Case Report of Acquired Generalized Lipodystrophy Associated With Common Variable Immunodeficiency

CONTEXT

Acquired generalized lipodystrophy (AGL), a rare disorder characterized by loss of subcutaneous adipose tissue, is estimated to occur in association with autoimmune diseases in ~25% of the cases. Common variable immunodeficiency (CVI) is a condition known for its strong association with autoimmune diseases often occurring with negative autoantibodies. To the best of our knowledge, we describe the first known case of AGL in a patient with CVI.

CASE DESCRIPTION

A 24-year-old man was referred to our center with hyperglycemia, hypertriglyceridemia, hepatomegaly, and a clear pattern of generalized fat loss. AGL had been diagnosed on the basis of the clinical and laboratory findings. Because of the presence of associated hypogammaglobulinemia, a diagnosis of CVI was subsequently established.

CONCLUSIONS

We propose that AGL be added to the list of possible diseases associated with CVI and, owing to the similar clinical presentation with type 1 diabetes mellitus, be included in the differential diagnosis of this condition, which is present in 1.5% of patients with CVI.

A Report of Three Cases With Acquired Generalized Lipodystrophy With Distinct Autoimmune Conditions Treated With Metreleptin

CONTEXT

Acquired generalized lipodystrophy (AGL) is associated with leptin deficiency as a result of adipose tissue loss and hypertriglyceridemia, insulin resistance, and hepatic steatosis. It may coexist with other autoimmune diseases such as Hashimoto's thyroiditis, rheumatoid arthritis, hemolytic anemia, and chronic active hepatitis. Metreleptin therapy has been shown to improve metabolic abnormalities in lipodystrophy, but the effect on AGL patients with active autoimmune disease is unknown.

CASE DESCRIPTION

We report 3 cases of pediatric patients with AGL and distinct active autoimmune diseases who were treated with metreleptin over a period of 4-6 years. Case 1 is a 9-year-old girl with active juvenile dermatomyositis, who was successfully treated with leptin with no worsening of her dermatomoysitis. Case 2 is a 16-year-old female with Graves' disease, who could discontinue all her antidiabetic medication completely with improved triglyceride levels. Case 3 is an 11-year-old boy with active autoimmune hepatitis and chronic urticaria, whose hyperphagia has resolved and his liver enzymes and hepatosplenomegaly have improved.

CONCLUSION

Metreleptin therapy is of considerable clinical benefit to reduce insulin resistance and hypertriglyceridemia and did not appear to alter the clinical course of autoimmune disease nor clinical efficacy of immunosuppressive treatments. Our observations suggest that risk or presence of autoimmune disease should not lead to withholding of metreleptin treatment from patients with AGL, but should prompt close clinical follow up in light of cautionary preclinical data.

Additive loss-of-function proteasome subunit mutations in CANDLE/PRAAS patients promote type I IFN production

Autosomal recessive mutations in proteasome subunit β 8 (PSMB8), which encodes the inducible proteasome subunit β5i, cause the immune-dysregulatory disease chronic atypical neutrophilic dermatosis with lipodystrophy and elevated temperature (CANDLE), which is classified as a proteasome-associated autoinflammatory syndrome (PRAAS). Here, we identified 8 mutations in 4 proteasome genes, PSMA3 (encodes α7), PSMB4 (encodes β7), PSMB9 (encodes β1i), and proteasome maturation protein (POMP), that have not been previously associated with disease and 1 mutation in PSMB8 that has not been previously reported. One patient was compound heterozygous for PSMB4 mutations, 6 patients from 4 families were heterozygous for a missense mutation in 1 inducible proteasome subunit and a mutation in a constitutive proteasome subunit, and 1 patient was heterozygous for a POMP mutation, thus establishing a digenic and autosomal dominant inheritance pattern of PRAAS. Function evaluation revealed that these mutations variably affect transcription, protein expression, protein folding, proteasome assembly, and, ultimately, proteasome activity. Moreover, defects in proteasome formation and function were recapitulated by siRNA-mediated knockdown of the respective subunits in primary fibroblasts from healthy individuals. Patient-isolated hematopoietic and nonhematopoietic cells exhibited a strong IFN gene-expression signature, irrespective of genotype. Additionally, chemical proteasome inhibition or progressive depletion of proteasome subunit gene transcription with siRNA induced transcription of type I IFN genes in healthy control cells. Our results provide further insight into CANDLE genetics and link global proteasome dysfunction to increased type I IFN production.

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.

Nakajo-Nishimura syndrome: an autoinflammatory disorder showing pernio-like rashes and progressive partial lipodystrophy

Nakajo-Nishimura syndrome (ORPHA2615; also registered as Nakajo syndrome in OMIM#256040) is a distinct inherited inflammatory and wasting disease, originally reported from Japan. This disease usually begins in early infancy with a pernio-like rash, especially in winter. The patients develop periodic high fever and nodular erythema-like eruptions, and gradually progress lipomuscular atrophy in the upper body, mainly the face and the upper extremities, to show the characteristic thin facial appearance and long clubbed fingers with joint contractures. So far about 30 cases have been reported from Kansai, especially Wakayama and Osaka, Tohoku and Kanto areas. At present, about 10 cases are confirmed to be alive only in the Kansai area, including one infant case in Wakayama. However, more cases are expected to be added in the near future. Although cause of the disease has long been undefined, a homozygous mutation of the PSMB8 gene, which encodes the β5i subunit of immunoproteasome, has been identified to be responsible in 2011. By analyses of the patients-derived cells and tissues, it has been suggested that accumulation of ubiquitinated and oxidated proteins due to immunoproteasome dysfunction causes hyperactivation of p38 mitogen-activated protein kinase and interleukin-6 overproduction. Since similar diseases with PSMB8 mutations have recently been reported from Europe and the United States, it is becoming clear that Nakajo-Nishimura syndrome and related disorders form proteasome disability syndromes, a new category of autoinflammatory diseases distributed globally.

Body fat abnormality in HIV-infected children and adolescents living in Europe: prevalence and risk factors

OBJECTIVES

To estimate the prevalence of and identify risk factors for lipodystrophy syndrome (LS) and body fat abnormality in a population of HIV-infected children and adolescents.

DESIGN

Cross-sectional observational study.

METHODS

HIV-infected subjects aged 2-18 years were recruited from 15 HIV centers in Belgium, Italy, and Poland between January 2007 and December 2008. Standardized assessments by the patient's long-term clinician were performed to establish the presence of abnormality. Risk factors were explored in logistic regression models for fat abnormality outcomes and LS (abnormality plus dyslipidemia).

RESULTS

Among 426 subjects (70% white), median age was 12.2 years (interquartile range: 9.0-15.0 years) and median duration of antiretroviral therapy was 5.2 years (interquartile range: 2.2-8.8 years). Prevalence was 57% (n = 235) for LS and 42% (n = 176) for fat abnormality; 90 subjects with abnormality were affected in ≥3 locations. Lipoatrophy occurred in 28% (n = 117) of subjects and lipohypertrophy in 27% (n = 115), most commonly in the face and trunk, respectively. In multivariable analysis, white ethnicity, body mass index, ritonavir/lopinavir, and nonnucleoside reverse transcriptase inhibitors were each associated with an increased risk of LS (P < 0.05). White ethnicity, history of Centers for Disease Control and Prevention-defined disease, and stavudine were associated with risk of lipoatrophy (P < 0.05). Increased risk of lipohypertrophy was associated with body mass index and prior HIV disease.

CONCLUSIONS

Fat abnormality was prevalent in close to half of children and adolescents, who had accumulated long treatment durations. Risk of fat abnormality was associated with specific drugs, including stavudine and ritonavir, and other variables. Our results underline the importance of continued surveillance of children treated with antiretroviral therapy.

Complement abnormalities in acquired lipodystrophy revisited

CONTEXT

Lipodystrophy is a heterogeneous condition characterized by an inherited or acquired deficiency in the number of adipocytes required for the storage of energy as triglycerides. Acquired lipodystrophy is frequently associated with other autoimmune disorders. One well-studied form is characterized by the selective loss of upper body fat in association with activation of the alternative complement pathway by C3 nephritic factor, low complement factor C3, and mesangiocapillary glomerulonephritis.

OBJECTIVE

We now describe an immunologically distinct form of acquired generalized lipodystrophy, with evidence of activation of the classical complement pathway (low C4) and autoimmune hepatitis. Patients and Research Design: Three unrelated patients with acquired lipodystrophy and low complement C4 levels are described. In vitro analysis of the complement pathway was undertaken to determine the reason for the low C4 complement levels. Biopsies were obtained from liver, bone marrow, and adipose tissue for histological analysis.

RESULTS

All three patients manifested near-total lipodystrophy, chronic hepatitis with autoimmune features, and low C4 complement levels. Additional autoimmune diseases, including severe hemolytic anemia, autoimmune thyroid disease, and polyneuropathy, were variably present. Detailed studies of complement pathways suggested constitutive classical pathway activation.

CONCLUSIONS

Although the previously described syndrome, which typically results in a cephalad pattern of partial lipodystrophy, results from activation of the alternative complement pathway, this form, in which lipodystrophy is generalized, is associated with activation of the classical pathway. Future therapeutic approaches to these disorders may benefit from being tailored to their distinct immunopathogenesis.

Dense deposit disease: new insights

PURPOSE OF REVIEW

Dense deposit disease is a rare but devastating disease primarily affecting children. This review focuses on new information regarding the pathophysiology of dense deposit disease, its appearance histopathologically, its relationship to other diseases including macular degeneration and acquired partial lipodystrophy and potential new therapies.

RECENT FINDINGS

The microscopic features of dense deposit disease have been separated into five patterns with only about 25% of patients showing membranoproliferative features. The subtle interplay between genetic changes in complement regulatory proteins and dysregulation of the alternative pathway of complement is now more evident. Haplotype mapping has shown at-risk phenotypes of complement factor H associated with the development of dense deposit disease. Treatment protocols are empiric and not very effective. New information on complement inhibitors and plasma exchange, however, has brought hope for new therapies in the near future.

SUMMARY

Understanding of the pathology and the pathophysiology of dense deposit disease has advanced rapidly in the last decade. New efforts in genetic mapping along with the development of novel inhibitors of the complement system will lead to improved care for patients afflicted with this uncommon condition.

Childhood acquired lipodystrophy: a retrospective study

OBJECTIVE

We sought to describe the clinical characteristics and complications of children with acquired lipodystrophy (LD).

METHODS

We conducted a retrospective chart review at a tertiary, academic children's hospital of children clinically given a diagnosis of acquired LD between January 1997 and December 2004.

RESULTS

During the study period, 23 patients were identified. Their mean age at diagnosis was 9.74 +/- 3.98 years. Of patients, 61% were girls. The length of the follow-up was 4.8 +/- 3.5 years from the time of LD diagnosis. Of patients, 30% had evidence of localized disease (7 of 23), 26% (6 of 23) had localized partial disease, and 44% (10 of 23) had generalized LD. The most common underlying diagnosis was dermatomyositis (78%), alone or in association with other autoimmune diseases (juvenile rheumatoid arthritis 17%). Panniculitis with autoimmunity was noted in 17% of the patients. More than half of the patients had at least one complication attributable to LD such as acanthosis nigricans (22%), hyperpigmentation (22%), hepatomegaly (13%), hypertension (13%), protuberant abdomen (9%), and hyperlipidemia (4%). The only predictor for development of complications was the age of diagnosis of LD, with younger age being associated with increased risk (7 vs 12 years, P = .04).

LIMITATIONS

Limitations were inherent to the retrospective design.

CONCLUSIONS

Childhood acquired LD is seen more frequently in the context of autoimmunity. Affected children should be monitored for the development of complications, particularly if given a diagnosis of LD at a younger age.

Role of CD95-mediated adipocyte loss in autoimmune lipodystrophy

CONTEXT

Lipodystrophies are rare disorders characterized by the selective loss of adipose tissue. Metabolic complications increase in severity with the extent of fat loss. In some forms of acquired lipodystrophy, the loss of fat is suggested to be a result of autoimmune destruction of adipocytes. Here, the pathogenic mechanism is still poorly understood.

OBJECTIVE

We have analyzed sc adipose tissue from a 5-yr-old girl with ongoing fat loss by immunohistochemistry. Using cultured human preadipocytes and adipocytes, we elucidated a possible mechanism leading to adipocyte loss in this patient.

RESULTS

Analysis of adipose tissue samples of the patient with acquired lipodystrophy obtained from skin areas affected by panniculitis suggested that loss of adipocytes was mediated by CD95-induced apoptosis. Regression of adipose tissue was accompanied by lymphohistiocytic infiltration/inflammation and increased serum levels of inflammatory cytokines interferon-gamma and TNF-alpha. In vitro studies with human adipocytes demonstrated that interferon-gamma and TNF-alpha are able to up-regulate CD95 expression and enhance CD95-death-inducing signaling complex formation resulting in a robust sensitization for CD95-mediated apoptosis.

CONCLUSION

We have identified here a possible mechanism responsible for the loss of adipocytes by apoptosis in autoimmune lipodystrophy.

Leptin replacement therapy modulates circulating lymphocyte subsets and cytokine responsiveness in severe lipodystrophy

CONTEXT

We conducted this study to understand the role of leptin therapy in immunomodulation.

OBJECTIVE

Our objective was to study lymphocyte subpopulations and in vitro peripheral blood mononuclear cell (PBMC) activation during a study evaluating the effects of leptin on metabolic functions in severe lipodystrophy (serum leptin levels < 4 ng/ml).

DESIGN AND SETTING

We conducted an open-label study with patients serving as their own control at the Clinical Research Center of the National Institutes of Health.

PATIENTS

Ten patients (age range, 15-63 yr; one male and nine females) with generalized forms of lipodystrophy were studied.

INTERVENTION

Patients were treated with recombinant human leptin to achieve high normal concentrations for 4 to 8 months.

RESULTS

Leptin levels increased from 1.8 +/- 0.4 to 16.5 +/- 3.9 ng/dl (P < 0.001), whereas metabolic control improved [glycosylated hemoglobin (HbA(1c)) fell from 9.3 +/- 0.4 to 7.1 +/- 1.4%, P < 0.001, and triglycerides decreased by 45 +/- 11% from a mean of 1490 +/- 710 mg/dl, P = 0.001]. Lymphocyte subsets were studied by flow cytometry at baseline and at 4 and 8 months of therapy. PBMC responsiveness was evaluated by cytokine release and proliferation after stimulation with phytohemagglutinin, phytohemagglutinin plus IL-12, lipopolysaccharide, and lipopolysaccharide plus interferon-gamma at baseline and 4 months. Various T lymphocyte subsets were significantly lower than age- and sex-matched controls at baseline; however, the CD4/CD8 ratio was normal. The relative percentages of B lymphocytes and monocytes were elevated, although the absolute levels were normal. Leptin therapy induced significant changes in T lymphocyte subsets, which normalized both the absolute number of T lymphocyte subsets and relative percentages of all lineages. Additionally, in vitro TNF-alpha secreted from PBMC of patients was significantly increased to normal after 4 months of leptin therapy compared with baseline.

CONCLUSION

These data support existing evidence that leptin has a modest immunomodulatory effect in hypoleptinemic humans.

Tumour necrosis factor alpha in fat redistribution syndromes associated with combination antiretroviral therapy in HIV-1-infected patients: potential role in subcutaneous adipocyte apoptosis

BACKGROUND

The pathogenesis of fat redistribution syndromes (FRS) observed in the setting of highly active antiretroviral therapy (HAART) for the treatment of HIV-1-infection remains elusive. A dysregulation of the tumour necrosis factor alpha (TNF-alpha) system occurs in HIV-infected patients with FRS.

MATERIALS AND METHODS

The study looked at both the in vivo and in vitro relationship between TNF-alpha and the degree of subcutaneous adipocyte apoptosis in 60 HIV-1-infected patients on HAART with FRS, another 60 HIV-1-infected patients on HAART without FRS and 60 uninfected control patients. Apoptosis was assessed by the terminal deoxynucleotidyl transferase dUTP (deoxyuridine 5'-triphosphate)-digoxigenin Nick End Labelling (TUNEL) method. Soluble receptors of TNF-alpha were determined by the sandwich enzyme immunoassay technique. The in vitro viability was assessed by staining with 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) and apoptosis by TUNEL.

RESULTS

HIV-1-infected patients with FRS had significantly higher degrees of subcutaneous adipocyte apoptosis than those without FRS (P = 0.0001) and uninfected controls (P < 0.0001). There was a statistically significant association between serum levels of soluble TNF-alpha receptors #1 and #2 and the degree of subcutaneous adipocyte apoptosis in patients with and without FRS (P < 0.0001 for both receptors). In vitro, the addition of TNF-alpha (10 ng mL(-1)) to an adipocyte culture embedded with indinavir, either alone or in clinically relevant combinations with stavudine (d4T) and lamivudine (3TC), significantly decreased adipocyte viability (P = 0.0001) and increased adipocyte apoptosis (P < 0.0001) with respect to that observed with the addition of antiretrovirals alone.

CONCLUSIONS

TNF-alpha plays a significant role in subcutaneous adipocyte apoptosis, which occurs in the setting of FRS in HIV-1-infected patients on highly active antiretroviral therapy.

Special coverage of the 43rd IDSA meeting. Study finds negative impact of smoking on HIV infection and immune activation

Research dating from the late 1990's has found that abnormal immune activation can lead to lipodystrophy syndrome, which now is broken down to lipoatrophy and lipohypertrophy, an investigator says.

Regulation of T cell-mediated hepatic inflammation by adiponectin and leptin

Concanavalin A-induced hepatotoxicity was compared in lipodystrophic aP2-nSREBP-1c transgenic mice (LD mice) lacking adipose tissue, obese leptin-deficient ob/ob mice, and lean wild-type (WT) mice. Serum leptin and adiponectin were low in LD mice, whereas ob/ob mice had undetectable leptin, but high adiponectin. Protection from hepatotoxicity was observed in ob/ob, but not in LD mice, despite low cytokine levels and reduced T cell activation and hepatic natural killer T cells in both groups. Administration of adiponectin protected LD mice from hepatotoxicity without altering cytokine levels. In contrast, administration of leptin heightened disease susceptibility by restoring cytokine production. Neutralization of TNF alpha protected LD mice from liver damage. Increased in vivo susceptibility to the hepatotoxic effect of TNF alpha was observed in LD mice. In vitro, adiponectin protected primary hepatocytes from TNF alpha-induced death, whereas leptin had no protective effect. In conclusion, although leptin increases susceptibility to hepatotoxicity by regulating cytokine production and T cell activation, adiponectin protects hepatocytes from TNF alpha-induced death.

A lamin A/C beta-strand containing the site of lipodystrophy mutations is a major surface epitope for a new panel of monoclonal antibodies

Using a phage-displayed peptide library, we have identified the epitope recognized by a new panel of five monoclonal antibodies (mAbs) raised against full-length recombinant human lamin A. The mAbs were found to recognize both lamin A and C by Western blotting and immunolocalization at the nuclear rim. A nine-amino acid consensus sequence PLLTYRFPP in the common immunoglobulin-like (Ig-like) domain of lamin A/C contains the binding site for all five mAbs. Three-dimensional structure of the Ig-like domain of lamin A/C shows this sequence is a complete beta-strand. This sequence includes arginine-482 (R482) which is mutated in most cases of Dunnigan-type familial partial lipodystrophy (FPLD). R482 may be part of an interaction site on the surface of lamin A/C for lamin-binding proteins associated with lipodystrophy.

Facial lipoatrophy following systemic lupus erythematosus

BACKGROUND

Acquired partial lipodystrophy is a rare disorder. An association with systemic lupus erythematosus has been reported. In these cases, an immunologic basis is suggested by the presence of C3 nephritic factor and hypocomplementemia.

OBJECTIVE

The following report presents the case of a woman who developed a rapid loss of facial subcutaneous fat a few months after complete spontaneous resolution of cutaneous lesions of lupus.

CONCLUSION

Absence of C3NeF in this case suggests that other immunological factors may be involved in the pathogenesis.

Insulin antibodies are associated with lipoatrophy but also with lipohypertrophy in children and adolescents with type 1 diabetes

AIM

To evaluate clinical and immunological factors that are associated with lipodystrophy, i.e. lipoatrophy and lipohypertrophy, in diabetic children and adolescents.

METHODS

We investigated in a cross-sectional study 112 children and adolescents (age 1.1-19.1 yrs.) with type 1 diabetes. To grade lipodystrophy, we developed a clinical score ranging from normal (grade 0), moderate hypertrophy of subcutaneous tissue (grade 1), severe hypertrophy with increased density of tissue (grade 2) to lipoatrophy (grade 3). In all children, grade of lipodystrophy, antibodies against insulin (IA) or beta cell antigens (IA-2 and GAD) and clinical parameters were documented.

RESULTS

The antibodies against insulin (IA) increased significantly after diabetes manifestation and initiation of insulin treatment, while beta cell specific antibodies (IA-2, GAD) did not. Lipoatrophy (grade 3) was seen in 4 children, severe lipohypertrophy (grade 2) in 18 and moderate lipohypertrophy (grade 1) in 27 children. No alteration of injection sites was found in 63 children. Amongst clinical and immunological parameters, IA levels were significantly associated with hypertrophy or atrophy of injection sites.

CONCLUSION

The strong association of lipoatrophy and lipohypertrophy with insulin antibodies might suggest that autoimmune phenomena with insulin play a role in the development of both. Despite an association of IA and lipodystrophy in type 1 diabetic children, the causal link between the two remains unproven and requires further longitudinal exploration.

Lipodystrophy in HIV-infected children is associated with high viral load and low CD4+ -lymphocyte count and CD4+ -lymphocyte percentage at baseline and use of protease inhibitors and stavudine

Alterations in regional fat, often associated with abnormalities in lipid and insulin metabolism, have been reported in HIV-infected adults. To determine whether similar abnormalities occur in children with HIV, patterns of change in regional body fat distribution were determined by dual energy x-ray absorptiometry in 28 prepubertal HIV-infected children. Eight (29%) children experienced lipodystrophy (LD), defined as extremity lipoatrophy together with trunk fat accumulation. Despite a mean body weight increase of 2.9 +/- 2.4 kg, children with LD experienced a mean loss of total fat in contrast to children without LD who increased total fat (-0.151 +/- 0.324 versus 0.981 +/- 1.041 kg; p <.01). Children with LD had significantly higher levels of HIV RNA and lower CD4 count and percentage at baseline. LD was associated with use of protease inhibitors or stavudine, (odds ratio [OR], 7.0, 95% confidence interval [CI], 1.1-45.2, p =.04; OR, 9.0, 95% CI, 1.4-59.8, p =.03, respectively). This observational study suggests that during a time in childhood when accumulation of extremity and trunk fat is expected, some HIV-infected children experience changes in fat distribution that are similar to HIV-associated LD reported in adults. Studies to determine whether HIV-infected children with changes in regional fat also experience increases in "atherogenic" lipids and insulin resistance as described in adults with HIV-associated LD are warranted.

A C3 convertase assay for nephritic factor functional activity

C3 nephritic factor (C3NeF) is an autoantibody against the C3 convertase which stabilizes this otherwise inherently labile neoenzyme and induces a continuous activation of the alternative pathway with C3 depletion. NeF is found in patients with membranoproliferative glomerulonephritis and/or partial lipodystrpohy. NeF activity is usually detected in plasma by hemolytic tests. In order to obtain reproducible data for the functional activity of purified C3NeF IgG a solid phase assay was developed. C3 convertase was generated on immobilized C3b by incubation with factors B and D in the presence of Ni(2+). Convertase sites were left to decay in the presence of normal IgG or NeF IgG. Residual convertase activity was measured by adding 125I-C3 and capturing nascent 125I-C3b on the plate surface via covalently coupled NH2-Glu-Tyr dipeptide. In the presence of factor H during C3 convertase decay, a dose dependent stabilizing activity was shown for NeF IgG including NeF IgG purified from urine. A second format of the assay was developed in which C3 convertase was assembled on C3b(2)-IgG complexes in the presence of Mg(2+). Since these complexes are more efficient as convertase precursors the signal was five-fold higher than with C3b. Convertase decay, on the other hand, was not influenced by the nature of the precursor and in both systems the stabilizing activity of NeF IgG was similar.

Changes in cortisol/DHEA ratio in HIV-infected men are related to immunological and metabolic perturbations leading to malnutrition and lipodystrophy

HIV-1 infection is associated with immune deficiency and metabolic perturbations leading to malnutrition and lipodystrophy. Because immune response and metabolic perturbations (protein and lipid metabolism) are partly regulated by glucocorticoids and DHEA, we determined serum cortisol and DHEA concentrations, and the cortisol/DHEA ratio in HIV-positive men, either untreated or receiving various antiretroviral treatments (ART), including highly active antiretroviral therapy (HAART). Cortisol levels were found increased in all patients, whatever the stage of the disease and independently of the ART treatment. In contrast, serum DHEA was elevated in the asymptomatic stage, and it was below normal values in AIDS patients, either untreated or mono-ART-treated. The DHEA level was low in HAART-treated patients with lipodystrophy (LD+) and highly increased in HAART-treated patients without lipodystrophy (LD-). Consequently, the cortisol/DHEA ratio was similar to controls in asymptomatic untreated or mono-ART-treated patients, but increased in AIDS patients. Interestingly, this ratio was increased in LD+ HAART-treated men, but normalized in LD- HAART-treated patients. Changes in the cortisol/DHEA ratio were negatively correlated with the in vivo CD4 T-cell counts, with the malnutrition markers, such as body-cell mass and fat mass, and with the increased circulating lipids (cholesterol, triglycerides, and apolipoprotein B) associated to the lipodystrophy syndrome. Our observations show that the cortisol/DHEA ratio is dramatically altered in HIV-infected men, particularly during the syndromes of malnutrition and lipodystrophy, and this ratio remains elevated whatever the antiretroviral treatment, including HAART. These findings have practical clinical implications, since manipulation of this ratio could prevent metabolic (protein and lipid) perturbations.

Adipose redistribution in human immunodeficiency virus-seropositive patients: association with CD4 response

We have noted that human immunodeficiency virus (HIV)-seropositive patients who develop adipose redistribution (AR) while receiving combination antiretroviral therapy (ART) also tend to have a better response to ART, as indicated by the relative change in CD4 percent compared to those who don't develop AR on therapy. Whether the possible benefits of the improved CD4 response outweigh the metabolic and cosmetic problems associated with lipodystrophy is not known.

Alteration of tumor necrosis factor-alpha T-cell homeostasis following potent antiretroviral therapy: contribution to the development of human immunodeficiency virus-associated lipodystrophy syndrome

Highly-active antiretroviral therapy (HAART) has lead to a dramatic decrease in the morbidity of patients infected with the human immunodeficiency virus (HIV). However, metabolic side effects, including lipodystrophy-associated (LD-associated) dyslipidemia, have been reported in patients treated with antiretroviral therapy. This study was designed to determine whether successful HAART was responsible for a dysregulation in the homeostasis of tumor necrosis factor-alpha (TNF-alpha), a cytokine involved in lipid metabolism. Cytokine production was assessed at the single cell level by flow cytometry after a short-term stimulation of peripheral blood T cells from HIV-infected (HIV(+)) patients who were followed during 18 months of HAART. A dramatic polarization to TNF-alpha synthesis of both CD4 and CD8 T cells was observed in all patients. Because it was previously shown that TNF-alpha synthesis by T cells was highly controlled by apoptosis, concomitant synthesis of TNF-alpha and priming for apoptosis were also analyzed. The accumulation of T cells primed for TNF-alpha synthesis is related to their escape from activation-induced apoptosis, partly due to the cosynthesis of interleukin-2 (IL-2) and TNF-alpha. Interestingly, we observed that LD is associated with a more dramatic TNF-alpha dysregulation, and positive correlations were found between the absolute number of TNF-alpha CD8 T-cell precursors and lipid parameters usually altered in LD including cholesterol, triglycerides, and the atherogenic ratio apolipoprotein B (apoB)/apoA1. Observations from the study indicate that HAART dysregulates homeostasis of TNF-alpha synthesis and suggest that this proinflammatory response induced by efficient antiretroviral therapy is a risk factor of LD development in HIV(+) patients.

Lipodystrophia centrifugalis abdominalis infantilis in a 4-year-old Caucasian girl: association with partial IgA deficiency and autoantibodies

We report the third case of lipodystrophia centrifugalis abdominalis outside East Asia. A 4-year-old Caucasian girl developed an area of bluish erythema on the left side of the lower abdomen which spread centrifugally to the umbilical and inguinal areas with depression of the skin resulting from the loss of subcutaneous fat, surrounded by an erythematous border. This unusual skin disease was characterized by clinical and histological examination. Laboratory tests revealed a partial IgA deficiency, antinuclear antibodies and IgG antibodies against gliadin.

Partial lipodystrophy, mesangiocapillary glomerulonephritis, and complement dysregulation. An autoimmune phenomenon

Partial lypodistrophy (PLD) is a rare disease in which, there is loss of fat usually from the upper part of the body. The disease is frequently associated with mesangiocapillary (membranoproliferative) glomerulonephritis Type II (MCGN II). In the early 1970s, it was noticed that MCGN II and/or PLD was sometimes associated with dysfunction of the complement system as reported in several case descriptions and studies. Subsequently, an IgG autoantibody was detected-C3 nephritic factor (C3NeF). The target of this autoantibody is the alternative pathway C3 convertase-C3bBb. There are sporadic case reports that linked PLD, MCGNII, and C3NeF with autoimmune diseases. This association may be more than a coincidence. The complement deficiency may lead to perturbation of the immune system, which may trigger some of the autoimmune diseases. This article will be focused on the association among PLD, MCGN II and C3NeF.

Localized lipoatrophia with persistent circulating autoantibodies and partial immunoglobulin A deficiency in a child

A 7-year-old Caucasian girl developed lipoatrophic areas on the abdomen and left thigh. Laboratory tests showed a partial IgA deficiency, circulating autoantibodies (ANAs, double- and single-stranded anti-DNAs, rheumatoid factor). The clinical aspect resembles lipodystrophia centrifugalis abdominalis infantilis, but autoimmune abnormalities suggest connective tissue panniculitis which underlines the overlap between the different forms of localized lipoatrophias.

A patient with one limb interstitial myositis with localised lipoatrophy presenting with severe cramps and fasciculations

A case of interstitial myositis associated with a localised lipoatrophy is reported. The patient is a 24 year old man who presented with severe painful cramps and fasciculations localised to one limb. The rarity of both disorders, and their likely common autoimmune mechanism, suggest that this is not a chance association.

Complement-mediated adipocyte lysis by nephritic factor sera

Recent data indicate a previously unsuspected link between the complement system and adipocyte biology. Murine adipocytes produce key components of the alternative pathway of complement and are able to activate this pathway. This suggested to us an explanation for adipose tissue loss in partial lipodystrophy, a rare human condition usually associated with the immunoglobulin G(IgG) autoantibody nephritic factor (NeF) which leads to enhanced alternative pathway activation in vivo. We hypothesized that in the presence of NeF, there is dysregulated complement activation at the membrane of the adipocyte, leading to adipocyte lysis. Here we show that adipocytes explanted from rat epididymal fat pads are lysed by NeF-containing sera but not by control sera. A similar pattern is seen with IgG fractions of these sera. Adipocyte lysis in the presence of NeF is associated with the generation of fluid-phase terminal complement complexes, the level of which correlates closely with the level of lactate dehydrogenase, a marker of cell lysis. Lysis is abolished by ethylenediaminetetraacetic acid, which chelates divalent cations and prevents complement activation, and reduced by an antibody to factor D, a key component of the alternative pathway. These data provide an explanation for the previously obscure link between NeF and fat cell damage.

Molecular analysis of C3 allotypes in patients with nephritic factor

The autoantibody nephritic factor (NeF) leads to complement consumption in vivo and is associated with type II mesangiocapillary glomerulonephritis (MCGN II) and partial lipodystrophy (PLD). The third component of complement (C3) exists in two common allotypic forms, C3S and C3F, distinguished at the protein level by electrophoresis. An increased frequency of the rarer C3F allele has been reported in several autoimmune conditions, including one small series of patients with NeF. However, patients with NeF have low levels of circulating C3 so that allotyping at the protein level is difficult. The molecular basis of the S/F polymorphism has recently been established: a single base change at the DNA level encodes a single amino acid substitution at the protein level. A second polymorphism, closely linked to the first, is defined by the MoAb HAV 4-1, and is also due to a single base change. These polymorphisms can therefore be analysed at the DNA level. We have used the amplification refractory mutation system (ARMS), a modification of the polymerase chain reaction (PCR), to analyse these two C3 polymorphisms at the DNA level in 26 patients with NeF. The allele frequencies of C3S and C3F were 0.673 and 0.327 (predicted values 0.79 and 0.2, chi 2 = 4.813, P < 0.05), giving a relative risk of 2.1 for the development of NeF conferred by the presence of a C3F allele. The HAV 4-1 allele frequencies were (-) 0.71 and (+) 0.29, i.e. not significantly different than predicted from the linked C3S/F allele frequencies. This is the largest series of patients with NeF yet published, and our data confirm an association between C3F and NeF. Possible mechanisms for for this link are discussed.

Two types of C3 nephritic factor: properdin-dependent C3NeF and properdin-independent C3NeF

The IgG fraction of serum from patients with membranoproliferative glomerulonephritis (MPGN) types I and II or partial lipodystrophy (PLD) was found to contain C3 nephritic factor (C3NeF) which reacts with the alternative pathway C3 convertase C3bBb and stabilizes it. Two types of C3NeF were detected, of which one was heat sensitive (56 degrees C for 30 min) and properdin dependent (C3NeF:P) but the other was heat stable and properdin independent (C3NeF:nP). C3NeF:P was found in sera from patients with MPGN types I and II and it displayed the properties of properdin and IgG. C3NeF:P was observed in patients with reduced serum concentrations of C3 and terminal complement components (TCC), and the generation of SC5b-9 complex was increased in mixtures with normal human serum. C3NeF:nP was found in sera from patients with MPGN type II and PLD, whose sera revealed a selective decrease in C3 concentrations.

[Production of C3 nephritic factor by cultured lymphocytes derived from glomerulonephritic patients]

C3 nephritic factor (C3 NeF) has been found mainly in the sera of patients with membranoproliferative glomerulonephritis (MPGN) and partial lipodystrophy (PLD). We examined whether peripheral blood mononuclear cells (PBMC) from patients with PLD and MPGN could produce C3 NeF. We investigated the in vitro immunoglobulin synthesis of PBMC with mitogen. We further studied whether or not C3 NeF was included in the IgG of the culture supernatants by the C3bBb stabilizing activity and agglutination assay. The IgG of PLD patient was able to agglutinate only EAC4bBb cells and none of the other intermediate cells. We thus demonstrated that C3 NeF could be produced in vitro by PBMC derived from the patient with PLD. However, as regard case of C3 NeF weakly positive and C3 NeF negative patients, C3 NeF couldn't be produced in vitro by PBMC derived from the patients.

Systemic lupus erythematosus in a patient with partial lipodystrophy

Systemic lupus erythematosus developed in a 35-year-old woman who had partial lipodystrophy since she was 7 years old. To our knowledge, this association has been reported only once. She also had hypocomplementemia, mesangiocapillary glomerulonephritis type II, and a serum assay with positive results for C3 nephritic factor. The association of partial lipodystrophy with other autoimmune disorders suggests an immunologic pathogenesis for this disease.

Congenital lipodystrophy with defective leucocyte function (a case report)

A 6 1/2 year old female child with congenital lipodystrophy is being presented. The noteworthy feature in this case was the defective leucocyte function and its association with tuberculous pericardial effusion.

Production of C3 nephritic factor by cultured lymphocytes derived from a patient with partial lipodystrophy

C3 nephritic factor (C3 NeF) has been found mainly in the sera of patients with membranoproliferative glomerulonephritis (MPGN) and partial lipodystrophy (PLD). We examined whether peripheral blood mononuclear cells (PBMC) from a patient with PLD could produce C3 NeF. We investigated the in vitro immunoglobulin synthesis of PBMC with mitogen. We further studied the C3bBb stabilizing activity and undertook agglutination assays of the IgG obtained from the culture supernatants. The patient IgG was able to agglutinate only EAC4b3bBb cells and none of the other intermediate cells. We this demonstrated that C3 NeF could be produced in vitro by PBMC derived from a patient with PLD.

C3 nephritic factor (C3NeF): dissociation of cell-bound and fluid phase stabilization of alternative pathway C3 convertase

Fluid phase C3 conversion by C3 nephritic factor (C3NeF) is usually easily detectable and forms the basis of the C3NeF screening test. We have described a group of patients with membranoproliferative glomerulonephritis or partial lipodystrophy and hypocomplementaemia who have an unusual C3NeF which stabilizes cell-bound C3 convertase of the alternative pathway (C3bBb) but causes such weak fluid phase C3 conversion that a C3NeF screening test is negative. These patients have low concentrations of C5 in serum.

Effect of nephritic factor on C3 and on the terminal pathway of complement in vivo and in vitro

Plasma samples from patients with nephritic factor (NeF) were examined for their C3 converting activity. C3, C3dg, C5 and the fluid phase terminal complement complex (TCC) were quantified. All patients had evidence of C3 activation with low plasma C3 and high C3dg. Some patients had normal C5 and normal TCC levels, and thus no evidence of terminal pathway activation in vivo; others, with slower C3 conversion in vitro, had low C5 levels with TCC either elevated or in the upper normal range, suggesting in vivo activation of the terminal pathway. These observations were confirmed by in vitro experiments using purified NeFs. It is concluded that considerable activation of C3 may occur in vivo without a simultaneous activation of the terminal pathway, and that NeF is heterogeneous with regard to its ability to activate complement.

The histopathology of localized lipoatrophy

We studied 11 patients with the clinical diagnosis of lipoatrophy and found two histopathological subsets. Six patients presented with a distinctive picture, which we termed 'involutional' fat, consisting of lobules of small lipocytes embedded in hyaline connective tissue with numerous capillaries. Five of these six patients had a single lesion, usually of the upper arm. Serological studies were normal, and direct immunofluorescence, performed in three cases, showed immunoreactants in the blood vessels in only one. The four patients with inflammation of the fat had multiple areas of localized lipoatrophy. Three had biopsies for direct immunofluorescence and all three showed immunoreactants involving the basement membrane zone (two cases) or blood vessels (one case); and three had serological abnormalities. We suggest that the involutional histopathological pattern is a distinctive subset of localized lipoatrophy.

Myasthenia gravis associated with lipodystrophy

Patients with partial lipodystrophy frequently show hypocomplementemia but rarely have associated autoimmune diseases. We report here a patient of myasthenia gravis associated with limb lipodystrophy, a variant form of partial lipodystrophy, and hypocomplementemia.

Physiologic inactivation of fluid phase C3b: isolation and structural analysis of C3c, C3d,g (alpha 2D), and C3g

The fragments that result from the inactivation of C3b have not been completely characterized. Initial inactivation is catalyzed by the protease factor I, which, in the presence of its cofactor (factor H), cleaves two peptide bonds in the alpha'-chain of C3b. This results in the release of a small peptide (C3f, Mr 3000) from iC3b, which consists of the C3 beta chain covalently bonded to two alpha'-chain-derived peptides (Mr 68,000 and Mr 43,000). Surface-bound iC3b is cleaved at a third site by factor I to produce C3c and C3d,g (or alpha 2D). The factor I cofactor for this cleavage is the C3b receptor that is present on erythrocyte and leukocyte membranes. This report describes the isolation and initial structural characterization of C3c and C3d,g generated in whole blood after complement activation with cobra venom factor. These fragments were compared with the C3 fragments isolated from the serum and plasma of a patient with complement activation in vivo. The fragments were isolated with two solid phase monoclonal antibodies, one of which recognizes a determinant on C3g (clone 9) and one of which recognizes a determinant on C3c (clone 4). C3c isolated from normal blood showed three polypeptides that had apparent m.w. of 75,000, 43,000, and 27,000. The C3d,g consisted of a single polypeptide chain with a m.w. of 40,000. Amino terminal sequence analysis showed that the Mr 27,000 peptide from C3c is derived from the amino terminal portion of the alpha'-chain of C3b, whereas the Mr 43,000 peptide is derived from the carboxy terminus of the same chain. Amino terminal sequence analysis showed also that C3g is derived from the amino terminus of C3d,g. The C3 fragments isolated from a patient with partial lipodystrophy, nephritic factor activity, low serum C3 levels, and circulating C3 cleavage products showed a more complicated pattern on SDS-PAGE. The fragment isolated with clone 9 had an apparent m.w. of 40,000, identical to C3d,g generated in vitro, and it had the same amino terminal sequence as C3d,g generated in vitro. The eluate from insolubilized clone 4, however, showed prominent bands with Mr of 75,000, 56,000, 43,000, and 27,000, together with a triple-banded pattern at 68,000 and a minor band at 80,000. This eluate thus appears to contain C3c, and iC3b or an iC3b-like product. The origin of the Mr 56,000 and Mr 80,000 peptides have not yet been determined. These studies, with previous data, definitively order the C3c and C3d,g peptides in the alpha-chain of C3.(ABSTRACT TRUNCATED AT 400 WORDS)

Panniculitis in connective tissue disease

Specific and nonspecific panniculitis occur in connective tissue diseases. Microscopic studies of the epidermis and dermis, immunofluorescent microscopy, and extensive serologic testing may aid in the diagnosis and classification of these unusual syndromes. Connective tissue panniculitis and focal lipoatrophy may be forms of immunoreactive panniculitis or connective tissue disease (or both) in which typical microscopic, serologic, or other events related to classic connective tissue disease have not occurred.