Association of postalimentary lipemia with atherosclerotic manifestations

We identified different lipemic and metabolic responses after the ingestion of a standardized meal by healthy adults and related them to atherosclerotic markers. Samples from 60 normolipidemic adults were collected before and after a liquid meal (40 g fat/m² body surface) at 0, 2, 4, 6, and 8 h for measurements of lipids, free fatty acids (FFA), insulin, cholesteryl ester transfer protein (CETP), autoantibodies to epitopes of oxidized LDL (oxLDL Ab), lipolytic activities, and apolipoprotein E polymorphism. Mean carotid intima-media thickness (cIMT) was determined by Doppler ultrasound. The volunteers were classified into early (N = 39) and late (N = 31) triacylglycerol (TAG) responders to the test meal. Late responders showed lower HDL cholesterol concentration at fasting and in the TAG peak, lower insulin and higher FFA concentrations compared to early responders. Multivariate regression analyses showed that mean cIMT was associated with gender (male) and age in early responders and by cholesterol levels at the 6th hour in late responders. oxLDL Ab were explained by lipoprotein lipase and negatively by hepatic lipase and oxLDL Ab (fasting period) by CETP (negative) and FFA (positive). This study is the first to identify a postalimentary insulin resistance state, combined with a reduced CETP response exclusively among late responders, and the identification of the regulators of postalimentary atherogenicity. Further research is required to determine the metabolic mechanisms described in the different postalimentary phenotypes observed in this study, as well as in different pathological states, as currently investigated in our laboratory.

Incapacitação e qualidade de vida não são influenciadas pela prevalência de autoanticorpos em pacientes com artrite reumatoide inicial - resultados da Coorte Brasília

INTRODUÇÃO: Embora muitos estudos sugiram que a presença de autoanticorpos, tais como fator reumatoide (FR) e/ou antipeptídeos citrulinados cíclicos (anti-CCP), sejam preditores de danos articulares na artrite reumatoide (AR), a associação entre os questionários de incapacidade e de qualidade de vida ainda são desconhecidos. OBJETIVOS: Avaliar a correlação entre os questionários Health Assessment Questionnaire (HAQ) e Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) com marcadores como FR, anti-CCP e antivimentina citrulinada (anti-Sa). PACIENTES E MÉTODOS: Foram avaliados no momento do diagnóstico 65 pacientes da Coorte Brasília com AR inicial. Foram realizadas sorologias (ELISA) para FR (IgM, IgG e IgA), anti-CCP (CCP2, CCP3 e CCP3.1) e anti-Sa, com a aplicação do HAQ e SF-36 na avaliação inicial. RESULTADOS: A idade média foi de 45 anos, predominando o gênero feminino (86%). Na avaliação inicial, o FR foi positivo em 32 indivíduos (49,23%); anti-CCP em 34 indivíduos (52,3%); e anti-Sa em nove indivíduos (13,8%). O escore inicial do HAQ foi de 1,8. Os escores dos domínios do SF-36 foram: emocional, 19,3; social, 43,1; dor, 25,43; estado geral, 57,6; saúde mental, 48,1; vitalidade, 49,5; físico, 4,6; e limitação por aspecto físico, 24,7. HAQ e escores do SF-36 não variaram com os níveis de autoanticorpos. CONCLUSÃO: Muitos pacientes com AR inicial apresentam comprometimento na qualidade de vida relacionada aos domínios da capacidade física e mental. Embora FR e anti-CCP tenham sido relacionados com dano articular e pior prognóstico clínico, não há correlação entre os questionários e as avaliações da qualidade de vida e incapacidade.

Anticorpos anti-C1q, anticromatina/nucleossomo e anti-dsDNA em pacientes com lúpus eritematoso sistêmico juvenil

OBJETIVO: Avaliar a presença de anticorpos anti-C1q, anticromatina/nucleossomo e anti-DNA de duplo filamento (dsDNA) em pacientes com lúpus eritematoso sistêmico juvenil (LESJ) e controles. MÉTODOS: Foram analisados 67 pacientes com LESJ e 34 controles saudáveis para presença de anticorpos anti-C1q, anticromatina/nucleossomo e anti-dsDNA pelo método ELISA. Os níveis de C1q foram avaliados por imunodifusão radial. RESULTADOS: Na época, a média de idade era similar entre os pacientes com LESJ e os controles (14,6 ± 3,86 vs. 13,6 ± 2,93 anos; P = 0,14). Foram observadas frequências mais altas de anticorpos anti-C1q, anticromatina/nucleossomo e anti-dsDNA em pacientes com LESJ em relação aos controles (20% vs. 0%; P = 0,0037; 48% vs. 0%; P < 0,0001 e 69% vs. 3%; P < 0,0001, respectivamente). A mediana dos anticorpos anti-C1q, anticromatina/nucleossomo e anti-dsDNA também foi significativamente mais alta em pacientes com LESJ em relação aos controles [9,6 (5,5-127) vs. 7,5 (5-20) unidades, P = 0,0006; 18 (1,9-212) vs. 3,2 (1,7-17) unidades, P < 0,0001; e 111 UI/mL (6-741) vs. 14 (6-33) UI/mL, P < 0,0001, respectivamente]. A sensibilidade para os anticorpos anti-C1q, anticromatina/nucleossomo e anti-dsDNA foi: 21% (IC: 11-33), 49% (IC: 36-62) e 70% (IC: 57-81). A especificidade foi de 100% (IC: 88-100), 100% (88-100) e 97% (IC: 83-99), respectivamente. Foi observada uma correlação positiva entre os níveis de anti-dsDNA e tanto anticorpos anti-C1q (r = 0,51; IC: 0,29-0,68; P < 0,0001) como anticromatina/nucleossomo (r = 0,87; IC: 0,79-0,92; P < 0,0001). Foi observada uma correlação negativa entre os níveis de anti-C1q e C1q (r = -0,33; IC: -0,56-0,05; P = 0,018). A frequência de anti-dsDNA foi mais alta em pacientes com SLEDAI-2K > 1 (P = 0,0047), e não foram observadas diferenças nas frequências desses três autoanticorpos e nefrite (P > 0,05). CONCLUSÃO: Nosso estudo demonstrou elevada especificidade para diagnóstico de lúpus envolvendo os três autoanticorpos, especialmente anti-C1q e anticromatina/nucleossomo.

PReS-FINAL-2177: Safety and lack of autoantibody production following influenza H1N1 vaccination in patients with juvenile idiopathic arthritis (JIA)

Introduction Vaccination is an effective tool against several infectious agents including influenza. In 2010, the Advisory Committee on Immunization Practices (ACIP) recommended influenza A H1N1/2009 immunization for high risk groups, including juvenile idiopathic arthritis (JIA) patients and more recently the EULAR task force reinforced the importance of vaccination in immunosuppressed pediatric rheumatologic patients. We have recently shown that Influenza A H1N1/2009 vaccination generated protective antibody production with short-term safety profile among 93 JIA patients, but the possible impact of the vaccine in autoimmune response in JIA have not been studied. Therefore, we aimed to assess the production of some autoantibodies generated following influenza H1N1 vaccination in JIA patients. Objectives To assess the autoimmune response and H1N1 serology following influenza H1N1 vaccination in patients with JIA. Methods Cepa A/California/7/2009 (NYMC X-179A) anti-H1N1 was used to vaccinate JIA patients: 1 dose of immunization was given to all participants and those <9yrs of age received a second booster 3 weeks apart. Sera were analyzed before and 3 weeks following complete vaccination. Serology against H1N1 virus was performed by hemagglutination inhibition antibody assay, rheumatoid factor (RF) by latex fixation test, antinuclear antibodies (ANA) by IIF, IgM and IgG anticardiolipin (aCL) by ELISA.Results Among 98 JIA patients that were vaccinated, 58 sera were available for this study. Mean age of 58 JIA patients was 23.9 ± 9.5 yrs, 38 were females and 20 males with mean disease duration of 14.7 ± 10.1 yrs. JIA subtypes were: 33 (57%) poliarticular, 10 (17%) oligoarticular, 6 (10%) systemic and 9 (16%) other. Sixteen patients were off drugs while 42 (72%) were under different pharmacotherapy: 32 (55%) were on 1 DMARD/IS, 10 (17%) on 2 DMARDs/IS, 19 (33%) antimalarials, 29 (50%) MTX, 8(14%) sulfasalazine, 6 (10%) anti-TNFs, 4 (7%) abatacept; no patient was using prednisone >0.5 mg/kg/d. Seroprotection rates against H1N1 influenza increased from 23 to 83% and seroconversion rates were achieved in 78% JIA. Prior to vaccination, 31(53.4%) JIA patients were ANA+, 6(10.3%) RF+, and 4 (7%) IgM + IgG aCL+. After complete H1N1 vaccination, positivity for ANA remained the same whereas 1 patient became negative for IgG aCL, and another for RF, IgM and IgG aCL. One (1.7%) patient turned low titer IgG aCL+. Conclusion Vaccination of JIA patients against pandemic influenza A (H1N1) generated successful protective antibody production without the induction of autoantibody production, except for 1 patient that became positive for low titer IgG aCL, supporting its safety.

Adaptive immunity is related to coronary artery disease severity after acute coronary syndrome in subjects with metabolic syndrome

Metabolic syndrome (MetS) is an inflammatory state associated with high coronary disease risk. Inflammation and adaptive immunity modulate atherosclerosis and plaque instability. We examined early changes in anti-oxidized lowdensity lipoprotein (LDL) (anti-oxLDL) autoantibodies (Abs) in patients with MetS after an acute coronary syndrome (ACS). Patients of both genders (n=116) with MetS were prospectively included after an acute yocardial infarction (MI) or hospitalization due to unstable angina. Anti-oxLDL Abs (IgG class) were assayed at baseline, three and six weeks after ACS. The severity of coronary disease was evaluated by the Gensini score. We observed a decrease in anti-oxLDL Abs titers (p<0.002 vs. baseline), mainly in males (p=0.01), in those under 65 y (p=0.03), and in subjects with Gensini score above median (p=0.04). In conclusion, early decrease in circulating anti-oxLDL Abs is associated with coronary disease severity among subjects with MetS.

Antismooth Muscle and Antiactin Antibodies Are Indirect Markers of Histological and Biochemical Activity of Autoimmune Hepatitis

Reactivity and titers of autoantibodies vary during the course of autoimmune hepatitis (AIH), and some autoantibodies have been associated with disease activity and adverse outcomes after treatment. The aim of this study was to assess the autoantibody behavior in AIH and its significance as predictors of biochemical and histological remission. A total of 117 patients with AIH (mean age 18.6 [4-69] years) were evaluated and tested for auto- antibodies at disease onset and successively (mean 3.2 [2-6] times) after a mean follow-up evaluation of 70 [20-185] months. Antismooth muscle (ASMA), antiliver kidney micro- some type 1 (anti-LKM1), antiliver cytosol type 1 (anti-LC1), antimitochondrial, antinu- clear (ANA), and antiactin antibodies (AAA) were determined at disease onset and 379 other times during the follow-up evaluation through indirect immunofluorescence in rodent tissues, HEp-2 cells, and human fibroblasts. Anti-SLA/LP were assessed 45 times in the follow-up evaluation of 19 patients using enzyme-linked immunosorbent assay (ELISA). Upon admission, AIH types 1 and 2 were observed in 95 and 17 patients, respectively. Five subjects had AIH with anti-SLA/LP as the sole markers. Patients initially negative for AAA did not develop these antibodies thereafter. ANA were detected de novo in six and three subjects with AIH types 1 and 2, respectively. After treatment, only ASMA ( > 1:80) and AAA ( > 1:40) were significantly associated with biochemical (76.9% and 79.8%) and histological features (100% and 100%) of disease activity ( P < 0.001). Conclusion: With the exception of ANA, the autoantibody profile does not markedly vary in the course of AIH. The persistence of high titers of ASMA and/or AAA in patients with AIH is associated with disease activity.

Humoral autoimmune response heterogeneity in the spectrum of primary biliary cirrhosis

Objective To compare autoantibody features in patients with primary biliary cirrhosis (PBC) and individuals presenting antimitochondria antibodies (AMAs) but no clinical or biochemical evidence of disease. Methods A total of 212 AMA-positive serum samples were classified into four groups: PBC (definite PBC, n = 93); PBC/autoimmune disease (AID; PBC plus other AID, n = 37); biochemically normal (BN) individuals (n = 61); and BN/AID (BN plus other AID, n = 21). Samples were tested by indirect immunofluorescence (IIF) on rat kidney (IIF-AMA) and ELISA [antibodies to pyruvate dehydrogenase E2-complex (PDC-E2), gp-210, Sp-100, and CENP-A/B]. AMA isotype was determined by IIF-AMA. Affinity of anti-PDC-E2 IgG was determined by 8 M urea-modified ELISA. Results High-titer IIF-AMA was more frequent in PBC and PBC/AID (57 and 70 %) than in BN and BN/AID samples (23 and 19 %) (p < 0.001). Triple isotype IIF-AMA (IgA/IgM/IgG) was more frequent in PBC and PBC/AID samples (35 and 43 %) than in BN sample (18 %; p = 0.008; p = 0.013, respectively). Anti-PDC-E2 levels were higher in PBC (mean 3.82; 95 % CI 3.36–4.29) and PBC/AID samples (3.89; 3.15–4.63) than in BN (2.43; 1.92–2.94) and BN/AID samples (2.52; 1.54–3.50) (p < 0.001). Anti-PDC-E2 avidity was higher in PBC (mean 64.5 %; 95 % CI 57.5–71.5 %) and PBC/AID samples (66.1 %; 54.4–77.8 %) than in BN samples (39.2 %; 30.9–37.5 %) (p < 0.001). PBC and PBC/AID recognized more cell domains (mitochondria, nuclear envelope, PML/sp-100 bodies, centromere) than BN (p = 0.008) and BN/AID samples (p = 0.002). Three variables were independently associated with established PBC: high-avidity anti-PDC-E2 (OR 4.121; 95 % CI 2.118–8.019); high-titer IIF-AMA (OR 4.890; 2.319–10.314); antibodies to three or more antigenic cell domains (OR 9.414; 1.924–46.060). Conclusion The autoantibody profile was quantitatively and qualitatively more robust in definite PBC as compared with AMA-positive biochemically normal individuals.

Mercury-induced autoimmunity : Genetics and immunoregulation

The existence of immune self-tolerance allows the immune system to mount responses against infectious agents, but not against self-molecular constitutes. Although self-tolerance is a robust phenomenon, in some individuals as well as in experimental models, the self-tolerance breaks down and as a result, a self-destructive autoimmune disease emerges. The underlying mechanisms for the development of autoimmune diseases are not known, but genetic, environmental and immunological factors are suggested to be involved. In this thesis, we used murine mercury-induced autoimmunity to test this suggestion. In susceptible mice mercuric chloride induces a systemic autoimmune disease characterized by increased serum levels of IgG1 and IgE, production of anti-nucleolar autoantibodies (ANolA) and formation of renal IgG deposits. In contrast, in resistant DBA/2 (H-2d) mice, none of these characteristics develop after exposure to mercury. By crossing and backcrossing mercury-resistant DBA/2 mice to mercury susceptible strains, we found that the resistance was inherited as a dominant trait in F1 hybrids and that one gene or a cluster of genes located in the H-2 loci determined the resistance to ANolA production, whereas resistance to the other characteristics was found to be controlled by two or three non-H-2 genes. We further put forward the “cryptic peptide hypothesis” to investigate whether mercury and another xenobiotic metal use similar pathway(s) to induce the H-2 linked production of ANolA. We found that while mercury stimulated ANolA synthesis in all H-2 susceptible (H-2s, H-2q and H-2f) mouse strains, silver induced only ANolA responses in H-2s and H-2q mice, but not in H-2f mice. Further studies showed that the resistance to silver-induced ANolA production in H-2f mice was inherited as a dominant trait. We next tested the proposition that mercury induces more adverse immunological effects in mouse strains, which are genetically prone to develop autoimmune diseases, using tight-skin 1 mice, an animal model for human Scleroderma. It was found that in this strain, mercury induced a strong immune activation with autoimmune characteristics, but did not accelerate the development of dermal fibrosis, a characteristic in Tsk/1 mice. Finally we addressed the Th1/Th2 cross-regulation paradigm by examining if a Th1-type of response could interact with a Th2-type of response if simultaneous induced in susceptible mice. Our findings demonstrated that mercury-induced autoimmunity (Th2-type) and collagen-induced arthritis (CIA) (Th1-type) can interact in a synergistic, antagonistic or additive fashion, depending on at which stage of CIA mercury is administered.

Pathomechanische Analysen zum Untergang retinaler Ganglienzellen im experimentellen autoimmunen Glaukom-Modell

In den vergangenen Jahren konnten zahlreiche Studien die Veränderung des natürlichen Autoantikörperrepertoirs bei Glaukompatienten aufzeigen. Zu den Antigenen zählen verschiedenen Hitzeschockproteinen, aber ebenso neuronal assoziierte Strukturproteine wie das Myelin basische Protein (MBP) oder das sauren Gliafaserprotein und einige neuropyhsiologische Proteine aus der Retina und dem Sehnerven. Da bei den Glaukompatienten nicht einzelne Antikörperreaktionen verändert sind, sondern vielmehr komplexe Autoantikörpermuster vorliegen, bestand das primäre Ziel der Dissertation zu zeigen, ob eine systemische Immunisierung mit MBP, Homogenaten opticus-assoziierter Antigene (ONA) und Antigenen der retinalen Ganglienzellschicht (RGA) den Verlust von retinalen Ganglienzellen (RGZ) in einem Experimentellen Autoimmunen Glaukom (EAG) Tiermodell auslösen können. Die systemische Injektion von MBP, ONA oder RGA induzierten ophthalmopathologische Veränderungen in der Retina, gekennzeichnet durch retinalen Ganglienzellverlust mitsamt Zerstörung der Axone im Sehnerv. Unter der Annahme, dass die Neurodegeneration durch Autoantiköper vermittelt ist, wurde ebenfalls untersucht, ob sich die Antikörperreaktivität gegen okulare Strukturen oder den Sehnerv im Verlauf der Studie verändern. Getestet wurde die Antikörperreaktivität gegen Gewebsschnitte gesunder Tiere mit dem Ergebnis einer signifikanten und zeitabhängigen Zunahme der Immunreaktivität. Darüber hinaus war es erstmals möglich die Ablagerung von IgG Autoantikörpern in der Retina und dem Sehnerv nachzuweisen sowie die Caspase mediierte Apoptose zu untersuchen. Ebenfalls konnte die Verteilung von aktivierten Mikroglia im optischen System evaluiert werden, wobei diese mehrmals in Kolokalisation mit den IgG-Autoantikörpern auftraten. Diese Beobachtungen lassen den Schluss zu, dass die Immunreaktionen von Autoantikörpern alleine und im Zusammenspiel mit der Mikroglia im Zusammenhang mit der Neurodegeneration der retinalen Ganglienzelle im EAG Modell stehen könnten.

Valutazione dell'efficacia di methotrexate e sua influenza sui titoli anticorpali patogenetici nei pazienti affetti da pemfigoide bolloso

Studio osservazionale condotto presso la Dermatologia dell'Università di Bologna atto a valutare l'efficacia di methotrexate e, in particolare, la sua influenza sui titoli degli autoanticorpi patogeni nei pazienti affetti dalla malattia rara Pemfigoide Bolloso

Untersuchungen zur autoimmunen Genese der thrombotisch thrombozytopenischen Purpura

Untersuchungen zur autoimmunen Genese der thrombotisch thrombozytopenischen Purpura. rnEinführung: Die idiopathische thrombotisch thrombozytopenische Purpura (TTP) ist eine lebensbedrohliche Mikroangiopathie und wird durch ein Autoantikörper-induziertes Defizit der ADAMTS13-Protease ausgelöst. Eine Assoziation zwischen Krankheitsprädisposition und Vorliegen bestimmter humaner Leukozytenantigene (HLA) wird vermutet. Untersuchungen zu diesem Zusammenhang stellen einen Teil dieser Arbeit dar. rnAutoimmunkrankheiten tendieren zum gemeinsamen Auftreten innerhalb eines Individuums. Im zweiten Teil dieser Arbeit wird untersucht, ob eine solche Kookkurrenz verschiedener Autoimmunkrankheiten auch bei Patienten mit idiopathischer TTP beobachtet werden kann.rnMethodik: Zur Untersuchung der ersten Fragestellung werden die HLA-Klasse I und II-Merkmale von 54 deutschen TTP-Patienten bestimmt. Alle Patienten weisen Autoantikörper gegen ADAMTS13 und eine Protease-Aktivität <5% vor. Die Blutproben werden mittels Sequence Specific Primer-Polymerase Chain Reaction (PCR) und Sequence Specific Oligonucleotid-PCR auf HLA-DRB1, -DRB3-5 und –DQB1 untersucht. Als Referenz dienen die Werte deutscher Knochenmark- und Blutspender, erhalten über www.allelefrequencies.net. Die statistische Auswertung erfolgt mittels zweiseitigem Binomialtest und die resultierenden p-Werte werden nach Benjamini-Hochberg korrigiert.rnZur Beantwortung der zweiten Fragestellung werden 76 deutsche TTP-Patienten anhand eines standardisierten Fragebogens nach Begleiterkrankungen befragt. Als Vergleichswerte dient die Prävalenz der jeweiligen Erkrankung in der Allgemeinbevölkerung. Die statistische Auswertung erfolgt mittels zweiseitigem Binomialtest. Da die p-Werte nicht korrigiert werden, sind die Ergebnisse nur deskriptiv zu verstehen.rnErgebnis: Der Vergleich der HLA-Frequenzen ergibt ein signifikant gehäuftes Vorkommen von HLA-DQB1*02:02 (p<0,001) und -DRB1*11 (p=0,003) innerhalb des Patientenkollektivs. 20% (DQB1*02:02) bzw. 48,1% (DRB1*11) der TTP-Patienten sind im Gegensatz zu nur 1,2% (DQB1*02:02) bzw. 23,5% (DRB1*11) innerhalb der Vergleichsgruppe für das jeweilige HLA-Merkmal positiv.rnDie Befragung der TTP-Patienten bezüglich weiterer Erkrankungen ergab im Vergleich mit der Allgemeinbevölkerung fünf auffällig häufig im Patientenkollektiv vorkommende Autoimmunkrankheiten: Hashimoto Thyreoiditis (23,5% in der Patientengruppe zu 0,7% in der Allgemeinbevölkerung; p<0,001), systemischer Lupus erythematodes (6,5% der Patienten im Gegensatz zu 0,025% in der Allgemeinbevölkerung, p<0,001), Immunthrombozytopenie (6,3% der Patienten zu 0,02% in der Allgemeinbevölkerung; p<0,001), Psoriasis (9,4% der Patienten zu 2,5% in der Allgemeinbevölkerung; p=0,005) und glutensensitive Enteropathie (3,1% der Patienten zu 0,2% in der Allgemeinbevölkerung; p=0,007). rnSchlussfolgerung: Das vermehrte Vorkommen bestimmter HLA-Merkmale im Patientenkollektiv spricht für eine prädisponierende Wirkung dieser Antigene im Krankheitsgeschehen. Eine mögliche HLA-vermittelte Assoziation zwischen TTP und den genannten Autoimmunkrankheiten wird vermutet, kann jedoch nicht in allen Fällen die beobachtete Kookkurrenz ausreichend erklären. Insgesamt bestätigt die vorliegende Arbeit die Assoziation verschiedener Autoimmunkrankheiten untereinander und spricht für eine genetische Prädisposition zur Ausbildung autoimmuner Störungen. rn

Pemphigus herpetiformis: analysis of the autoantibody profile during the disease course with changes in the clinical phenotype

Pemphigus herpetiformis (PH) is a rare dapsone-responsive variant of pemphigus, characterized by annular and vesiculopustular cutaneous lesions. Most PH serum samples contain autoantibodies against desmoglein (Dsg)1, but not Dsg3, and the presence of the latter is almost invariably associated with mucosal involvement, as predicted based on the 'Dsg compensation theory'. We describe a patient with features characteristic of PH with histologically eosinophilic spongiosis who repeatedly tested positive for anti-Dsg3 but not anti-Dsg1 autoantibodies by ELISA. To investigate whether the peculiar clinical phenotype was due to a distinct immunological profile, the patient's serum was tested by ELISA and immunoblotting using recombinant forms of Dsg3. Serum samples were found to have low and high reactivity against the EC1 and the EC4 domains of Dsg3, respectively, whereas the autoantibodies belonged predominantly to the IgG1 and IgG4 subclasses. The overall immunological profile was typical of pemphigus vulgaris. The patient finally developed isolated oral erosions 22 months after initial presentation, without significant changes in the autoantibody profile and of the targeted antigenic sites. Our patient presented features characteristic of PH. Although circulating anti-Dsg3 antibodies were present, the patient had only cutaneous involvement for a long period. Our findings indicate that the proposed Dsg compensation theory cannot always explain the clinical phenotype, changes in which may occur without apparent modification of the autoantibody profile and antibody specificity. Hence, additional factors, such as Fcgamma-dependent neutrophil activation, may critically affect the clinical presentation of pemphigus.

[Which clinical symptoms suggest distinct autoantibody measurements?]

The detection of autoantibodies is an important cornerstone in the diagnosis of systemic autoimmune disorders such as autoimmune connectivitides and small vessel vasculitides. Antinuclear antibodies (ANAs ) and antineutrophil cytoplasmic antibodies (c+p-ANCAs) are appropriate diagnostic screening tools for autoimmune connectivitides and small vessel vasculitides. For economic and intellectual/didactic reasons more extensive autoantibody diagnostics should be performed only in particular situations when patients history and clinical exam lead to strong diagnostic suspicion.

TNFR1 is essential for CD40, but not for lipopolysaccharide-induced sickness behavior and clock gene dysregulation

Autoimmune and infectious diseases are associated with behavioral changes referred to as sickness behavior syndrome (SBS). In autoimmunity, the generation of anti-self T lymphocytes and autoantibodies critically involves binding of CD40 ligand on T-cells to its receptor CD40 on B-cells, dendritic cells and macrophages. Activation of CD40 leads to production of proinflammatory cytokines and, as shown here, induces SBS. Here we report that these behavioral changes depend on the expression of tumor necrosis factor alpha receptor 1 (TNFR1), but not on interleukin-1 receptor 1 or interleukin-6. Moreover, the intensity of SBS correlates with suppression of E-box controlled clock genes, including Dbp, and upregulation of Bmal1. However, the absence of TNFR1 does not interfere with the development of SBS and dysregulation of clock genes in mice treated with lipopolysaccharide. Thus, our results suggest that TNFR1 mediates SBS and dysregulation of clock genes in autoimmune diseases.

Narcolepsy: autoimmunity, effector T cell activation due to infection, or T cell independent, major histocompatibility complex class II induced neuronal loss?

Human narcolepsy with cataplexy is a neurological disorder, which develops due to a deficiency in hypocretin producing neurons in the hypothalamus. There is a strong association with human leucocyte antigens HLA-DR2 and HLA-DQB1*0602. The disease typically starts in adolescence. Recent developments in narcolepsy research support the hypothesis of narcolepsy being an immune-mediated disease. Narcolepsy is associated with polymorphisms of the genes encoding T cell receptor alpha chain, tumour necrosis factor alpha and tumour necrosis factor receptor II. Moreover the rate of streptococcal infection is increased at onset of narcolepsy. The hallmarks of anti-self reactions in the tissue--namely upregulation of major histocompatibility antigens and lymphocyte infiltrates--are missing in the hypothalamus. These findings are questionable because they were obtained by analyses performed many years after onset of disease. In some patients with narcolepsy autoantibodies to Tribbles homolog 2, which is expressed by hypocretin neurons, have been detected recently. Immune-mediated destruction of hypocretin producing neurons may be mediated by microglia/macrophages that become activated either by autoantigen specific CD4(+) T cells or superantigen stimulated CD8(+) T cells, or independent of T cells by activation of DQB1*0602 signalling. Activation of microglia and macrophages may lead to the release of neurotoxic molecules such as quinolinic acid, which has been shown to cause selective destruction of hypocretin neurons in the hypothalamus.