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Background: The etiopathogenesis of autoimmune diseases is multifactorial, including hormonal factors. Remission of autoimmunity has been observed following treatment for concomitant hyperparathyroidism. Additionally, patients with autoimmune diseases have shown increased expression of parathyroid hormone receptor (PTH1R) and altered distribution of B cells subsets. Hence, this study aims to evaluate potential mechanisms and in vitro effects of PTH stimulation on B lymphocytes. Methods: Using the human B-cell line Ramos (RA.1), various biological effects were evaluated with and without parathyroid hormone (PTH) stimulation at varying concentrations. Flow cytometry was employed to evaluate the phenotype of B lymphocytes based on IgD and CD38 expression, apoptosis induction via Annexin V and proliferation using CFSE. IgM production was quantified through ELISA, and Western blot analysis was performed to assess syk protein phosphorylation as an indicator of cell activation. Results: Ramos cells (RA.1) evidenced a statistically significant change in the phenotype under human PTH stimulation, demonstrating an increased proportion of germinal centre cells (Bm3-Bm4) when stimulated with high concentrations of PTH. Conclusions: The in vitro effects of PTH in B cells subsets align with previous findings of an altered phenotype in B lymphocytes expressing PTH1R among autoimmune disease patients, suggesting a potential role of this hormone in the pathophysiology of autoimmune diseases. However, further studies are necessary to elucidate the mechanisms by which PTH generates observed effects in B lymphocytes and to determine if PTH plays a role in autoimmunity.

Abstract Background Viruses are constantly changing as a result of mutations, and new viral variants are expected to appear over time. The virus that causes coronavirus disease 2019, severe acute respiratory syndrome coronavirus 2, is not excluded from this condition. Patients with some types of immunodeficiency have been reported to experience symptoms that vary from mild to severe, or even death, after being infected with severe acute respiratory syndrome coronavirus 2. We report a case of a woman with severe hypogammaglobulinemia who developed a prolonged and fatal severe acute respiratory syndrome coronavirus 2 infection. Case presentation A 60-year-old mestizo female with a previous history of severe hypogammaglobulinemia manifested by recurrent pulmonary infections and follicular bronchiolitis. She received a monthly treatment of intravenous immunoglobulins and was admitted after report of a neurological manifestation related to a left thalamic inflammatory lesion, for a duration of 2 weeks of hospitalization, indicated for the study of her neurological condition, including brain biopsy. Both on admission and 1 week later, nasopharyngeal polymerase chain reaction tests for severe acute respiratory syndrome coronavirus 2 were performed and reported negative. In the third week of hospitalization, she developed pulmonary symptoms, and a positive test result for severe acute respiratory syndrome coronavirus 2 was evidenced. On Day 3, the patients’ condition worsened as the infection progressed to respiratory failure and required mechanical ventilation. On Day 8 after the coronavirus disease 2019 diagnosis, the polymerase chain reaction test for severe acute respiratory syndrome coronavirus 2 showed persistent detection of the virus. Various bacterial coinfections, including Klebsiella pneumoniae and Enterobacter cloacae, were diagnosed and treated. On Day 35, her pulmonary symptoms worsened, and the results of the severe acute respiratory syndrome coronavirus 2 polymerase chain reaction test remained positive. On Day 36, despite all the respiratory support, the patient died. The severe acute respiratory syndrome coronavirus 2 virus was sequenced at the beginning and 8 days after the onset of the disease, and the strain, without obvious mutations in the gene that encodes spike protein, was identified. Conclusions This clinical case showed persistent severe acute respiratory syndrome coronavirus 2 detection after 35 days of infection in a patient with severe hypogammaglobulinemia. The sequencing of the virus showed no mutations on the spike protein at 8 days, indicating that, in this case, the persistence of the viral detection was associated with immunodeficiency instead of changes in the viral components.

We report a case of 65-year-old male patient with primary hyperparathyroidism (PHPT) who was admitted to the hospital for autoimmune manifestations (including autoimmune hepatitis and autoantibody development) and exhibited subsequent clinical and paraclinical improvement after parathyroidectomy. By flow cytometry, the expression of PTH receptor 1 (PTHR1) on B lymphocytes of peripheral blood was documented to be higher than that in healthy controls. After parathyroidectomy, autoimmune manifestations improved, while PTH1R expression on B-lymphocytes increased. The possible role of the dynamics of B-lymphocyte PTHR1 in the development of this autoimmune phenomenon is discussed.

Snake venoms have components with diverse biological actions that are extensively studied to identify elements that may be useful in biomedical sciences. In the field of autoimmunity and rheumatology, various findings useful for the study of diseases and potential drug development have been reported. The study of disintegrins, proteins that block the action of integrins, has been useful for the development of antiplatelet agents and principles for the development of immunosuppressants and antineoplastics. Several proteins in snake venoms act on the coagulation cascade, activating factors that have allowed the development of tests for the study of coagulation, including Russell’s viper venom time, which is useful in the diagnosis of antiphospholipid syndrome. Neurotoxins with either pre- or postsynaptic effects have been used to study neurogenic synapses and neuromuscular plaques and the development of analgesics, muscle relaxants and drugs for neurodegenerative diseases. Various components act by inhibiting cells and proteins of the immune system, which will allow the development of anti-inflammatory and immunosuppressive drugs. This review summarizes the usefulness of the components of snake venoms in the fields of autoimmunity and rheumatology, which can serve as a basis for diverse translational research.

Sjögren’s syndrome (SS) is a systemic autoimmune disease characterised by a wide range of clinical manifestations and complications, including B-cell lymphoma.This study aims to describe the predictors associated with lymphomagenesis in patients with Sjögren’s syndrome, emphasising the pathophysiological bases that support this association. We performed a review of the literature published through a comprehensive search strategy in PubMed/MEDLINE, Scopus, and Web of science. Forty publications describing a total of 45,208 patients with SS were retrieved. The predictors were grouped according to their pathophysiological role in the lymphoproliferation process. Also, some new biomarkers such as MicroRNAs, P2X7 receptor-NLRP3 inflammasome, Thymic stromal lymphopoietin, and Three-prime repair exonuclease 1 (TREX1) were identified.The knowledge of the pathophysiology allows the discrimination of markers that participate in the initial stages. Considering that the lymphoproliferation process includes the progression of lymphoma towards more aggressive subtypes, it is essential to recognise biomarkers associated with a worse prognosis.

Genomic incorporation of viruses as human endogenous retroviruses (HERVs) are components of our genome that possibly originated by incorporating ancestral of exogenous viruses. Their roles in the evolution of the human genome, gene expression, and the pathogenesis of autoimmune diseases (ADs) and neoplastic phenomena are the subject of intense research. This review analyzes the evolutionary and virological aspects of HERVs and other viruses that incorporate their genome into the human genome and have known role in the genesis of ADs. These insights are helpful to understand further the possible role in autoimmunity genesis of HERVs, other ancestral viruses no HERVs and modern viruses with the ability to incorporate into the human genome or interact with HERVs.

Venoms are products of specialized glands and serve many living organisms to immobilize and kill prey, start digestive processes and act as a defense mechanism. Venoms affect different cells, cellular structures and tissues, such as skin, nervous, hematological, digestive, excretory and immune systems, as well as the heart, among other structures. Components of both the innate and adaptive immune systems can be stimulated or suppressed. Studying the effects on the cells and molecules produced by the immune system has been useful in many biomedical fields. The effects of venoms can be the basis for research and development of therapeutic protocols useful in the modulation of the immunological system, including different autoimmune diseases. This review focuses on the understanding of biological effects of diverse venom on the human immune system and how some of their components can be useful for the study and development of immunomodulatory drugs.

Background: B-cell activating factor (BAFF), a proliferation-inducing ligand (APRIL), and their receptors BAFF-R, BCMA, and TACI are crucial factors for the survival of B lymphocytes. Recent evidence has also demonstrated the importance of BAFF/APRIL signaling in lupus nephritis (LN). This study evaluated the relationships between LN clinical characteristics and the urinary expression levels of BAFF, APRIL, and cognate receptors to assess their potential value as disease biomarkers. Methods: Expression levels of these genes were assessed in urine samples collected from systemic lupus erythematosus (SLE) patients before renal biopsy using reverse transcription real-time PCR. Results: Thirty-five patients with LN were included. Most of the patients were female (82.86%) with median Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) of 15. BAFF mRNA was detectable in 28.57%, APRIL mRNA in 42.85%, BR3 mRNA in 48.57%, and TACI mRNA in 42.85% of urine samples. On the other hand, urinary (u)BCMA mRNA was not found in any sample. Urinary expression of most biomarkers was detected with greater frequency in class III and IV LN compared to class V LN. The expression level of uBR3 mRNA was correlated with SLEDAI-2K and histological activity index. Conclusion: Urinary expression of BAFF/APRIL signaling factors, especially TACI, APRIL, and BR3 mRNAs, may be useful biomarkers for LN.

Cathelicidin LL-37 is an antimicrobial peptide that is synthesized by epithelial cells, neutrophils, or lymphocytes and act as an essential defense mechanism against bacterial, viral, or fungi infection of eukaryotic organisms. However, in recent years, this cathelicidin has gained the interest of the scientific community because, besides its antimicrobial properties, LL-37 is an immunomodulator that can contribute to the development of autoimmune diseases. The other non-antimicrobial function of this cathelicidin is its ability to form complexes with the DNA, stimulating plasmacytoid dendritic cells (pDCs) to produce type I IFN, deciding the course of autoimmune diseases, including systemic lupus erythematosus (SLE). The chronic activation of pDCs by surrounding complexes is a crucial factor for the early development of autoimmunity in SLE patients. This stimulation is given by the complexes (LL-37-DNA/anti-DNA) recognized by the receptor FcγRII on pDCs, allowing its endocytosis and its recognition via TLR9, leading to the activation of pDCs and enhanced type I IFN production. In this article, we reviewed the structure, function, and importance of LL-37 in innate immunity, as well as its biological plausibility in the pathophysiology of autoimmune diseases such as SLE. In this narrative review, we included primary journal articles describing the function, structure, prevalence, and importance of LL-37 in various manifestations of SLE, as well as LL-37 and anti-LL37 antibodies in patients with SLE or other autoimmune diseases. In conclusion, LL-37 is an essential molecule in the pathophysiology of SLE, mainly by its role in increasing the production of IFN by pDCs, which postulates it as a crucial molecule in the pathophysiology of SLE and, given plausibility biology, could serve as a biomarker of the disease.

Systemic lupus erythematosus (SLE) is the prototypical autoimmune disease that can affect any organ of the body. Multiple mechanisms may contribute to the pathophysiology of systemic lupus, including failure to remove apoptotic bodies, hyperactivity of self-reactive B and T lymphocytes, abnormal exposure to autoantigens, and increased levels of B-cell stimulatory cytokines. The involvement of the kidney, called lupus nephritis (LN), during the course of the disease affects between 30% and 60% of adult SLE patients, and up to 70% of children. LN is an immune-mediated glomerulonephritis that is a common and serious finding in patients with SLE. Nowadays, renal biopsy is considered the gold standard for classifying LN, besides its degree of activity or chronicity. Nevertheless, renal biopsy lacks the ability to predict which patients will respond to immunosuppressive therapy and is a costly and risky procedure that is not practical in the monitoring of LN because serial repetitions would be necessary. Consequently, many serum and urinary biomarkers have been studied in SLE patients for the complementary study of LN, existing conventional biomarkers like proteinuria, protein/creatinine ratio in spot urine, 24 ​h urine proteinuria, creatinine clearance, among others and non-conventional biomarkers, like Monocyte chemoattractant protein-1 (MCP-1), have been correlated with the histological findings of the different types of LN. In this article, we review the advances in lupus nephritis urinary biomarkers. Such markers ideally should be capable of predicting early sub-clinical flares and could be used to follow response to therapy. In addition, some of these markers have been found to be involved in the pathogenesis of lupus nephritis.

Non-tuberculous mycobacterias (NTM) are important pathogens responsible for a broad spectrum of diseases in humans. Although exposure is widespread since they are distributed in the environment, the development of the disease is rare. It will depend on the specific species, their virulence (only 50 have been found to cause disease), and the host’s immune response. M Mycobacterium Malmoense is a NTM first reported in 1977 at Malmö, Sweden, based on four cases of lung infections. After these, other infections have been reported mainly involving the respiratory tract. Extrapulmonary infections are limited to cervical adenitis, and rarely to tenosynovitis and disseminated disease. We are hence reporting, to our knowledge, the first case of M. malmoense as the cause of bacterial endocarditis in the world.

Introduction. Therapeutic plasma exchange (TPE) is commonly used as treatment of certain autoimmune neurological diseases (ANDs), and its main objective is the removal of pathogenic autoantibodies. Our aim was to describe the clinical profile and the experience with the usage of TPE in patients with ANDs at our institution. Methods. This is an observational retrospective study, including medical records of patients with diagnosis of ANDs who received TPE, between 2011 and 2018. Characteristics of TPE, such as number of cycles, type of replacement solution, and adverse effects, were evaluated. The modified Rankin Scale (mRS) was applied to measure the clinical response after the therapy. Results. 187 patients were included with the following diagnoses: myasthenia gravis (MG), n = 70 (37%); Guillain–Barré syndrome (GBS), n = 53 (28.3%), neuromyelitis optica spectrum disorders (NMOSD), n = 35 (18.7%); chronic inflammatory demyelinating polyneuropathy (CIDP), n = 23 (12.2%); and autoimmune encephalitis (AE), n = 6 (3.2%). The most used types of replacement solution were albumin (n = 131, 70%) and succinylated gelatin (n = 45, 24%). All patients received a median of five cycles (IQR 5-5). Hypotension and hydroelectrolytic disorders were the main complications. After TPE, 99 patients (52.9%) showed improvement in the mRS scores and a statistical significance (p

Objective: Bariatric surgery is a widely used procedure for the treatment of obesity. Our aim is to describe the main immunological changes in patients who undergo bariatric surgery. Methods: A prospective study was conducted within a cohort of patients undergoing bariatric surgery and without previous evidence of systemic or organ-specific autoimmune diseases in whom 3 blood samples were collected – one day before surgery (Time 0), and 5 (Time 1) and 10 months (Time 2) after surgery. Results: Thirty four obese patients underwent surgery (Time 0):30(88.24%) were women, mean age 38.3 years. When comparing Time 0 and Time 2, there were statistically significant changes in CD4+T cell count, with an increase from 1074/mL(IQR:860–1316) to 1217.5/mL(IQR:838–1510),p = 0.0002. The CD4/CD8 ratio increased from 2.2(IQR: 1.7–2.7) to 2.4(1.8–2.8), p = 0.0001. As for humoral variables, the C3 fraction of complement decreased from 164 ± 40.6 mg/dL to 112.4 ± 31.4 mg/dL(p 200 IU/mL at Time 2. Conclusions: Patients undergoing bariatric surgery show immunological changes which might eventually lead to develop an autoimmune disease. Keywords: Bariatric surgery, Autoimmune diseases, Immunology

Introducción y objetivo: El lupus eritematoso sistémico (LES) es una enfermedad multiorgánica mediada principalmente por el depósito de complejos inmunes en órganos blanco, los cuales pueden ser removidos rápidamente mediante plasmaféresis, considerándose esta modalidad terapéutica clave para el manejo de pacientes críticos, sumado al tratamiento inmunosupresor. Nuestro objetivo es describir las principales características clínicas y desenlaces de pacientes con LES quienes recibieron manejo con recambio plasmático terapéutico (PEX) en un hospital de alta complejidad del suroccidente colombiano. Métodos: Se realizó un estudio descriptivo, donde se incluyeron pacientes con diagnóstico de LES quienes hayan recibido PEX. Resultados: Un total de 40 pacientes fueron incluidos. El promedio de edad fue de 28.5 años, la mayoría de pacientes eran de sexo femenino n=32 (80%). Los pacientes presentaban una enfermedad con actividad severa, calculada por SLEDAI, con una mediana de 19.5 (8.530), así como elevación de anti-DNA de doble cadena y consumo del complemento (Tabla 1). La principal indicación de PEX en esta serie fue la hemorragia alveolar difusa (HAD) en 11 (27.5%) pacientes, seguido de Neurolupus en 9 (22.5%) (Tabla 2). Ningún paciente murió a causa de la plasmaféresis y la mayor complicación fue sangrado no amenazante para la vida (Tabla 3). Los desenlaces generales fueron mejoría en 25 pacientes (62.5%) (Tabla 4). Conclusiones: El PEX es un procedimiento seguro y efectivo en pacientes con LES severo, sin embargo, faltan estudios que aporten mayor información acerca del número de sesiones y tipo de recambio plasmático que se debería utilizar.

Implication for health policy/practice/research/medical education: Despite Chikungunya virus was considered a benign illness, it is very important to recall thatsevere atypical manifestations can occur generating high morbidity rates. Early detection ofthese complications may help clinicians to improve clinical outcomes.

Introduction. Autoimmune diseases include a diverse and complex group of pathologies with a broad clinical spectrum due to the production of autoantibodies, which generates multisystemic compromise. Therapeutic plasma exchange (TPE) is a good additive treatment for immunosuppression due to its action over the autoantibodies. Objectives. To describe the main clinical characteristics and outcomes of patients with systemic lupus erythematosus and other systemic autoimmune diseases managed with TPE. Methodology. This descriptive retrospective study enrolled patients with systemic autoimmune diseases who received TPE. Results. In total, 66 patients with a median age of 33.5 years (24-53 years) were included; the majority were females [n=51 (77.27%)]. Forty (60.61%) patients were diagnosed with systemic lupus erythematosus. In these cases, the main indication for TPE was diffuse alveolar hemorrhage (DAH; n=20, 30.3%) and neurolupus (n=9, 13.6%). No TPE-related deaths occurred, and the main complication was hemorrhage, without significant differences among the four types of TPE solutions used. The overall outcome was improvement in 41 (62.12%) patients. Conclusion. TPE is safe and effective in patients with severe manifestations of autoimmune diseases.

The current goals in the development of novel therapeutics of systemic autoimmune diseases are to develop agents more effective than conventional therapies as well as to reduce the risk of organ damage. To achieve this goal, large multicentre randomised controlled trials are needed to confirm the efficacy and safety of novel agents. Whether these novel modalities are synergistic to conventional drugs, the optimal dosages, and duration of treatment, need to be explored. As expected, the development of new molecules for the treatment of autoimmune diseases is constant, and there are different ongoing clinical trials. We review the different molecules in the pipeline, summarised in Tables 1, 2, and 3. We also show the successes, failures, and molecules that require more evidence.

Introducción: La diferenciación entre actividad lúpica de infecciones en pacientes con lupus eritematoso sistémico (LES) es difícil debido a una presentación clínica similar. El objetivo es evaluar la utilidad de una serie de biomarcadores para diferenciar infecciones de actividad en pacientes con LES admitidos con respuesta inflamatoria sistémica (SIRS). Métodos: Pacientes con LES y SIRS que consultaron al servicio de urgencias fueron seleccionados. Se realizaron mediciones de diferentes marcadores como procalcitonina, expresión de CD64 de neutrófilos y presepsina al ingreso y fueron comparados con la presencia o no de infección, la cual se consideró presente con cultivos positivos y/o evidencia microbiológica por PCR. Se calculó la sensibilidad y especificidad de cada biomarcador y puntos de corte usando curvas ROC. Resultados: Se incluyeron 27 pacientes, 23 mujeres (82,5%), edad media de 33,2 años. En 12 casos se confirmó infección. Marcadores de actividad lúpica como el anti-ADN por IFI (p=0,041) y ELISA (p=0,009) fueron asociados a actividad, mientras que los niveles de C3 (p=1) y C4 (p=0,547) no fueron diferentes entre los pacientes con y sin infección. Por el contrario, los niveles elevados de procalcitonina (p=0.047), expresión de CD64 de neutrófilos (p=0.037) y niveles de presepsina (p=0.037) fueron encontrados de forma significativa en pacientes infectados (Tabla 1). Conclusiones: La expresión de CD64 de neutrófilos, los niveles de presepsina y procalcitonina son útiles para diferenciar las infecciones de actividad en pacientes con LES y SIRS. Un bioscore positivo que incluye estos tres marcadores permite demostrar la presencia de una enfermedad infecciosa (Figura 1).

We present a 74-year-old female patient who developed a pityriasis lichenoides chronica (PLC) during etanercept therapy. This association is not described in the literature and might be considered in the spectrum of cutaneous adverse reactions of etanercept.

En el presente estudio se examinó la especificidad y la sensibilidad de los anticuerpos antipéptidos citrulinados cíclicos (CCP) en pacientes latinoamericanas con artritis reumatoidea (AR), así como su relación con la actividad de la enfermedad, manifestaciones extraarticulares (MEA), síntesis de citocinas (IL-4, IL-10, IL-12, TNF-? e IFN-?) y factor reumatoideo (FR) IgM e IgA, y con el polimorfismo del HLA-DRB1. Se examinaron 79 pacientes con AR (69 con AR establecida y 10 con AR temprana sin previo tratamiento), 56 pacientes con espondilitis anquilosante (EA), 25 con lupus eritematoso sistémico (LES), 50 con síndrome de Sjögren primario (SSp) y diez individuos sanos. De las 69 pacientes con AR establecida, 36 fueron reevaluadas 2 años después. La actividad de la AR se examinó según los criterios del Colegio Americano de Reumatología. Los anticuerpos anti-CCP2, el FR y los niveles de citocinas se determinaron mediante inmunoensayo, y la genotipificación del HLA se llevó a cabo por reacción en cadena de la polimerasa utilizando mezclas de iniciadores específicos. Los anticuerpos anti-CCP se observaron en 96% de los pacientes con AR en la primera evaluación y en 86% en la segunda (p=0,12), sin modificación significativa en los valores (131±58,7 vs. 130,6±67,1 UI). Su sensibilidad y especificidad global fue de 94% y 92%, respectivamente, pero cuando sólo se consideraron los niveles altos (>60 UI) fueron de 84% y 95%, respectivamente. La razón de probabilidades (RP) positiva fue de 12 y la RP negativa de 0,06. El valor predictivo (VP) positivo fue de 87% y el VP negativo de 96%. Los anticuerpos anti-CCP se observaron en 12% de los pacientes con LES y con SSp, en 2% de los de EA y en 10% de los controles sanos. En los pacientes con AR no se asociaron con la actividad de la enfermedad, MEA y alelos del HLA-DRB1. Tampoco se observaron correlaciones significativas entre sus valores y los niveles de citocinas. En conclusión, los anticuerpos anti-CCP tienen un interés diagnóstico para la AR en nuestra población, pero su utilidad en el seguimiento clínico es limitada y su síntesis es independiente del HLA-DRB1 y no se correlacionan con niveles de citocinas Th1/Th2.

Rheumatoid arthritis (RA) is an autoimmune disease characterized by synovial membrane inflammation and joint cartilage destruction. Abatacept is a biologic agent that blocks the costimulation signals, preventing antigen presentation and proliferation of T lymphocytes. It is approved for the treatment of patients with RA. Pneumocystis jirovecii pneumonia (PJP) is an infectious disease complicating several immunosuppressive drugs. PJP associated with abatacept has not been reported yet in the medical literature. Various factors, such as the mechanism of action of abatacept, may contribute to predisposing to Pneumocystis jirovecii infection. In this paper, we report a patient with RA who developed PJP under abatacept treatment.

Systemic lupus erythematosus (SLE) is a chronic inflammatory autoimmune disease with high morbidity if untreated. Sometimes, despite aggressive treatments, the disease remains active with cumulative organic damage. We conducted a retrospective and descriptive observational study of patients with SLE refractory to conventional treatment who were treated with rituximab (RTX) as remission induction therapy and maintenance. There was a significant reduction in the conventional immunosuppressive drug dose and the number of relapses of disease. RTX appeared to be effective and safe for the induction and maintenance of remission in patient with SLE refractory to conventional treatment.

We describe a 67-year-old woman who developed c-ANCA positive vasculitis with involvement in eyes, skin, kidney, peripheral nerves, and upper and lower airway during treatment with etanercept therapy for rheumatoid arthritis. A diagnosis of Granulomatosis with Polyangiitis was done. Thus, anti-TNF therapy may be associated with the development of ANCA positive vasculitis.

Still's disease (SD) is a multisystemic inflammatory disease characterized by persistent arthritis and in many cases with fever of unknown origin. Diagnosis of SD is challenging because of nonspecific characteristics and especially in the case of a patient with solid organ transplantation and immunosuppressive therapy where multiple causes of fever are possible. There is no diagnostic test for SD, even though some useful diagnostic criteria or laboratory findings, such as serum ferritin levels, have been proposed, and useful imaging studies for the diagnosis or followup of SD have not been developed. We report the case of a 9-year-old child who presented with high grade fever associated with joint pain after a history of liver transplantation and immunosuppressive therapy. Laboratory tests showed increased acute phase reactants, elevated ferritin, and leukocytosis. An 18 F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) was performed identifying abnormal hypermetabolic areas localized in spleen, transplanted liver, and bone marrow secondary to inflammatory process. All infectious, autoimmune, and malignant causes were ruled out. A diagnosis of SD was performed and a steroid-based regimen was initiated with adequate response and no evidence of recurrence. To our knowledge this is the first case of SD following a solid organ transplant.

Primary Sjögren's syndrome (pSS) is an autoimmune disorder of the exocrine glands presenting with progressive ocular and oral dryness, parotid gland enlargement, and often with extraglandular manifestations. In this group of patients the risk of development of non-Hodgkin's lymphoma is 16-fold compared to healthy population, mainly of the MALT lymphoma type. This case reports a 52-year-old woman with pSS developing a progressively growing mass at face and neck compatible with blastoid variant mantle cell lymphoma and a fatal outcome.

B lymphocytes are the effectors of humoral immunity, providing defense against pathogens through different functions including antibody production. B cells constitute approximately 15% of peripheral blood leukocytes and arise from hemopoietic stem cells in the bone marrow. It is here that their antigen receptors (surface immunoglobulin) are assembled. In the context of autoimmune diseases defined by B and/or T cell autoreactive that upon activation lead to chronic tissue inflammation and often irreversible structural and functional damage, B lymphocytes play an essential role by not only producing autoantibodies but also functioning as antigen-presenting cells (APC) and as a source of cytokines. In this paper, we describe B lymphocyte functions in autoimmunity and autoimmune diseases with a special focus on their abnormalities in systemic lupus erythematosus.

The primary angiitis of the central nervous system (PACNS) is an entity with a very low incidence and prevalence. It is not clear why the inflammatory process of this entity is limited to the cerebral vasculature without systemic manifestations. Its clinical manifestations are very heterogeneous and make clinical diagnosis difficult. In most cases, a brain biopsy is required. Only the clinical suspicion and the ability to recognize the possible clinical and imagenological patterns of presentation make an accurate diagnosis possible. The vast majority of the treatment recommendations are given by series of case reports. The following paper described the clinical, imagenological, and histopathological characteristics of three Colombian patients with PACNS. The strategic therapeutic used in shown.

Sjögren's syndrome is an autoimmune disease characterized by an autoimmune exocrinopathy involving mainly salivary and lacrimal glands. The histopathological hallmark is periductal lymphocytic infiltration of the exocrine glands, resulting in loss of their secretory function. Several systemic manifestations may be found in patients with Sjögren's syndrome including neurological disorders. Neurological involvement ranges from 0 to 70% among various series and may present with central nervous system and/or peripheral nervous system involvement. This paper endeavors to review the main clinical neurological manifestations in Sjögren syndrome, the physiopathology, and their therapeutic response.