Leptin treatment has vasculo-protective effects in lipodystrophic mice.

Lipodystrophy syndromes (LDs) are characterized by loss of adipose tissue, metabolic complications such as dyslipidemia, insulin resistance, and fatty liver disease, as well as accelerated atherosclerosis. As a result of adipose tissue deficiency, the systemic concentration of the adipokine leptin is reduced. A current promising therapeutic option for patients with LD is treatment with recombinant leptin (metreleptin), resulting in reduced risk of mortality. Here, we investigate the effects of leptin on endothelial to mesenchymal transition (EndMT), which impair the functional properties of endothelial cells and promotes atherogenesis in LD. Leptin treatment reduced inflammation and TGF-ß2-induced expression of mesenchymal genes and prevented impairment of endothelial barrier function. Treatment of lipodystrophic- and atherosclerosis-prone animals (Ldlr-/-; aP2-nSrebp1c-Tg) with leptin reduced macrophage accumulation in atherosclerotic lesions, vascular plaque protrusion, and the number of endothelial cells with mesenchymal gene expression, confirming a reduction in EndMT in LD after leptin treatment. Treatment with leptin inhibited LD-mediated induction of the proatherosclerotic cytokine growth/differentiation factor 15 (GDF15). Inhibition of GDF15 reduced EndMT induction triggered by plasma from patients with LD. Our study reveals that in addition to the effects on adipose tissue function, leptin treatment exerts beneficial effects protecting endothelial function and identity in LD by reducing GDF15.

Increased Growth Differentiation Factor 15 in Patients with Hypoleptinemia-Associated Lipodystrophy.

Objective. Similar to obesity, lipodystrophy (LD) causes adipose tissue dysfunction and severe metabolic complications. Growth differentiation factor 15 (GDF15) belongs to the transforming growth factor ß superfamily and is dysregulated in metabolic disease including obesity and diabetes mellitus. Circulating levels in LD and the impact of leptin treatment have not been investigated so far. Material and Methods. GDF15 serum levels were quantified in 60 LD patients without human immunodeficiency virus infection and 60 controls matched for age, gender, and body mass index. The impact of metreleptin treatment on circulating GDF15 was assessed in a subgroup of patients. GDF15 mRNA expression was determined in metabolic tissues of leptin-deficient lipodystrophic aP2-nSREBP1c-Tg mice, obese ob/ob mice, and control C57Bl6 mice. Results. Median GDF15 serum concentrations were significantly higher in LD patients (819 ng/L) as compared to the control group (415 ng/L) (p < 0.001). In multiple linear regression analysis, an independent and positive association remained between GDF15 on one hand and age, patient group, hemoglobin A1c, triglycerides, and C-reactive protein on the other hand. Moreover, there was an independent negative association between GFD15 and estimated glomerular filtration rate. Circulating GDF15 was not significantly affected by metreleptin treatment in LD patients. Gdf15 was upregulated in leptin-deficient lipodystrophic mice as compared to controls. Moreover, Gdf15 mRNA expression was downregulated by leptin treatment in lipodystrophic and obese animals. Conclusions. Serum concentrations of GDF15 are elevated in LD patients and independently associated with markers of metabolic dysfunction. Gdf15 expression is higher in lipodystrophic mice and downregulated by leptin treatment.

Beneficial effects of leptin substitution on impaired eating behavior in lipodystrophy are sustained beyond 150 weeks of treatment.

AIM: Metreleptin treatment in lipodystrophy patients improves eating behavior with increased satiety and reduced hunger. However, no data are available whether effects are maintained beyond 52 weeks of treatment. METHODS: A prospective study with measurements at baseline and at >150 weeks of metreleptin treatment was performed. Five female lipodystrophy patients with indication for metreleptin were included. Behavioral aspects of hunger- and satiety regulation were assessed by validated eating behavior questionnaires and visual analog scales assessing hunger and satiety feelings before and after a standardized meal. RESULTS: Hunger rated on visual analog scales at 120 min after the meal significantly decreased from 46 ±â€¯10 mm at baseline to 17 ±â€¯6 mm at long-term assessment. Furthermore, satiety at 5 and 120 min after the meal significantly increased from baseline to long-term assessment (5 min: 70 ±â€¯7 mm to 87 ±â€¯3 mm; 120 min: 43 ±â€¯10 mm to 79 ±â€¯8 mm). On the Three Factor Eating Questionnaire, the mean value of factor 3 (hunger) significantly decreased from 9.2 ±â€¯0.2 at baseline to 2.6 ±â€¯1.5 at long-term assessment. In the Inventory of Eating Behavior and Weight Problems Questionnaire, mean values for scale 2 (strength and triggering of desire to eat) and scale 7 (cognitive restraint of eating) significantly decreased from baseline (31.6 ±â€¯4.8 and 11.4 ±â€¯2.2, respectively) to long-term assessment (14.0 ±â€¯2.1 and 10.0 ±â€¯1.9). CONCLUSION: First evidence is presented that long-term metreleptin treatment of >150 weeks has sustained effects on eating behavior with increased satiety, as well as reduced hunger and hunger-related measures.

Serum concentrations of fetuin B in lipodystrophic patients.

OBJECTIVE: Fetuin B is an adipokine/hepatokine which is significantly elevated in insulin resistance/type 2 diabetes mellitus and hepatic steatosis. Regulation of fetuin B in patients with lipodystrophy (LD) - a disease group which is characterized by subcutaneous adipose tissue loss, hypertriglyceridemia, hepatic steatosis, insulin resistance, and dysregulation of several adipokines - has not been elucidated so far. MATERIAL AND METHODS: Serum fetuin B levels were determined in 37 patients with LD, as well as in a control cohort consisting of 37 non-LD participants matched for age, gender, and body mass index. Furthermore, fetuin B was correlated with parameters of lipid metabolism, glucose control, renal function, and inflammation. RESULTS: Median fetuin B serum levels were not significantly different between patients with LD (2980.7 µg/l; interquartile range: 841.7 µg/l) and non-LD controls (2647.3 µg/l; interquartile range: 923.6 µg/l; p = .105). Fetuin B was associated with age, body mass index, markers of renal function, and C reactive protein (CRP) in univariate correlation analyses. The associations with age and creatinine remained significant in multiple linear regression analysis. CONCLUSIONS: Fetuin B serum concentrations are not significantly different between patients with LD and non-LD controls. Fetuin B does not seem to be a major pathogenetic factor in LD.

Adipocyte and epidermal fatty acid-binding protein serum concentrations in patients with lipodystrophy.

OBJECTIVE: Lipodystrophy (LD) syndromes are associated with diabetes mellitus, hypertriglyceridemia, and coronary artery disease. One pathogenetic factor of LD is dysregulation of several adipokines. However, the insulin resistance- and dyslipidemia-promoting adipokines adipocyte (AFABP) and epidermal (EFABP) fatty acid-binding protein have not been investigated in non-HIV-associated LD so far. MATERIAL AND METHODS: We performed a cross-sectional analysis of AFABP and EFABP serum concentrations in 37 LD patients and 37 age-, gender-, and body mass index-matched healthy controls. Moreover, AFABP and EFABP were correlated to clinical and biochemical parameters of inflammation, glucose control, and lipid metabolism. RESULTS: There was no significant difference in median circulating AFABP and EFABP levels between LD patients (21.7µg/l and 7.5µg/l, respectively) and healthy controls (24.5µg/l and 8.6µg/l, respectively). Neither AFABP nor EFABP were related to markers of impaired glucose control or lipid metabolism. Multiple linear regression analysis showed a positive and independent association of AFABP with gender, serum leptin levels, and body mass index. CONCLUSIONS: Circulating levels of AFABP and EFABP are not decreased in LD despite adipose tissue loss in contrast to other adipokines including leptin and adiponectin.

Novel peroxisome proliferator-activated receptor gamma mutation in a family with familial partial lipodystrophy type 3.

OBJECTIVE: Familial partial lipodystrophy type 3 (FPLD3) is an autosomal dominant disorder with loss of subcutaneous adipose tissue at the extremities and metabolic complications such as insulin resistance, hypertriglyceridaemia and hypertension. The aim of this study was to characterize the molecular basis of a family of 5 affected members with FPLD3. METHODS: A 61-year-old female index patient and her relatives were assessed by detailed clinical and biochemical examinations. Sequence analysis of the LMNA and PPARG gene was performed. Structure analysis of the identified mutation was carried out using published X-ray crystal structures. RESULTS: A novel heterozygous PPARG mutation c.1040A>C was identified in all 5 patients of the family but not in unaffected controls. The resulting amino acid substitution p.Lys347Thr is located at the ligand-binding domain (LBD) of the protein and is predicted to disrupt critical molecular interactions to the helix 12 of the LBD. CONCLUSIONS: A novel PPARG mutation leading to FPLD3 is described. The results emphasize the importance of the clinical diagnosis and of further molecular genetic analyses in patients with clinical signs of FPLD but unremarkable LMNA findings.

Circulating serum chemerin levels are elevated in lipodystrophy.

OBJECTIVE: Lipodystrophy (LD) is characterized by loss of adipose tissue, dysregulation of adipokines and severe metabolic complications. Regulation of the insulin resistance-inducing and proinflammatory adipokine chemerin has not been assessed in LD. Therefore, we determined chemerin serum levels in LD, chemerin mRNA expression in insulin-sensitive tissues of LD mice, as well as the impact of metreleptin treatment on circulating chemerin in LD patients. RESEARCH DESIGN AND METHODS: Serum chemerin, as well as clinical and biochemical parameters of glucose metabolism, lipid metabolism, and inflammation, was measured in 37 LD patients and 37 age-, gender- and body mass index-matched controls. Furthermore, chemerin mRNA expression was determined in LD mice and controls. Moreover, circulating chemerin was assessed at five different time points in 10 LD patients treated with metreleptin over 1 year. RESULTS: Median serum chemerin levels were significantly higher in 37 subjects with LD (234·3 µg/l) as compared to controls (204·0 µg/l) (P = 0·002). Multiple linear regression analysis showed that circulating chemerin was independently and positively associated with glycosylated haemoglobin A1c (HbA1c) and C-reactive protein (CRP). Chemerin mRNA expression was significantly increased 2·5-fold in visceral adipose tissue (VAT) and 5·3-fold in brown adipose tissue (BAT) of LD mice as compared to controls (P < 0·01). Circulating chemerin was not significantly altered by metreleptin treatment. CONCLUSIONS: Circulating levels of the adipokine chemerin are elevated in LD, as well as independently and positively associated with HbA1c and CRP. Increased chemerin might originate from VAT and BAT.

Serum concentrations of fibroblast growth factor 21 are elevated in patients with congenital or acquired lipodystrophy.

OBJECTIVE: Patients with lipodystrophy (LD) suffer from loss of subcutaneous adipose tissue accompanied by dysregulation of several adipocyte-secreted factors. However, regulation of adipocyte-expressed fibroblast growth factor (FGF) 21 which acts in an insulin-mimetic, lipid-lowering, and anti-atherogenic manner has not been investigated in non-human immunodeficiency virus (HIV) LD. MATERIAL AND METHODS: Circulating serum FGF21 levels were quantified in 37 patients with non-HIV LD and 37 controls matched for age, gender, and body mass index. Moreover, FGF21 plasma levels and mRNA expression were measured in LD mice and control animals. Additionally, serum FGF21 levels were assessed in 10 LD patients before and during metreleptin therapy. RESULTS: Median FGF21 serum concentrations were significantly higher in LD patients (381.2ng/l) as compared to the control group (231.2ng/l; p=0.023). There was an independent and positive association between circulating FGF21 and serum triglycerides (TG), as well as fibrate treatment, in multiple linear regression analysis. LD mice showed significantly upregulated FGF21 plasma levels (4.5-fold), as well as mRNA expression in various adipose tissue depots and liver as compared to controls (p<0.05). Metreleptin treatment did not significantly alter circulating FGF21 levels in human subjects. CONCLUSIONS: Serum concentrations of FGF21 are elevated in patients with non-HIV LD with adipose tissue and liver being potential sources of increased production. TG and fibrate treatment are independent positive predictors of circulating FGF21.

Biochemical diagnosis of phaeochromocytoma using plasma-free normetanephrine, metanephrine and methoxytyramine: importance of supine sampling under fasting conditions.

OBJECTIVE: To document the influences of blood sampling under supine fasting versus seated nonfasting conditions on diagnosis of phaeochromocytomas and paragangliomas (PPGL) using plasma concentrations of normetanephrine, metanephrine and methoxytyramine. DESIGN AND METHODS: Biochemical testing for PPGL was performed on 762 patients at six centres, two of which complied with requirements for supine sampling after an overnight fast and four of which did not. Phaeochromocytomas and paragangliomas were found in 129 patients (67 noncompliant, 62 compliant) and not in 633 patients (195 noncompliant, 438 compliant). RESULTS: Plasma concentrations of normetanephrine and methoxytyramine did not differ between compliant and noncompliant sampling conditions in patients with PPGL but were 49-51% higher in patients without PPGL sampled under noncompliant compared with compliant conditions. The 97·5 percentiles of distributions were also higher under noncompliant compared with compliant conditions for normetanephrine (1·29 vs 0·79 nmol/l), metanephrine (0·49 vs 0·41 nmol/l) and methoxytyramine (0·42 vs 0·18 nmol/l). Use of upper cut-offs established from seated nonfasting sampling conditions resulted in substantially decreased diagnostic sensitivity (98% vs 85%). In contrast, use of upper cut-offs established from supine fasting conditions resulted in decreased diagnostic specificity for testing under noncompliant compared with compliant conditions (71% vs 95%). CONCLUSIONS: High diagnostic sensitivity of plasma normetanephrine, metanephrine and methoxytyramine for the detection of PPGL can only be guaranteed using upper cut-offs of reference intervals established with blood sampling under supine fasting conditions. With such cut-offs, sampling under seated nonfasting conditions can lead to a 5·7-fold increase in false-positive results necessitating repeat sampling under supine fasting conditions.

Metreleptin Robustly Increases Resting-state Brain Connectivity in Treatment-naïve Female Patients With Lipodystrophy.

Context: Research in lipodystrophy (LD) and its treatment with metreleptin has not only helped patients with LD but has opened new directions in investigating leptin's role in metabolism and the regulation of eating behavior. Previously, in a study with patients with LD undergoing metreleptin treatment using functional magnetic resonance imaging (MRI), we found significantly increased resting-state brain connectivity in 3 brain areas including the hypothalamus. Objective: In this study, we aimed to reproduce our functional MRI findings in an independent sample and compare results to healthy participants. Design: Measurements in 4 female patients with LD undergoing metreleptin treatment and 3 healthy untreated controls were performed at 4 different time points over 12 weeks. To identify treatment-related brain connectivity alterations, eigenvector centrality was computed from resting-state functional MRI data for each patient and each session. Thereafter, analysis aimed at detecting consistent brain connectivity changes over time across all patients. Results: In parallel to metreleptin treatment of the patients with LD, we found a significant brain connectivity increase in the hypothalamus and bilaterally in posterior cingulate gyrus. Using a 3-factorial model, a significant interaction between group and time was found in the hypothalamus. Conclusions: Investigating brain connectivity alterations with metreleptin treatment using an independent sample of patients with LD, we have reproduced an increase of brain connectivity in hedonic and homeostatic central nervous networks observed previously with metreleptin treatment. These results are an important contribution to ascertain brain leptin action and help build a foundation for further research of central nervous effects of this important metabolic hormone.

Reward Processing During Monetary Incentive Delay Task After Leptin Substitution in Lipodystrophy-an fMRI Case Series.

Context: Behaviorally, the most pronounced effects of leptin substitution in leptin deficiency are the hunger-decreasing and postprandial satiety-prolonging effects of the adipokine. Previously, with functional magnetic resonance imaging (MRI), we and others showed that eating behavior-controlling effects are at least in part conveyed by the reward system. However, to date, it is unclear if leptin only modulates eating behavior specific brain reward action or if it also alters the reward function of the brain unrelated to eating behavior. Objective: We investigated with functional MRI the effects of metreleptin on the reward system in a reward task unrelated to eating behavior, the monetary incentive delay task. Design: Measurements in 4 patients with the very rare disease of lipodystrophy (LD), resulting in leptin deficiency, and 3 untreated healthy control persons were performed at 4 different time points: before start and over 12 weeks of metreleptin treatment. Inside the MRI scanner, participants performed the monetary incentive delay task and brain activity during the reward receipt phase of the trial was analyzed. Results: We found a reward-related brain activity decrease in our 4 patients with LD over the 12 weeks of metreleptin treatment in the subgenual region, a brain area associated with the reward network, which was not observed in our 3 untreated healthy control persons. Conclusions: These results suggest that leptin replacement in LD induces changes of brain activity during reward reception processing completely unrelated to eating behavior or food stimuli. This could suggest eating behavior-unrelated functions of leptin in the human reward system. Trial registration: The trial is registered as trial No. 147/10-ek at the ethics committee of the University of Leipzig and at the State Directorate of Saxony (Landesdirektion Sachsen).

Leptin, adiponectin and other adipokines in gestational diabetes mellitus and pre-eclampsia.

Proteins secreted from adipocytes - so-called adipokines - influence metabolic and vascular function. Recent data suggest that various adipokines are dysregulated in gestational diabetes mellitus (GDM) and pre-eclampsia (PE) and might be of pathophysiological and prognostic significance in these complications of pregnancy. This review gives an overview on the regulation and pathophysiology of leptin and adiponectin in GDM and PE. Furthermore, data on novel adipokines including resistin, visfatin, retinol-binding protein 4 and vaspin are summarized.

Suggestive Evidence for an Antidepressant Effect of Metreleptin Treatment in Patients with Lipodystrophy.

INTRODUCTION: Lipodystrophy (LD) syndromes are rare heterogeneous disorders characterized by reduction or absence of subcutaneous fat, low or nondetectable leptin concentrations in blood and impaired hunger/satiety regulation. Metreleptin treatment reverses metabolic complications and improves eating behavior in LD. Because depression in anorexia nervosa (AN), which is also characterized by hypoleptinemia, improves substantially upon treatment with metreleptin, we hypothesized that metreleptin substitution may be associated with an antidepressant effect in patients with LD, too. METHODS: In this ancillary study, 10 adult patients with LD were treated with metreleptin. To assess depressive symptoms, the self-rating questionnaire Beck's Depression Inventory (BDI) was filled in at preestablished time points prior (T1) and after initiation of metreleptin (T2: 1 week; T3: 4 weeks; T4: 12 weeks) dosing. The differences between time points were tested with nonparametric Friedman's analysis of variance. Sensitivity analyses were performed upon exclusion of the BDI items addressing appetite and weight changes. RESULTS: According to their BDI scores, 4 patients had mild depression and 2 had moderate depression at baseline. Friedman's test revealed significant differences in BDI scores between the four time points. Post hoc analyses revealed that the difference between T1 and T3 was significant upon Bonferroni correction (p = 0.034, effect size r = 0.88). The sensitivity analyses upon exclusion of the appetite and weight change items again revealed a significant Friedman's test and significant Bonferroni corrected differences in the revised BDI scores between T1 versus T2 (p = 0.002, r = 0.99) and T1 versus T3 (p = 0.007, r = 0.79). DISCUSSION/CONCLUSION: Our study for the first time revealed suggestive evidence for an antidepressant effect of metreleptin in patients with LD. Metreleptin caused a rapid drop in depression scores within 1 week of treatment. A reduction of the depression score was also observed in 2 of the 3 LD patients whose BDI scores were in the normal range before start of the treatment. The reduction in total scores of BDI was still apparent after 3 months (T4) of dosing. This observation matches findings obtained in clinical case studies of AN patients, in whom depression scores also dropped during the first week of metreleptin treatment. It needs to be noted that by the nature of this observational study without a placebo group, nonspecific treatment expectation affecting mood cannot fully be ruled out.

Proceedings of the annual meeting of the European Consortium of Lipodystrophies (ECLip) Cambridge, UK, 7-8 April 2022.

Lipodystrophy syndromes are rare diseases with defects in the development or maintenance of adipose tissue, frequently leading to severe metabolic complications. They may be genetic or acquired, with variable clinical forms, and are largely underdiagnosed. The European Consortium of Lipodystrophies, ECLip, is a fully functional non-profit network of European centers of excellence working in the field of lipodystrophies. It provides a favorable environment to promote large Europe-wide and international collaborations to increase the basic scientific understanding and clinical management of these diseases. It works with patient advocacy groups to increase public awareness. The network also promotes a European Patient Registry of lipodystrophies, as a collaborative research platform for consortium members. The annual congress organized gives an update of the findings of network research groups, highlighting clinical and fundamental aspects. The talks presented during the meeting in Cambridge, UK, in 2022 are summarized in these minutes.

Risk profiles and penetrance estimations in multiple endocrine neoplasia type 2A caused by germline RET mutations located in exon 10.

Multiple endocrine neoplasia type 2 is characterized by germline mutations in RET. For exon 10, comprehensive molecular and corresponding phenotypic data are scarce. The International RET Exon 10 Consortium, comprising 27 centers from 15 countries, analyzed patients with RET exon 10 mutations for clinical-risk profiles. Presentation, age-dependent penetrance, and stage at presentation of medullary thyroid carcinoma (MTC), pheochromocytoma, and hyperparathyroidism were studied. A total of 340 subjects from 103 families, age 4-86, were registered. There were 21 distinct single nucleotide germline mutations located in codons 609 (45 subjects), 611 (50), 618 (94), and 620 (151). MTC was present in 263 registrants, pheochromocytoma in 54, and hyperparathyroidism in 8 subjects. Of the patients with MTC, 53% were detected when asymptomatic, and among those with pheochromocytoma, 54%. Penetrance for MTC was 4% by age 10, 25% by 25, and 80% by 50. Codon-associated penetrance by age 50 ranged from 60% (codon 611) to 86% (620). More advanced stage and increasing risk of metastases correlated with mutation in codon position (609→620) near the juxtamembrane domain. Our data provide rigorous bases for timing of premorbid diagnosis and personalized treatment/prophylactic procedure decisions depending on specific RET exon 10 codons affected.

Leptin Improves Parameters of Brown Adipose Tissue Thermogenesis in Lipodystrophic Mice.

Lipodystrophy syndromes (LD) are a heterogeneous group of very rare congenital or acquired disorders characterized by a generalized or partial lack of adipose tissue. They are strongly associated with severe metabolic dysfunction due to ectopic fat accumulation in the liver and other organs and the dysregulation of several key adipokines, including leptin. Treatment with leptin or its analogues is therefore sufficient to reverse some of the metabolic symptoms of LD in patients and in mouse models through distinct mechanisms. Brown adipose tissue (BAT) thermogenesis has emerged as an important regulator of systemic metabolism in rodents and in humans, but it is poorly understood how leptin impacts BAT in LD. Here, we show in transgenic C57Bl/6 mice overexpressing sterol regulatory element-binding protein 1c in adipose tissue (Tg (aP2-nSREBP1c)), an established model of congenital LD, that daily subcutaneous administration of 3 mg/kg leptin for 6 to 8 weeks increases body temperature without affecting food intake or body weight. This is associated with increased protein expression of the thermogenic molecule uncoupling protein 1 (UCP1) and the sympathetic nerve marker tyrosine hydroxylase (TH) in BAT. These findings suggest that leptin treatment in LD stimulates BAT thermogenesis through sympathetic nerves, which might contribute to some of its metabolic benefits by providing a healthy reservoir for excess circulating nutrients.

European lipodystrophy registry: background and structure.

BACKGROUND: Lipodystrophy syndromes comprise a group of extremely rare and heterogeneous diseases characterized by a selective loss of adipose tissue in the absence of nutritional deprivation or catabolic state. Because of the rarity of each lipodystrophy subform, research in this area is difficult and international co-operation mandatory. Therefore, in 2016, the European Consortium of Lipodystrophies (ECLip) decided to create a registry for patients with lipodystrophy. RESULTS: The registry was build using the information technology Open Source Registry System for Rare Diseases in the EU (OSSE), an open-source software and toolbox. Lipodystrophy specific data forms were developed based on current knowledge of typical signs and symptoms of lipodystrophy. The platform complies with the new General Data Protection Regulation (EU) 2016/679 by ensuring patient pseudonymization, informational separation of powers, secure data storage and security of communication, user authentication, person specific access to data, and recording of access granted to any data. Inclusion criteria are all patients with any form of lipodystrophy (with the exception of HIV-associated lipodystrophy). So far 246 patients from nine centres (Amsterdam, Bologna, Izmir, Leipzig, Münster, Moscow, Pisa, Santiago de Compostela, Ulm) have been recruited. With the help from the six centres on the brink of recruitment (Cambridge, Lille, Nicosia, Paris, Porto, Rome) this number is expected to double within the next one or 2 years. CONCLUSIONS: A European registry for all patients with lipodystrophy will provide a platform for improved research in the area of lipodystrophy. All physicians from Europe and neighbouring countries caring for patients with lipodystrophy are invited to participate in the ECLip Registry. STUDY REGISTRATION: ClinicalTrials.gov (NCT03553420). Registered 14 March 2018, retrospectively registered.

Leptin induces TNFα-dependent inflammation in acquired generalized lipodystrophy and combined Crohn's disease.

Leptin has been shown to modulate intestinal inflammation in mice. However, clinical evidence regarding its immune-stimulatory potential in human Crohn's disease remains sparse. We here describe a patient with the unique combination of acquired generalized lipodystrophy and Crohn's disease (AGLCD) featuring a lack of adipose tissue, leptin deficiency and intestinal inflammation. Using mass and flow cytometry, immunohistochemistry and functional metabolic analyses, the AGLCD patient was compared to healthy individuals and Crohn's disease patients regarding immune cell composition, function and metabolism and the effects of recombinant N-methionylleptin (rLeptin) were evaluated. We provide evidence that rLeptin exerts diverse pro-inflammatory effects on immune cell differentiation and function, including the metabolic reprogramming of immune cells and the induction of TNFα, ultimately aggravating Crohn's disease in the AGLCD patient, which can be reversed by anti-TNFα therapy. Our results indicate that leptin is required for human immune homeostasis and contributes to autoimmunity in a TNFα-dependent manner.

Facial soft tissue volume decreases during metreleptin treatment in patients with partial and generalized lipodystrophy.

PURPOSE: Lipodystrophy (LD) patients suffer from loss or maldistribution of subcutaneous adipose tissue accompanied by dysregulation of several adipocyte-secreted factors, e.g., leptin. The effect of recombinant leptin (metreleptin) therapy on facial soft tissue volume in patients with non-human immunodeficiency virus LD has not been quantified to date. METHODS: Eight LD patients (six female, two male; six familial partial LD [FPLD], two generalized LD) were treated with metreleptin over 1 year. Anthropometric parameters and 3D stereophotogrammetric imaging of the patients´ faces were assessed at baseline and after 1 year of metreleptin treatment. RESULTS: Median fat mass was significantly reduced during metreleptin treatment from 22.3 kg at baseline to 20.0 kg at 1 year (p = 0.031); however, body weight, body mass index, and waist-to-hip ratio were not significantly affected. Five of the six patients with FPLD lost between 4 and 114 cm3 of facial soft tissue volume in the pre-auricular, buccal, and submandibular area during metreleptin treatment whereas a slight volume gain was seen in one FPLD patient. The two patients with generalized LD developed a volume loss of 20 and 8 cm3 in the buccal region between baseline and 1 year of metreleptin therapy, respectively. CONCLUSIONS: Metreleptin replacement leads to loss of facial soft tissue volume in FPLD and generalized LD. However, volume changes in most patients are not visible by the naked eye.

Progranulin is increased in human and murine lipodystrophy.

AIMS: Lipodystrophies (LD) are genetic or acquired disorders sharing the symptom of partial or complete adipose tissue deficiency and a dysregulation of adipokines including leptin and adiponectin. Progranulin, an adipokine with proinflammatory and insulin resistance-inducing characteristics, has not been investigated in LD so far. METHODS: Circulating progranulin was determined in LD patients (N=37) and in age-, gender-, and body mass index-matched healthy control subjects (N=37). Additionally, we investigated progranulin expression in an LD mouse model as compared to wild-type mice. Moreover, we elucidated circulating progranulin before and during metreleptin supplementation in 10 patients with LD. RESULTS: Median [interquartile range] circulating progranulin was increased in patients with LD (82.9 [25.9] µg/l) as compared to controls (73.6 [22.8] µg/l) (p=0.005). C-reactive protein (CRP) remained an independent and positive predictor of progranulin in multivariate analysis. Progranulin mRNA was significantly upregulated in all adipose tissue depots, i.e. visceral, subcutaneous, and brown adipose tissue, and in muscle of LD animals versus wild-type mice. Progranulin levels did not significantly change during metreleptin supplementation. CONCLUSIONS: Progranulin serum concentration is increased in patients with LD, and shows an independent and positive correlation with CRP. Different adipose tissue depots and muscle might be potential origins of elevated progranulin.