Development and Validation of Nosocomial Bacterial Infection Prediction Models for Patients With Systemic Lupus Erythematosus.

BACKGROUND: Hospital-acquired bacterial infections are associated with high morbidity and mortality rates in patients with systemic lupus erythematosus (SLE). This study aimed to develop and validate predictive models for the risk of hospital-acquired bacterial infections in patients with SLE. METHODS: A historical cohort study was designed for development, and another bidirectional cohort study was used for external validation. The risk of bacterial infection was assessed upon admission and after 5 days of hospitalization. Predictor selection employed the least absolute shrinkage and selection operator (LASSO) techniques. Multiple imputations were used to handle missing data. Logistic regression models were applied, and the properties of discrimination, calibration, and decision curve analysis were evaluated. RESULTS: The development cohort comprised 1686 patients and 237 events (14.1%) from 3 tertiary hospitals. The external validation cohort included 531 patients and 84 infection outcomes (15.8%) from 10 hospital centers in Colombia (secondary and tertiary level). The models applied at admission and after 120 hours of stay exhibited good discrimination (AUC > 0.74). External validation demonstrated good performance among patients from the same tertiary institutions where the models were developed. However, geographic validation at other institutions has been suboptimal. CONCLUSIONS: Two predictive models for nosocomial bacterial infections in patients with SLE are presented. All infection prevention recommendations should be maximized in patients at moderate/high risk. Further validation studies in diverse contexts, as well as clinical impact trials, are necessary before potential applications in research and clinical care.

Circulating extracellular vesicles in Systemic Lupus Erythematosus: physicochemical properties and phenotype.

OBJECTIVE: This study aimed to identify the physicochemical and phenotypic characteristics of circulating Extracellular Vesicles (EVs) in the plasma of patients with SLE, with or without Lupus Nephritis (LN), and their potential utility as disease biomarkers. METHODS: Plasma-circulating EVs were concentrated using differential centrifugation from adult female patients (n=38) who met the 'American College of Rheumatology/European Alliance of Associations for Rheumatology 2019' criteria for SLE diagnosis with (LN) or without LN (nLN), confirmed by renal biopsy. Controls (n=18) were healthy volunteers matched by gender and similar age. The structure, size and Energy Dispersion Spectrum (EDS) of EVs were observed by electron microscopy. The surface charge and size distribution were evaluated using dynamic light scattering. The counts and phenotype of EVs from patients (SLE-EVs) and controls (Ctrl-EVs) were obtained using flow cytometry. Non-parametric statistical tests and exploratory analysis of multiple variables were performed. The discriminatory power of some variables as potential biomarkers of the disease was also evaluated. RESULTS: Circulating EVs were heterogeneous in morphology and size, but SLE-EVs reached larger diameters than Ctrl-EVs (p<0.0001). Small SLE-EVs and large SLE-EVs were increased compared with Ctrl-EV (p<0.0001 and p<0.05, respectively). Likewise, patients with SLE (LN or nLN) had higher concentrations of large EVs compared with controls (p<0.001 and p<0.0001, respectively). SLE-EVs showed a different EDS (p<0.001) and were less electronegative (p<0.0001) than Ctrl-EVs. EV-CD45+, EV-CD14+ and EV-IgM+ were more frequent in patients with SLE compared with controls (p<0.001, p<0.05 and p<0.001, respectively). The concentrations of large EVs and EV-IgM+ allowed better discrimination of patients from controls. CONCLUSIONS: Plasma-circulating EVs from patients with SLE with and without nephritis are increased in peripheral blood and have different physicochemical properties than controls. Characteristics of EVs such as larger size and the presence of IgM on the surface could help discriminate patients from controls.

NETosis Secondary to the Use of Levamisole-Adulterated Cocaine: A Likely Underlying Mechanism of Vasculopathy.

Background: Since 2010, several cases of a new vasculopathy induced by the use of levamisole-adulterated cocaine (LAC) have been reported. This vasculopathy is characterized by retiform purpura, earlobe necrosis, multisystem compromise, and multiple autoantibodies. Given its similarity to antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis, LAC-associated vasculopathy is postulated to be mediated by pathophysiologic processes resulting from neutrophil cell death by NETosis, a phenomenon previously described in ANCA vasculitis. This study tries to establish the presence of NETosis induced by cocaine, levamisole, or both. Methodology. Neutrophils were isolated from the peripheral blood of healthy controls by Ficoll-Hystopaque density gradient centrifugation followed by dextran sedimentation. Cell viability and purity were evaluated by flow cytometry after staining with PI/DiOC6 and labeling with fluorescent anti-CD45/anti-CD3 monoclonal antibodies (mAbs), respectively. Neutrophils were exposed to levamisole, cocaine, a cocaine-levamisole mixture, and sera pools from healthy controls and patients with LAC-associated vasculopathy. NETosis was then assessed by flow cytometry after staining cells with Sytox Green, Hoechst-33342, and fluorescent antineutrophil elastase (NE) and antimyeloperoxidase (MPO) mAbs. In addition, NETosis was morphologically confirmed by fluorescence microscopy. Proinflammatory cytokine levels in culture supernatants and reactive oxygen species (ROS) synthesis were determined by flow cytometry. The involvement of calcium and muscarinic receptors in cell death induction was evaluated in parallel experiments carried out in the presence of 1,2-bis (o-aminophenoxy) ethane-N, N, N', N'-tetraacetic acid (BAPTA) and hyoscine butylbromide (HBB), their respective inhibitors. Results: Cocaine, levamisole, and a cocaine-levamisole mixture induced neutrophil cell death. DNA/MPO extrusion and cell morphology patterns were consistent with NETosis. Neither proinflammatory cytokines nor ROS behaved as proNETotic factors. Preliminary results suggested that muscarinic receptors and calcium-dependent signals were involved in LAC-induced NETosis. Conclusions: Cocaine, levamisole, and a cocaine-levamisole mixture can induce NETosis through mechanisms involving muscarinic receptors and calcium-dependent pathways.

Lupus enteritis: A 10-year experience in a single Latin American center.

OBJECTIVE: The objective is to compare the clinical and laboratory characteristics of systemic lupus erythematosus (SLE) patients with and without lupus enteritis (LE) and to identify the factors associated with the occurrence of LE. METHODS: We performed a retrospective, case-control study in hospitalized patients with SLE who were admitted to our tertiary hospital between January 2012 and December 2021. Sixteen LE patients (cases) were matched (1:3 ratio) for sex and birth year with 48 non-LE patients (controls). Univariable and multivariable logistic regression analyses were used to identify the variables associated with LE. RESULTS: Of 2,479 SLE patients who were admitted to our hospital as inpatients, 16 (0.65%) were diagnosed as having LE. All patients, cases and controls, were of Mestizo ethnicity. SLE was diagnosed simultaneously with the first episode of LE in 10 (62.5%) patients. The median time from SLE diagnosis to the first episode of LE was 7 (IQR 0-78) months. LE patients had a shorter median disease duration [7 (0-78) vs 34 (9.5-79) months], and a significantly longer hospital stay (28.3 ± 15.8 vs 6.5 ± 7.9 days, p < 0.001) than non-LE patients. Most LE patients (93.8%) had concomitant lupus nephritis. LE patients had higher SLEDAI-2K scores than those without LE (20.5 ± 9.4 vs 9.8 ± 10.4, p < 0.001). By multivariable analysis, a higher SLEDAI-2K score (OR 1.10, 95% CI 1.02-1.18; p = 0.015) was independently associated with LE occurrence after adjusting for cutaneous involvement, lymphocyte count, serum creatinine, and serum complement C4. Recurrence was observed in two patients (12.5%), both with a bowel wall thickening > 8 mm. The two patients with large intestine-dominant LE developed intestinal pseudo-obstruction. No patient had life-threatening complications (intestinal hemorrhage, infarction, or perforation), and there were no deaths induced directly by LE itself. CONCLUSION: In patients of Mestizo ethnicity, LE occurs during the early course of SLE, frequently is one of the presenting manifestations of SLE, and in most cases, it presents with concomitant lupus nephritis. Higher levels of disease activity at diagnosis were independently associated with LE occurrence and when recurrences occur, they do so in the context of severe wall thickness.

Relevance of non-criteria antiphospholipid antibodies titers among patients with antiphospholipid syndrome and patients with systemic lupus erythematosus.

BACKGROUND: There is an increasing interest in the study of non-criteria antiphospholipid antibodies (aPL) including antibodies targeting domain 1 of the B2 glycoprotein 1 (anti-D1 B2GP1) and antibodies anti phosphatidylserine/ prothrombin (PS/PT). OBJECTIVES: Our aim was to analyze a panel of conventional and non-criteria aPL in a cohort of patients with systemic lupus erythematosus (SLE) and primary antiphospholipid syndrome (APS), to describe if there are differences in aPL titers among groups, to evaluate clinical associations including risk of recurrent events of novel aPL. METHODS: Observational study that evaluated at baseline antibodies against anti-D1 B2GP1 and anti PS/PT. Anti-D1 B2GP1 antibodies were tested using a chemiluminescent immunoassay. IgG and IgM anti PS/PT, aCL and anti B2GP1 by ELISA techniques. Therefore, patients were followed in order to identify new thrombotic events. RESULTS: 133 patients with SLE and 23 with primary APS patients were included. Main APS manifestations were DVT (27%), obstetric morbidity (22%) and arterial thrombosis (10.1%). IgM anti PS/PT antibodies levels were (20.6 - 127) vs 21.9 (11.2 - 39.2) U/ml, p<0.001 in primary APS vs SLE with APS, respectively. Anti-D1 B2GP1, IgG and IgM anti PS/PT were associated with thrombotic and non-thrombotic manifestations. During follow-up, IgG B2GP1 were related with a significant cumulative risk of thrombosis. CONCLUSIONS: We found significant differences in serum titers of non-criteria aPL among patients with primary APS vs SLE with APS. Whether non-criteria aPL antibodies titers are useful to differentiate patients with primary and secondary APS requires further analysis in other populations.

Cardiac involvement in anti-MDA5 dermatomyositis: a case-based review.

Among myositis-specific antibodies, anti-melanoma differentiation-associated gene 5 (anti-MDA5) is one of the antibodies with a unique spectrum that is expressed principally in clinically amyopathic dermatomyositis (CADM) and, to a lesser extent, in dermatomyositis (DM). In addition to muscle and classical skin involvement, patients with anti-MDA5 DM/CADM are characterized by the expression of rapidly progressive interstitial lung diseases, vasculopathic lesions, and non-erosive arthritis. Although cardiac involvement has been described in other inflammatory myopathies, such as myocarditis, pericarditis, and conduction disorders, in anti-MDA5 DM/CADM patients, heart disease is infrequent. We report a case of a young male presenting with constitutional symptoms, polyarthritis, skin ulcers, and mild muscle weakness who developed an episode of high ventricular rate atrial fibrillation during his hospitalization. The anti-MDA5 DM diagnosis was supported by increased muscular enzymes, positive anti-MDA5 and anti-Ro52 antibodies, and the presence of organizing pneumonia. He was treated with high-dose glucocorticoids, rituximab, and beta-blocker drugs and received pharmacological cardioversion, which improved his myopathy symptoms and stabilized his heart rhythm. Here, we describe eight similar cases of anti-MDA5 DM/CADM with cardiac involvement. The case presented and the literature reviewed reveal that although rare, physicians must be aware of cardiac disease in patients with suggestive symptoms to guarantee early assessment and treatment, thereby reducing life-treating consequences.

Modulation of B cell activation by extracellular vesicles and potential alteration of this pathway in patients with rheumatoid arthritis.

BACKGROUND: Extracellular vesicles are involved in the intercellular communication of the immune system. In rheumatoid arthritis (RA), these structures are considered a source of autoantigens that drive proinflammatory responses of innate immune cells. A high concentration of circulating medium/large size extracellular vesicles (m/lEVs) and m/lEVs forming immune complexes (m/lEV-ICs) have been associated with disease activity and systemic inflammation in patients with RA. B cells are central components of RA immunopathology because of their involvement in the production of autoantibodies, antigen presentation, and cytokine production. However, the effect of m/lEVs on B cell function in the context of RA and other autoimmune diseases remains unknown. METHODS: We evaluated the effect of m/lEVs obtained from healthy donors (HD) and patients with RA on B cell responses in vitro. In addition, we evaluated the effect of pre-exposition of monocyte-derived macrophages (MDM) to m/lEVs on activation of autologous B cells from HD and patients. RESULTS: The presence of m/lEVs reduced the frequency of CD69+ and CD86+ B cells from HD activated by an agonist of antigen receptor. This regulation of the B cell activation markers by m/lEVs was partially dependent on phosphatidylserine binging. These m/lEVs also reduced the proliferation, calcium mobilization, and global phosphorylation of tyrosine. Similar responses were observed in B cells from patients with RA. However, the presence of m/lEVs promoted high antibody levels in B cells cultured with T cell-dependent stimuli by 7 days. In addition, despite the direct inhibitory effect of m/lEVs on early B cell responses, when B cells were cocultured with autologous MDM previously exposed to m/lEVs or m/lEV-ICs, an increased frequency of CD69+ B cells from patients with RA was observed, albeit not with cells from HD. CONCLUSIONS: These data together suggest that m/lEVs have a direct modulatory effect in early responses of B cells through B cell receptor that can potentially fail in patients with RA because of the impact of these vesicles over cells of the innate immune system. This phenomenon can potentially contribute to the loss of tolerance and disease activity in patients with RA.

Perfil demográfico y clínico de la poliarteritis nodosa sistémica y cutánea en un grupo de pacientes pediátricos de Medellín, 2010-2019 / Demographic and clinical profile of systemic and cutaneous Polyarteritis nodosa in a group of pediatric patients in Medellin, 2010-2019

Resumen Objetivo: describir las principales características demográficas y clínicas de los pacientes pediátricos con poliarteritis nodosa (PAN). Metodología: estudio descriptivo retrospectivo. Resultados: se obtuvieron las historias clínicas de menores de 18 años con diagnóstico de vasculitis o PAN atendidos entre el 2010 y 2019 en dos hospitales de Medellín. Se incluyeron 19 pacientes, 11 clasificados como PAN cutánea (PANC) según la definición de la Liga Europea contra el Reumatismo y la Sociedad Europea de Reumatología Pediátrica, y 8 como PAN sistémica (PANS) acorde con los criterios de Ankara 2008. El 57,9 % fueron varones (n = 11). La mediana de la edad en el diagnóstico fue 10 años (3-17 años) y del tiempo de seguimiento: 15 meses (0-105 meses). Las manifestaciones más frecuentes fueron nódulos subcutáneos (84,2 %), fiebre (57,9 %), artralgias (57,9 %) y dolor en las pantorrillas (52,6 %). Los pacientes con PANS presentaron más pérdida de peso y hemoglobina baja. 5 niños cursaron con úlceras (26,3 %) cuatro con PANC; 2 exhibieron necrosis lingual (10,5 %) y 2 necrosis digital (10,5 %), todos con PANC. El promedio de la PCR fue de 10,2 mg/dl (0,33-45,3) y, de la eritrosedimentación: 74 mm/hora (15-127 mm/hora). En las imágenes hubo un realce meníngeo, aneurismas intrahepáticas y mesentéricos, entre otros hallazgos. Todos recibieron esteroides sistémicos. Ninguno falleció. Conclusión: en esta serie, la PAN pediátrica fue más común en niños de edad escolar. La PANC fue más frecuente que la PANS. Las manifestaciones más descritas fueron los nódulos subcutáneos, las mialgias, la fiebre, las artralgias y el dolor en las pantorrillas. Aunque se ha considerado la PANC como una enfermedad benigna, estos pacientes pueden requerir tratamiento con glucocorticoides e inmunosupresores.

Summary Objective: To describe the main demographic and clinical characteristics of patients who were diagnosed with childhood polyarteritis nodosa (PAN). Methods: A descriptive study was conducted using retrospective data Results: The clinical registries from patients under 18th years with vasculitis or PAN diagnosis attended between 2010 and 2019 in two Medical Centers from Medellín were obtained. Nineteen patients were included: eleven classified as cutaneous PAN (PANC) according to the definition of the European League Against Rheumatism and the European Society of Pediatric Rheumatology and eight as systemic PAN according to Ankara 2008 Criteria. 57.9% were male. The median age at diagnosis was ten years (3-17), and the median follow-up period was 15 months (0-105). The most common clinical characteristics were subcutaneous nodules (84.2%), fever (57.9%), arthralgias (57.9%), and calf pain (52.6%). SPAN patients had more frequent weight loss and lower hemoglobin. Five patients had ulcers (26.3%), four of them with CPAN; two patients had lingual necrosis (10.5%), and two digital necrosis (10.5%), all of them also with CPAN. CRP mean was 10.2 mg/dl (0.33-45.3) and mean erythrocyte sedimentation rate (ESR) was 74 mm/h (15-127 mm/h). Meningeal enhancing, intrahepatic, and mesenteric aneurism, among others, were reported in diagnostic images. All patients required treatment with systemic glucocorticoid. None of the patients died during the follow-up period. Conclusions: In this pediatric series from Medellín-Colombia, PAN was more common in boys of school age. CPAN was more frequent than SPAN. The clinical characteristics most reported were subcutaneous nodules, myalgias, arthralgias, and calf pain. Although CPAN has been considered a benign disease, these patients may require systemic glucocorticoid and immunosuppressive therapy.

Ultrasonido Doppler de arterias temporales en pacientes con arteritis de células gigantes: estado del arte y revisión sistemática de la literatura / Temporal artery Doppler ultrasound in patients with giant cell arteritis: State of the art and systematic review of the literature

RESUMEN La arteritis de células gigantes es una vasculitis que afecta de manera predominante a vasos de gran calibre y aparece en personas mayores de 50 arios. Su presentación clínica incluye cefalea, alteraciones auditivas o síntomas similares a polimialgia reumática. En su forma más grave puede causar pérdida de visión uni- o bilateral, secundaria a neuropatía óptica isquémica de tipo arterítico. En la actualidad, el estándar de referencia para su diagnóstico es la biopsia de arterias temporales, procedimiento que no es inocuo y que puede tener como complicaciones infección, lesión nerviosa o sangrado, entre otras. Entre las técnicas no invasivas de diagnóstico, el ultrasonido y el Doppler de arterias temporales han tomado un rol cada vez más importante en el diagnóstico de esta entidad, dado que son pruebas benignas, con nulos efectos adversos y, a través de estrategias como las clínicas fast-track apoyadas en este método diagnóstico, se ha logrado reducir las complicaciones isquémicas de la enfermedad.

ABSTRACT Giant cell arteritis is a vasculitis that predominantly affects large calibre vessels, and usually appears in people over 50 years-old. Its clinical presentation includes headache, hearing impairment, or polymyalgia rheumatica-like symptoms. In its most severe form, it can cause uni- or bilateral vision loss secondary to arteritic ischaemic optic neuropathy. Currently, the gold standard for its diagnosis is the temporal artery biopsy, a procedure that is not harmless and may have complications such as infection, nerve injury, bleeding, among others. Among non-invasive diagnostic methods, the ultrasound and temporal artery Doppler have gained a predominant role in the diagnosis of giant cell arteritis, as it is a benign test with no adverse effects. Through strategies such as «fast-track¼ clinics, supported by this diagnostic method, a reduction has been achieved in ischaemic complications of the disease.

Desenlaces obstétricos en pacientes con arteritis de Takayasu: serie de casos / Pregnancy outcomes in patients with Takayasu's arteritis: Case series

RESUMEN Objetivo: La actividad y el riesgo de recaída de la arteritis de Takayasu son bajos durante la gestación. Hasta el 40% de las pacientes puede tener desenlaces obstétricos desfavorables, por lo que es importante conocer su comportamiento clínico. Describimos las características clínicas y el desenlace obstétrico de gestantes con arteritis de Takayasu atendidas en un hospital de alta complejidad. Materiales y métodos: Evaluación retrospectiva de historias clínicas de gestantes con arteritis de Takayasu atendidas en el Hospital Universitario San Vicente Fundación de Medellín, Colombia, entre 2011 y 2018. Resultados: Se incluyó en el estudio a 6 pacientes con mediana de edad al diagnóstico de 17,5 arios (RI 9,25), al parto de 24 arios (RI 8,25) y con una duración de la enfermedad de 5,5 arios (RI 10,5). Del total, 3 pacientes tenían compromiso aórtico extenso; al parto, 3 pacientes esta ban activas y requirieron inmunosupresores, 5 tenían hipertensión arterial, una desarrolló preeclampsia en el segundo trimestre, una tenía insuficiencia mitral y tricuspídea grave con disminución de la fracción de eyección del ventrículo izquierdo; 2 tenían aneurismas (arte ria subclavia izquierda y aorta ascendente). Ningún embarazo resultó en aborto ni parto pretérmino; hubo 2 óbitos fetales, uno por restricción del crecimiento intrauterino e insuficiencia placentaria, y otro de etiología desconocida; ambas pacientes con actividad de la enfermedad, afección aórtica extensa e hipertensión arterial. Fueron por cesárea 5 par tos por indicación materna; no hubo disección aórtica, rotura aneurismática ni hemorragia cerebral. Conclusión: Las pacientes con enfermedad activa y afección aórtica extensa presentaron resultados obstétricos desfavorables, lo que indica que el inadecuado control de la vasculitis genera mayores complicaciones materno-fetales.

ABSTRACT Objective: The activity and risk of relapse of Takayasu's arteritis are low during pregnancy. Up to 40% of patients may have unfavorable obstetric outcomes therefore it is important to know their clinical behavior. We describe the clinical characteristics and obstetric outcome of pregnant women with Takayasu arteritis treated in a hospital of high complexity. Materials and methods: A retrospective evaluation of medical records of pregnant patients with Takayasu's arteritis treated at Hospital Universitario San Vicente Fundación in Medellin, Colombia between 2011 and 2018. Results: Six patients with a median age at diagnosis 17.5 (RI 9.25) years, at delivery 24 (RI 8.25) years, disease duration 5.5 (RI 10.5) years. Three patients had extensive aortic involvement; at delivery, 3 patients were active and required immunosuppressants, 5 had high blood pres sure, one developed preeclampsia in the second trimester, one had severe mitral and tricus pid insufficiency with a decreased ejection fraction of the left ventricle; 2 had aneurysms (left subclavian artery and ascending aorta). No pregnancy resulted in abortion or preterm birth; there were 2 fetal deaths, one due to intrauterine growth restriction and placental insuffi ciency and another of unknown etiology; both patients with disease activity, extensive aortic condition, and arterial hypertension. Five deliveries were by cesarean section by maternal indication; there was no aortic dissection, aneurysmal rupture or cerebral hemorrhage. Conclusion: Patients with active disease and extensive aortic compromise presented unfa vorable obstetric results, suggesting that inadequate control of vasculitis leads to greater maternal-fetal complications.

Desarrollo y validación interna de un modelo de predicción clínica del riesgo de infección bacteriana nosocomial en pacientes con lupus eritematoso sistémico / Development and internal validation of a clinical prediction model of the risk of nosocomial bacterial infection in patients with systemic lupus erythematosus

RESUMEN Introducción: Los pacientes con lupus eritematoso sistémico (LES) tienen un riesgo aumen tado de padecer infecciones tanto adquiridas en la comunidad como asociadas con el cuidado de la salud. Las infecciones bacterianas son las más frecuentes y graves durante la hospitalización de estos pacientes. Objetivo: Desarrollar y validar internamente un modelo de predicción clínica de pronóstico del riesgo de infección bacteriana adquirida en el hospital en pacientes con LES, usando datos clínicos y de laboratorio obtenidos durante las primeras horas de hospitalización. Métodos: Se analizó una cohorte retrospectiva de pacientes con LES mayores de 16 arios, hos pitalizados por motivos diferentes a infección bacteriana en 2 hospitales de alta complejidad de Medellín entre 2011 y 2016. Se compararon las características de los pacientes que des arrollaron el desenlace de infección bacteriana entre el día 3 y el día 15 de hospitalización con aquellos que no lo presentaron. Las variables significativas en el análisis bivariado fueron consideradas para la construcción del modelo por medio de regresión logística multivariada. Resultados: Se incluyeron 765 episodios, de los cuales 98 (12,8%) presentaron el desenlace de interés. Se consideraron 35 predictores candidatos. Las variables incorporadas en el modelo final fueron: edad, recuento de neutrófilos, puntaje de actividad lúpica SLEDAI, uso de sonda vesical, uso de catéter venoso central en las primeras 72 h, dosis de glucocorticoides en el mes previo y el uso de un antimalárico en los 3 meses previos. La capacidad de discrimi nación del modelo fue aceptable a buena (AUC-ROC 0,74; IC 95% 0,69-0,80). La prueba de bondad de ajuste de Hosmer-Lemeshow (p = 0,637) evidenció una adecuada calibración. Conclusión: Desarrollamos un modelo de predicción clínica de pronóstico del riesgo de infec ción bacteriana nosocomial en pacientes con LES. El modelo desarrollado está compuesto por variables clínicas y de laboratorio simples disponibles en el momento del ingreso al hospital. Se requieren estudios de validación externa y de impacto clínico antes de su implementación rutinaria.

ABSTRACT Introduction: Patients with systemic lupus erythematosus (SLE) have an increased risk of developing community-acquired infections, as well as those associated with health care. Bacterial infections are the most common and serious while these patients are in hospital. Objective: To develop, and internally validate, a clinical prediction model for the prognosis of the risk of hospital-acquired bacterial infection in SLE patients using clinical and laboratory data obtained during the first hours of hospital admission. Methods: An analysis was performed on retrospective cohort of patients with SLE older than 16 years and admitted for reasons other than bacterial infection in 2 highly complex hospitals in Medellín between 2011 and 2016. The characteristics of the patients who developed a bacterial infection were compared between day 3 and day 15 of hospital admission with those who did not develop one. The significant variables in the bivariate analysis were used for the construction of the model using multivariate logistic regression. Results: A total of 765 episodes were included, of which 98 (12.8%) presented the outcome of interest. Thirty-five candidate predictors were considered. The variables incorporated in the final model were: age, neutrophil count, SLEDAI lupus activity score, use of a bladder catheter, use of a central venous catheter in the first 72 h, glucocorticoid doses in the previous month, and use of an antimalarial drug in the 3 previous months. The discrimination capacity of the model was acceptable to good (AUC-ROC 0.74; 95% CI 0.69-0.80). The Hosmer-Lemeshow goodness of fit test (P = .637) suggested adequate calibration. Conclusion: A clinical prediction model of prognostic risk of nosocomial bacterial infection in patients with SLE has been developed. This model is made up of simple clinical and laboratory variables available at the time of hospital admission. External validation and clinical impact studies are required before routine implementation.

Factors associated with active tuberculosis in Colombian patients with systemic lupus erythematosus: a case-control study.

OBJECTIVE: To identify factors associated with active tuberculosis (TB) in patients with systemic lupus erythematosus (SLE). METHODS: We performed a retrospective case-control study in two tertiary care teaching hospitals in Medellín, Colombia. From January 2007 to December 2017, a total of 268 patients with SLE were included. SLE patients with TB (cases) were matched 1:3 with SLE patients without TB (controls) by disease duration and the date of the hospitalization in which the diagnosis of TB was made (index date of cases) to the nearest available rheumatology hospitalization in the matched controls (± 2 years). Conditional univariable and multivariable logistic regression analyses were performed. RESULTS: Sixty-seven cases and 201 controls were assessed. Only pulmonary TB occurred in 46.3%, only extrapulmonary TB in 16.4% and disseminated TB in 37.3% of cases. Multivariable logistic regression analysis showed that lymphopenia (OR, 2.91; 95% CI 1.41-6.03; P = 0.004), 12-month cumulative glucocorticoid dose ≥ 1830 mg (OR, 2.74; 95% CI 1.26-5.98; P = 0.011), and having been treated with ≥ 2 immunosuppressants during the last 12 months (OR, 2.81; 95% CI 1.16-6.82; P = 0.022) were associated with TB after adjusting for age, sex, ethnicity, disease duration, disease activity, and comorbidity index. A trend towards an association of kidney transplantation with TB was also found (OR, 3.77; 95% CI 0.99-14.30; P = 0.051). CONCLUSION: Among SLE patients, cumulative glucocorticoid dose, lymphopenia, and the use of ≥ 2 immunosuppressants during the last 12 months were associated with active TB infection. Key Points • Among SLE patients, a cumulative dose of glucocorticoids equivalent to 5 mg/day of prednisone during the last 12 months is independently associated with the development of TB. • The use of two or more immunosuppressants during the last 12 months is also a risk factor for TB infection development is SLE patients. • Lymphopenia is predominant in SLE patients with TB, being especially profound in those with disseminated TB. • Renal transplant recipients with SLE also have an elevated risk of TB.

Urinary levels of ceruloplasmin and monocyte chemoattractant protein-1 correlate with extra-capillary proliferation and chronic damage in patients with lupus nephritis.

BACKGROUND AND AIM: There are few studies of urinary biomarkers and histopathologic features in lupus nephritis (LN). The aim was to analyze the correlation between a wide panel of urinary biomarkers and serum concentrations of anti C1q antibodies with histological items of activity and chronicity on kidney biopsy in LN patients. METHODS: Patients with systemic lupus erythematosus (SLE) according to American College of Rheumatology (ACR) criteria were included. LN diagnosis was based on ACR criteria. Histologic features of activity and chronicity indices were analyzed according to the Austin classification. Serum Anti C1q levels were determined by commercial ELISA. Urinary levels of transferrin, ceruloplasmin (CP), VCAM-1, TWEAK, monocyte chemoattractant protein-1 (MCP-1), neutrophil gelatinase-associated lipocalin (NGAL), and alpha-1-acid glycoprotein were measured by commercial ELISA. RESULTS: We included 120 SLE patients (81% female, mean age 33.1 ± 9.3 years, 59.4% Mestizo, 37.8% Afro-Latin American): 64% had LN. Kidney biopsy was performed in 55 patients, but only 37 were made in our center. Anti C1q antibodies were associated with endocapillary proliferation. In patients with cellular crescents, urinary concentrations of CP were significantly higher. In patients with a chronicity index (CI) ≥ 4, fibrous crescents, tubular atrophy, and interstitial fibrosis, urinary MCP-1 levels were higher. CONCLUSIONS: In SLE patients, serum anti C1q antibodies and urinary CP were associated with activity on kidney biopsy and MCP-1 with chronic damage. This panel of biomarkers could be validated in larger, multi-ethnic population as a complementary tool for better stratification of LN patients. Key Points • Urinary biomarkers are complementary useful tools for the assessment of SLE patients. • Urinary levels of CP correlated with activity findings on kidney biopsy in LN patients. • Urinary levels of MCP-1 correlated with chronic damage, especially with fibrous crescents, tubular atrophy, and interstitial fibrosis.

Utility of urinary transferrin and ceruloplasmin in patients with systemic lupus erythematosus for differentiating patients with lupus nephritis. / Transferrina y ceruloplasmina en orina de pacientes con lupus eritematoso sistémico. ¿Son útiles para diferenciar pacientes con nefritis lúpica?

BACKGROUND AND OBJECTIVE: Diagnosis of lupus nephritis (LN) is usually based on renal biopsy, which is an invasive technique that involves multiple risks. Therefore, different biomarkers have emerged as alternatives for the diagnosis of LN. Nonetheless, studies regarding urinary biomarkers in Latin American patients are limited. The objective of this study was to assess the diagnostic value of urinary transferrin and ceruloplasmin to differentiate patients who have renal involvement from those who do not. MATERIALS AND METHODS: Systemic lupus erythematosus (SLE) patients that met the revised American College of Rheumatology (ACR) classification criteria were recruited. Patients with another autoimmune disease, active infection (urinary tract or systemic infection), renal replacement therapy, human immunodeficiency virus infection or pregnancy were excluded. A urine sample was collected from each patient. LN was diagnosed according to ACR criteria. The activity and chronicity of LN were measured using the Austin indices. Urinary transferrin and ceruloplasmin levels were measured using commercial enzyme-linked immunosorbent assay (ELISA) kits. Mann-Whitney U test and Student's t-test were used to compare data. Spearman's rank correlation was used to determine associations. Lastly, receiver operating characteristic (ROC) curves were created. RESULTS: The study involved 120 SLE patients. In all, 85% were female, 76% mestizo, the mean age was 32.8±12.1years and mean systemic lupus erythematosus disease activity index (SLEDAI) was 8.4±8.9; 64% had renal involvement. Urinary levels of the two biomarkers were significantly higher in patients with LN compared to those without LN. Similarly, urinary levels of both biomarkers were significantly higher in patients with active LN compared to those with inactive LN. Furthermore, urinary transferrin levels were significantly higher in Afro-Latin American patients. On the other hand, urinary transferrin levels correlated with SLEDAI and proteinuria, and transferrin and ceruloplasmin levels correlated with each other. The diagnostic value of ROC curves for these urinary biomarkers for LN were good. CONCLUSIONS: In our cohort of SLE patients, we found that transferrin and ceruloplasmin were potential biomarkers for LN, and can even differentiate active LN.

Cryoglobulinemic vasculitis and psoriatic arthritis: Case report of an unusual association. / Vasculitis crioglobulinémica y artritis psoriásica: reporte de caso de una inusual asociación.

We report the case of a 47-year-old man with a 9-year history of psoriatic arthritis (PsA) in whom we detected renal involvement, hypocomplementemia, peripheral neuropathy, acral necrotic lesions and positive cryoglobulins. The results of the diagnosis led us to conclude that the clinical picture corresponded to cryoglobulinemic vasculitis concomitant with PsA. In addition, we present a review of the literature on the presence of these two diseases in a single patient.

Induction of NF-κB inflammatory pathway in monocytes by microparticles from patients with systemic lupus erythematosus.

BACKGROUND: Elevated levels of circulating microparticles (MPs) and molecules of the complement system have been reported in patients with systemic lupus erythematosus (SLE). Moreover, microparticles isolated from patients with SLE (SLE-MPs) contain higher levels of damage-associated molecular patterns (DAMPs) than MPs from healthy controls (CMPs). We hypothesize that the uptake of MPs by monocytes could contribute to the chronic inflammatory processes observed in patients with SLE. Therefore, the aim of this study was to evaluate the expression of activation markers, production of proinflammatory mediators, and activation of the NF-κB signaling pathway in monocytes treated with CMPs and SLE-MPs. METHODOLOGY: Monocytes isolated from healthy individuals were pretreated or not with pyrrolidine dithiocarbamate (PDTC) and cultured with CMPs and SLE-MPs. The cell surface expression of CD69 and HLA-DR were evaluated by flow cytometry; cytokine and eicosanoid levels were quantified in culture supernatants by Cytokine Bead Array and ELISA, respectively; and the NF-κB activation was evaluated by Western blot and epifluorescence microscopy. RESULTS: The cell surface expression of HLA-DR and CD69, and the supernatant levels of IL-6, IL-1ß, PGE2, and LTB4 were higher in cultures of monocytes treated with SLE-MPs than CMPs. These responses were blocked in the presence of PDTC, a pharmacological inhibitor of the NF-κB pathway, with concomitant reduction of IκBα and cytoplasmic p65, and increased nuclear translocation of p65. CONCLUSIONS: The present findings indicate that significant uptake of SLE-MPs by monocytes results in activation, production of inflammatory mediators, and triggering of the NF-κB signaling pathway.

Altered recruitment of Lyn, Syk and ZAP-70 into lipid rafts of activated B cells in Systemic Lupus Erythematosus.

There is evidence that B cells from patients with Systemic Lupus Erythematosus (SLE) could be hyperactivated due to changes in their lipid rafts (LR) composition, leading to altered BCR-dependent signals. This study aimed to characterize possible alterations in the recruitment of protein tyrosine kinases (PTK) into B cells LR from SLE patients. Fifteen patients with SLE and ten healthy controls were included. Circulating B cells were isolated by negative selection and stimulated with goat Fab´2 anti-human IgM/IgG. LR were isolated with a non-ionic detergent and ultracentrifuged on 5-45% discontinuous sucrose gradients. Proteins from each fraction were analyzed by Western Blot. Total levels of Lyn, Syk, and ZAP-70 in resting B cells were similar in SLE patients and healthy controls. Upon BCR activation, Lyn, Syk and ZAP-70 recruitment into LR increased significantly in B cells of healthy controls and patients with inactive SLE. In contrast, in active SLE patients there was a great heterogeneity in the recruitment of signaling molecules and the recruitment of ZAP-70 was mainly observed in patients with decreased Syk recruitment into LR of activated B cells. The reduction in Flotilin-1 and Lyn recruitment in SLE patients seem to be associated with disease activity. These findings suggest that in SLE patients the PTK recruitment into B cell LR is dysregulated and that B cells are under constant activation through BCR signaling. The decrease of Lyn and Syk, the expression of ZAP-70 by B cells and the increase in Calcium fluxes in response to BCR stimulation in active SLE patients, further support that B cells from SLE patients are under constant activation through BCR signaling, as has been proposed.

Endothelial activation and injury by microparticles in patients with systemic lupus erythematosus and rheumatoid arthritis.

BACKGROUND: Endothelial activation and damage is commonly observed in patients with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) and is related to development of atherosclerosis and cardiovascular diseases. Different components of the immune system seem to participate in the endothelial injury, such as generation of autoantibodies and formation of immune complexes (ICs). Microparticles (MPs) and their immune complexes (MPs-ICs) are increased in the circulation of patients with SLE and RA; therefore, we propose these extracellular vesicles could interact and modulate the function of endothelial cells. Hence, the effect of MPs and MPs-ICs from patients with SLE and RA in endothelial cells was evaluated. METHODS: Macrovascular and microvascular endothelial cells were exposed to MPs and MPs-ICs from healthy donors and patients with SLE and RA. Vesicles uptake/binding, expression of adhesion molecules, cytokine and chemokine production, monocyte adherence, and alterations of endothelial monolayer were evaluated by flow cytometry and fluorescence microscopy. RESULTS: Endothelial cells internalized MPs and MPs-ICs and increased CD54 and CD102 expression and CCL2, CCL5, and IL-6 production after the treatment with these extracellular vesicles, which led to an increase in the adherence of classic monocytes. These vesicles also induced low expression of VE-cadherin in membrane, depolymerization of actin filaments, and formation of intercellular spaces, which led to endothelial death and increased permeability after MPs and MPs-ICs exposure. CONCLUSIONS: MPs and MPs-ICs from patients with SLE and RA increase adhesion molecules expression, chemokine production, and structural alterations in macrovascular and microvascular endothelial cells. Therefore, high counts of these vesicles in patients would promote endothelial alterations and secondary tissue leukocyte infiltration.