 10 g/L) and a controversial atherogenic risk. Lifestyle modification is the treatment cornerstone. Nevertheless, statins are generally considered as the first drug if a medication is necessary for mixed hyperlipidemia. Fibrates may be used in combination with statin for patient with high atherogenic risk and simultaneous residual hypertriglycéridémie and low HDLc or in high risk patient with severe pure hypertriglyceridemia.

Increased lipid peroxidation in LDL from type-2 diabetic patients

Increased oxidative stress is associated with type-2 diabetes and related cardiovascular diseases, but oxidative modification of LDL has been partially characterized. Our aim was to compare the lipid and fatty acid composition as well as the redox status of LDL from diabetic patients and healthy subjects. First, to ensure that isolation of LDL by sequential ultracentrifugation did not result in lipid modifications, lipid composition and peroxide content were determined in LDL isolated either by ultracentrifugation or fast-protein liquid chromatography. Both methods resulted in similar concentrations of lipids, fatty acids, hydroxy-octadecadienoic acid (HODE) and malondialdehyde (MDA). Then, LDLs were isolated by ultracentrifugation from eight type-2 diabetic patients and eight control subjects. Compared to control LDL, diabetic LDL contained decreased cholesteryl esters and increased triglyceride concentrations. Ethanolamine plasmalogens decreased by 49%. Proportions of linoleic acid decreased in all lipid classes, while proportions of arachidonic acid increased in cholesteryl esters. Total HODE concentrations increased by 56%, 12- and 15-hydroxy-eicosatetraenoic acid by 161 and 86%, respectively, and MDA levels increased by twofold. alpha-Tocopherol concentrations, expressed relative to triglycerides, were lower in LDL from patients compared to controls, while gamma-tocopherol did not differ. Overall, LDL from type-2 diabetic patients displayed increased oxidative stress. Determination of hydroxylated fatty acids and ethanolamine plasmalogen depletion could be especially relevant in diabetes.

Glycaemic control and cardiovascular morbi-mortality: the contribution of the 2008 studies

The year 2008 was rich in teachings and suspense in diabetology. Past studies, i.e. United Kingdom Prospective Diabetes Study (UKPDS) in type 2 diabetic patients and Diabetes Control and Complications Trial (DCCT) in type 1 diabetic patients, have shown that in the short term, intensive treatment reduces the incidence of microvascular complications linked to diabetes and in the long term that of both microvascular and macrovascular ones. The in-the-raw conclusions of the recent Action to Control Cardiovascular risk in Diabetes (ACCORD) study note an increase in mortality in type 2 diabetic patients treated intensively, while the Action in Diabetes and Vascular disease, Perindopril and Indapamide Controlled Evaluation (ADVANCE) study evidences a reduction in microvascular complications and the Veterans Affairs Diabetes Trial (VADT) study shows that intensive treatment has no significant effect. A well thought-out analysis of the studies published in 2008 (ACCORD, STENO 2 post-trial, ADVANCE, VADT, UKPDS post-trial, Epidemiology of Diabetes Interventions and Complications [EDIC]) is particularly instructive and highlights the existence of glycaemic memory, the non-existence of blood pressure memory, the need to control all cardiovascular risk factors and to treat diabetes early while avoiding hypoglycaemic incidents. The glycaemic target based on HbA1c must take into account the patient's age and the duration of his diabetes, as well as his cardiovascular risk factors and previous glycaemic control. All in all, the intensive treatment of type 2 diabetes must begin early; it must not be too rapid and must avoid hypoglycaemic incidents and be combined with a strict control of other cardiovascular risk factors.