Dysregulation of insulin-like growth factors in a case of generalized acquired lipoatrophic diabetes mellitus (Lawrence Syndrome) connected with autoantibodies against adipocyte membranes

Characterization and Clinical Association of Autoantibodies Against Perilipin 1 in Patients With Acquired Generalized Lipodystrophy

Acquired generalized lipodystrophy (AGL) is a rare condition characterized by massive loss of adipose tissue through the body, causing severe metabolic complications. Autoimmune destruction of adipocytes is strongly suspected based on the frequent association of AGL with autoimmune disorders. In 2018, autoantibodies against perilipin 1 (PLIN1) were identified in three patients with autoimmune-associated AGL. However, the pathogenic mechanism and clinical impact of anti-PLIN1 remain unsolved. The prevalence of anti-PLIN1 autoantibodies in an AGL cohort of 40 patients was 50% (20 of 40). Among positive patients, 10 had the autoimmune variety and 10 had panniculitis-associated AGL. The IgG isotype was predominant, although some IgM antibodies were detected. Epitope-mapping studies did not identify a single, major epitope. Instead, autoantibodies typically bound to several different peptides, among which the central (233-405) domain was detected in all antibody-positive patients, for both IgG and IgM autoantibodies. In-depth epitope mapping indicated that anti-PLIN1 autoantibodies predominantly recognize the αβ-hydrolase domain containing 5 (ABHD5) binding site (383-405). Autoantibodies dose-dependently blocked the binding of PLIN1 to ABHD5 and caused a dislocation of ABHD5 toward the cytosol, leading to an increase in lipolysis and lipase activities. Finally, anti-PLIN1 titers significantly correlated with the amount of fat loss, metabolic control impairment, and severity of liver injury. Our data strongly support that anti-PLIN1 autoantibodies are a diagnostic biomarker and a cause of lipodystrophy in patients with AGL.

Autoimmunity in lipodystrophy syndromes

Lipodystrophy syndromes are rare, heterogeneous disorders characterized by the complete or partial deficiency of adipose tissue and are classified according to the extent of fat loss in generalized or partial subtypes, or based on the pathogenic mechanisms in genetic or acquired. While in most cases of congenital forms of lipodystrophy a genetic alteration can be identified, the pathogenic mechanisms responsible for the acquired diseases are not fully clarified. Based on the evidence of a positive association between most acquired lipodystrophies and autoimmune disorders including immune mediated alterations in the adipose tissue of patients affected by acquired lipodystrophy, a reaction against white adipose tissue antigens is postulated. Recent acquisitions have shed new light on the possible pathogenic mechanisms and identified novel forms of acquired lipodystrophy which are possibly immune-mediated. The aim of this review is to give an update on acquired lipodystrophies describing pathogenic mechanisms involved and the relationships between acquired lipodystrophies and other autoimmune disorders. Larger studies based on international disease registries are needed to collect accurate information on the prevalence, risk factors, genetic predisposition, natural history, disease markers and treatment efficacy of these ultrarare disorders.

Immunological features of patients affected by Barraquer-Simons syndrome

Background

C3 hypocomplementemia and the presence of C3 nephritic factor (C3NeF), an autoantibody causing complement system over-activation, are common features among most patients affected by Barraquer-Simons syndrome (BSS), an acquired form of partial lipodystrophy. Moreover, BSS is frequently associated with autoimmune diseases. However, the relationship between complement system dysregulation and BSS remains to be fully elucidated. The aim of this study was to provide a comprehensive immunological analysis of the complement system status, autoantibody signatures and HLA profile in BSS. Thirteen subjects with BSS were recruited for the study. The circulating levels of complement components, C3, C4, Factor B (FB) and Properdin (P), as well as an extended autoantibody profile including autoantibodies targeting complement components and regulators were assessed in serum. Additionally, HLA genotyping was carried out using DNA extracted from peripheral blood mononuclear cells.

Results

C3, C4 and FB levels were significantly reduced in patients with BSS as compared with healthy subjects. C3NeF was the most frequently found autoantibody (69.2% of cases), followed by anti-C3 (38.5%), and anti-P and anti-FB (30.8% each). Clinical data showed high prevalence of autoimmune diseases (38.5%), the majority of patients (61.5%) being positive for at least one of the autoantibodies tested. The HLA allele DRB1*11 was present in 54% of BSS patients, and the majority of them (31%) were positive for *11:03 (vs 1.3% allelic frequency in the general population).

Conclusions

Our results confirmed the association between BSS, autoimmunity and C3 hypocomplementemia. Moreover, the finding of autoantibodies targeting complement system proteins points to complement dysregulation as a central pathological event in the development of BSS.

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.

Acquired partial lipoatrophy as graft-versus-host disease and treatment with metreleptin: two case reports

Introduction

Acquired partial lipoatrophy has been reported after bone marrow transplantation during childhood; however, no adult cases have previously been reported. We herein report two adult cases of acquired partial lipoatrophy after transplantation.

Case presentation

A 28-year-old Japanese woman developed diabetic ketoacidosis and received insulin therapy after bone marrow transplantation. She manifested partial lipoatrophy of the extremities, prominent insulin resistance, hyperglycemia, hypertriglyceridemia, and fatty liver. A 40-year-old Japanese woman underwent liver transplantation from a living donor for alcoholic liver disease after abstinence from alcohol. She newly developed non-alcoholic steatohepatitis and diabetes. Non-alcoholic steatohepatitis progressed to liver failure, and a second liver transplantation from a brain-dead donor was performed at 42 years of age. She demonstrated loss of subdermal fat of the upper and lower extremities, prominent insulin resistance, hyperglycemia, and hypertriglyceridemia. In both cases, the injection of recombinant methionyl human leptin reversed all of the metabolic abnormalities.

Conclusions

Acquired partial lipoatrophy after transplantation is a manifestation of chronic graft-versus-host disease in adults. This entity is associated with diabetes with prominent insulin resistance and severe hypertriglycemia and can be successfully treated with metreleptin for the long term.

Autoantibodies Against Perilipin 1 as a Cause of Acquired Generalized Lipodystrophy

Acquired generalized lipodystrophy (AGL) is a rare condition characterized by an altered distribution of adipose tissue and predisposition to develop hepatic steatosis and fibrosis, diabetes, and hypertriglyceridemia. Diagnosis of AGL is based on the observation of generalized fat loss, autoimmunity and lack of family history of lipodystrophy. The pathogenic mechanism of fat destruction remains unknown but evidences suggest an autoimmune origin. Anti-adipocyte antibodies have been previously reported in patients with AGL, although their involvement in the pathogenesis has been poorly studied and the autoantibody target/s remain/s to be identified. Using a combination of immunochemical and cellular studies, we investigated the presence of anti-adipocyte autoantibodies in patients with AGL, acquired partial lipodystrophy, localized lipoatrophy due to intradermic insulin injections or systemic lupus erythematosus. Moreover, the impact of anti-adipocyte autoantibodies from AGL patients was assessed in cultured mouse preadipocytes. Following this approach, we identified anti-perilipin 1 IgG autoantibodies in the serum of patients with autoimmune variety-AGL, but in no other lipodystrophies tested. These autoantibodies altered the ability of perilipin 1 to regulate lipolysis in cultured preadipocytes causing abnormal, significantly elevated basal lipolysis. Our data provide strong support for the conclusion that perilipin 1 autoantibodies are a cause of generalized lipodystrophy in these patients.

New advances in the treatment of generalized lipodystrophy: role of metreleptin

Recombinant methionyl human leptin or metreleptin is a synthetic leptin analog that has been trialed in patients with leptin-deficient conditions, such as leptin deficiency due to mutations in the leptin gene, hypothalamic amenorrhea, and lipodystrophy syndromes. These syndromes are characterized by partial or complete absence of adipose tissue and hormones derived from adipose tissue, most importantly leptin. Patients deficient in leptin exhibit a number of severe metabolic abnormalities such as hyperglycemia, hypertriglyceridemia, and hepatic steatosis, which can progress to diabetes mellitus, acute pancreatitis, and hepatic cirrhosis, respectively. For the management of these abnormalities, multiple therapies are usually required, and advanced stages may be progressively difficult to treat. Following many successful trials, the US Food and Drug Administration approved metreleptin for the treatment of non-HIV-related forms of generalized lipodystrophy. Leptin replacement therapy with metreleptin has, in many cases, reversed these metabolic complications, with improvements in glucose-insulin-lipid homeostasis, and regression of fatty liver disease. Besides being effective, a daily subcutaneous administration of metreleptin is generally safe, but the causal association between metreleptin and immune complications (such as lymphoma) is still unclear. Moreover, further investigation is needed to elucidate mechanisms by which metreleptin leads to the development of anti-leptin antibodies. Herein, we review clinical aspects of generalized lipodystrophy and the pharmacological profile of metreleptin. Further, we examine studies that assessed the safety and efficacy of metreleptin, and outline some clinical perspectives on the drug.

Lymphoma in acquired generalized lipodystrophy

Acquired generalized lipodystrophy (AGL) is a rare disease thought to result from autoimmune destruction of adipose tissue. Peripheral T-cell lymphoma (PTCL) has been reported in two AGL patients. We report five additional cases of lymphoma in AGL, and analyze the role of underlying autoimmunity and recombinant human leptin (metreleptin) replacement in lymphoma development. Three patients developed lymphoma during metreleptin treatment (two PTCL and one ALK-positive anaplastic large cell lymphoma), and two developed lymphomas (mycosis fungoides and Burkitt lymphoma) without metreleptin. AGL is associated with high risk for lymphoma, especially PTCL. Autoimmunity likely contributes to this risk. Lymphoma developed with or without metreleptin, suggesting metreleptin does not directly cause lymphoma development; a theoretical role of metreleptin in lymphoma progression remains possible. For most patients with AGL and severe metabolic complications, the proven benefits of metreleptin on metabolic disease will likely outweigh theoretical risks of metreleptin in lymphoma development or progression.

A case of acquired generalized lipodystrophy with cerebellar degeneration and type 2 diabetes mellitus

Acquired generalized lipodystrophy (AGL) is a rare disorder of adipose tissue characterized by loss of fat from large regions of the body, occurring after birth. Its etiology remains unknown. Most AGL patients have had fasting and/or postprandial hyperinsulinemia, diabetes mellitus, hypertriglyceridemia, and fatty liver. We describe the case of a 30-year-old woman with a progressively unsteady gait and a generalized loss of body fat beginning at the age of 7. Cerebellar degeneration was revealed by imaging study, and the patient was eventually bedridden at the age of 15, due to progressive ataxia. She developed diabetes at the age of 25 without the presence of any evidence of ketoacidosis. The glutamic acid decarboxylase antibody was negative, C-peptide level 3.6 ng/ml, HbA1c 13%, triglyceride 412 mg/dl, total cholesterol 196 mg/dl, high-density lipoprotein-cholesterol 28 mg/dl, adiponectin 0.76 microg/ml, and resistin was 22.8 ng/ml at the initial state of diabetes. AGL accompanied by type 2 diabetes and cerebellar degeneration was diagnosed on the basis of the clinical features and metabolic derangements.

Lipodystrophies: rare disorders causing metabolic syndrome

Recent advances in the understanding of the molecular basis of genetic lipodystrophies have promoted understanding of how adipose tissue disorders can cause the metabolic syndrome and its complications. These discoveries hold promise for elucidating pathways and mechanisms by which common disorders of obesity cause metabolic complications. Novel therapeutic approaches for patients with lipodystrophies also may have implications for treatment of the metabolic syndrome in patients with regional adiposity. This article reviews these recent advances in our knowledge of the clinical features, metabolic abnormalities, and pathogenetic or other bases of various types of lipodystrophies.

Prevalence of mutations in AGPAT2 among human lipodystrophies

Berardinelli-Seip congenital lipodystrophy (BSCL) is a heterogeneous genetic disease characterized by near absence of adipose tissue and severe insulin resistance. We have previously identified mutations in the seipin gene in a subset of our patients' cohort. Recently, disease-causing mutations in AGPAT2 have been reported in BSCL patients. In this study, we have performed mutation screening in AGPAT2 and the related AGPAT1 in patients with BSCL or other forms of lipodystrophy who have no detectable mutation in the seipin gene. We found 38 BSCL patients from 30 families with mutations in AGPAT2. Three of the known mutations were frequently found in our families. Of the eight new alterations, six are null mutations and two are missense mutations (Glu172Lys and Ala238Gly). All the patients harboring AGPAT2 mutations presented with typical features of BSCL. We did not find mutations in patients with other forms of lipodystrophies, including the syndromes of Lawrence, Dunnigan, and Barraquer-Simons, or with type A insulin resistance. In conclusion, mutations in the seipin gene and AGPAT2 are confined to the BSCL phenotype. Because we found mutations in 92 of the 94 BSCL patients studied, the seipin gene and AGPAT2 are the two major genes involved in the etiology of BSCL.

Clinical features and metabolic derangements in acquired generalized lipodystrophy: case reports and review of the literature

We present clinical descriptions, metabolic features, and patterns of body fat loss of 16 patients with acquired generalized lipodystrophy (AGL) seen by us over the last 10 years. In addition, we review 63 cases of AGL reported in the literature. Based on these data, we propose new diagnostic criteria for AGL, the essential criterion being selective loss of body fat from large regions of the body occurring after birth. We also propose a subclassification of AGL into 3 varieties, type 1, the panniculitis variety; type 2, the autoimmune disease variety; and type 3, the idiopathic variety, which affect nearly 25%, 25%, and 50% of patients, respectively. Most of the patients presented in childhood and adolescence. Females were affected approximately 3 times more than males. Subcutaneous fat loss was severe and usually affected the face, trunk, abdomen, and extremities. In some patients, fat loss also involved the palms and soles and intraabdominal region; however, the bone marrow and retroorbital fat were preserved in all patients. Clinically, patients may have voracious appetite, fatigue, and acanthosis nigricans. Hepatomegaly was common, mostly due to hepatic steatosis. Most AGL patients had fasting and/or postprandial hyperinsulinemia, diabetes mellitus, hypertriglyceridemia, and low serum levels of high-density lipoprotein cholesterol, leptin, and adiponectin. Diabetes mellitus and hypertriglyceridemia were less prevalent in the panniculitis variety compared with the idiopathic and autoimmune varieties. The management of AGL includes cosmetic surgery for loss of fat. Severe hypertriglyceridemia should be treated with a very low-fat diet and omega-3 polyunsaturated fatty acid supplementation from fish oils. Management of diabetes is difficult and may necessitate insulin therapy in large doses. Insulin sensitizers such as metformin and thiazolidinediones have been used, although their long-term efficacy and safety remain unknown. Subcutaneous administration of recombinant leptin in AGL patients with hypoleptinemia effectively improves hyperglycemia, hypertriglyceridemia, and hepatic steatosis. Leptin therapy, however, remains investigational. Fibrates alone or in combination with statins may be used to treat hypertriglyceridemia.

Strategies for the Management of Patients with Obesity

The prevalence of overweight and obesity is increasing worldwide. During the last two decades, the prevalence of adults in the higher body mass index (BMI) categories in the US has increased the most, as much as 300% for those with a BMI above 40kg/m2. In children and adolescents, a doubling of the prevalence of severe overweight poses a serious health risk to future generations of young adults who may develop chronic diseases normally associated with aging. The simple definition of obesity, an imbalance between energy intake and energy expenditure, ignores the complexity of, and largely unknown interactions between, genes, food intake and physical activity, which together determine bodyweight and fat distribution. Although the etiology and manifestations of overweight and obesity are complex, the assessment of overweight and obesity requires only an accurate measurement of bodyweight, height and abdominal circumference, as well as a history and physical examination attuned to the morbidities that commonly accompany overweight and obesity such as diabetes mellitus, hypertension, dyslipidemia and sleep apnea. The treatment of patients with overweight and obesity continues to be based on changes to diet and physical activity. Simple behavior modification techniques are within the reach of busy clinicians. The additional use of available bodyweight reduction medications can reliably lead to a 5 to 10% reduction from initial bodyweight, a loss that has been shown to provide significant health benefit. The use of meal replacements has also been shown to be effective and is probably an under-appreciated treatment resource. Surgery is the most successful treatment for those with severe obesity and should be discussed as an option for those in the appropriate bodyweight categories. Because societal trends favor the greater intake of calorie-dense foods and less physical activity to accomplish the activities of daily life, the future of obesity treatment will require the development of bodyweight reduction medications that work by a variety of mechanisms to decrease food intake or increase energy expenditure. Such medications should not be viewed as a 'crutch' but rather as a 'helping hand' that enable people to better adhere to a healthier lifestyle.

Lipoatrophy revisited

The lipoatrophy syndromes are a heterogeneous group of syndromes characterized by a paucity of adipose tissue. Severe lipoatrophy is associated with insulin-resistant diabetes mellitus (DM). The loss of adipose tissue can have a genetic, immune, or infectious/drug-associated etiology. Causative mutations have been identified in patients for one form of partial lipoatrophy--Dunnigan-type familial partial lipodystrophy. Experiments using lipoatrophic mice demonstrate that the diabetes results from the lack of fat and that leptin deficiency is a contributing factor. Thiazolidinedione therapy improves metabolic control in lipoatrophic patients; the efficacy of leptin treatment is currently being investigated.

Lipodystrophy syndrome in HIV infection: what is it, what causes it and how can it be managed?

Since the introduction of HIV-1 protease inhibitors as components of antiretroviral drug combination regimens, the clinical course of HIV disease and opportunistic infections has changed dramatically. Besides the favourable virological, immunological and clinical impact of highly active antiretroviral therapy (HAART), several adverse drug reactions have been observed in patients with HIV receiving therapy. Particularly, peripheral lipodystrophy, central adiposity, dyslipidaemia and insulin resistance have been described with a prevalence of up to 80% in patients infected with HIV, and attributed to almost all components of HAART. Hyperlipidaemia is characterised by an increase of low and very low density lipoprotein-cholesterol as well as apolipoproteins B and E. Several studies strongly suggest that there are either multiple syndromes or a variety of factors inducing different changes that influence the ultimate phenotype. Similarities between HIV-associated fat redistribution and metabolic abnormalities with both inherited lipodystrophies and benign symmetric lipomatosis suggest the pathophysiological involvement of, for example, nuclear factors like lamin A/C and drug-induced mitochondrial dysfunction. Moreover, there is some evidence that cytokines and hormones impair fat and glucose homeostasis in patients with HIV receiving HAART. Three years after the first description of HIV therapy-associated abnormal fat redistribution, there is still an ongoing discussion about the case definition, diagnostic procedure and treatment options for both body shape changes and metabolic disturbances. Regarding therapy, there is a major concern about possible complex pharmacological interactions and overlapping adverse effects between HAART and, for example, lipid-lowering therapy. In addition, the likely contribution of both nucleoside analogue reverse transcriptase inhibitors and protease inhibitors to the development of abnormal fat redistribution in patients with HIV limits options of changing to alternative effective antiretroviral drug combinations. Thus, the occurrence of hyperlipidaemia, maturity onset diabetes mellitus, and marked changes in body habitus resulted in important social and clinical consequences such as an increased risk of atherosclerosis. It also sheds new light on the use of protease inhibitors regarding risk factors for the initial treatment decision. In this article, we discuss the features, pathogenesis and treatment options for body fat redistribution and metabolic disturbances associated with HAART in HIV-1 infection.

Acquired generalized lipoatrophy (AGL): highly selective MR lipid imaging and localized (1)H-MRS

Frequency-selective chemical shift magnetic resonance (MR) imaging was applied on the calf musculature and the abdomen of a patient with acquired generalized lipoatrophy (AGL; Lawrence syndrome), a very rare syndrome affecting selectively several types of adipose tissue accompanied by alterations in glucose and energy metabolism. In addition, (1)H-MRS was used for assessment of intra- (IMCL) and extramyocellular lipid stores (EMCL) in the skeletal musculature of the calf. Results from the AGL patient were compared with an age-matched group of five healthy volunteers. Fat-selective imaging of the calf revealed a total lack of subcutaneous adipose tissue. No EMCL signal was found in the spectra from the soleus muscle of the AGL patient. IMCL signals were present in the spectra but were clearly lower than in the controls (14% of normal value in the soleus muscle). In abdominal images, subcutaneous fat signal was not detectable, as in the calf, but nearly normal conditions were shown for visceral adipose tissue between abdominal organs. Fat-selective images showed the liver with high signal intensity, indicating hepatic steatosis combined with hepatosplenomegaly. Modern chemical shift-selective MR imaging and localized spectroscopy allow a noninvasive and quantitative assessment of tissue composition in patients with disorders of carbohydrate and lipid metabolism.

Lipodystrophy syndrome in HIV infection: what is it, what causes it and how can it be managed?

Since the introduction of HIV-1 protease inhibitors as components of antiretroviral drug combination regimens, the clinical course of HIV disease and opportunistic infections has changed dramatically. Besides the favourable virological, immunological and clinical impact of highly active antiretroviral therapy (HAART), several adverse drug reactions have been observed in patients with HIV receiving therapy. Particularly, peripheral lipodystrophy, central adiposity, dyslipidaemia and insulin resistance have been described with a prevalence of up to 80% in patients infected with HIV, and attributed to almost all components of HAART. Hyperlipidaemia is characterised by an increase of low and very low density lipoprotein-cholesterol as well as apolipoproteins B and E. Several studies strongly suggest that there are either multiple syndromes or a variety of factors inducing different changes that influence the ultimate phenotype. Similarities between HIV-associated fat redistribution and metabolic abnormalities with both inherited lipodystrophies and benign symmetric lipomatosis suggest the pathophysiological involvement of, for example, nuclear factors like lamin A/C and drug-induced mitochondrial dysfunction. Moreover, there is some evidence that cytokines and hormones impair fat and glucose homeostasis in patients with HIV receiving HAART. Three years after the first description of HIV therapy-associated abnormal fat redistribution, there is still an ongoing discussion about the case definition, diagnostic procedure and treatment options for both body shape changes and metabolic disturbances. Regarding therapy, there is a major concern about possible complex pharmacological interactions and overlapping adverse effects between HAART and, for example, lipid-lowering therapy. In addition, the likely contribution of both nucleoside analogue reverse transcriptase inhibitors and protease inhibitors to the development of abnormal fat redistribution in patients with HIV limits options of changing to alternative effective antiretroviral drug combinations. Thus, the occurrence of hyperlipidaemia, maturity onset diabetes mellitus, and marked changes in body habitus resulted in important social and clinical consequences such as an increased risk of atherosclerosis. It also sheds new light on the use of protease inhibitors regarding risk factors for the initial treatment decision. In this article, we discuss the features, pathogenesis and treatment options for body fat redistribution and metabolic disturbances associated with HAART in HIV-1 infection.

Lipodystrophies

The lipodystrophies are rare disorders characterized by selective but variable loss of adipose tissue. Metabolic complications, such as insulin resistance, diabetes mellitus, hypertriglyceridemia, and fatty liver, increase in severity with the extent of fat loss. The lipodystrophies can be classified into two major types: familial and acquired. The main subtypes of familial lipodystrophies are congenital generalized lipodystrophy, an autosomal recessive disorder characterized by near complete lack of metabolically active adipose tissue from birth, and familial partial lipodystrophy, Dunnigan type, an autosomal dominant disorder characterized by loss of subcutaneous fat from the extremities at puberty and excess fat accumulation in the face and neck. Recently, a gene for congenital generalized lipodystrophy was localized to chromosome 9q34, and a gene for familial partial lipodystrophy, Dunnigan type, to chromosome 1q21-22; the genes, however, remain to be identified. Patients with acquired generalized lipodystrophy have generalized loss of subcutaneous fat, but those with acquired partial lipodystrophy have fat loss limited to the face, trunk, and upper extremities. Both varieties occur approximately three times more often in women, begin during childhood, and have underlying autoimmunity. Patients infected with the human immunodeficiency virus (HIV) who are receiving therapy that includes HIV-1 protease inhibitors have been reported to develop a lipodystrophy characterized by loss of subcutaneous fat from the extremities and face but excess fat deposition in the neck and trunk. Localized lipodystrophies can be caused by drugs, pressure, panniculitis, or unknown mechanisms. Current management of patients includes cosmetic surgery, diet, and drug therapy for control of diabetes and dyslipidemia.