Are 'buffalo hump' syndrome, Madelung's disease and multiple symmetrical lipomatosis variants of the same dysmetabolism?

Lipomatosen

Als Lipomatosen bezeichnet man gutartige, meist ohne eindeutige Auslöser auftretende Vermehrungen des Fettgewebes, oft mit typischem Verteilungsmuster. Im Gegensatz zu umschriebenen Lipomen entwickeln sie sich meist diffus-symmetrisch und sind nicht von einer fibrösen Pseudokapsel umgeben. Am häufigsten ist die benigne symmetrische Lipomatose (BSL; Launois-Bensaude-Syndrom), von der aufgrund des Verteilungsmusters des hyperplastischen Fettgewebes vier Typen unterschieden werden. Ätiologie und Pathogenese der Erkrankung sind noch weitgehend unbekannt, wobei manche Formen eine hereditäre Basis zu haben oder mit vermehrtem Alkoholkonsum assoziiert zu sein scheinen. In einigen Fällen wurden mitochondriale Fehlfunktionen nachgewiesen. Lipomatosen können isoliert, aber auch mit Begleitsymptomen oder -erkrankungen (Komorbidität) vergesellschaftet auftreten. Wirksame medikamentöse Therapien sind nicht bekannt; chirurgische Verfahren können hingegen zur Besserung der Symptome führen. Die von der BSL abzugrenzende Lipomatosis dolorosa tritt bevorzugt bei Frauen mittleren Alters auf und ist durch Vermehrung des Fettgewebes sowie starke Schmerzen in den betroffenen Bereichen gekennzeichnet. Verschiedene Differenzialdiagnosen und Begleiterkrankungen sind abzuklären, insbesondere Depressionen. Evidenzbasierte Therapieempfehlungen existieren nicht. Repetitive Lidocain-Infusionen können temporäre Besserungen bewirken; nach chirurgischen Interventionen treten häufig Rezidive auf, allerdings werden auch langfristige Erfolge erzielt.

Lipomatoses

Lipomatoses are benign proliferations of adipose tissue, often with typical distribution patterns, which usually occur without clear causes. In contrast to circumscribed lipomas, they develop diffusely and symmetrically and are not surrounded by a fibrous pseudocapsule. The most common form is benign symmetric lipomatosis (BSL; Launois-Bensaude syndrome), of which four types are distinguished based on the distribution pattern of hyperplastic adipose tissue. The etiology and pathogenesis of the disease are still largely unknown, although some forms appear to have a hereditary basis or to be associated with increased alcohol consumption. In some cases, mitochondrial dysfunctions have been detected. Lipomatoses may be solitary, but may also be associated with other symptoms or illnesses (comorbidity). Effective drug therapies are not known, but surgical procedures can alleviate the symptoms. Lipomatosis dolorosa, which can be distinguished from BSL, occurs predominantly in middle-aged women and is characterized by proliferation of adipose tissue and severe pain in the affected areas. Various differential diagnoses and concomitant illnesses need to be considered, in particular depression. There are no evidence-based recommendations for therapy. Repetitive lidocaine infusions can achieve temporary improvement. Recurrence after surgical intervention is not uncommon, but long-term success is also possible.

State of diagnostic quandary solved by modern technology: a rare case of Madelung's disease

Madelung's disease is a neglected metabolic disease characterised by generalised multiple fatty tissue deposits. A 64-year-old Caucasian woman presented with generalised weakness and symptomatic hypoglycaemia with altered mental status. Physical examination showed very distinct physical characteristics with multiple lumps distributed over the upper body. Her neurological symptoms were solved by giving intravenous glucose and optimisation of medical treatment. Even though she had unique characteristics of Madelung's disease, many physicians, on several occasions, failed to recognise her 'hidden diagnosis'. This diagnostic uncertainty was able to be solved by searching the Internet for similar clinical features and images. This case demonstrates characteristics and unique features of a rare disease that can be seen in a female patient even though it is mostly found in males.

Rare adipose disorders (RADs) masquerading as obesity

Rare adipose disorders (RADs) including multiple symmetric lipomatosis (MSL), lipedema and Dercum's disease (DD) may be misdiagnosed as obesity. Lifestyle changes, such as reduced caloric intake and increased physical activity are standard care for obesity. Although lifestyle changes and bariatric surgery work effectively for the obesity component of RADs, these treatments do not routinely reduce the abnormal subcutaneous adipose tissue (SAT) of RADs. RAD SAT likely results from the growth of a brown stem cell population with secondary lymphatic dysfunction in MSL, or by primary vascular and lymphatic dysfunction in lipedema and DD. People with RADs do not lose SAT from caloric limitation and increased energy expenditure alone. In order to improve recognition of RADs apart from obesity, the diagnostic criteria, histology and pathophysiology of RADs are presented and contrasted to familial partial lipodystrophies, acquired partial lipodystrophies and obesity with which they may be confused. Treatment recommendations focus on evidence-based data and include lymphatic decongestive therapy, medications and supplements that support loss of RAD SAT. Associated RAD conditions including depression, anxiety and pain will improve as healthcare providers learn to identify and adopt alternative treatment regimens for the abnormal SAT component of RADs. Effective dietary and exercise regimens are needed in RAD populations to improve quality of life and construct advanced treatment regimens for future generations.

Differential gene expression indicates that 'buffalo hump' is a distinct adipose tissue disturbance in HIV-1-associated lipodystrophy

OBJECTIVE

To elucidate the molecular basis of the progressive enlargement of dorso-cervical adipose tissue, the so-called 'buffalo hump', that appears in a sub-set of patients with HIV-1/HAART-associated lipodystrophy.

DESIGN

Analysis of the expression of marker genes of mitochondrial function, adipogenesis, inflammation and cell proliferation in ten 'buffalo hump' samples and ten subcutaneous fat samples from HIV-1-infected/HAART-treated patients, and in ten healthy controls.

METHODS

Quantitative real-time polymerase chain reaction analysis of mitochondrial DNA and gene transcripts, and immunoblot for specific proteins.

RESULTS

'Buffalo hump' patients had lower levels of mitochondrial DNA and mitochondrial DNA-encoded transcripts with respect to healthy controls. The uncoupling protein (UCP)-1 gene was expressed only in 'buffalo hump' fat. There were no significant changes in the expression of UCP2, UCP3 or of marker genes of adipogenesis in 'buffalo hump' patients relative to healthy controls. 'Buffalo hump' fat did not show the high expression of tumor necrosis factor-alpha and beta2-microglobulin identified in lipoatrophic subcutaneous fat from patients. The expression of the macrophage marker CD68 was also lower in 'buffalo hump' than in subcutaneous fat from patients. In contrast, 'buffalo hump' showed a higher expression of the cell proliferation marker PCNA.

CONCLUSIONS

'Buffalo hump' adipose tissue shows specific disturbances in gene expression with respect to subcutaneous fat from HIV-1-infected/HAART-treated patients. Mitochondrial alterations cannot explain the differential behavior of 'buffalo hump' with respect to adipose depots prone to lipoatrophy. The absence of a local inflammatory status in 'buffalo hump' may explain in part the differential behavior of this adipose tissue.

Lipodystrophy in HIV 1-infected patients: lessons for obesity research

Lipodystrophy is a common alteration in HIV 1-infected patients under anti-retroviral treatment. This syndrome is usually associated with peripheral lipoatrophy, central adiposity and, in some cases, lipomatosis, as well as systemic insulin resistance and hyperlipidemia. Research on the ethiopathogenesis of the disease revealed novel aspects of adipose tissue biology highly relevant to obesity research: the pivotal role of mitochondria in white adipose tissue function, the role that interference with master transcription factors of adipogenesis may have in human adipose tissue, the capacity of human white adipose tissue to acquire brown fat-like features, as well as the importance of apoptosis and the potential impact of viral infections in adipose tissue. The dramatic difference between subcutaneous adipose depots, prone to lipoatrophy, and the visceral adipose depots, prone to enlargement, has been further evidenced in the study of the lipodystrophy syndrome. The recognition of a local pro-inflammatory environment in lipoatrophic adipose tissue from affected patients, including macrophage infiltration and enhanced expression of chemokines and cytokines, points to events paradoxically similar to those in the hypertrophied adipose tissue in obesity. However, this also potentially provides an explanation for the existence of systemic alterations common to lipodystrophy and obese patients and reminiscent of the metabolic syndrome.

Lipomatous disorder of the peri-trochanteric soft tissue: case report and review

Disorders of fatty tissue metabolism and body contour are frequently described in the literature. Several different syndromes have been ascribed to recurring characteristics of fatty deposition with similar underlying etiologies. These syndromes can generally be classified into the lipomatoses (abnormal accumulations of fat) and the lipodystrophies (abnormal fat atrophy). The authors describe a case of isolated symmetrical lipomatosis of the soft tissue overlying the trochanters that developed a recurrence after treatment with liposuction. They have attempted to match this patient's disorder into 1 of several reported syndromes, with benign symmetric lipomatosis and acquired partial lipodystrophy at the top of the differential diagnosis. However, some characteristics of this patient may warrant a separate categorization for her condition. In this case report, the current literature on disorders of fatty tissue metabolism is reviewed and a discussion of relevant factors and issues surrounding their clinical significance and management is provided.

Lipodystrophy associated with highly active anti-retroviral therapy for HIV infection: the adipocyte as a target of anti-retroviral-induced mitochondrial toxicity

The lipodystrophy syndrome and associated metabolic alterations are the most prevalent adverse effects in HIV-infected patients taking highly active anti-retroviral therapy (HAART). This syndrome involves profound disturbances in adipose tissue. The toxic effect of nucleoside reverse transcriptase inhibitors on mitochondrial function is a major contributor to the lipodystrophy syndrome. Although adipocytes were not expected to be preferential targets of mitochondrial toxicity, recent re-evaluation of the role of mitochondria in white adipocytes helps to explain the molecular basis of HAART-associated lipodystrophy. Adipocytes are a source of paracrine and endocrine signals that influence adipocyte biology and systemic metabolism. Mitochondrial disturbances elicited by HAART result in an abnormal perception of the bioenergetic status by adipocytes, thus leading to enhancement of catalytic pathways and apoptosis in peripheral adipose tissue, alterations in the differentiation of brown versus white adipocytes, and the release of hormonal signals that lead to systemic metabolic disturbances.

Reconstitution of virus-specific CD4 proliferative responses in pediatric HIV-1 infection

Gag-specific CD4 proliferative responses correlate inversely with HIV-1 RNA levels in infected adults, and robust responses are characteristic of long-term nonprogressive infection. However, strong responses are seldom detected in adult subjects with progressive infection and are not generally reconstituted on highly active antiretroviral therapy (HAART). To date, the role of HIV-1-specific Th responses in children has not been thoroughly examined. We characterized Gag-specific CD4 responses among 35 perinatally infected subjects, including 2 children who spontaneously control viremia without antiretroviral therapy, 21 children with viral loads (VL) of <400 on HAART, and 12 viremic children. Gag-specific Th activity was assessed by lymphoproliferative assay, and responses were mapped using overlapping Gag peptides in an IFN-gamma ELISPOT. Robust proliferative responses were detected in the children exhibiting spontaneous control of viremia, and mapping of targeted Gag regions in one such subject identified multiple epitopes. Among children >or=5 years old, 14 of 17 subjects with VL of <400 on HAART demonstrated a significant p24 proliferative response (median p24 stimulation index, 20), in contrast with only 1 of 9 viremic children (median p24 stimulation index, 2.0; p = 0.0008). However, no subject younger than 5 years of age possessed a significant response, even when viremia was fully suppressed. When compared with adults with VL of <400 on HAART, Th responses among children with VL of <400 were both more frequent (p = 0.009) and of greater magnitude (p = 0.002). These data suggest that children may have a greater intrinsic capacity to reconstitute HIV-1-specific immunity than adults, and may be excellent candidates for immune-based therapies.

Toxicidad mitocondrial de los antirretrovirales: diagnóstico y monitorización

Combination of antiretroviral drugs has dramatically improved the prognosis of individuals with HIV infection. However, their long-term benefit is limited by two main factors: the selection of drug-resistant strains and side effects. A large part of the toxicity of antiretroviral drugs has been associated with mitochondrial damage. Nucleoside analogue reverse transcriptase inhibitors (NRTI), which lack the hydroxyl group needed for further DNA chain elongation, block HIV reverse transcriptase. These nucleosides can be mistaken as natural substrates by the polymerase gamma, the enzyme responsible for the replication of mitochondrial DNA (mtDNA). Depletion or damage of mtDNA may affect the aerobic metabolism of carbohydrates and lipids, resulting in the accumulation of pyruvate/lactate and fatty acids, and ultimately in lactic acidosis and lipoatrophy, respectively. However, the relationship between hyperlactatemia and/or lipoatrophy and mtDNA depletion due to NRTIs has not been demonstrated conclusively. The design of methods to measure mtDNA may help to recognize the mitochondrial toxicity of antiretroviral therapy.