[Spectroscopic investigation of the middle ear mucosa]. / Spektroskopische Untersuchung der Mittelohrschleimhaut.

BACKGROUND: The middle ear mucosa (MEM) plays a central role in the middle ear due to its function of providing regular ventilation. To date, assessment of the state of the MEM is only possible subjectively by the surgeon. An objective characterization of the state of the MEM is desirable. OBJECTIVE: The aim of this study was to enable objective characterization of the MEM and test infrared (IR) spectroscopy as a possible diagnostic tool for clinical use. MATERIALS AND METHODS: During middle ear surgery, 48 MEM samples were collected and divided into four groups according to clinical appearance: group I: normal MEM; group II: sclerotic MEM; group III: inflammatory thickened MEM; group IV: granulated MEM. After collection, samples were analyzed by IR spectroscopy to identify characteristic IR spectra. RESULTS: In the supervised analysis of the selected images, the biochemical differences representing the decisive factors for classification into groups I to IV were characterized. The differences in amide bands, carbohydrates, lipids, and proteins permit reliable separation of the clinical categories. CONCLUSION: Spectroscopic investigations enable objective characterization of the MEM. Conclusions regarding biochemical differences make it possible to weigh up treatment options. Routine use of IR spectroscopy in the operating theater requires histopathological comparison and an extended dataset with reference values of the individual groups.

Current approaches to avoid the culling of day-old male chicks in the layer industry, with special reference to spectroscopic methods.

The negative correlation between fattening and laying performance prevents breeding improvement in both laying performance and meat yield. Therefore, specialized chicken lines have been bred in order to achieve either an efficient production of high-quality eggs or high growth rates. As a result, day-old male chicks are culled in the layer hatchery, which poses animal welfare and ethical problems. Breeding companies, scientific groups, and hatcheries are attempting to resolve this issue, with a common aim to find feasible alternatives for the routine killing of male layer chicks. Some approaches aim to influence the sex ratio, while others target at the economically feasible use of the male layer offspring, such as the fattening of "laying hen brothers" or crossbreedings of layers and broilers to create "dual-purpose chickens." Another approach is the sex determination prior to hatch. One of the prerequisites of in ovo sex determination is a practicable method that can be used in industry. The analysis needs to be rapid, cost-efficient, and highly precise; in addition, negative impacts on hatching rate, animal health, and/or performance parameters should be limited. Furthermore, sex determination should be performed before the sensory nervous system's response of the chick embryo to certain or potentially harmful stimuli is developed, which according to current knowledge is before the d 7 of incubation.

Production of neutral molecular clusters by controlled neutralization of mobility standards.

Measuring aerosols and molecular clusters below the 3 nm size limit is essential to increase our understanding of new particle formation. Instruments for the detection of sub-3 nm aerosols and clusters exist and need to be carefully calibrated and characterized. So far calibrations and laboratory tests have been carried out using mainly electrically charged aerosols, as they are easier to handle experimentally. However, the charging state of the cluster is an important variable to take into account. Furthermore, instrument characterization performed with charged aerosols could be biased, preventing a correct interpretation of data when electrically neutral sub-3 nm aerosols are involved. This article presents the first steps to generate electrically neutral molecular clusters as standards for calibration. We show two methods: One based on the neutralization of well-known molecular clusters (mobility standards) by ions generated in a switchable aerosol neutralizer. The second is based on the controlled neutralization of mobility standards with mobility standards of opposite polarity in a recombination cell. We highlight the challenges of these two techniques and, where possible, point out solutions. In addition, we give an outlook on the next steps toward generating well-defined neutral molecular clusters with a known chemical composition and concentration. Published with license by American Association for Aerosol Research.

[Diffuse idiopathic skeletal hyperostosis in the dog (DISH): a review]. / Diffuse idiopathische skelettale Hyperostose (DISH) beim Hund: Eine Übersicht.

INTRODUCTION: Diffuse idiopathic skeletal hyperostosis (DISH) is a common, non-inflammatory, systemic disease of the spine and the abaxial skeleton in humans and dogs. Spondylosis deformans (SD) must be considered as an important differential diagnosis which in humans, unlike DISH, is always accompanied by degenerative disc disease. In the veterinary literature, usually no difference is made between these diseases. The aim of the present review is to summarize essentials of DISH regarding its definition, etiology, prevalence, clinical findings and therapy in both, the human and dog. In particular, the various classification schemes and the most important differential diagnoses are discussed. Specific aspects of canine DISH are highlighted.

INTRODUCTION: L'hyperostose squelettique idiopathique diffuse (DISH) est une affection systémique non-inflammatoire de la colonne vertébrale et du squelette périphérique chez l'homme et le chien. La spondylose déformante (SD) qui, chez l'homme, contrairement à la DISH, s'accompagne d'une atteinte dégénérative des disques intervertébraux et représente donc une entité pathologique propre constitue un diagnostic différentiel important. Dans la littérature vétérinaire, par contre, on ne distingue souvent pas de façon explicite entre SD et DISH. Le but du présent travail est de donner un aperçu de la définition, de l'étiologie, de la prévalence, de la clinique et du traitement de la DISH chez l'homme et le chien. On discute en particulier les divers schémas de classification et les principaux diagnostics différentiels et on relève particulièrement les aspects spécifiques de l'affection chez le chien.

From autoantibody research to standardized diagnostic assays in the management of human diseases - report of the 12th Dresden Symposium on Autoantibodies.

Testing for autoantibodies (AABs) is becoming more and more relevant, not only for diagnosing autoimmune diseases (AIDs) but also for the differentiation of defined AID subtypes with different clinical manifestations, course and prognosis as well as the very early diagnosis for adequate management in the context of personalized medicine. A major challenge to improve diagnostic accuracy is to harmonize or even standardize AAB analyses. This review presents the results of the 12th Dresden Symposium on Autoantibodies that focused on several aspects of improving autoimmune diagnostics. Topics that are addressed include the International Consensus on ANA Patterns (ICAP) and the International Autoantibody Standardization (IAS) initiatives, the optimization of diagnostic algorithms, the description and evaluation of novel disease-specific AABs as well as the development and introduction of novel assays into routine diagnostics. This review also highlights important developments of recent years, most notably the improvement in diagnosing and predicting the course of rheumatoid arthritis, systemic sclerosis, idiopathic inflammatory myopathies, and of autoimmune neurological, gastrointestinal and liver diseases; the potential diagnostic role of anti-DFS70 antibodies and tumor-associated AABs. Furthermore, some hot topics in autoimmunity regarding disease pathogenesis and management are described.

Pathological brain plasticity and cognition in the offspring of males subjected to postnatal traumatic stress.

Traumatic stress in early-life increases the risk for cognitive and neuropsychiatric disorders later in life. Such early stress can also impact the progeny even if not directly exposed, likely through epigenetic mechanisms. Here, we report in mice that the offspring of males subjected to postnatal traumatic stress have decreased gene expression in molecular pathways necessary for neuronal signaling, and altered synaptic plasticity when adult. Long-term potentiation is abolished and long-term depression is enhanced in the hippocampus, and these defects are associated with impaired long-term memory in both the exposed fathers and their offspring. The brain-specific gamma isoform of protein kinase C (Prkcc) is one of the affected signaling components in the hippocampus. Its expression is reduced in the offspring, and DNA methylation at its promoter is altered both in the hippocampus of the offspring and the sperm of fathers. These results suggest that postnatal traumatic stress in males can affect brain plasticity and cognitive functions in the adult progeny, possibly through epigenetic alterations in the male germline.

Pristane-induced lupus as a model of human lupus arthritis: evolvement of autoantibodies, internal organ and joint inflammation.

OBJECTIVE: Arthritis is frequently seen in human lupus, but rarely in lupus models. Pristane-induced lupus (PIL) can be induced in various mouse strains such as BALB/c and C57BL/6. We herein characterize clinical and histological features of arthritis in the context of systemic lupus and provide a prudent comparison with models of rheumatoid arthritis (RA). METHODS: A total of 57 BALB/c mice received pristane (PIL group) and were analyzed for serum autoantibodies (anti-chromatin-, -histone, -Sm, -dsDNA), as well as for clinical features and histopathology of joints, lungs and kidneys. Joint pathology was quantified by image analysis and tissue cytometry. Ten C57BL/6 mice (Bl/6-PIL) and historical groups of two different RA models were analyzed accordingly. RESULTS: In BALB/c PIL, clinical arthritis started at three months, occurred finally in 79% of PIL (but not in controls, p<0.001) and correlated with areas of inflammation, erosion, cartilage damage, osteoclast numbers and total severity score (for all: r>0.7, p<0.001). After eight months, 58% of PIL (but no controls, p<0.001) had mild-erosive arthritis. In contrast to RA, the most frequent inflammatory cell type of the pannus was granulocytes (17.7%), PIL had lower numbers of osteoclasts, erosions rarely affected both layers of the cortical bone and there was no progression to complete joint destruction (even after one year of observation). Serum autoantibodies (auto-abs) preceded arthritis and became significantly elevated in all PIL; affected joints showed increased deposits of IgG (and IgM) within the inflammatory tissue, indicative of an ab-mediated process. PIL mice with arthritis also showed signs of pulmonary (100%) and renal (46%) lupus. In contrast to BALB/c, Bl/6-PIL mice did not develop any signs of arthritis. CONCLUSION: PIL in BALB/c mice is characterized by severe organ involvement, typical autoabs and by a mild-erosive arthritis with similarities to, but also with distinct differences from, RA. PIL may help to study arthritis along with other key features of systemic lupus erythematosus after therapeutic interventions or in knock-out models based on a BALB/c but not on a C57BL/6 background.

Molecular imaging of paper cross sections by FT-IR spectroscopy and principal component analysis.

The molecular imaging of paper cross sections containing the wet-strength additive poly(amidoamine)-epichlorohydrin (PAE) was effected by Fourier transform infrared (FT-IR) spectroscopic imaging. Thin cross sections of laboratory sheet samples were prepared and transferred onto CaF2 substrates. A laboratory sheet sample without PAE acted as a reference. Principal component analysis (PCA) was applied to identify and to reveal the distribution of PAE across the section. Differences in the loading plots of the fourth and fifth principal components for the sheets with and without PAE were found in the region of the amide I, amide II, and amine bands within a variance of 0.4-0.8%. The score images of the PCA reveal inhomogeneous distribution of PAE. Small areas of higher concentration of PAE occur across the cross section. The aim of this study was to demonstrate that FT-IR spectroscopic imaging provides spatially resolved quantitative information about the chemical composition of paper, which was successfully achieved.

Comparison of particulate number concentrations in three Central European capital cities.

Number size distributions of atmospheric aerosol particles in the mobility diameter range from 10 to 1000 nm were determined in Budapest, Prague and Vienna for a one-year-long period. Particle number concentrations in various size fractions, their diurnal and seasonal variations, mean size distributions and some properties of new particle formation events were derived and compared. Yearly median particle number concentrations for Budapest, Prague and Vienna were 10.6×10(3), 7.3×10(3) and 8.0×10(3) cm(-3). Differences were linked to the different pollution levels of the cities, and to diverse measurement environments and local conditions. Mean contributions of ultrafine particles (particles with a mobility diameter <100 nm) to the total number concentration were 80%, 84% and 74% for Budapest, Prague and Vienna, thus these particles represent an overwhelming share of all particles in each city. Seasonal variation of particle number concentrations was not obvious. Diurnal variations of particles with a diameter between 100 and 1000 nm (N(100-1000)) exhibited similar shape for the cities, which was related to the time-activity pattern of inhabitants and regional influences. The structure of the diurnal variation for ultrafine particles was also similar. It contained a huge morning peak in each city which was explained by emissions from vehicular traffic. The second peak was shifted from afternoon rush hours to late evenings as a result of the daily cycling in meteorological parameters. The character of the measurement site also influenced the diurnal variation. Diurnal variation of the mean ratio of ultrafine particles to N(100-1000) clearly revealed the presence and importance of new particle formation and subsequent growth in urban environments. Nucleation frequencies in Budapest and Prague were 27% and 23%, respectively on a yearly time scale. They showed a minimum in winter for both places, while the largest nucleation activity was observed in spring for Budapest, and in summer for Prague.

Expression patterns of CD44 and CD44 splice variants in patients with rheumatoid arthritis.

OBJECTIVES: It has been suggested that CD44 is involved in the pathogenesis of rheumatoid arthritis (RA). By alternative splicing, numerous CD44 isoforms can be generated which may play different roles the inflammatory process. We therefore studied the expression of various CD44 splicevariants in the circulation and synovial tissue of patients with RA and correlated expression with clinical features. METHODS: Expression of distinct CD44 splice variants was analysed by FACS in peripheral monocytes of 46 RA patients and 36 healthy controls. Expression of CD44 splice variants in synovial tissue of RA and OA patients was analysed by immunohistochemistry and the effects of blocking CD44v4 on RA-fibroblast like synoviocytes (FLS) were studied. RESULTS: On monocytes, the expression of CD44 and CD44v3 was significantly lower in patients with erosive disease than in those without radiographic progression (p<0.05 for CD44 and p<0.01 for CD44v3). CD44v6 on monocytes was significantly associated with the clinical disease activity index (r=0.34, p<0.05) and CRP-levels (r=0.37, p<0.02). Immunhistochemical analyses revealed that most variants were expressed to a significantly higher extent in RA than in OA synovial membranes. Particularly the variants CD44v4, CD44v6 and CD44v7-8 were highly expressed in the RA lining and also abundantly in the endothelium. Blocking CD44v4 in RA-FLS reduced the proliferation to 68±8% (p<0.02) when compared to control experiments and led to a reduction in IL-1ß mRNA expression (p<0.05). CONCLUSIONS: Expression of CD44 splice variants is generally increased in the synovial lining of RA patients when compared to OA. The inverse association of CD44v3 expression on monocytes with the development of erosive disease and the functional impacts of CD44v4 blockade in RA-FLS suggests a pathogenetic role of this splice variants which needs to be further investigated.

Inhibitors of p38 and ERK1/2 MAPkinase and hydrogen sulphide block constitutive and IL-1ß-induced IL-6 and IL-8 expression in the human chondrocyte cell line C-28/I2.

Mitogen-activated protein kinases (MAPKs) play a central role in inflammatory processes, and their blockage represents pharmacological approaches in the treatment of autoimmune diseases like rheumatoid arthritis (RA). Alternatively, H(2)S has long been used in sulphur bath therapy for patients suffering from different types of rheumatic disorders, but reports about the beneficial effects of this form of therapy are controversial, rare and of poor scientific quality. The human chondrocyte cell line C-28/I2 was treated with two different MAPK inhibitors (SB203580 and U0126) or with various concentrations of the H(2)S donor Natrium hydrogen sulphide (NaHS). Thereafter, the secretion of IL-6 and IL-8 was quantified by enzyme-linked immunosorbent assays (ELISAs). The impact of NaHS on the regulation of p38 and ERK1/2 MAPK was confirmed by Western blot experiments. Furthermore, IL-6 and IL-8 expression was quantified by real-time polymerase chain reaction (RT-PCR) and ELISAs from cells which were exposed to SB203580, U0126 and NaHS and stimulated by IL-1ß. The C-28/I2 cells constitutively expressed large quantities of IL-6 and IL-8. The data provided prove that in these cells, constitutive as well as IL-1ß-induced IL-6 and IL-8 expression was partially and transiently blocked by the treatment of cells with both MAPK inhibitors and NaHS. Presented data seem to be important in evaluating the beneficial functions of MAPK inhibitors and H(2)S in immune-pathophysiological processes.

Avidity maturation of anti-citrullinated protein antibodies in rheumatoid arthritis.

OBJECTIVE: Anti-citrullinated protein antibodies (ACPAs) are highly specific for rheumatoid arthritis (RA) and are present years before the onset of symptoms. The avidity of autoantibodies can have a strong impact on their effector potency. This study was undertaken to analyze the avidity of ACPAs in serum samples obtained from ACPA-positive healthy individuals (predisease), patients with early disease, and patients with established RA as well as the avidity maturation over time in samples from healthy subjects who later developed RA. METHODS: We measured ACPA avidity in serum samples from ACPA-positive healthy individuals, symptomatic individuals, and patients with established RA in 5 collections from The Netherlands, Canada, and Austria. We determined the dynamics of avidity maturation of ACPAs from the predisease stage to established disease in 1 case from the native North American population and in 10 cases from a Dutch blood donor cohort. RESULTS: The overall ACPA response was characterized by low-avidity antibodies. Higher-avidity ACPAs were observed in symptomatic patients only, while low-avidity ACPAs were observed in both healthy subjects and patients. In longitudinal samples obtained from subjects prior to disease onset, ACPA avidity increased over time until disease onset. No further avidity maturation was observed after disease onset. CONCLUSION: Our findings indicate that avidity maturation of the ACPA response takes place prior to disease onset.

Long-term study of cloud condensation nuclei (CCN) activation of the atmospheric aerosol in Vienna.

During a total of 11 months, cloud condensation nuclei (CCN at super-saturation S 0.5%) and condensation nuclei (CN) concentrations were measured in the urban background aerosol of Vienna, Austria. For several months, number size distributions between 13.22 nm and 929 nm were also measured with a scanning mobility particle spectrometer (SMPS). Activation ratios (i.e. CCN/CN ratios) were calculated and apparent activation diameters obtained by integrating the SMPS size distributions. Variations in all CCN parameters (concentration, activation ratio, apparent activation diameter) are quite large on timescales of days to weeks. Passages of fronts influenced CCN parameters. Concentrations decreased with the passage of a front. No significant differences were found for fronts from different sectors (for Vienna mainly north to west and south to east). CCN concentrations at 0.5% S ranged from 160 cm(-3) to 3600 cm(-3) with a campaign average of 820 cm(-3). Activation ratios were quite low (0.02-0.47, average: 0.13) and comparable to activation ratios found in other polluted regions (e.g. Cubison et al., 2008). Apparent activation diameters were found to be much larger (campaign average: 169 nm, range: (69-370) nm) than activation diameters for single-salt particles (around 50 nm depending on the salt). Contrary to CN concentrations, which are influenced by source patterns, CCN concentrations did not exhibit distinct diurnal patterns. Activation ratios showed diurnal variations counter-current to the variations of CN concentrations.

Characterizing the performance of two optical particle counters (Grimm OPC1.108 and OPC1.109) under urban aerosol conditions.

The performance of Grimm optical particle counters (OPC, models 1.108 and 1.109) was characterized under urban aerosol conditions. Number concentrations were well correlated. The different lower cut-off diameters (0.25 and 0.3 µm) give an average difference of 23.5%. Both detect less than 10% of the total particle concentration (0.01-1 µm; Differential Mobility Analyzer), but in the respective size ranges, differences are <10%. OPC number size distributions were converted to mass concentrations using instrument-specific factors given by the manufacturer. Mass concentrations for OPC1.108 were 60% higher than for OPC1.109 and (in case of OPC1.109) much lower than those measured with an impactor in the relevant size range or a TSP filter. Using the C-factor correction suggested by the manufacturer, OPC1.109 underestimated mass concentrations by 21% (impactor) and by about 36% (TSP filter), which is in the range of comparability of co-located different mass concentration methods (Hitzenberger, Berner, Maenhaut, Cafmeyer, Schwarz, & Mueller et al., 2004).

Autoantibody profiling in patients with very early rheumatoid arthritis: a follow-up study.

OBJECTIVE: To investigate time courses of autoantibody profiles in patients with early arthritis. PATIENTS AND METHODS: A total of 200 patients with very early arthritis (<3 months duration), among them 102 patients with a final diagnosis of rheumatoid arthritis (RA) and 98 with other rheumatic diseases, were followed up for several years. First follow-up testing was performed in all patients (mean 5 months from baseline), and 82 patients with RA and 35 patients without RA were available for last follow-up testing (mean 32 months from baseline). IgM-rheumatoid factor (RF) was measured by nephelometry, IgA-RF, IgG-RF and anti-cyclic citrullinated peptide antibodies (ACPA) by ELISA, and anti-RA33 antibodies were determined by immunoblotting. RESULTS: At baseline, IgA-RF was detectable in 29% and IgG-RF in 14% of patients with RA while IgM-RF>50 IU/ml (RF50) was positive in 45% of the patients; specificities were 97%, 99% and 96%, respectively. However, the vast majority of patients positive for IgA-RF or IgG-RF were also positive for RF50 or ACPA. During follow-up, the prevalence of ACPA slightly increased while prevalence of all RF subtypes and anti-RA33 decreased. Remarkably, the number of patients positive for RF50 and/or ACPA remained constant, and these patients had a highly increased risk for developing erosive disease in contrast to patients solely positive for anti-RA33. CONCLUSIONS: Testing for RF subtypes did not provide additional diagnostic information. Patients positive for RF50 and/or ACPA had an unfavourable prognosis, irrespectively of changes in the antibody profile during follow-up, whereas anti-RA33 positivity was inversely associated with erosiveness at baseline and at later time points.

El colgajo fasciocutáneo en cono / Use of a new cone shaped flap to cover skin defects: experience in 108 patients

Background: A new type of fasciocutaneous flap with the shape of an ice cream cone that is formed by locally rotated and V-Y advance flaps joined together, that can be used to cover complex defects, was developed. Previously, the irrigation of these flaps was ascertained in the legs of ten corpses. Aim: To report the results with the use of this type of ice cream cone shaped flap. Material and Methods: Retrospective analysis of 108 patients aged 20 to 52 years (99 males) in whom an ice cream cone shaped flap was used. Results: The defects covered were located in the leg in 27 percent, in the ankle in 10 percent, in the sole in 9 percent, in the heel in 8 percent and in other locations in the rest of patients. Eighty flaps (74 percent) had a good evolution, 11 (10 percent) had a major dehiscence, 13 (12 percent) had a minor dehiscence and 4 flaps (4 percent) had necrosis. Conclusions: This ice cream cone shaped flap is easy to use, safe and devoid of complications in most cases.

Se presenta un colgajo no descrito previamente en la literatura internacional ni nacional. El colgajo se denomina "en cono" por la forma final que se obtiene un barquillo de helado con su bocado. Consta de 2 colgajos acoplados: uno de rotación local y otro un avance en V-Y, ambos fasciocutáneos. Para comprobar su irrigación se practicó disección anatómica de las piernas de 10 cadáveres frescos inyectando azul de metileno y bario en la arteria poplítea. El resultado demostró un rico y amplio plexo tanto infra como supra fascial que irriga muy bien la piel de ambos colgajos a nivel de 1/3 distal de la pierna. Se realizó también un análisis geométrico del avance en V-Y para demostrar como los tejidos pueden avanzar y para determinar las dimensiones que debe tener este colgajo. Se operó 108 pacientes con lesiones en diferentes partes del organismo con complicaciones de un 3,7 por ciento. Los resultados permitieron determinar que el colgajo en cono es versátil, reproducible, sencillo y seguro de realizar. Es un colgajo que servirá para que los cirujanos plásticos resuelvan complejos problemas quirúrgicos en forma muy segura y a bajo costo.

Does damage cause inflammation? Revisiting the link between joint damage and inflammation.

Rheumatoid arthritis (RA) is characterised by both inflammation, as manifested by pain and swelling, and destruction of the joints. Unequivocal evidence indicates that disease activity, and thus the inflammatory response, is linked to joint damage. From this viewpoint we suggest that, vice versa, joint damage might be a cause of the active disease process, thus leading to a vicious cycle of events. The background to this notion stems from the known autoimmune response in RA, the potential of cartilage and bone breakdown products to elicit inflammation and notions that in joints that have undergone surgery with cartilage removal RA does not flare. However, the clinical evidence for this relationship is still to be provided as proof of the concept.

B cell epitopes of the heterogeneous nuclear ribonucleoprotein A2: identification of a new specific antibody marker for active lupus disease.

OBJECTIVES: Autoantibody formation and T cell reactivity against the heterogeneous nuclear ribonucleoprotein A2 (hnRNP-A2) has been observed in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). Since no differences in epitope recognition were reported and the usefulness of anti-hnRNP-A2 antibodies as diagnostic markers of SLE is unknown, it was our objective to characterise linear B cell epitopes of hnRNP-A2 and to relate the anti-hnRNP-A2 antibody responses to disease activity and clinical features of SLE. METHODS: Sequential serum samples from 15 patients with SLE and sera from patients with other rheumatic diseases and healthy subjects were investigated by ELISA for autoantibody reactivities against a set of 13 overlapping peptides spanning the RNA-binding region of hnRNP-A2. Antibody reactivity against the complete protein was determined by western immunoblotting and ELISA. SLE disease activity was assessed by European Consensus Lupus Activity Measure scores, by SLE Index scores and the British Isles Lupus Assessment index. RESULTS: Anti-peptide antibody reactivities were found in 60% of SLE sera but in only 5% of control samples, and were mainly directed to four peptides, one of which (p155-175) appeared to be immunodominant. Antibodies to p155-175 were exclusively seen in patients with SLE and correlated with clinical disease activity as well as kidney and skin involvement. No correlations were found for the other anti-peptide antibody responses. CONCLUSION: Peptide p155-175 encompasses a disease-specific immunodominant epitope of hnRNP-A2. Since antibodies to p155-175 correlate with disease activity and nephritis, they may be useful as markers for active SLE.

Characterisation of cellular and humoral autoimmune responses to histone H1 and core histones in human systemic lupus erythaematosus.

OBJECTIVE: To address key aspects of anti-histone autoimmunity in systemic lupus erythaematosus (SLE), we performed a detailed characterisation of cellular and humoral autoreactivity to histone H1 and the four core histones H2A, H2B, H3, H4 in patients with SLE and healthy controls. METHODS: Peripheral blood mononuclear cells of 41 patients with SLE and 28 healthy controls were exposed to individual histones and proliferation was measured by [(3)H]-thymidine incorporation. H1-reactive T cell clones were obtained by limiting dilution. Cytokines and total IgG in culture supernatants was measured by ELISA, and autoantibodies to histones were determined by ELISA and immunoblotting. RESULTS: Proliferative responses to H1 were more frequent and more pronounced in cell cultures from patients with SLE (p<0.002), while among the core histones only the response to H2A was increased in patient cultures (p<0.01). All histones elicited a Th1-like cytokine response in patients and controls (high interferon (IFN)gamma and tumour necrosis factor (TNF)alpha, no interleukin (IL)4) with H1 inducing the highest levels of TNFalpha. However, H1 stimulated production of IgG and anti-histone antibodies only in cell cultures derived from patients with SLE. H1-specific T cell clones from patients and controls showed a CD4+CD28+ phenotype and a Th1 cytokine profile. Anti-histone antibodies were detected in 51% of patients with SLE, were primarily directed to H1, H3 and H4, and predominantly of the IgG2 subtype. CONCLUSIONS: Histone H1 constitutes a major B cell and T cell autoantigen in SLE, triggering a proinflammatory Th1 response and driving autoantibody production. This suggests that histone H1 may be of considerable relevance for the pathogenesis of SLE.

Systemic lupus erythematosus patients exhibit functional deficiencies of endothelial progenitor cells.

OBJECTIVE: SLE is characterized by an increased cardiovascular risk. Since endothelial progenitor cells (EPCs) have been described to serve as a biomarker for the CV risk and are known to be depleted in various diseases, we were interested if SLE would also be associated with altered peripheral EPC levels or functional abnormalities of these cells. METHODS: EPCs were quantified in 31 female SLE patients with different disease activity and in age-matched healthy controls (HCs) by FACS analysis and by colony forming unit (CFU) assay. Furthermore, EPC adhesion and migration capacity were tested. RESULTS: EPC levels were similar in HC and SLE when assessed by FACS (0.045 +/- 0.006% vs 0.036 +/- 0.007% within the lymphocyte gate) and by the CFU assay (18 +/- 3 vs 15 +/- 2 colonies/well). No correlation with disease activity could be observed, but SLE patients treated with chloroquine exhibited significantly decreased EPC levels (0.058 +/- 0.005% without vs 0.024 +/- 0.008% with chloroquine, P < 0.05). Addition of chloroquine to in vitro cultures also led to a decreased colony formation in SLE and in HC. When testing the adhesion and migration capacity of EPC on human umbilical vein endothelial cells (HUVEC), cells from SLE patients had reduced adhesion (19.2 +/- 3.5% vs 36.6 +/- 5.2% EPC/high power field, P < 0.02) and migratory activity (56 +/- 6 cells/random microscopic field in SLE vs 121 +/- 28 in controls, P < 0.02). CONCLUSION: The data reveal that EPCs are significantly affected in SLE. While circulating EPC levels are in the range of HC, they exhibit functional deficiencies that may lead to impaired tissue availability.