Expression of Non-T Cell Activation Linker (NTAL) in Jurkat Cells Negatively Regulates TCR Signaling: Potential Role in Rheumatoid Arthritis.

T lymphocytes are key players in adaptive immune responses through the recognition of peptide antigens through the T Cell Receptor (TCR). After TCR engagement, a signaling cascade is activated, leading to T cell activation, proliferation, and differentiation into effector cells. Delicate control of activation signals coupled to the TCR is needed to avoid uncontrolled immune responses involving T cells. It has been previously shown that mice deficient in the expression of the adaptor NTAL (Non-T cell activation linker), a molecule structurally and evolutionarily related to the transmembrane adaptor LAT (Linker for the Activation of T cells), develop an autoimmune syndrome characterized by the presence of autoantibodies and enlarged spleens. In the present work we intended to deepen investigation into the negative regulatory functions of the NTAL adaptor in T cells and its potential relationship with autoimmune disorders. For this purpose, in this work we used Jurkat cells as a T cell model, and we lentivirally transfected them to express the NTAL adaptor in order to analyze the effect on intracellular signals associated with the TCR. In addition, we analyzed the expression of NTAL in primary CD4+ T cells from healthy donors and Rheumatoid Arthritis (RA) patients. Our results showed that NTAL expression in Jurkat cells decreased calcium fluxes and PLC-γ1 activation upon stimulation through the TCR complex. Moreover, we showed that NTAL was also expressed in activated human CD4+ T cells, and that the increase of its expression was reduced in CD4+ T cells from RA patients. Our results, together with previous reports, suggest a relevant role for the NTAL adaptor as a negative regulator of early intracellular TCR signaling, with a potential implication in RA.

Prevalencia de enfermedades reumáticas en población adulta en España (estudio EPISER 2016). Objetivos y metodología / Prevalence of rheumatic diseases in adult population in Spain (EPISER 2016 study): Aims and methodology

Objetivos: Describir la metodología del estudio de prevalencia de las enfermedades reumáticas en la población adulta en España, EPISER 2016, así como sus fortalezas y limitaciones. El objetivo del proyecto es estimar la prevalencia de artritis reumatoide (AR), artropatía psoriásica (APs), espondilitis anquilosante (EA), lupus eritematoso sistémico (LES), síndrome de Sjögren (SS), artrosis (de rodilla, cadera, manos, columna cervical y lumbar), fibromialgia, gota y fractura osteoporótica clínica. Material y método: Estudio transversal multicéntrico de base poblacional en el que participan 45 municipios de las 17 comunidades autónomas. La población de referencia está compuesta por adultos de 20 o más años residentes en España. La recogida de información se llevará a cabo mediante encuesta telefónica empleando el sistema Computer Assisted Telephone Interview (CATI). Las sospechas diagnósticas y los diagnósticos autorreferidos serán estudiadas por reumatólogos del hospital de referencia de los municipios seleccionados. Análisis estadístico: se calcularán las prevalencias de enfermedades reumáticas mediante estimadores y sus IC del 95%. Se calcularán factores de ponderación en función de la probabilidad de selección en cada una de las etapas del muestreo. Se tendrá en cuenta la distribución de la población en España según datos del Instituto Nacional de Estadística. Conclusiones: Los cambios sociodemográficos y en hábitos de vida durante los últimos 16 años justifican la realización de EPISER 2016. El estudio ofrecerá datos actualizados de prevalencia en AR, EA, APs, LES, SS, artrosis, fibromialgia, gota y fractura osteoporótica clínica. Los resultados permitirán comparar los datos con estudios de otros países y con el EPISER 2000

Aims: To describe the methodology of the EPISER 2016 (study of the prevalence of rheumatic diseases in adult population in Spain), as well its strengths and limitations. The aim of this study is to estimate the prevalence of rheumatoid arthritis (RA), psoriatic arthritis (PsA), ankylosing spondylitis (AS), systemic lupus erythematosus (SLE), Sjögren's syndrome (SS), osteoarthritis (knee, hip, hands, and cervical and lumbar spine), fibromyalgia, gout and clinical osteoporotic fracture. Material and method: Population-based, multicenter, cross-sectional study, with the participation of 45 municipalities in the 17 Spanish autonomous communities. The reference population will consist of adults aged 20 years and over residing in Spain. A computer-assisted telephone interview (CATI) system will be used for data collection. Diagnostic suspicions and diagnoses received by the participants will be studied by rheumatologists in the referral hospitals in the selected municipalities. Statistical analysis: the prevalence of the rheumatic diseases will be calculated using estimators and their 95% confidence intervals. Weights will be calculated in each of the sampling stages in accordance with the probability of selection. The distribution of the population in Spain will be obtained from the Spanish Statistics Institute. Conclusions: Sociodemographic and lifestyle changes over the last 16 years justify EPISER 2016. This study will provide current data about the prevalences of RA, AS, PsA, SLE, SS, osteoarthritis, fibromyalgia, gout and clinical osteoporotic fracture. The results will allow comparisons with studies from other countries and EPISER 2000

Autoreactive B-lymphocytes in SLE and RA patients: Isolation and characterisation using extractable nuclear and citrullinated antigens bound to immunobeads.

Systemic lupus erythematosus and rheumatoid arthritis are autoimmune diseases characterised by B-cell hyperactivation and production of autoantibodies (AutoAbs) against various self-antigens, including extractable nuclear antigens and citrullinated peptides. Therefore, B lymphocytes and antibody-secreting cells are considered relevant targets for therapies. However, isolation and characterisation of auto-reactive specific B lymphocytes are limited, primarily due to technical issues. In this work, we purified extractable nuclear antigen-specific and citrullinated peptide-specific auto-reactive B lymphocytes by magnetic selection with ENA- and citrullinated peptide-bound immunobeads. We obtained blood auto-reactive B lymphocytes from most patients. Their nature was primarily naïve B cells, some of them in an active status, with low levels of somatic hypermutations in the immunoglobulin heavy-chain variable regions. Their presence correlated with serum levels of autoAb. Auto-reactive B lymphocytes were able to differentiate into auto-reactive antibody-secreting cells under conditions of stimulation. In addition, based on the presence of circulating auto-reactive B cells and/or antibody-secreting cells, four different profiles were described in lupus patients. Thus, tracking auto-reactive B cells and/or antibody-secreting cells in patient blood could represent a biomarker for deciding whether to use therapies blocking either B cells, plasma cells or both, as well as a new tool for monitoring minimal residual autoimmune disease in patients.

Prevalence of rheumatic diseases in adult population in Spain (EPISER 2016 study): Aims and methodology. / Prevalencia de enfermedades reumáticas en población adulta en España (estudio EPISER 2016). Objetivos y metodología.

AIMS: To describe the methodology of the EPISER 2016 (study of the prevalence of rheumatic diseases in adult population in Spain), as well its strengths and limitations. The aim of this study is to estimate the prevalence of rheumatoid arthritis (RA), psoriatic arthritis (PsA), ankylosing spondylitis (AS), systemic lupus erythematosus (SLE), Sjögren's syndrome (SS), osteoarthritis (knee, hip, hands, and cervical and lumbar spine), fibromyalgia, gout and clinical osteoporotic fracture. MATERIAL AND METHOD: Population-based, multicenter, cross-sectional study, with the participation of 45 municipalities in the 17 Spanish autonomous communities. The reference population will consist of adults aged 20 years and over residing in Spain. A computer-assisted telephone interview (CATI) system will be used for data collection. Diagnostic suspicions and diagnoses received by the participants will be studied by rheumatologists in the referral hospitals in the selected municipalities. STATISTICAL ANALYSIS: the prevalence of the rheumatic diseases will be calculated using estimators and their 95% confidence intervals. Weights will be calculated in each of the sampling stages in accordance with the probability of selection. The distribution of the population in Spain will be obtained from the Spanish Statistics Institute. CONCLUSIONS: Sociodemographic and lifestyle changes over the last 16 years justify EPISER 2016. This study will provide current data about the prevalences of RA, AS, PsA, SLE, SS, osteoarthritis, fibromyalgia, gout and clinical osteoporotic fracture. The results will allow comparisons with studies from other countries and EPISER 2000.

Hypersensitivity to alemtuzumab. A safe and effective desensitization protocol: A case report.

We describe a successful desensitization to alemtuzumab in one patient diagnosed with T-cell prolymphocytic leukaemia. Alemtuzumab treatment was initiated during infusion number 18, the patient showed cutaneous eruption with a miliary pattern, despite premedication with corticosteroids and antihistamines. The eruption returned with successive alemtuzumab infusions (infusions 19, 20 and 21), remained present for longer and was more severe with each infusion. The patient was referred to our Allergy Unit as it was necessary to maintain alemtuzumab treatment. Total immunoglobulin E level was 3 UI/ml and specific immunoglobulin E against more common pneumo-allergens, food, latex and hamster were inferior to 0.35 UI/ml. Prick test using the undiluted drug (30 mg/ml) and intradermal tests using serial dilutions (1/10, 1/100) were performed. The result of alemtuzumab skin prick test was 4 mm. The intradermal skin test result was positive at 1/100 dilution (papule: 8 mm; erythema: 12 mm). The basophil activation test with alemtuzumab was performed concluding that 10% of the basophils were activated by alemtuzumab. The patient underwent alemtuzumab desensitization according to a 12-step protocol that resolved to be safe and efficacious. Our experience may be helpful for similar clinical cases where the therapeutic options are very limited and a life-threatening condition such T-cell prolymphocytic leukaemia is present. In addition, a careful risk/benefit ratio should be considered and accurate informed consent is mandatory.

Clinical relevance of circulating anti-ENA and anti-dsDNA secreting cells from SLE patients and their dependence on STAT-3 activation.

Disturbances of plasma cell homeostasis and auto-antibody production are hallmarks of systemic lupus erythematosus. The aim of this study was to explore the presence of circulating anti-ENA and anti-dsDNA antibody-secreting cells, to determine their dependence on plasma cell-niche cytokines and to analyze their clinical value. The study was performed in SLE patients with serum anti-ENA and/or anti-dsDNA antibodies (n = 57). Enriched B-cell fractions and sorted antibody-secreting cells (CD19low CD38high ) were obtained from blood. dsDNA- and ENA-specific antibody-secreting cells were identified as cells capable of active auto-antibody production in culture. The addition of a combination of IL-6, IL-21, BAFF, APRIL, and CXCL12 to the cultures significantly augmented auto-antibody production and antibody-secreting cell proliferation, whereas it diminished apoptosis. The effect on auto-antibody production was dependent on STAT-3 activation as it was abrogated in the presence of the JAK/STAT-3 pathway inhibitors ruxolitinib and stattic. Among patients with serum anti-dsDNA antibodies, the detection of circulating anti-dsDNA-antibody-secreting cells was associated with higher disease activity markers. In conclusion, auto-antibody production in response to plasma cell-niche cytokines that are usually at high levels in SLE patients is dependent on JAK/STAT-3 activation. Thus, patients with circulating anti-dsDNA antibody-secreting cells and active disease could potentially benefit from therapies targeting the JAK/STAT3 pathway.