Low P-Selectin Glycoprotein Ligand-1 Expression in Neutrophils Associates with Disease Activity and Deregulated NET Formation in Systemic Lupus Erythematosus.

Systemic Lupus Erythematosus (SLE) is an autoimmune disease characterized by the generation of anti-DNA autoantibodies due to exposure of immune cells to excessive amounts of extracellular DNA. Lack of P-selectin in mice induces the development of a lupus-like syndrome and patients with cutaneous lupus have reduced P-selectin expression in skin vessels. Using flow cytometry we analyzed in healthy donors and patients the expression of P-selectin Glycoprotein Ligand-1 (PSGL-1) in circulating neutrophils and the implication of PSGL-1/P-selectin interaction in neutrophil extracellular traps (NETs) generation. We found a statistical significance that neutrophils from active SLE patients have a reduced expression of PSGL-1 and low levels of PSGL-1 in neutrophils from SLE patients associated with the presence of anti-dsDNA antibodies, clinical lung involvement, Raynaud's phenomenon, and positive lupus anticoagulant. PSGL-1 is present along the DNA in the NET. In healthy donors, neutrophil interaction with immobilized P-selectin triggers Syk activation, increases the NETs percentage and reduces the amount of DNA extruded in the NETs. In active SLE patients, neutrophil interaction with P-selectin does not activate Syk or reduce the amount of DNA extruded in the NETs, that might contribute to increase the extracellular level of DNA and hence, to disease pathogenesis.

PSGL-1, ADAM8, and selectins as potential biomarkers in the diagnostic process of systemic lupus erythematosus and systemic sclerosis: an observational study.

Background: Early diagnosis and treatment of Systemic lupus erythematosus (SLE) and Systemic sclerosis (SSc) present significant challenges for clinicians. Although various studies have observed changes in serum levels of selectins between healthy donors and patients with autoimmune diseases, including SLE and SSc, their potential as biomarkers has not been thoroughly explored. We aimed to investigate serum profiles of PSGL-1 (sPSGL-1), ADAM8 (sADAM8) and P-, E- and L-selectins (sP-, sE- and sL-selectins) in defined SLE and SSc patient cohorts to identify disease-associated molecular patterns. Methods: We collected blood samples from 64 SLE patients, 58 SSc patients, and 81 healthy donors (HD). Levels of sPSGL-1, sADAM8 and selectins were analyzed by ELISA and leukocyte membrane expression of L-selectin and ADAM8 by flow cytometry. Results: Compared to HD, SLE and SSc patients exhibited elevated sE-selectin and reduced sL-selectin levels. Additionally, SLE patients exhibited elevated sPSGL-1 and sADAM8 levels. Compared to SSc, SLE patients had decreased sL-selectin and increased sADAM8 levels. Furthermore, L-selectin membrane expression was lower in SLE and SSc leukocytes than in HD leukocytes, and ADAM8 membrane expression was lower in SLE neutrophils compared to SSc neutrophils. These alterations associated with some clinical characteristics of each disease. Using logistic regression analysis, the sL-selectin/sADAM8 ratio in SLE, and a combination of sL-selectin/sE-selectin and sE-selectin/sPSGL-1 ratios in SSc were identified and cross-validated as potential serum markers to discriminate these patients from HD. Compared to available diagnostic biomarkers for each disease, both sL-selectin/sADAM8 ratio for SLE and combined ratios for SSc provided higher sensitivity (98% SLE and and 67% SSc correctly classified patients). Importantly, the sADAM8/% ADAM8(+) neutrophils ratio discriminated between SSc and SLE patients with the same sensitivity and specificity than current disease-specific biomarkers. Conclusion: SLE and SSc present specific profiles of sPSGL-1, sE-, sL-selectins, sADAM8 and neutrophil membrane expression which are potentially relevant to their pathogenesis and might aid in their early diagnosis.

Regulation of monocyte apoptosis and DNA extrusion in monocyte extracellular traps by PSGL-1: Relevance in systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is a heterogeneous autoimmune disease characterized by severe organ damage and lacking curative treatment. While various immune cell types, especially dysfunctional B and T cells and neutrophils, have been related with disease pathogenesis, limited research has focused on the role of monocytes in SLE. Increased DNA extracellular traps, apoptosis and necrosis have been related to lupus pathogenesis. Our goal is to analyze the contribution of P-selectin glycoprotein ligand 1 (PSGL-1) in SLE monocytes to disease pathogenesis by investigating the control exerted by PSGL-1 on monocyte apoptosis and DNA extrusion in extracellular traps (METs). Monocytes from active disease patients (aSLE) exhibited reduced levels of PSGL-1. Importantly, lower PSGL-1 levels in SLE monocytes associated with several clinical characteristics, including anti-dsDNA autoantibodies, lupus anticoagulant, clinical lung involvement, and anemia. Monocytes from SLE patients showed higher susceptibility to apoptosis than healthy donors (HD) monocytes and PSGL-1/P-selectin interaction decreased secondary necrosis in HD but not in aSLE monocytes. Regarding METs, aSLE monocytes exhibited higher susceptibility to generate METs than HD monocytes. The interaction of HD monocytes with P-selectin induced Syk activation and reduced the levels of DNA extruded in METs. However, in aSLE monocytes, PSGL-1/P-selectin interaction did not activate Syk or reduce the amount of extruded DNA. Our data suggest a dysfunctional PSGL-1/P-selectin axis in aSLE monocytes, unable to reduce secondary necrosis or the amount of DNA released into the extracellular medium in METs, potentially contributing to lupus pathogenesis.

Cogan syndrome: Descriptive analysis and clinical experience of 7 cases diagnosed and treated in two third level hospitals. / Síndrome de Cogan: análisis descriptivo y experiencia clínica de 7 casos diagnosticados y tratados en 2 hospitales de tercer nivel.

OBJECTIVE: Cogan's syndrome (CS) is an inflammatory disease classified as variable vessel vasculitis. It is a rare disease with few published series, and therefore we reviewed our experience in the last ten years in two centres. MATERIALS AND METHODS: Description of 7 diagnosed cases of CS, according to the classification criteria (typical or atypical), their clinical manifestations, treatments used and their complications. A comparative analysis was performed with the series and cases described in the literature. RESULTS: Seven cases were included, three men and four women, with a mean age at diagnosis of 43 years, and an average disease duration of 47 months. Five patients met the typical characteristics according to the 1980 classical criteria, the rest being atypical cases, one due to the absence of interstitial keratitis and another due to a period between the onset of ocular and auditory-vestibular clinical symptoms greater than two years. All received immunosuppressants, methotrexate being the most commonly used, followed by azathioprine. In 5 cases, biological drugs were used, infliximab in 4 times and 2 tocilizumab. One patient died from bacterial endocarditis and septic shock. CONCLUSION: The characteristics of the series presented are like those published to date, with clinical differences mainly in the involvement of large vessels. Given the low frequency, it seems necessary to create multicentre records to improve the evidence regarding the management of patients with CS.

Baseline serum RANKL levels may serve to predict remission in rheumatoid arthritis patients treated with TNF antagonists.

AIMS: The objective of this study was to investigate whether baseline receptor activator for nuclear factor kappaB ligand (RANKL) and osteoprotegerin (OPG) serum (s) levels can predict the therapeutic response to TNF antagonists (a-TNF). METHODS: We studied 75 rheumatoid arthritis patients (81% female) with a longstanding refractory disease. The variables of disease activity, physical function and sRANKL and sOPG levels were determined before and after both 12-14 and 28-30 weeks of a-TNF therapy (65 adalimumab, 10 infliximab). Remission was defined by a 28 joint count disease activity score (DAS28) /=1.2 at both 3- and 7-month follow-up visits. RESULTS: In most patients, disease activity was severe, as reflected by a baseline DAS28 score of 5.9+/-1 (mean+/-SD), an HAQ of 1.6 (1.1 to 2.1) (median (interquartile range (IQR))) and a CRP 15 mg/l (IQR: 9 to 24). The sRANKL levels and RANKL/OPG ratio in patients that achieved remission were significantly lower at baseline than in the remaining patients at both 3 and 7 months of follow-up. The sOPG levels correlated with the HAQ and the physician's disease assessment and diminished significantly after a-TNF treatment. However, no significant association was detected between the therapeutic response profile and sOPG levels. CONCLUSIONS: These data suggest that in patients receiving a-TNF treatment, lower serum levels of RANKL and RANKL/OPG ratio may serve to predict remission.

Independent Candidate Serum Protein Biomarkers of Response to Adalimumab and to Infliximab in Rheumatoid Arthritis: An Exploratory Study.

Response to treatment of rheumatoid arthritis shows large inter-individual variability. This heterogeneity is observed with all the anti-rheumatic drugs, including the commonly used TNF inhibitors. It seems that drug-specific and target-specific factors lead individual patients to respond or not to a given drug, although this point has been challenged. The search of biomarkers distinguishing responders from non-responders has included shotgun proteomics of serum, as a previous study of response to infliximab, an anti-TNF antibody. Here, we have used the same study design and technology to search biomarkers of response to a different anti-TNF antibody, adalimumab, and we have compared the results obtained for the two anti-TNF drugs. Search of biomarkers of response to adalimumab included depletion of the most abundant serum proteins, 8-plex isobaric tag for relative and absolute quantitation (iTRAQ) labeling, two-dimensional liquid chromatography fractionation and relative quantification with a hybrid Orbitrap mass spectrometer. With this approach, 264 proteins were identified in all the samples with at least 2 peptides and 95% confidence. Nine proteins showed differences between non-responders and responders (P < 0.05), representing putative biomarkers of response to adalimumab. These results were compared with the previous study of infliximab. Surprisingly, the non-responder/responder differences in the two studies were not correlated (rs = 0.07; P = 0.40). This overall independence with all the proteins showed two identifiable components. On one side, the putative biomarkers of response to either adalimumab or infliximab, which were not shared and showed an inverse correlation (rs = -0.69; P = 0.0023). On the other, eight proteins showing significant non-responder/responder differences in the analysis combining data of response to the two drugs. These results identify new putative biomarkers of response to treatment of rheumatoid arthritis and indicate that they are notably drug-specific.

Interleukin 15 levels in serum may predict a severe disease course in patients with early arthritis.

BACKGROUND: Interleukin-15 (IL-15) is thought to be involved in the physiopathological mechanisms of RA and it can be detected in the serum and the synovial fluid of inflamed joints in patients with RA but not in patients with osteoarthritis or other inflammatory joint diseases. Therefore, the objective of this work is to analyse whether serum IL-15 (sIL-15) levels serve as a biomarker of disease severity in patients with early arthritis (EA). METHODOLOGY AND RESULTS: Data from 190 patients in an EA register were analysed (77.2% female; median age 53 years; 6-month median disease duration at entry). Clinical and treatment information was recorded systematically, especially the prescription of disease modifying anti-rheumatic drugs. Two multivariate longitudinal analyses were performed with different dependent variables: 1) DAS28 and 2) a variable reflecting intensive treatment. Both included sIL-15 as predictive variable and other variables associated with disease severity, including rheumatoid factor (RF) and anti-cyclic citrullinated peptide antibodies (ACPA). Of the 171 patients (638 visits analysed) completing the follow-up, 71% suffered rheumatoid arthritis and 29% were considered as undifferentiated arthritis. Elevated sIL-15 was detected in 29% of this population and this biomarker did not overlap extensively with RF or ACPA. High sIL-15 levels (ß Coefficient [95% confidence interval]: 0.12 [0.06-0.18]; p<0.001) or ACPA (0.34 [0.01-0.67]; p = 0.044) were significantly and independently associated with a higher DAS28 during follow-up, after adjusting for confounding variables such as gender, age and treatment. In addition, those patients with elevated sIL-15 had a significantly higher risk of receiving intensive treatment (RR 1.78, 95% confidence interval 1.18-2.7; p = 0.007). CONCLUSIONS: Patients with EA displaying high baseline sIL-15 suffered a more severe disease and received more intensive treatment. Thus, sIL-15 may be a biomarker for patients that are candidates for early and more intensive treatment.

[The therapeutic blockade of TNF reduces serum levels of interleukin 15 in patients with rheumatoid arthritis]. / El bloqueo terapéutico del factor de necrosis tumoral disminuye la concentración sérica de interleucina 15 en pacientes con artritis reumatoide.

OBJECTIVE: To analyze the effect of the TNF blocking agents (aTNF) on the serum levels of interleukin 15 (IL-15). To determine whether baseline IL15 serum levels or their response to aTNF therapy can predict the clinical response to this treatment. PATIENTS AND METHOD: We studied 75 patients suffering from rheumatoid arthritis that were selected to start aTNF therapy. Serum samples were obtained at baseline visit and after three months of aTNF treatment. Measurement of IL-15 serum concentration was performed through immune-enzyme assay. We collected the clinical and analytical parameters needed to calculate DAS28 both at baseline and final visit, as well as sociodemographic variables and other such as rheumatoid factor, previous disease modifying anti-rheumatic drugs (DMARD), etc. We defined remission as a DAS28 < 2.6 and clinical response when the decrease in DAS28 value was higher than 1.2. RESULTS: There was a significant correlation between IL-15 serum level and the number of previous DMARD. We also detected a significant decrease in the concentration of serum IL-15 after three months of treatment with aTNF. However, neither the baseline IL-15 serum level nor the decrease in the concentration of IL-15 were associated with a specific pattern of response to aTNF. CONCLUSIONS: Our data seem to support previous in vitro findings suggesting that TNF is involved in the regulation of IL-15 expression. Nevertheless, the measurement of IL-15 serum levels does not seem to be a useful tool to select those patients that should be treated with aTNF therapy.