Causes of death in patients with Berardinelli-Seip congenital generalized lipodystrophy

Familial partial lipodystrophy resulting from loss-of-function PPARγ pathogenic variants: phenotypic, clinical, and genetic features

The PPARG gene encodes a member of a nuclear receptor superfamily known as peroxisome proliferator-activated gamma (PPARγ). PPARγ plays an essential role in adipogenesis, stimulating the differentiation of preadipocytes into adipocytes. Loss-of-function pathogenic variants in PPARG reduce the activity of the PPARγ receptor and can lead to severe metabolic consequences associated with familial partial lipodystrophy type 3 (FPLD3). This review focuses on recent scientific data related to FPLD3, including the role of PPARγ in adipose tissue metabolism and the phenotypic and clinical consequences of loss-of-function variants in the PPARG gene. The clinical features of 41 PPARG pathogenic variants associated with FPLD3 patients were reviewed, highlighting the genetic and clinical heterogeneity observed among 91 patients. Most of them were female, and the average age at the onset and diagnosis of lipoatrophy was 21 years and 33 years, respectively. Considering the metabolic profile, hypertriglyceridemia (91.9% of cases), diabetes (77%), hypertension (59.5%), polycystic ovary syndrome (58.2% of women), and metabolic-dysfunction-associated fatty liver disease (87,5%). We also discuss the current treatment for FPLD3. This review provides new data concerning the genetic and clinical heterogeneity in FPLD3 and highlights the importance of further understanding the genetics of this rare disease.

Preclinical evaluation of tissue-selective gene therapies for congenital generalised lipodystrophy

Lipodystrophy is a rare disorder which can be life-threatening. Here individuals fail to develop or maintain appropriate adipose tissue stores. This typically causes severe metabolic complications, including hepatic steatosis and lipoatrophic diabetes. There is no cure for lipodystrophy, and treatment options remain very limited. Here we evaluate whether tissue-selective adeno-associated virus (AAV) vectors can provide a targeted form of gene therapy for lipodystrophy, using a preclinical lipodystrophic mouse model of Bscl2 deficiency. We designed AAV vectors containing the mini/aP2 or thyroxine-binding globulin promoter to selectively target adipose or liver respectively. The AAV-aP2 vectors also contained the liver-specific microRNA-122 target sequence, restricting hepatic transgene expression. Systemic delivery of AAV-aP2 vectors overexpressing human BSCL2 restored adipose tissue development and metabolic health in lipodystrophic mice without detectable expression in the liver. High doses (1 × 1012 GCs) of liver-selective vectors led to off target expression and adipose tissue development, whilst low doses (1 × 1010 GCs) expressed selectively and robustly in the liver but did not improve metabolic health. This reveals that adipose tissue-selective, but not liver directed, AAV-mediated gene therapy is sufficient to substantially recover metabolic health in generalised lipodystrophy. This provides an exciting potential new avenue for an effective, targeted, and thereby safer therapeutic intervention.

Obesity and 1-year all-cause survival of adult intensive care patients with heart failure: data from the MIMIC-IV

BACKGROUND

Heart failure is a disease that threatens global public safety. In recent years, the obesity paradox has been studied in cardiovascular disease and other fields. With the progress of aging, metabolic changes and regulation of fat function, it also provides many bridges for the dialogue between disease and molecular metabolism. The purpose of this study is to investigate the effect of obesity on the outcome of adult intensive care patients with heart failure combined with age factors.

METHOD

Data were derived from the fourth-generation Medical Information Marketplace for Intensive Care (MIMIC-IV version2.1) using structured query language on the Navicat (12.0.11) platform. People were divided into two groups based on the body mass index (BMI), one group with BMI ≥ 30 kg/m² and another group with BMI < 30 kg/m². Afterwards, the patients were divided into two subgroups based on their ages. One group included patients aged<60, and the other included patients aged ≥ 60. The extracted information includes demographic characteristics, laboratory findings, comorbidities, scores. Main results included in-hospital mortality, ICU mortality, and 1-year mortality. Secondary outcomes included hospital interval and ICU interval, use of renal replacement therapy, and rates of noninvasive and invasive ventilation support.

RESULT

In this cohort study, 3390 people were in the BMI<30 group, 2301 people were in the BMI ≥ 30 group, 960 people were in the age<60 group, and 4731 people were in the age ≥ 60 group, including 3557 patients after propensity score matching in high age group. Among patients aged ≥ 60, BMI ≥ 30 group vs. BMI<30 group showed significantly lower in-hospital mortality (13% vs. 16%) and one-year mortality (41% vs. 55%), respectively. Neither primary nor secondary outcomes were significantly described in the competition among patients aged under 60. Restricted cubic spline reveals a J-shaped nonlinear association between BMI and clinical endpoints within the entire cohort. Kaplan-Meier curves revealed a survival advantage in BMI ≥ 30 group (p < 0.001). Following age stratification, a beneficial effect of BMI categories on one-year mortality risk was observed in heart failure patients aged ≥ 60 (Univariable HR, 0.71, 95% CI, 0.65-0.78, p < 0.001; Multivariable HR, 0.74, 95% CI, 0.67-0.81, p < 0.001), but not in those under 60 years old.

OUTCOME

In ICU patients with heart failure, obesity offers a survival benefit to those aged ≥ 60. No obesity paradox was observed in patients younger than 60 years old. The obesity paradox applies to patients aged ≥ 60 with heart failure.

Echocardiographic Alterations of Cardiac Geometry and Function in Patients with Familial Partial Lipodystrophy

BACKGROUND

Cardiomyopathy associated with partial lipodystrophy (PL) has not been well described yet.

OBJECTIVE

To characterize cardiac morphology and function in PL.

METHODS

Patients with familial PL and controls were prospectively assessed by transthoracic echocardiography and with speckle-tracking echocardiography (global longitudinal strain, GLS). The relationship between echocardiographic variables and PL diagnosis was tested with regression models, considering the effect of systolic blood pressure (SBP). Significance level of 5% was adopted.

RESULTS

Twenty-nine patients with PL were compared to 17 controls. They did not differ in age (p=0.94), gender or body mass index (p= 0.05). Patients with PL had statistically higher SBP (p=0.02) than controls. Also, PL patients had higher left atrial dimension (37.3 ± 4.4 vs. 32.1 ± 4.3 mm, p= 0.001) and left atrial (30.2 ± 7.2 vs. 24.9 ± 9.0 mL/m2,p=0.02), left ventricular (LV) mass (79.3 ± 17.4 vs. 67.1 ± 19.4, p=0.02), and reduced diastolic LV parameters (E' lateral, p= 0.001) (E' septal, p= 0.001), (E/E' ratio, p= 0.02). LV ejection fraction (64.7 ± 4.6 vs. 62.2 ± 4.4 %, p= 0.08) and GLS were not statistically different between groups (-17.1 ± 2.7 vs. -18.0 ± 2.0 %, p= 0.25). There was a positive relationship of left atrium (β 5.6, p<0.001), posterior wall thickness, (β 1.3, p=0.011), E' lateral (β -3.5, p=0.002) and E' septal (β -3.2, p<0.001) with PL diagnosis, even after adjusted for SBP.

CONCLUSION

LP patients have LV hypertrophy, left atrial enlargement, and LV diastolic dysfunction although preserved LVEF and GLS. Echocardiographic parameters are related to PL diagnosis independent of SBP.

Impaired signaling pathways on Berardinelli-Seip congenital lipodystrophy macrophages during Leishmania infantum infection

Berardinelli-Seip congenital lipodystrophy (CGL), a rare autosomal recessive disorder, is characterized by a lack of adipose tissue. Infections are one of the major causes of CGL individuals' premature death. The mechanisms that predispose to infections are poorly understood. We used Leishmania infantum as an in vitro model of intracellular infection to explore mechanisms underlying the CGL infection processes, and to understand the impact of host mutations on Leishmania survival, since this pathogen enters macrophages through specialized membrane lipid domains. The transcriptomic profiles of both uninfected and infected monocyte-derived macrophages (MDMs) from CGL (types 1 and 2) and controls were studied. MDMs infected with L. infantum showed significantly downregulated expression of genes associated with infection-response pathways (MHC-I, TCR-CD3, and granzymes). There was a transcriptomic signature in CGL cells associated with impaired membrane trafficking and signaling in response to infection, with concomitant changes in the expression of membrane-associated genes in parasites (e.g. δ-amastins). We identified pathways suggesting the lipid storage dysfunction led to changes in phospholipids expression and impaired responses to infection, including immune synapse (antigen presentation, IFN-γ signaling, JAK/STAT); endocytosis; NF-kappaB signaling; and phosphatidylinositol biosynthesis. In summary, lipid metabolism of the host plays an important role in determining antigen presentation pathways.

Adipose tissue as a linchpin of organismal ageing

Ageing is a conserved biological process, modulated by intrinsic and extrinsic factors, that leads to changes in life expectancy. In humans, ageing is characterized by greatly increased prevalence of cardiometabolic disease, type 2 diabetes and disorders associated with impaired immune surveillance. Adipose tissue displays species-conserved, temporal changes with ageing, including redistribution from peripheral to central depots, loss of thermogenic capacity and expansion within the bone marrow. Adipose tissue is localized to discrete depots, and also diffusely distributed within multiple organs and tissues in direct proximity to specialized cells. Thus, through their potent endocrine properties, adipocytes are capable of modulating tissue and organ function throughout the body. In addition to adipocytes, multipotent progenitor/stem cells in adipose tissue play a crucial role in maintenance and repair of tissues throughout the lifetime. Adipose tissue may therefore be a central driver for organismal ageing and age-associated diseases. Here we review the features of adipose tissue during ageing, and discuss potential mechanisms by which these changes affect whole-body metabolism, immunity and longevity. We also explore the potential of adipose tissue-targeted therapies to ameliorate age-associated disease burdens.

Heterogeneity and high prevalence of bone manifestations, and bone mineral density in congenital generalized lipodystrophy subtypes 1 and 2

Introduction

Congenital Generalized Lipodystrophy (CGL) is a rare autosomal recessive disease caused by mutations in genes responsible for the formation and development of adipocytes. Bone abnormalities are described. However, there is a scarcity of data.

Objective

To describe bone characteristics in a large CGL1 and 2 case series.

Methods

Cross-sectional study that assessed bone radiological features of CGL patients of a reference hospital in Fortaleza (CE), Brazil. Patients underwent clinical and bone mineral metabolism evaluation, radiographs of the axial and appendicular skeleton and bone mineral density (BMD) assessment by DEXA (dual energy X-ray absorptiometry).

Results

Nineteen patients were included, fourteen were CGL1 and 5, CGL2. Median age was 20 years (8-42) and 58% were women. Median BMI and percentage of body fat were, respectively, 21 Kg/m² (16-24), and 10.5% (7.6-15). The median leptin concentration was 1 ng/mL (0.1-3.3). Diabetes mellitus and dyslipidemia were present in 79% and 63% of patients, respectively. Median calcium and phosphate were normal in almost all patients (95%). Median parathyroid hormone and 25-OH-vitamin D were 23 pg/mL (7-75) and 28 ng/mL (18-43). Osteolytic lesions, osteosclerosis and pseudo-osteopoikylosis, were present in 74%, 42% and 32% of patients, respectively. Lytic lesions were found predominantly in the extremities of long bones, bilaterally and symmetrically, spine was spared. Osteosclerosis was present in axial and appendicular skeleton. Pseudo-osteopoikilosis was found symmetrically in epiphyses of femur and humerus, in addition to the pelvis. BMD Z-score greater than +2.5 SD was observed in 13 patients (68.4%). BMD was higher in CGL1 compared to CGL2 in lumbar spine and total body in adults. No associations were found between high BMD and HOMA-IR (p=0.686), DM (p=0.750), osteosclerosis (p=0.127) or pseudo-osteopoikilosis (p=0.342), and, between pain and bone lesions. Fractures were found in 3 patients.

Conclusion

Bone manifestations are prevalent, heterogeneous, and silent in CGL1 and CGL2. Osteolytic lesions are the most common, followed by osteosclerosis and pseudo-osteopoikilosis. Bone mass is high in most cases. There was no pain complaint related to bone lesions. Thus, systematic assessment of bone manifestations in CGL is essential. Studies are needed to better understand its pathogenesis and clinical consequences.

Liver transplantation in patient with Berardinelli-Seip syndrome: A literature review and case report

BACKGROUND

Berardinelli-Seip syndrome is an infrequently seen and potentially fatal genetic disorder characterized by the absence of adipose tissue. Herein, we report a first-in-literature liver transplant done on a 7-year-old girl because of liver cirrhosis caused by the Berardinelli-Seip syndrome.

CASE REPORT

Physical examination showed prominent subdermal fat tissue loss and mild muscle hypertrophy, giving her a slim appearance, hirsutism, thick hair, a large head in contrast to the body, low anterior hairline, icterus, prominent facial contours, prominent mandibula, loss of buccal fat, low set ears, and large limbs. After the diagnosis, she admitted to our clinic because of variceal esophageal bleeding and increasing liver enzymes. Transplantation decision was made and orthothopic liver transplantation done by the surgery team.

DISCUSSION

Common causes of death in Berardinelli-Seip syndrome patients are infections and liver cirrhosis. The mean age of the patients was 27.1 at the time of death. There is no any established cure for congenital lipodystrophies so far. However, some symptomatic treatment methods are found to be helpful. The main point of the case report to be discussed is the liver transplantation done by our surgical team. There are no examples of any transplantation in Berardinelli-Seip syndrome patients, but several reports can be found of patients with kidney or liver failure.

CONCLUSION

Berardinelli-Seip syndrome is a rare disorder with no cure but a chance of improving lifestyle and life expectancy. The transplantation option should be considered in young patients after a multidisciplinary review.

Impact of lipodystrophy on health-related quality of life: the QuaLip study

BACKGROUND

Lipodystrophy is a rare disease characterized by loss of adipose tissue. Natural history studies have demonstrated significant burden of disease; however, there is limited data on the impact of lipodystrophy on quality of life (QoL) and psychoemotional well-being. The QuaLip study is a prospective observational real-world study that aims to determine the impact of lipodystrophy on QoL and psychoemotional well-being and explore subjective burden of the disease. Sixty-seven adult patients and eight pediatric patients with lipodystrophy were included. Patients were followed up for 24 months and assessments were repeated every three months. Patients were examined by licensed psychiatrists at baseline, and at year 1 and year 2 visits.

RESULTS

Eighteen (27.69%) of 65 adult patients (two subjects refused psychiatric assessment) were diagnosed with a psychiatric disorder (e.g., depressive episodes, mixed anxiety and depressive disorder, anxiety disorder, adjustment disorder, recurrent depression, panic disorder, generalized anxiety disorder, unspecified mood disorder, nonorganic sleep disorder, post-traumatic stress disorder, depressive episode comorbidity, social phobia and obsessive-compulsive disorder comorbidity). Lipodystrophy disease and QoL questionnaires revealed a significant disease burden over the study period. More than one-third of patients reported depression symptoms on the Beck Depression Inventory and more than one-fourth of the patients reported significant hunger throughout the study period. Physical appearance, fatigue, and pain contributed to the disease burden. QoL scores were lower in patients with psychiatric disease and in those with poor metabolic control. Attention deficit hyperactivity disorder, depressive disorder, sub-threshold depressive symptoms, obsessive-compulsive disorder, appetite problems, and issues with physical appearance were identified in selected pediatric subjects.

CONCLUSIONS

Lipodystrophy has a significant impact on QoL and psychoemotional well-being. Psychiatric disorders seem to be underdiagnosed among patients with lipodystrophy.

Body Fat Distribution Contributes to Defining the Relationship between Insulin Resistance and Obesity in Human Diseases

The risk for metabolic and cardiovascular complications of obesity is defined by body fat distribution rather than global adiposity. Unlike subcutaneous fat, visceral fat (including hepatic steatosis) reflects insulin resistance and predicts type 2 diabetes and cardiovascular disease. In humans, available evidence indicates that the ability to store triglycerides in the subcutaneous adipose tissue reflects enhanced insulin sensitivity. Prospective studies document an association between larger subcutaneous fat mass at baseline and reduced incidence of impaired glucose tolerance. Case-control studies reveal an association between genetic predisposition to insulin resistance and a lower amount of subcutaneous adipose tissue. Human peroxisome proliferator-activated receptorgamma (PPAR-γ) promotes subcutaneous adipocyte differentiation and subcutaneous fat deposition, improving insulin resistance and reducing visceral fat. Thiazolidinediones reproduce the effects of PPAR-γ activation and therefore increase the amount of subcutaneous fat while enhancing insulin sensitivity and reducing visceral fat. Partial or virtually complete lack of adipose tissue (lipodystrophy) is associated with insulin resistance and its clinical manifestations, including essential hypertension, hypertriglyceridemia, reduced HDL-c, type 2 diabetes, cardiovascular disease, and kidney disease. Patients with Prader Willi syndrome manifest severe subcutaneous obesity without insulin resistance. The impaired ability to accumulate fat in the subcutaneous adipose tissue may be due to deficient triglyceride synthesis, inadequate formation of lipid droplets, or defective adipocyte differentiation. Lean and obese humans develop insulin resistance when the capacity to store fat in the subcutaneous adipose tissue is exhausted and deposition of triglycerides is no longer attainable at that location. Existing adipocytes become large and reflect the presence of insulin resistance.

From scarcity to solutions: Therapeutic strategies to restore adipose tissue functionality in rare disorders of lipodystrophy

AIMS

Lipodystrophy is a rare disorder characterised by abnormal or deficient adipose tissue formation and distribution. It poses significant challenges to affected individuals, including the development of severe metabolic complications like diabetes and fatty liver disease. These conditions are often chronic, debilitating and life-threatening, with limited treatment options and a lack of specialised expertise. This review aims to raise awareness of lipodystrophy disorders and highlights therapeutic strategies to restore adipose tissue functionality.

METHODS

Extensive research has been conducted, including both historical and recent advances. We have examined and summarised the literature to provide an overview of potential strategies to restore adipose tissue functionality and treat/reverse metabolic complications in lipodystrophy disorders.

RESULTS

A wealth of basic and clinical research has investigated various therapeutic approaches for lipodystrophy. These include ground-breaking methods such as adipose tissue transplantation, innovative leptin replacement therapy, targeted inhibition of lipolysis and cutting-edge gene and cell therapies. Each approach shows great potential in addressing the complex challenges posed by lipodystrophy.

CONCLUSIONS

Lipodystrophy disorders require urgent attention and innovative treatments. Through rigorous basic and clinical research, several promising therapeutic strategies have emerged that could restore adipose tissue functionality and reverse the severe metabolic complications associated with this condition. However, further research and collaboration between academics, clinicians, patient advocacy groups and pharmaceutical companies will be crucial in transforming these scientific breakthroughs into effective and viable treatment options for individuals and families affected by lipodystrophy. Fostering such interdisciplinary partnerships could pave the way for a brighter future for those battling this debilitating disorder.

Natural history and comorbidities of generalised and partial lipodystrophy syndromes in Spain

The rarity of lipodystrophies implies that they are not well-known, leading to delays in diagnosis/misdiagnosis. The aim of this study was to assess the natural course and comorbidities of generalised and partial lipodystrophy in Spain to contribute to their understanding. Thus, a total of 140 patients were evaluated (77.1% with partial lipodystrophy and 22.9% with generalised lipodystrophy). Clinical data were collected in a longitudinal setting with a median follow-up of 4.7 (0.5-17.6) years. Anthropometry and body composition studies were carried out and analytical parameters were also recorded. The estimated prevalence of all lipodystrophies in Spain, excluding Köbberling syndrome, was 2.78 cases/million. The onset of phenotype occurred during childhood in generalised lipodystrophy and during adolescence-adulthood in partial lipodystrophy, with the delay in diagnosis being considerable for both cohorts. There are specific clinical findings that should be highlighted as useful features to take into account when making the differential diagnosis of these disorders. Patients with generalised lipodystrophy were found to develop their first metabolic abnormalities sooner and a different lipid profile has also been observed. Mean time to death was 83.8 ± 2.5 years, being shorter among patients with generalised lipodystrophy. These results provide an initial point of comparison for ongoing prospective studies such as the ECLip Registry study.

Plasma signatures of Congenital Generalized Lipodystrophy patients identified by untargeted lipidomic profiling are not changed after a fat-containing breakfast meal

BACKGROUND

The incapacity to store lipids in adipose tissue in Congenital Generalized Lipodystrophy (CGL) causes hypoleptinemia, increased appetite, ectopic fat deposition and lipotoxicity. CGL patients experience shortened life expectancy. The plasma lipidomic profile has not been characterized fully in CGL, nor has the extent of dietary intake in its modulation. The present work investigated the plasma lipidomic profile of CGL patients in comparison to eutrophic individuals at the fasted state and after a breakfast meal.

METHOD

Blood samples from 11 CGL patients and 10 eutrophic controls were collected after 12 h fasting (T0) and 90 min after an ad libitum fat-containing breakfast (T90). The lipidomic profile of extracted plasma lipids was characterized by non-target liquid chromatography mass spectrometry.

RESULTS

Important differences between groups were observed at T0 and at T90. Several molecular species of fatty acyls, glycerolipids, sphingolipids and glycerophospholipids were altered in CGL. All the detected fatty acyl molecular species, several diacylglycerols and one triacylglycerol species were upregulated in CGL. Among sphingolipids, one sphingomyelin and one glycosphingolipid species showed downregulation in CGL. Alterations in the glycerophospholipids glycerophosphoethanolamines, glycerophosphoserines and cardiolipins were more complex. Interestingly, when comparing T90 versus T0, the lipidomic profile in CGL did not change as intensely as it did for control participants.

CONCLUSIONS

The present study found profound alterations in the plasma lipidomic profile of complex lipids in CGL patients as compared to control subjects. A fat-containing breakfast meal did not appear to significantly influence the CGL profile observed in the fasted state. Our study may have implications for clinical practice, also aiding to a deeper comprehension of the role of complex lipids in CGL in view of novel therapeutic strategies.

Clinical features of generalized lipodystrophy in Turkey: A cohort analysis

AIM

To describe the Turkish generalized lipodystrophy (GL) cohort with the frequency of each complication and the death rate during the period of the follow-up.

METHODS

This study reports on 72 patients with GL (47 families) registered at different centres in Turkey that cover all regions of the country. The mean ± SD follow-up was 86 ± 78 months.

RESULTS

The Kaplan-Meier estimate of the median time to diagnosis of diabetes and/or prediabetes was 16 years. Hyperglycaemia was not controlled in 37 of 45 patients (82.2%) with diabetes. Hypertriglyceridaemia developed in 65 patients (90.3%). The Kaplan-Meier estimate of the median time to diagnosis of hypertriglyceridaemia was 14 years. Hypertriglyceridaemia was severe (≥ 500 mg/dl) in 38 patients (52.8%). Seven (9.7%) patients suffered from pancreatitis. The Kaplan-Meier estimate of the median time to diagnosis of hepatic steatosis was 15 years. Liver disease progressed to cirrhosis in nine patients (12.5%). Liver disease was more severe in congenital lipodystrophy type 2 (CGL2). Proteinuric chronic kidney disease (CKD) developed in 32 patients (44.4%) and cardiac disease in 23 patients (31.9%). Kaplan-Meier estimates of the median time to diagnosis of CKD and cardiac disease were 25 and 45 years, respectively. Females appeared to have a more severe metabolic disease, with an earlier onset of metabolic abnormalities. Ten patients died during the follow-up period. Causes of death were end-stage renal disease, sepsis (because of recurrent intestinal perforations, coronavirus disease, diabetic foot infection and following coronary artery bypass graft surgery), myocardial infarction, heart failure because of dilated cardiomyopathy, stroke, liver complications and angiosarcoma.

CONCLUSIONS

Standard treatment approaches have only a limited impact and do not prevent the development of severe metabolic abnormalities and early onset of organ complications in GL.

Is it possible to achieve an acceptable disease control by dietary therapy alone in Berardinelli Seip type 1? Experience from a case report

Background and objective

Severe metabolic complications generally manifest at an early age in Berardinelli - Seip congenital lipodystrophy (BSCL) and their management is especially challenging. Nutritional intervention with low lipid diets is considered by experts to be fundamental in treating the disease when associated with medical therapy, however little is known about the beneficial effects of dietary interventions alone.

Aim

To underline the importance of a well-structured low-fat diet in BSCL patients.

Methods and results

A BSCL male patient strictly followed a hypocaloric hypolipemic diet (60% carbohydrates, 22% fats and 18% proteins) since clinical diagnosis at the age of one year. Interestingly, pharmacological interventions were not required at any point during the follow-up. Aged 16 years the patient was referred to our center. Biochemistry, hormonal evaluation, 75 mg oral glucose tolerance test, cardiac evaluation and abdominal ultrasound were performed, revealing no abnormalities. Genetic analysis and leptin dosage were carried out, confirming the diagnosis of BSCL type 1 (homozygosity for c.493-1G>C pathogenic variant in AGPAT2 gene) and showing undetectable circulating levels of leptin (< 0.2 mcg/L). Diet therapy alone was therefore maintained, scheduling follow-up visits every six months, with acceptable disease control ever since.

Conclusions

This report proves how a low-fat diet is of great help in the management of BSCL and its complications. In addition, a specific hypolipemic diet could be used alone as an effective treatment in selected cases with high compliance and, probably, a milder phenotype.

Delayed Presentation of Berardinelli-Siep Lipodystrophy in an Adolescent Female

Berardinelli-Siep syndrome (BSS) is a form of congenital generalized lipodystrophy that disrupts the pathways of lipid metabolism. It presents with physical exam findings, including muscular hypertrophy and lipoatrophy as well as serious metabolic consequences such as diabetes mellitus, hypertriglyceridemia, acute pancreatitis, hepatomegaly, and hepatic steatosis. Diagnosis generally occurs soon after birth or in childhood. The case presented is significant for a delayed diagnosis of suspected BSS Type 1 which is rather uncommon in a developed country. Due to the detrimental complications of BSS, such as hypertrophic cardiomyopathy, pancreatitis, and liver disease, early diagnosis and intervention are crucial. Pediatric providers must be knowledgeable about physical features of BSS and common presentations such as new onset diabetes, hypertriglyceridemia, or pancreatitis throughout early childhood and adolescence in order to avoid delayed diagnoses.

Impaired functional exercise capacity and greater cardiovascular response to the 6-min walk test in congenital generalized lipodystrophy

BACKGROUND

Congenital Generalized Lipodystrophy (CGL) is an ultra-rare disease characterized by metabolic disorders. However, the evaluation of functional exercise capacity, cardiovascular (CV) response to exercise, and peripheral arterial disease (PAD) in CGL is scarce. Here we evaluated the performance and CV response to exercise and their association with PAD in CGL compared to healthy individuals.

METHODS

Twelve CGL and 12 healthy subjects matched for age and gender were included. Functional exercise capacity, CV response, and PAD were measured using the six-minute walk test (6MWT) and ankle-brachial index (ABI), respectively.

RESULTS

At baseline, CGL subjects showed reduced predicted walked distance (6MWD) (p = 0.009) and increased heart rate (HR), systolic (SBP), and diastolic (DBP) pressures compared to healthy subjects (p < 0.05). Most CGL subjects presented normal ABI values (1.0 ≤ ABI ≤ 1.4). Only 25% (n = 3) had ABI ≤ 0.9. CGL subjects did not present changes in ABI and blood pressure 12 months after metreleptin (MLP) replacement, but they walked a greater 6MWD than baseline (p = 0.04). Further, 6MWD and right ABI measurements were positively correlated in CGL subjects (p = 0.03). Right ABI negatively correlated with glucose, triglycerides, and VLDL-c (p < 0.05).

CONCLUSIONS

We observed that CGL subjects had lower functional exercise capacity and higher cardiovascular effort for similar performance of 6MWT, suggesting that strategies for decreasing exercise effort in this population should be essential. Furthermore, better physical performance was associated with high ABI in CGL. Additional studies are needed to clarify leptin's role in preserving functional exercise capacity in CGL.

Advances in the care of lipodystrophies

PURPOSE OF REVIEW

Lipodystrophies are a group of rare, heterogeneous disorders characterized by a lack or maldistribution of adipose tissue. Treatment focusses on the management of complications, including hypertriglyceridemia, which can be severe. Patients are predisposed to early atherosclerotic cardiovascular disease and acute pancreatitis. This review summarizes the recent advances in the treatment of lipodystrophies, with a particular focus on the treatment of hypertriglyceridemia in familial partial lipodystrophy (FPLD).

RECENT FINDINGS

Treatment of dyslipidemia in FPLD requires management of secondary exacerbating factors, particularly insulin resistance and diabetes, together with modification of atherosclerotic cardiovascular disease risk factors. In addition, specific lipid-lowering therapies are usually needed, starting with statins and fibrates. Leptin therapy improves triglycerides. Several emerging treatments for hypertriglyceridemia include apo C-III antagonists (volanesorsen, AKCEA-APOCIII-LRx and ARO-APOC3) and angiopoietin-like 3 antagonists (evinacumab, vupanorsen and ARO-ANG3); efficacy observed in clinical trials of these agents in nonlipodystrophic patients with severe hypertriglyceridemia suggests that they may also be helpful in lipodystrophy.

SUMMARY

Emerging therapies for dyslipidemia show promise in advancing the care of patients with lipodystrophy. However, these treatments are not yet approved for use in lipodystrophy. Further study of their efficacy and safety in this patient population is needed.

Obesity, Body Composition, and Sex Hormones: Implications for Cardiovascular Risk

Cardiovascular disease (CVD) continues to be the leading cause of death in adults, highlighting the need to develop novel strategies to mitigate cardiovascular risk. The advancing obesity epidemic is now threatening the gains in CVD risk reduction brought about by contemporary pharmaceutical and surgical interventions. There are sex differences in the development and outcomes of CVD; premenopausal women have significantly lower CVD risk than men of the same age, but women lose this advantage as they transition to menopause, an observation suggesting potential role of sex hormones in determining CVD risk. Clear differences in obesity and regional fat distribution among men and women also exist. While men have relatively high fat in the abdominal area, women tend to distribute a larger proportion of their fat in the lower body. Considering that regional body fat distribution is an important CVD risk factor, differences in how men and women store their body fat may partly contribute to sex-based alterations in CVD risk as well. This article presents findings related to the role of obesity and sex hormones in determining CVD risk. Evidence for the role of sex hormones in determining body composition in men and women is also presented. Lastly, the clinical potential for using sex hormones to alter body composition and reduce CVD risk is outlined. © 2022 American Physiological Society. Compr Physiol 12:1-45, 2022.

Complications of lipodystrophy syndromes

Lipodystrophy syndromes are rare complex multisystem disorders caused by generalized or partial lack of adipose tissue. Adipose tissue dysfunction in lipodystrophy is associated with leptin deficiency. Lipodystrophy leads to severe metabolic problems. These abnormalities include, but are not limited to, insulin-resistant diabetes, severe hypertriglyceridemia, and lipid accumulation in ectopic organs such as the liver, and are associated with end-organ complications. Metabolic abnormalities can be present at the time of diagnosis or may develop over time as the disease progresses. In addition to metabolic abnormalities, subtype-specific presentations due to underlying molecular etiology in genetic forms and autoimmunity in acquired forms contribute to severe morbidity in lipodystrophy.

Risk factors for diabetic foot ulcers in metreleptin naïve patients with lipodystrophy

AIM

Patients with lipodystrophy are at high risk for chronic complications of diabetes. Recently, we have reported 18 diabetic foot ulcer episodes in 9 subjects with lipodystrophy. This current study aims to determine risk factors associated with foot ulcer development in this rare disease population.

METHODS

Ninety metreleptin naïve patients with diabetes registered in our national lipodystrophy database were included in this observational retrospective cohort study (9 with and 81 without foot ulcers).

RESULTS

Patients with lipodystrophy developing foot ulcers had longer diabetes duration (p = 0.007), longer time since lipodystrophy diagnosis (p = 0.008), and higher HbA1c levels (p = 0.041). Insulin use was more prevalent (p = 0.003). The time from diagnosis of diabetes to first foot ulcer was shorter for patients with generalized lipodystrophy compared to partial lipodystrophy (p = 0.036). Retinopathy (p < 0.001), neuropathy (p < 0.001), peripheral artery disease (p = 0.001), and kidney failure (p = 0.003) were more commonly detected in patients with foot ulcers. Patients with foot ulcers tended to have lower leptin levels (p = 0.052). Multiple logistic regression estimated significant associations between foot ulcers and generalized lipodystrophy (OR: 40.81, 95% CI: 3.31-503.93, p = 0.004), long-term diabetes (≥ 15 years; OR: 27.07, 95% CI: 2.97-246.39, p = 0.003), and decreased eGFR (OR: 13.35, 95% CI: 1.96-90.67, p = 0.008).

CONCLUSIONS

Our study identified several clinical factors associated with foot ulceration among patients with lipodystrophy and diabetes. Preventive measures and effective treatment of metabolic consequences of lipodystrophy are essential to prevent the occurrence of foot ulcers in these high-risk individuals.

Metreleptin treatment of non-HIV lipodystrophy syndromes

Lipodystrophy syndromes (LS) constitute a group of rare diseases of the adipose tissue, characterized by a complete or selective deficiency of the fat mass. These disorders are associated with important insulin resistance, cardiovascular and metabolic comorbidities that impact patient's survival and quality of life. Management is challenging and includes diet, physical activity, and specific pharmacological treatment of LS-associated comorbidities. Because of a common pathophysiology involving decreased concentration of the adipokine leptin, efforts have been made to develop therapeutic strategies with leptin replacement therapy. Metreleptin, a recombinant human leptin analogue, has been proposed in hypoleptinemic patients since the beginning of 2000's. The treatment leads to an improvement in metabolic parameters, more important in generalized than in partial LS forms. In this review, the current knowledge about the development of the drug, its outcomes in the treatment of lipodystrophic patients as well as the peculiarities of its use will be presented.

Generalized lipoatrophy syndromes

Generalized lipodystrophy (GL) syndromes are a group of rare heterogenous disorders, characterized by total subcutaneous fat loss. The frequency of GL is currently assessed as approximately 0,23 cases per million of the population, in Europe - as 0,96 cases per million of the population. They can be congenital (CGL) or acquired (AGL) depending on the etiology and the time of the onset of fat loss. Both CGL and AGL are often associated with different metabolic complications, such as hypertriglyceridemia, insulin resistance and lipoatrophic diabetes mellitus, metabolically associated FLD, arterial hypertension, proteinuria, reproductive system disorders. In this review we aimed to summarize the information on all forms of generalized lipodystrophy, especially the ones of genetic etiology, their clinical manifestations and complications, the perspectives for diagnostics, treatment and further research.

Lipid droplets and the host-pathogen dynamic: FATal attraction?

In the ongoing conflict between eukaryotic cells and pathogens, lipid droplets (LDs) emerge as a choke point in the battle for nutrients. While many pathogens seek the lipids stored in LDs to fuel an expensive lifestyle, innate immunity rewires lipid metabolism and weaponizes LDs to defend cells and animals. Viruses, bacteria, and parasites directly and remotely manipulate LDs to obtain substrates for metabolic energy, replication compartments, assembly platforms, membrane blocks, and tools for host colonization and/or evasion such as anti-inflammatory mediators, lipoviroparticles, and even exosomes. Host LDs counterattack such advances by synthesizing bioactive lipids and toxic nucleotides, organizing immune signaling platforms, and recruiting a plethora of antimicrobial proteins to provide a front-line defense against the invader. Here, we review the current state of this conflict. We will discuss why, when, and how LDs efficiently coordinate and precisely execute a plethora of immune defenses. In the age of antimicrobial resistance and viral pandemics, understanding innate immune strategies developed by eukaryotic cells to fight and defeat dangerous microorganisms may inform future anti-infective strategies.

Prevalence of severe hypertriglyceridemia and pancreatitis in familial partial lipodystrophy type 2

Familial partial lipodystrophy (FPLD) is a rare Mendelian condition listed in the differential diagnosis of severe hypertriglyceridemia (HTG) and pancreatitis. Here we determined the prevalence of severe HTG and pancreatitis among a cohort of 74 FPLD patients assessed in a lipid clinic. We studied lipid profiles from individuals with either of the two most common pathogenic monoallelic variants in LMNA, namely p.R482Q (N= 51) and p.R482W (N= 23). In total, 28 (37.8%) patients with a mean age of 41.8 ± 14.8 years had diabetes, while 46 (62.2%) patients with a mean age of 35.4 ± 19.4 years had no diabetes. Among patients with and without diabetes, median TG levels (interquartile range) were 2.73 (4.78) and 1.86 (1.66) mmol/L (242 [423] and 165 [147] mg/dL), respectively. Overall, 4 subjects (5.4%) had triglyceride levels > 10 mmol/L (> 885 mg/dL), of whom 3 (4.1%) had a history of hospitalization for acute pancreatitis. All 4 patients with severe HTG had diabetes, i.e. 14.3% of those with diabetes. In contrast, FPLD2 patients without diabetes had only mild HTG, with no instances of severe HTG or pancreatitis. Thus, among this selected lipid clinic cohort with lipodystrophy, severe HTG and pancreatitis in FPLD2 are relatively common when diabetes is present.

Effect of Leptin Therapy on Survival in Generalized and Partial Lipodystrophy: A Matched Cohort Analysis

CONTEXT

Data quantifying the impact of metreleptin therapy on survival in non-human immunodeficiency virus (HIV)-related generalized lipodystrophy (GL) and partial lipodystrophy (PL) are unavailable.

OBJECTIVE

This study aimed to estimate the treatment effect of metreleptin on survival in patients with GL and PL.

DESIGN/SETTING/PATIENTS

Demographic and clinical characteristics were used to match metreleptin-treated and metreleptin-naïve patients with GL and PL. Differences in mortality risk were estimated between matched cohorts of metreleptin-treated and metreleptin-naïve patient cohorts using Cox proportional hazard models. Sensitivity analyses assessed the impact of study assumptions and the robustness of results.

OUTCOME MEASURES

This study assessed time-to-mortality and risk of mortality.

RESULTS

The analysis evaluated 103 metreleptin-naïve patients with characteristics matched to 103 metreleptin-treated patients at treatment initiation. Even after matching, some metabolic and organ abnormalities were more prevalent in the metreleptin-treated cohort due to bias toward treating more severely affected patients. A Cox proportional hazards model associated metreleptin therapy with an estimated 65% decrease in mortality risk (hazard ratio [HR] 0.348, 95% confidence interval (CI): 0.134-0.900; P = 0.029) even though the actual number of events were relatively small. Results were robust across a broad range of alternate methodological assumptions. Kaplan-Meier estimates of time-to-mortality for the metreleptin-treated and the matched metreleptin-naïve cohorts were comparable.

CONCLUSIONS

Metreleptin therapy was associated with a reduction in mortality risk in patients with lipodystrophy syndromes despite greater disease severity in treated patients, supporting the view that metreleptin can have a positive disease-modifying impact. Confirmatory studies in additional real-world and clinical datasets are warranted.

SARS-COV-2 infection outcomes in patients with congenital generalized lipodystrophy

BACKGROUND

A new strain of human coronavirus (HCoV) spread rapidly around the world. Diabetes and obesity are associated with a worse prognosis in these patients. Congenital Generalized Lipodystrophy (CGL) patients generally have poorly controlled diabetes and require extremely high doses of insulin. There is no documentation in the literature of cases of COVID in CGL patients. Thus, we aimed to evaluate the prevalence of SARS-CoV-2 infection in CGL patients, and the association of their clinical and metabolic characteristics and outcomes.

METHODS

This is a cross-sectional study carried out between July and October 2020. Clinical data collected were respiratory or other flu-like symptoms, need of hospitalization in the last three months, CGL comorbidities, and medications in use. Cholesterol, triglycerides, glycohemoglobin A1c levels, anti-SARS-CoV-2 antibodies and nasopharyngeal swab for RT-qPCR were also obtained in all CGL patients. Mann-Whitney U test was used to analyze the characteristics of the participants, verifying the non-adherence of the data to the Gaussian distribution. In investigating the association between categorical variables, we used Pearson's chi-square test and Fisher's exact test. A significance level of 5% was adopted.

RESULTS

Twenty-two CGL patients were assessed. Eight subjects (36.4%) had reactive anti-SARS-CoV-2 antibodies. Only one of these, also presented detectable RT-qPCR. Five individuals (62.5%) were women, median age of 13.5 years (1 to 37). Symptoms like fever, malaise, nausea, diarrhea and chest pain were present, and all asymptomatic patients were children. All subjects had inadequate metabolic control, with no difference between groups. Among positive individuals there was no difference between those with AGPAT2 (75%) and BSCL2 gene mutations (25%) (p > 0.05). No patient needed hospitalization or died.

CONCLUSIONS

We described a high prevalence of SARS-CoV-2 infection in CGL patients with a good outcome in all of them. These findings suggest that at least young CGL patients infected by SARS-COV-2 are not at higher risk of poor outcome, despite known severe metabolic comorbidities.

Celia's Encephalopathy (BSCL2-Gene-Related): Current Understanding

Seipin, encoded by the BSCL2 gene, is a protein that in humans is expressed mainly in the central nervous system. Uniquely, certain variants in BSCL2 can cause both generalized congenital lipodystrophy type 2, upper and/or lower motor neuron diseases, or progressive encephalopathy, with a poor prognosis during childhood. The latter, Celia's encephalopathy, which may or may not be associated with generalized lipodystrophy, is caused by the c.985C >T variant. This cytosine to thymine transition creates a cryptic splicing zone that leads to intronization of exon 7, resulting in an aberrant form of seipin, Celia seipin. It has been proposed that the accumulation of this protein, both in the endoplasmic reticulum and in the nucleus of neurons, might be the pathogenetic mechanism of this neurodegenerative condition. In recent years, other variants in BSCL2 associated with generalized lipodystrophy and progressive epileptic encephalopathy have been reported. Interestingly, most of these variants could also lead to the loss of exon 7. In this review, we analyzed the molecular bases of Celia's encephalopathy and its pathogenic mechanisms, the clinical features of the different variants, and a therapeutic approach in order to slow down the progression of this fatal neurological disorder.

Bscl2 Deficiency Does Not Directly Impair the Innate Immune Response in a Murine Model of Generalized Lipodystrophy

Congenital Generalized Lipodystrophy type 2 (CGL2) is the most severe form of lipodystrophy and is caused by mutations in the BSCL2 gene. Affected patients exhibit a near complete lack of adipose tissue and suffer severe metabolic disease. A recent study identified infection as a major cause of death in CGL2 patients, leading us to examine whether Bscl2 loss could directly affect the innate immune response. We generated a novel mouse model selectively lacking Bscl2 in the myeloid lineage (LysM-B2KO) and also examined the function of bone-marrow-derived macrophages (BMDM) isolated from global Bscl2 knockout (SKO) mice. LysM-B2KO mice failed to develop lipodystrophy and metabolic disease, providing a model to study the direct role of Bscl2 in myeloid lineage cells. Lipopolysaccharide-mediated stimulation of inflammatory cytokines was not impaired in LysM-B2KO mice or in BMDM isolated from either LysM-B2KO or SKO mice. Additionally, intracellular fate and clearance of bacteria in SKO BMDM challenged with Staphylococcus aureus was indistinguishable from that in BMDM isolated from littermate controls. Overall, our findings reveal that selective Bscl2 deficiency in macrophages does not critically impact the innate immune response to infection. Instead, an increased susceptibility to infection in CGL2 patients is likely to result from severe metabolic disease.

Altered acylated ghrelin response to food intake in congenital generalized lipodystrophy

BACKGROUND

Patients with congenital generalized lipodystrophy (CGL) have very low levels of leptin and are described as having a voracious appetite. However, a direct comparison between CGL and eutrophic individuals is lacking, regarding both appetite parameters and acylated ghrelin, the hormone form that is active in acute food intake stimulation. The objective of the present study was to address whether and in what extent the subjective appetite parameters and acylated ghrelin response to a meal are affected in CGL individuals, in comparison to eutrophic individuals. Additionally, an obese group was included in the study, to allow the comparison between a leptin-resistant and a leptin-deficient condition on these aspects.

METHODS

Eutrophic controls (EUT, n = 10), obese subjects (OB, n = 10) and CGL (n = 11) were fasted overnight and then received an ad libitum meal. Blood was collected and the visual analogue scale was applied before and 90 minutes after the meal. An additional blood sample was collected at 60 minutes for ghrelin determination.

RESULTS

The CGL patients showed low fasting levels of leptin and adiponectin, dyslipidemia, and insulin resistance. The caloric intake was similar among the 3 groups. However, both CGL (p = 0.02) and OB (p = 0.04) had shorter satiation times than EUT. The CGL patients also had lower satiety time (p = 0.01) and their sensation of hunger was less attenuated by the meal (p = 0.03). Fasting acylated ghrelin levels were lower in CGL than in EUT (p = 0.003). After the meal, the levels tended to decrease in EUT but not in CGL and OB individuals.

CONCLUSION

The data indicate that, although not hyperphagic, the CGL patients present appetite disturbances in relation to eutrophic individuals. Their low fasting levels of acylated ghrelin and the absence of the physiological drop after meal intake suggest a role of these disturbances in hunger attenuation and satiety but not in acute satiation.

[Multiple subcutaneous nodules for 46 days in an infant aged 66 days]

A boy, aged 66 days, was admitted to the hospital due to subcutaneous nodules for 46 days and abdominal distension for 10 days. The main clinical manifestations were loss of adipose tissue, subcutaneous nodules, insulin-resistant diabetes, hypertriglyceridemia, and hepatic steatosis. The boy was diagnosed with congenital generalized lipodystrophy type 1 (CGL1). His condition was improved after administration of middle-chain fatty acid formula milk and insulin injection or oral metformin. Gene testing revealed a homozygous mutation, c.646A>T, in the AGPAT2 gene, and both his parents were carriers of this mutation. This case of CGL1 has the youngest age of onset ever reported in China and multiple subcutaneous nodules as the initial symptom.

Pediatric Dyslipidemia-Beyond Familial Hypercholesterolemia

Dyslipidemia is seen with increasing prevalence in young Canadians, mainly mild to moderate hypertriglyceridemia secondary to obesity. This review focuses on pediatric dyslipidemias excluding familial hypercholesterolemia (FH), but including both severe and mild to moderate hypertriglyceridemia, combined hyperlipidemia, and elevated lipoprotein(a) [Lp(a)]. We suggest that for Canadian children and adolescents with dyslipidemia, atherosclerotic cardiovascular disease (ASCVD) risk assessment should include both low-density lipoprotein cholesterol and triglyceride measurement. To further stratify risk, determination of non-high-density lipoprotein cholesterol is recommended, for both its ability to predict ASCVD and convenience for the patient because fasting is not required. Similarly, apolipoprotein B measurement (fasting or nonfasting), where available, can be helpful. Lp(a) measurement should not be routine in childhood, but it can be considered in special circumstances. After ruling out secondary causes, the foundation for management of pediatric dyslipidemia includes weight regulation, optimizing diet, and increasing activity level. At present, randomized clinical trial data to guide pharmaceutical management of pediatric hypertriglyceridemia or other non-FH pediatric dyslipidemias are scarce. Pharmaceutical management should be reserved for special situations in which risk of complications such as acute pancreatitis or ASCVD over the intermediate term is high and conservative lifestyle-based interventions have been ineffective.

Genotype-phenotype correlations of Berardinelli-Seip congenital lipodystrophy and novel candidate genes prediction

BACKGROUND

Berardinelli-Seip congenital lipodystrophy (BSCL) is a heterogeneous autosomal recessive disorder characterized by an almost total lack of adipose tissue in the body. Mutations in the AGPAT2, BSCL2, CAV1 and PTRF genes define I-IV subtype of BSLC respectively and clinical data indicate that new causative genes remain to be discovered. Here, we retrieved 341 cases from 60 BSCL-related studies worldwide and aimed to explore genotype-phenotype correlations based on mutations of AGPAT2 and BSCL2 genes from 251 cases. We also inferred new candidate genes for BSCL through protein-protein interaction and phenotype-similarity.

RESULTS

Analysis results show that BSCL type II with earlier age of onset of diabetes mellitus, higher risk to suffer from premature death and mental retardation, is a more severe disorder than BSCL type I, but BSCL type I patients are more likely to have bone cysts. In BSCL type I, females are at higher risk of developing diabetes mellitus and acanthosis nigricans than males, while in BSCL type II, males suffer from diabetes mellitus earlier than females. In addition, some significant correlations among BSCL-related phenotypes were identified. New candidate genes prediction through protein-protein interaction and phenotype-similarity was conducted and we found that CAV3, EBP, SNAP29, HK1, CHRM3, OBSL1 and DNAJC13 genes could be the pathogenic factors for BSCL. Particularly, CAV3 and EBP could be high-priority candidate genes contributing to pathogenesis of BSCL.

CONCLUSIONS

Our study largely enhances the current knowledge of phenotypic and genotypic heterogeneity of BSCL and promotes the more comprehensive understanding of pathogenic mechanisms for BSCL.

Acquired lipodystrophy associated with immune checkpoint inhibitors

Immune checkpoint inhibitors have become the mainstay of treatment for metastatic melanoma. This article presents a new case of acquired generalised lipodystrophy (AGL) during anti-programmed cell death-1 (anti-PD-1) therapy and a systematic review of the literature with an aim to further understand the pathogenesis. A comprehensive search was conducted using PubMed, Embase, MEDLINE and Cochrane Central databases. We identified four cases of lipodystrophy associated with anti-PD-1 immunotherapy, including our own. Of these, three were associated with nivolumab, and one with pembrolizumab. Body composition changes occurred at a median of 7 months after anti-PD-1 initiation. All cases reported AGL, with subcutaneous fat loss affecting majority of the body. There were three reported cases of insulin resistance associated with AGL. AGL should be a recognised adverse event associated with anti-PD-1 therapy.

Current Diagnosis, Treatment and Clinical Challenges in the Management of Lipodystrophy Syndromes in Children and Young People

Lipodystrophy is a heterogeneous group of disorders characterized by lack of body fat in characteristic patterns, which can be genetic or acquired. Lipodystrophy is associated with insulin resistance that can develop in childhood and adolescence, and usually leads to severe metabolic complications. Diabetes mellitus, hypertriglyceridemia, and hepatic steatosis ordinarily develop in these patients, and most girls suffer from menstrual abnormalities. Severe complications develop at a relatively young age, which include episodes of acute pancreatitis, renal failure, cirrhosis, and complex cardiovascular diseases, and all of these are associated with serious morbidity. Treatment of lipodystrophy consists of medical nutritional therapy, exercise, and the use of anti-hyperglycemic and lipid-lowering agents. New treatment modalities, such as metreleptin replacement, promise much in the treatment of metabolic abnormalities secondary to lipodystrophy. Current challenges in the management of lipodystrophy in children and adolescents include, but are not limited to: (1) establishing specialized centers with experience in providing care for lipodystrophy presenting in childhood and adolescence; (2) optimizing algorithms that can provide some guidance for the use of standard and novel therapies to ensure adequate metabolic control and to prevent complications; (3) educating patients and their parents about lipodystrophy management; (4) improving patient adherence to chronic therapies; (5) reducing barriers to access to novel treatments; and (5) improving the quality of life of these patients and their families.

Diagnostic strategies and clinical management of lipodystrophy

Introduction: Lipodystrophy is a heterogeneous group of rare diseases characterized by various degrees of fat loss which leads to serious morbidity due to metabolic abnormalities associated with insulin resistance and subtype-specific clinical features associated with underlying molecular etiology.Areas covered: This article aims to help physicians address challenges in diagnosing and managing lipodystrophy. We systematically reviewed the literature on PubMed and Google Scholar databases to summarize the current knowledge in lipodystrophy management.Expert opinion: Adipose tissue is a highly active endocrine organ that regulates metabolic homeostasis in the human body through a comprehensive communication network with other organ systems such as the central nervous system, liver, digestive system, and the immune system. The adipose tissue is capable of producing and secreting numerous factors with important endocrine functions such as leptin that regulates energy homeostasis. Recent developments in the field have helped to solve some of the mysteries behind lipodystrophy that allowed us to get a better understanding of adipocyte function and differentiation. From a clinical standpoint, physicians who suspect lipodystrophy should distinguish the disease from several others that may present with similar clinical features. It is also important for physicians to carefully interpret clinical features, laboratory, and imaging results before moving to more sophisticated tests and making decisions about therapy.

Changes in redox and endoplasmic reticulum homeostasis are related to congenital generalized lipodystrophy type 2

CGL type 2 is a rare autosomal recessive syndrome characterized by an almost complete lack of body fat. CGL is caused by loss-of-function mutations in both alleles of the BSCL2 gene that codifies to seipin. Subjects often show hyperglycemia, decreased HDL-c, and hypoadiponectinemia. These laboratory findings are important triggers for changes in redox and ER homeostasis. Therefore, our aim was to investigate whether these intracellular mechanisms are associated with this syndrome. We collected blood from people from Northeastern Brazil with 0, 1, and 2 mutant alleles for the rs786205071 in the BSCL2 gene. Through the qPCR technique, we evaluated the expression of genes responsible for triggering the antioxidant response, DNA repair, and ER stress in leukocytes. Colorimetric tests were applied to quantify lipid peroxidation and to evaluate the redox status of glutathione, as well as to access the panorama of energy metabolism. Long extension PCR was performed to observe leukocyte mitochondrial DNA lesions, and the immunoblot technique to investigate plasma adiponectin concentrations. Subjects with the rs786205071 in both BSCL2 alleles showed increased transcription of NFE2L2, APEX1, and OGG1 in leukocytes, as well as high concentrations of malondialdehyde and the GSSG:GSH ratio in plasma. We also observed increase of mitochondrial DNA lesions and XBP1 splicing, as well as a decrease in adiponectin and HDL-c. Our data suggest the presence of lipid lesions due to changes in redox homeostasis in that group, associated with increased levels of mitochondrial DNA damage and transcriptional activation of genes involved with antioxidant response and DNA repair.

Congenital Generalized Lipoatrophy (Berardinelli-Seip Syndrome) Type 1: Description of Novel AGPAT2 Homozygous Variants Showing the Highly Heterogeneous Presentation of the Disease

Berardinelli-Seip congenital lipoatrophy (BSCL) is characterized by near total fat atrophy, associated with the progressive development of metabolic complications. BSCL type 1 (BSCL1) is caused by mutations in AGPAT2, encoding 1-acylglycerol-3phosphate-O-acyltransferase β (recently renamed lysophosphatidic acid acyltransferase beta), which catalyzes the transformation of lysophosphatidic acid in phosphatidic acid, the precursor of glycerophospholipids and triglycerides. BSCL1 is an autosomal recessive disease due to AGPAT2 pathogenic variants leading to a depletion of triglycerides inside the adipose organ, and to a defective signaling of key elements involved in proper adipogenesis. We herein investigated the characteristics of two AGPAT2 variants in Caucasian Italian patients with Berardinelli-Seip congenital lipoatrophy. The first patient exhibited a novel homozygous nonsense c.430 C > T AGPAT2 mutation (p.Gln144^*) predicting the synthesis of a truncated enzyme of approximately half of the proper size. The second patient harbored a homozygous AGPAT2 missense variant (p.Arg159Cys), never described previously in BSCL1 patients: the segregation of the disease with the mutation in the pedigree of the family and the in silico analysis are compatible with a causative role of the p.Arg159Cys variant. We remark that BSCL1 can be clinically very heterogeneous at presentation and that the associated complications, occurring in the natural history of the disease, reduce life-expectancy. We point to the necessity for medical treatments capable of reducing the risk of cardiovascular death. In BSCL1 patients, the assessment of cardiovascular disease with conventional diagnostic means maybe particularly challenging.

Lipodystrophic syndromes: From diagnosis to treatment

Lipodystrophic syndromes are acquired or genetic rare diseases, characterised by a generalised or partial lack of adipose tissue leading to metabolic alterations linked to strong insulin resistance. They encompass a variety of clinical entities due to primary defects in adipose differentiation, in the structure and/or regulation of the adipocyte lipid droplet, or due to immune-inflammatory aggressions, chromatin deregulations and/or mitochondrial dysfunctions affecting adipose tissue. Diagnosis is based on clinical examination, pathological context and comorbidities, and on results of metabolic investigations and genetic analyses, which together determine management and genetic counselling. Early lifestyle and dietary measures focusing on regular physical activity and avoiding excess energy intake are crucial. They are accompanied by multidisciplinary follow-up adapted to each clinical form. In case of hyperglycemia, antidiabetic medications, with metformin as a first-line therapy in adults, are used in addition to lifestyle and dietary modifications. When standard treatments have failed to control metabolic disorders, the orphan drug metreleptin, an analog of leptin, can be effective in certain forms of lipodystrophy syndrome. Metreleptin therapy indications, prescription and monitoring were recently defined in France, representing a major improvement in patient care.

Comorbidities and Survival in Patients With Lipodystrophy: An International Chart Review Study

CONTEXT

Limited natural history data are available in patients with non-HIV-related lipodystrophy syndromes who never received disease-specific therapies, making interpretation of benefits of therapies in lipodystrophy syndromes challenging.

OBJECTIVE

We assessed the natural history of non-HIV-related generalized lipodystrophy (GL) and partial lipodystrophy (PL) in patients who have never received leptin or other lipodystrophy-specific therapies.

DESIGN/SETTING/PATIENTS

We conducted an international chart review of 230 patients with confirmed GL or PL at five treatment centers who never received leptin or other lipodystrophy-specific therapies. Patients were observed from birth to loss to follow-up, death, or date of chart abstraction.

OUTCOME MEASURES

Lifetime prevalence of diabetes/insulin resistance and select organ abnormalities, time to diabetes/insulin resistance, first organ abnormality, disease progression, and mortality were described.

RESULTS

Diabetes/insulin resistance was identified in 58.3% of patients. Liver abnormalities were the most common organ abnormality (71.7%), followed by kidney (40.4%), heart (30.4%), and pancreatitis (13.0%). Kaplan-Meier estimates of mean (SE) time to first organ abnormality were 7.7 years (0.9) in GL and 16.1 years (1.5) in PL (P < 0.001). Mean time to diabetes/insulin resistance was 12.7 years (1.2) in GL and 19.1 years (1.7) in PL (P = 0.131). Mean time to disease progression was 7.6 years (0.8) and comparable between GL and PL subgroups (P = 0.393). Mean time to death was 51.2 years (3.5) in GL and 66.6 years (1.0) in PL (P < 0.001).

CONCLUSIONS

This large-scale study provides comprehensive, long-term data across multiple countries on the natural history of non-HIV-related lipodystrophy.

Recent advances in understanding lipodystrophy: a focus on lipodystrophy-associated cardiovascular disease and potential effects of leptin therapy on cardiovascular function

Lipodystrophy is a disease characterized by a partial or total absence of adipose tissue leading to severe metabolic derangements including marked insulin resistance, type 2 diabetes, hypertriglyceridemia, and steatohepatitis. Lipodystrophy is also a source of major cardiovascular disorders which, in addition to hepatic failure and infection, contribute to a significant reduction in life expectancy. Metreleptin, the synthetic analog of the adipocyte-derived hormone leptin and current therapy of choice for patients with lipodystrophy, successfully improves metabolic function. However, while leptin has been associated with hypertension, vascular diseases, and inflammation in the context of obesity, it remains unknown whether its daily administration could further impair cardiovascular function in patients with lipodystrophy. The goal of this short review is to describe the cardiovascular phenotype of patients with lipodystrophy, speculate on the etiology of the disorders, and discuss how the use of murine models of lipodystrophy could be beneficial to address the question of the contribution of leptin to lipodystrophy-associated cardiovascular disease.

Fatty liver in lipodystrophy: A review with a focus on therapeutic perspectives of adiponectin and/or leptin replacement

Lipodystrophy is a group of clinically heterogeneous, inherited or acquired, disorders characterized by complete or partial absence of subcutaneous adipose tissue that may occur simultaneously with the pathological, ectopic, accumulation of fat in other regions of the body, including the liver. Fatty liver adds significantly to hepatic and extra-hepatic morbidity in patients with lipodystrophy. Lipodystrophy is strongly associated with severe insulin resistance and related comorbidities, such as hyperglycemia, hyperlipidemia and nonalcoholic fatty liver disease (NAFLD), but other hepatic diseases may co-exist in some types of lipodystrophy, including autoimmune hepatitis in acquired lipodystrophies, or viral hepatitis in human immunodeficiency virus (HIV)-associated lipodystrophy. The aim of this review is to summarize evidence linking lipodystrophy with hepatic disease and to provide a special focus on potential therapeutic perspectives of leptin replacement therapy and adiponectin upregulation in lipodystrophy.

An overview of lipodystrophy and the role of the complement system

The complement system is a major component of innate immunity playing essential roles in the destruction of pathogens, the clearance of apoptotic cells and immune complexes, the enhancement of phagocytosis, inflammation, and the modulation of adaptive immune responses. During the last decades, numerous studies have shown that the complement system has key functions in the biology of certain tissues. For example, complement contributes to normal brain and embryonic development and to the homeostasis of lipid metabolism. However, the complement system is subjected to the effective balance between activation-inactivation to maintain complement homeostasis and to prevent self-injury to cells or tissues. When this control is disrupted, serious pathologies eventually develop, such as C3 glomerulopathy, autoimmune conditions and infections. Another heterogeneous group of ultra-rare diseases in which complement abnormalities have been described are the lipodystrophy syndromes. These diseases are characterized by the loss of adipose tissue throughout the entire body or partially. Complement over-activation has been reported in most of the patients with acquired partial lipodystrophy (also called Barraquer-Simons Syndrome) and in some cases of the generalized variety of the disease (Lawrence Syndrome). Even so, the mechanism through which the complement system induces adipose tissue abnormalities remains unclear. This review focuses on describing the link between the complement system and certain forms of lipodystrophy. In addition, we present an overview regarding the clinical presentation, differential diagnosis, classification, and management of patients with lipodystrophy associated with complement abnormalities.

The worldwide mutational landscape of Berardinelli-Seip congenital lipodystrophy

Berardinelli-Seip congenital lipodystrophy (BSCL) is a rare disease characterized by the near total absence of body fat at birth. BSCL etiology involves genetic variations in four different genes: AGPAT2, BSCL2, CAV1, and CAVIN1. The four different biochemical subtypes of the disease are distinguished depending on which gene is mutated. The diagnosis of lipodystrophy can be based on clinical criteria, but the gold standard remains genetic testing. Since many different mutations have already been correlated with the onset of the disease, the most indicative method is DNA sequencing. However, not all laboratories have the resources to perform sequencing. Thus, less expensive techniques that include narrow gene regions may be applied. In such cases, the target mutations to be tested must be carefully determined taking into account the frequency of the description of the mutations in the literature, the nationality of the patient, as well as their phenotype. This review considers the molecular basis of BSCL, including the manual count of the majority of mutations reported in the literature up to the year 2018. Ninety different genetic mutations in 332 cases were reported at different frequencies. Some mutations were distributed homogeneously and others were specific to geographic regions. Type 2 BSCL was mentioned most often in the literature (50.3% of the cases), followed by Type 1 (38.0%), Type 4 (10.2%), and Type 3 (1.5%). The mutations comprised frameshifts (34.4%), nonsense (26.6%), and missense (21.1%). The c.517dupA in the BSCL2 gene was the most frequent (13.3%), followed by c.589-2A>G in the AGPAT2 gene (11.5%), c.507_511delGTATC in the BSCL2 gene (9.7%), c.317-588del in the AGPAT2 gene (7.3%), and c.202C>T in the AGPAT2 gene (4.5%). This information should prove valuable for analysts in making decisions regarding the best therapeutic targets in a population-specific context, which will benefit patients and enable faster and less expensive treatment.

Monogenic forms of lipodystrophic syndromes: diagnosis, detection, and practical management considerations from clinical cases

BACKGROUND

Lipodystrophic syndromes are rare diseases of genetic or acquired origin characterized by partial or generalized lack of body fat. Early detection and diagnosis are crucial to prevent and manage associated metabolic dysfunctions, i.e. insulin resistance, dyslipidemia, fatty liver, and diabetes, and to provide appropriate genetic counseling. By means of several representative case studies, this article illustrates the diagnostic and management challenges of lipodystrophic syndromes.

REVIEW

Berardinelli-Seip congenital lipodystrophy (BSCL) is typically diagnosed at birth, or soon thereafter, with generalized lipoatrophy and hepatomegaly secondary to hepatic steatosis. Physicians must also consider this diagnosis in adults with atypical non-autoimmune diabetes, hypertriglyceridemia, and a lean and muscular phenotype. The BSCL1 subtype due to mutations in the AGPAT2 gene can have an unusual presentation, especially in neonates and infants. Particular attention should be paid to infants presenting failure to thrive who also have hepatomegaly and metabolic derangements. The BSCL2 sub-type due to mutations in the BSCL gene tends to be more severe than BSCL1, and is characterized by greater fat loss, mild intellectual disability, earlier onset of diabetes, and higher incidence of premature death. Effective management from an earlier age may moderate the natural disease course. Partial lipodystrophies may easily be confused with common central obesity and/or metabolic syndrome. In patients with unexplained pancreatitis and hypertriglyceridemia, lipodystrophies such as familial partial lipodystrophy type 2 (FPLD2; Dunnigan type, due to LMNA mutations) should be considered. Oral combined contraceptives, which can reveal the disease by inducing severe hypertriglyceridemia, are contraindicated. Endogenous estrogens may also lead to "unmasking" of the FPLD2 phenotype, which often appears at puberty, and is more severe in females than males.

CONCLUSIONS

Diet and exercise, adapted to age and potential comorbidities, are essential prerequisites for therapeutic management of lipodystrophic syndromes. Metreleptin therapy can be useful to manage lipodystrophy-related metabolic complications.

Lipodystrophies, dyslipidaemias and atherosclerotic cardiovascular disease

Lipodystrophies are rare, heterogeneous, genetic or acquired, disorders characterised by varying degrees of body fat loss and associated metabolic complications, including insulin resistance, dyslipidaemias, hepatic steatosis and predisposition to atherosclerotic cardiovascular disease (ASCVD). The four main types of lipodystrophy, excluding antiretroviral therapy-induced lipodystrophy in HIV-infected patients, are congenital generalised lipodystrophy (CGL), familial partial lipodystrophy (FPLD), acquired generalised lipodystrophy (AGL) and acquired partial lipodystrophy (APL). This paper reviews the literature related to the prevalence of dyslipidaemias and ASCVD in patients with lipodystrophies. Patients with CGL, AGL and FPLD have increased prevalence of dyslipidaemia but those with APL do not. Patients with CGL as well as AGL present in childhood, and have severe dyslipidaemias (mainly hypertriglyceridaemia) and early onset diabetes mellitus as a consequence of extreme fat loss. However, only a few patients with CGL and AGL have been reported to develop coronary heart disease. In contrast, data from some small cohorts of FPLD patients reveal increased prevalence of ASCVD especially among women. Patients with APL have a relatively low prevalence of hypertriglyceridaemia and diabetes mellitus. Overall, patients with lipodystrophies appear to be at high risk of ASCVD due to increased prevalence of dyslipidaemia and diabetes and efforts should be made to manage these metabolic complications aggressively to prevent ASCVD.

Phenotypic and Genetic Characteristics of Lipodystrophy: Pathophysiology, Metabolic Abnormalities, and Comorbidities

PURPOSE OF REVIEW

This article focuses on recent progress in understanding the genetics of lipodystrophy syndromes, the pathophysiology of severe metabolic abnormalities caused by these syndromes, and causes of severe morbidity and a possible signal of increased mortality associated with lipodystrophy. An updated classification scheme is also presented.

RECENT FINDINGS

Lipodystrophy encompasses a group of heterogeneous rare diseases characterized by generalized or partial lack of adipose tissue and associated metabolic abnormalities including altered lipid metabolism and insulin resistance. Recent advances in the field have led to the discovery of new genes associated with lipodystrophy and have also improved our understanding of adipose biology, including differentiation, lipid droplet assembly, and metabolism. Several registries have documented the natural history of the disease and the serious comorbidities that patients with lipodystrophy face. There is also evolving evidence for increased mortality rates associated with lipodystrophy. Lipodystrophy syndromes represent a challenging cluster of diseases that lead to severe insulin resistance, a myriad of metabolic abnormalities, and serious morbidity. The understanding of these syndromes is evolving in parallel with the identification of novel disease-causing mechanisms.

Exploring Seipin: From Biochemistry to Bioinformatics Predictions

Seipin is a nonenzymatic protein encoded by the BSCL2 gene. It is involved in lipodystrophy and seipinopathy diseases. Named in 2001, all seipin functions are still far from being understood. Therefore, we reviewed much of the research, trying to find a pattern that could explain commonly observed features of seipin expression disorders. Likewise, this review shows how this protein seems to have tissue-specific functions. In an integrative view, we conclude by proposing a theoretical model to explain how seipin might be involved in the triacylglycerol synthesis pathway.