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Vitamin D deficiency in undifferentiated connective tissue disease

IntroductionBoth experimental and clinical data provide evidence that vitamin D is one of those important environmental factors that can increase the prevalence of certain autoimmune diseases such as systemic lupus erythematosus, rheumatoid arthritis, insulin-dependent diabetes mellitus, and inflammatory bowel disease. The aim of the present study was to investigate the prevalence of vitamin D insufficiency in patients with undifferentiated connective tissue disease (UCTD).MethodsPlasma 25(OH)D3 levels in 161 UCTD patients were measured in both summer and winter periods. Autoantibody profiles (antinuclear antibody, anti-U1-ribonucleoprotein, anti-SSA, anti-SSB, anti-Jo1, anti-Scl70, anti-double-stranded DNA, anti-centromere, anti-cardiolipin, rheumatoid factor, and anti-cyclic citrullinated peptide) and clinical symptoms of the patients were assessed.ResultsPlasma levels of 25(OH)D3 in UCTD patients were significantly lower compared with controls in both summer and winter periods (UCTD summer: 33 ± 13.4 ng/mL versus control: 39.9 ± 11.7 ng/mL, P = 0.01; UCTD winter: 27.8 ± 12.48 ng/mL versus control: 37.8 ± 12.3 ng/mL, P = 0.0001). The presence of dermatological symptoms (photosensitivity, erythema, and chronic discoid rash) and pleuritis was associated with low levels of vitamin D. During the average follow-up period of 2.3 years, 35 out of 161 patients (21.7%) with UCTD further developed into well-established connective tissue disease (CTD). Patients who progressed into CTDs had lower vitamin D levels than those who remained in the UCTD stage (vitamin D levels: CTD: 14.7 ± 6.45 ng/mL versus UCTD: 33.0 ± 13.4 ng/mL, P = 0.0001).ConclusionsIn patients with UCTD, a seasonal variance in levels of 25(OH)D3 was identified and showed that these levels were significantly lower than in controls during the corresponding seasons. Our results suggest that vitamin D deficiency in UCTD patients may play a role in the subsequent progression into well-defined CTDs.

Met-enkephalin induced alterations of macrophage functions

Met-enkephalin /Met-enk/ was found to stimulate IgG2a-mediated antibody dependent cytotoxicity /ADCC/ of thioglycollate elicited rat peritoneal macrophages /PM/ through naloxone-sensitive opiate receptors in concentrations ranging from 10(-9) - 14(-7) M. Phagocytosis of IgG2a coated 51Cr-sheep red blood cell /SRBC/ was suppressed by M-enk in the same concentration range. In the same range of concentrations, M-enk was observed to induce a significant increase in the generation of luminol dependent chemiluminescence /LDCL/. The observed stimulation of ADCC was abolished by calmodulin inhibitor triflouroperazine /TFP/ in 10(-6) M concentration. The involvement of cyclic nucleotides in the M-enk induced functional alterations is indicated by finding cGMP accumulation to be augmented in M-enk treated PMs.

Follicular helper T cells may play an important role in the severity of primary Sjögren's syndrome

The aim of this study was to investigate the possible role of follicular helper T (TFH) cells in the pathogenesis of primary Sjögrens syndrome (pSS) by analyzing immune-competent cells and serological markers with special emphasis on clinical symptoms. We enrolled 50 pSS patients and 16 healthy individuals in the study. Patients had elevated ratio of peripheral TFH cells, however, when dividing patients into two groups defined by the presence of extraglandular manifestations (EGMs), only patients with EGMs differed from controls significantly. Moreover, TFH cell percentages correlated positively with both activated T cell and Tr1 cell values. On the contrary, TFH cell percentages showed negative correlation with both IgM and IgG memory B cell proportions. Elevated TFH percent\ages were observed in the anti-SSA/SSB positive patients, and also in patients with higher IL-12, IL-21 levels and focus score values. Increased TFH cell proportions seem to have an important role in disease development.

Plasma Endothelin Correlates With Antiendothelial Antibodies in Patients With Mixed Connective Tissue Disease

BACKGROUND Elevated circulating levels of the vasoactive peptide endothelin-1 have been reported in various cardiovascular disorders. Because these conditions are frequently associated with endothelial dysfunction and damage and the vasoconstrictor effect of endothelin-1 is believed to be produced at the local vascular level, it is uncertain whether circulating endothelin-1 is a causal factor in enhanced vascular tone or instead a marker of endothelial injury. METHODS AND RESULTS We tested whether elevated immunoreactive endothelin-1 could be detected by radioimmunoassay in plasma and whether endothelin-1 levels correlated with antiendothelial autoantibodies in patients with mixed connective tissue disease. Venous blood samples were collected from 21 patients in the morning after an overnight fast and before medication. The plasma immunoreactive endothelin-1 level was 2.7 +/- 0.5 pg/mL (range, 1.1 to 5.2 pg/ml; n = 9) and 7.3 +/- 1.5 pg/mL (range, 2.8 to 20.7 pg/mL; n = 12) in patients who had no antiendothelial antibodies and in patients with antiendothelial antibodies, respectively. These latter values were significantly (P < .001) increased compared with 10 age-matched healthy volunteers (2.0 +/- 0.3 pg/mL; range, 0.5 to 3.0 pg/mL). Plasma endothelin-1 level strongly correlated with antiendothelial antibodies (rs = .836, n = 21, P < .001), whereas there was no correlation between age, systolic and diastolic blood pressures, antinuclear antibodies, and duration of the disease and endothelin-1 values. The incidence of Raynauds phenomenon and angina did not differ significantly in patients with low and high endothelin-1 levels. CONCLUSIONS This study showed that mixed connective tissue disease is associated with elevated plasma immunoreactive endothelin-1 and that endothelin-1 levels significantly correlate with antiendothelial autoantibodies. These findings suggest that increases in plasma endothelin-1 concentration may be secondary to vascular injury and do not necessarily represent enhanced susceptibility to vasoconstriction.

Basophil CD63 expression assay on highly sensitized atopic donor leucocytes—a useful method in chronic autoimmune urticaria

Background  The autoimmune subclass of chronic idiopathic urticaria (CU) has been characterized by the occurrence of biologically relevant IgG antibodies against the IgE molecule or the α chain of the high‐affinity Fcɛ receptor (FcɛRIα) on basophils and mast cells. These antibodies are usually detected by autologous serum skin testing and confirmed by histamine release studies, immunoblotting, or enzyme‐linked immunosorbent assay, but not always.

Altered T-cell and regulatory cell repertoire in patients with diffuse cutaneous systemic sclerosis

Objectives: The aim of this study was to evaluate a wide spectrum of peripheral immune-competent cell types, reflecting overall disturbances in immune homeostasis, characteristic of systemic sclerosis (SSc). We also assessed visceral organ involvement and evaluated the relationship between cell proportions and clinical symptoms of the disease. Methods: Twenty-one patients with diffuse cutaneous SSc (dcSSc) and 15 healthy individuals participated in the study. Peripheral blood lymphocyte subgroups were quantified by flow cytometry, soluble cytokines were assessed by enzyme-linked immunosorbent assay (ELISA), serum complement levels were measured by nephelometry, and autoantibodies were determined by indirect immunofluorescence staining and ELISA technique. Functional tests of regulatory T (Treg) cells were also carried out. Results: Patients with SSc had higher percentages of activated CD3+/HLA-DR+ T cells. Comparing naive vs. memory subsets of CD4+ and CD8+ T cells, a shift towards central memory phenotype was observed in SSc. Natural killer (NK) and T-helper (Th)17 cell percentages were increased, while NKT, Th1, Treg type 1 (Tr1), and CD4+CD25+ Treg cell percentages were decreased in patients. Moreover, the suppressor activity of CD4+CD25+ Treg cells was lower in SSc. Negative correlations occurred between modified Rodnan skin score (MRSS) and Tr1 cell percentages and between complement levels and CD4+CD25+ Treg cells. We also found decreased interleukin (IL)-10 levels in SSc. Conclusions: Our data suggest that the increased Th17/CD4+CD25+ Treg ratio and the altered regulatory function of CD4+CD25+ Treg cells play an important role in the development of SSc. Moreover, our study reveals the potential role of the decreased profile of IL-10-producing Tr1 cells in the progression of disproportionate immune responses in SSc.

Significant correlation between the CD63 assay and the histamine release assay in chronic urticaria

Background  Antibodies directed to the α subunit of the high affinity IgE receptor and the IgE molecule are proposed to be of pathogenetic relevance in a group of patients with chronic urticaria (CU). The diagnosis of autoimmune chronic urticaria (ACU) is difficult; the autologous serum skin test (ASST) seems to be a useful screening test, but reliable, additional confirmatory methods are needed.

Targeting of Pseudomonas aeruginosa in the Bloodstream with Bispecific Monoclonal Antibodies

We examined the ability of a bispecific mAb reagent, consisting of a mAb specific for the primate erythrocyte complement receptor cross-linked with an anti-bacterial mAb, to target bacteria in the bloodstream in an acute infusion model in monkeys. In vitro studies demonstrated a variable level of complement-mediated binding (immune adherence) of Pseudomonas aeruginosa (strain PAO1) to primate E in serum. In vivo experiments in animals depleted of complement revealed that binding of bacteria to E was <1% before administration of the bispecific reagent, but within 5 min of its infusion, >99% of the bacteria bound to E. In complement-replete monkeys, a variable fraction of infused bacteria bound to E. This finding may have significant implications in the interpretation of animal models and in the understanding of bacteremias in humans. Treatment of these complement-replete monkeys with the bispecific reagent led to >99% binding of bacteria to E. Twenty-four-hour survival studies were conducted; several clinical parameters, including the degree of lung damage, cytokine levels, and liver enzymes in the circulation, indicate that the bispecific mAb reagent provides a degree of protection against the bacterial challenge.

Correlation of increased susceptibility to apoptosis of CD4+ T cells with lymphocyte activation and activity of disease in patients with primary Sjögren's syndrome

OBJECTIVE To investigate whether a change in the CD95-related apoptosis of T lymphocytes might have a share in the development of the disease in patients with primary Sjögrens syndrome (SS). METHODS Two-color cytometric analysis was used to study the phenotype of freshly separated mononuclear cells, while Western blotting was used to detect CD95 ligand (CD95L) expression in total homogenates of isolated CD4+ T lymphocytes. The ability of various subpopulations of T cells to undergo apoptosis was investigated in 1-day cultures in medium alone or following various (anti-CD3, anti-CD95 monoclonal antibody, calcium ionophore) treatments. Apoptosis was detected using 7-aminoactinomycin D dye. RESULTS Compared with the findings in healthy controls, the number of CD4+ T lymphocytes was decreased, while their expression of CD95, HLA-DR, and CD45RO was significantly increased in patients with primary SS. A positive correlation was found between the activity of disease, the decrease in the CD4+ T cell number, and the increase in the expression of CD95, CD95L, HLA-DR, and CD45RO molecules within the CD4+ T cell subset. An increased rate of spontaneous, anti-CD3-, or anti-CD95-induced apoptosis was found in the T cells of SS patients, and this was more pronounced in the CD4+ T cell population, correlated with the decreased CD4+ T cell number, increased CD45RO expression, and activity of disease, and concerned mainly the CD95+ cells. CONCLUSION These observations indicate that the increased susceptibility to apoptosis of peripheral CD4+ T cells from SS patients correlates with disease activity. These findings support the hypothesis that the chronic activation of the immune system that occurs in this autoimmune disease is the primary mechanism responsible for this cell-deletion process.

No short-term immunological effects of Pneumococcus vaccination in patients with systemic lupus erythematosus

Objective : to investigate the early immunological effects of Pneumococcus vaccination in SLE patients and healthy controls. Methods : First-four-week follow-up of 18 patients and 9 healthy controls by repeated measurements of anti-nuclear antibodies, anti-dsDNA, C-reactive protein, complement factor 3 (C3) and 4 (C4), total IgG, IgA and IgM. Specific antibody response, percentage of blood lymphocyte populations and whole blood chemiluminescence measurements were carried out in six patients and six controls. Results : No disease flare was detected in the vaccinated patients, all side effects were mild. The concentrations of serum IgG, IgA, C3 and C4 decreased significantly, but still remained within the normal range. The other changes were statistically non-significant. The specific antibody responses to 6B and 23F Pneumococcus serotypes showed striking individual differences. Conclusion : There was no short-term immunological effect of Pneumococcus vaccination in the patients with SLE. The non-responders, without any sign of disease activation should possibly be given more immunogenic, new vaccines to avoid life-threatening Pneumococcus infections.