Effectiveness of methotrexate and leflunomide as corticoid-sparing drugs in patients with polymyalgia rheumatica.

Objectives: The need for glucocorticoid-sparing drugs (GCSD) remains an important issue and is an unmet need in the treatment of polymyalgia rheumatica (PMR). We therefore aimed to assess the effectiveness and safety of methotrexate (MTX) and of leflunomide (LEF) in daily clinical practice in PMR patients from Argentina. Methods: A multicentre and observational study (medical records review) of PMR patients seen between 2007 and 2023, who had at least three months of follow-up after starting a GCSD, either MTX or LEF, was performed. Results are expressed as medians and interquartile ranges [25th-75th (IQR)] for continuous variables and percentages for categorical ones. The two treatment groups were compared using χ2 test for categorical variables, Mann-Whitney U test for continuous variables and the log-rank test for time-to-event data. Crude and adjusted odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using logistic regression. In all cases, a p-value <0.05 was considered statistically significant. Results: One-hundred and eighty-six patients (79% female) with a median age of 72 years (IQR, 65-77 years) were included. One-hundred and forty-three patients (77%) were prescribed MTX (15, IQR 10-15) and 43 (23%) LEF (20 mg, fixed dose). Flare-ups (relapses and recurrences) occurred in 13 patients (7%) and were comparable between both groups. Persistent GCSD intake was observed in 145 patients (78%). Glucocorticoid (GC) withdrawal was achieved in 67 of these 145 patients (46%) and this occurred more frequently in the LEF group (P = 0.001). Furthermore, time until prednisone discontinuation was shorter in the LEF-treated patients (4.7 months, IQR 3-20 on LEF versus 31.8 months, IQR 10-82 on MTX, P = 0.000). Remission was found more frequently in the LEF group (P = 0.003). In the multivariate analysis, the probability of remission was higher with LEF therapy (P = 0.010) and this finding persisted in the subgroup analysis who were followed up < 40 months (OR 3.12, 95% CI = 1.30-7.47, P = 0.011). Conclusions: This study demonstrated the clinical effectiveness of LEF and even its superiority in achieving remission when compared with MTX as GCSD in PMR patients. Further research is needed to support these findings.

Compromiso oftálmico en enfermedad relacionada con IgG4 / Ophthalmic involvement in IgG4-related disease

Resumen Introducción: la enfermedad oftálmica relacionada con IgG4 (EOR-IgG4) presenta una frecuencia del 11-59%. Pocos estudios describen las disparidades con los pacientes con ER-IgG4 extraoftálmica (NO EOR-IgG4). Objetivos: describir las características clínicas, imagenológicas, anatomopatológicas, resultados de laboratorio y tratamiento de la EOR-IgG4, y compararlas con las de los pacientes NO EOR-IgG4. Materiales y métodos: se realizó un estudio descriptivo sobre una cohorte de 54 pacientes con ER-IgG4. Se reclutaron 16 pacientes con EOR-IgG4 y 38 con NO EOR-IgG4. Se compararon ambos grupos. Resultados: la EOR-IgG4 predominó en mujeres. El 75% presentó afectación oftálmica bilateral. El antecedente de asma se asoció al grupo NO EOR-IgG4 (p=0,018). Los pacientes con EOR-IgG4 presentaron niveles séricos menores de IgE e IgG total, y la glándula lagrimal fue la estructura más afectada. Predominó el infiltrado linfoplasmocitario y eosinofílico, siendo la fibrosis estoriforme más frecuente que la no estoriforme en el grupo EOR-IgG4. Conclusiones: si bien los resultados fueron similares a lo reportado previamente, en discordancia con otras series, encontramos asociación negativa entre el asma y los niveles de IgG total sérica en los pacientes EOR-IgG4.

Abstract Introduction: IgG4-related ophthalmic disease (IgG4-ROD) presents a frequency of 11-58.8%. Few studies describe the disparities with patients with extraophthalmic IgG4-related disease (NOT IgG4-ROD). Objectives: describe the clinical, imaging, pathological characteristics, laboratory results, and treatment of IgG4-ROD characteristics; and compare them with those of the NOT IgG4-ROD patients. Materials and methods: a descriptive study was carried out on a cohort of 54 patients with ER-IgG4. 16 patients with IgG4-ROD and 38 with NOT IgG4-ROD were recruited. The data was analyzed with the SPSS Statistics 19 software. Results: IgG4-ROD predominated in women. 75% presented bilateral ophthalmic involvement. A history of asthma was associated with the NOT IgG4-ROD group (p=0,018). Patients with IgG4-ROD presented lower serum levels of IgE and total IgG, and the lacrimal gland was the most affected structure. Lymphoplasmacytic and eosinophilic infiltrates predominated, with storiform fibrosis being more frequent than non-storiform in the IgG4-ROD group. Conclusions: although the results were similar to those previously reported, in disagreement with other series, we found a negative association between asthma and serum total IgG levels with EOR-IgG4 patients.

Sociodemographic and clinical factors associated with poor COVID-19 outcomes in patients with rheumatic diseases: data from the SAR-COVID Registry.

BACKGROUND/OBJECTIVE: This study aims to describe the course and to identify poor prognostic factors of SARS-CoV-2 infection in patients with rheumatic diseases. METHODS: Patients ≥ 18 years of age, with a rheumatic disease, who had confirmed SARS-CoV-2 infection were consecutively included by major rheumatology centers from Argentina, in the national, observational SAR-COVID registry between August 13, 2020 and July 31, 2021. Hospitalization, oxygen requirement, and death were considered poor COVID-19 outcomes. RESULTS: A total of 1915 patients were included. The most frequent rheumatic diseases were rheumatoid arthritis (42%) and systemic lupus erythematosus (16%). Comorbidities were reported in half of them (48%). Symptoms were reported by 95% of the patients, 28% were hospitalized, 8% were admitted to the intensive care unit (ICU), and 4% died due to COVID-19. During hospitalization, 9% required non-invasive mechanical ventilation (NIMV) or high flow oxygen devices and 17% invasive mechanical ventilation (IMV). In multivariate analysis models, using poor COVID-19 outcomes as dependent variables, older age, male gender, higher disease activity, treatment with glucocorticoids or rituximab, and the presence of at least one comorbidity and a greater number of them were associated with worse prognosis. In addition, patients with public health insurance and Mestizos were more likely to require hospitalization. CONCLUSIONS: In addition to the known poor prognostic factors, in this cohort of patients with rheumatic diseases, high disease activity, and treatment with glucocorticoids and rituximab were associated with worse COVID-19 outcomes. Furthermore, patients with public health insurance and Mestizos were 44% and 39% more likely to be hospitalized, respectively. STUDY REGISTRATION: This study has been registered in ClinicalTrials.gov under the number NCT04568421. Key Points • High disease activity, and treatment with glucocorticoids and rituximab were associated with poor COVID-19 outcome in patients with rheumatic diseases. • Some socioeconomic factors related to social inequality, including non-Caucasian ethnicity and public health insurance, were associated with hospitalization due to COVID-19.

Características clínicas y evolución de la infección por SARS-CoV-2 en pacientes con lupus eritematoso sistémico en Argentina: datos del registro nacional SAR-COVID / Clinical characteristics and course of SARS-CoV-2 infection in patients with systemic lupus erythematosus in Argentina: data from the SAR-COVID national registry

Introducción: el lupus eritematoso sistémico (LES) es una enfermedad sistémica que se ha asociado a mayor severidad con la infección por SARS-CoV-2. Particularmente la alta actividad de la enfermedad y algunos inmunosupresores se han vinculado a peores desenlaces. Objetivos: describir las características por SARS-CoV-2 en pacientes con LES en Argentina del registro SAR-COVID y establecer los factores asociados a peor desenlace de la misma. Materiales y métodos: estudio observacional. Se incluyeron pacientes con diagnóstico de LES con infección confirmada por SARS-CoV-2 (RT-PCR y/o serología positiva) del registro SAR-COVID. Los datos se recolectaron desde agosto de 2020 hasta marzo de 2022. El desenlace de la infección se midió mediante la escala ordinal de la Organización Mundial de la Salud (EO-OMS). Se definió COVID-19 severo con un valor EO-OMS ≥5. Análisis descriptivo, test T de Student, test de Mann Whitney U, ANOVA, chi2 y Fisher. Regresión logística múltiple. Resultados: se incluyeron 399 pacientes, el 93% de sexo femenino, con una edad media de 40,9 años (DE 12,2). El 39,6% tenía al menos una comorbilidad. Al momento de la infección, el 54,9% recibía glucocorticoides, el 30,8% inmunosupresores y el 3,3% agentes biológicos. La infección por SARS-CoV-2 fue leve en la mayoría de los casos, mientras que un 4,6% tuvo curso severo y/o falleció. Estos últimos presentaban comorbilidades, usaban glucocorticoides y tenían síndrome antifosfolipídico (SAF) con mayor frecuencia y mayor actividad de la enfermedad al momento de la infección. En el análisis multivariado, la hipertensión arterial, el diagnóstico de SAF y el uso de glucocorticoides se asociaron a hospitalización severa y/o muerte por COVID-19 (EO-OMS ≥5). Conclusiones: en esta cohorte de pacientes con LES con infección por SARS-CoV-2 confirmada, la mayoría cursó de manera sintomática, un 22,1% fue hospitalizado y un 5% requirió ventilación mecánica. La mortalidad fue cercana al 3%. El diagnóstico de SAF, tener hipertensión arterial y el uso de glucocorticoides se asociaron significativamente con COVID-19 severo.

Introduction: systemic lupus erythematosus (SLE) is a systemic disease that has been associated with greater severity with SARS-CoV-2 infection. Particularly high disease activity and some immunosuppressants have been linked to worse outcomes. Objectives: to describe the characteristics due to SARS-CoV-2 in patients with SLE in Argentina from the SAR-COVID registry and to establish the factors associated with a worse outcome of the same. Materials and methods: observational study. Patients diagnosed with SLE with confirmed SARS-CoV-2 infection (RT-PCR and/or positive serology) from the SAR-COVID registry were included. Data was collected from August 2020 to March 2022. The outcome of the infection was measured using the World Health Organization - ordinal scale (WHO-OS). Severe COVID-19 was defined as an WHO-OS value ≥5. Descriptive analysis, Student's T test, Mann Whitney U, ANOVA, chi2 and Fisher. Multiple logistic regression. Results: a total of 399 patients were included, 93% female, with a mean age of 40.9 years (SD 12.2), 39.6% had at least one comorbidity. At the time of infection, 54.9% were receiving glucocorticoids, 30.8% immunosuppressants, and 3.3% biological agents. SARS-CoV-2 infection was mild in most cases, while 4.6% had a severe course and/or died. The latter had comorbidities, used glucocorticoids and had antiphospholipid syndrome (APS) more frequently and higher disease activity at the time of infection. In the multivariate analysis, high blood pressure, the diagnosis of APS, and the use of glucocorticoids were associated with severe hospitalization and/or death from COVID-19 (WHO-EO ≥5). Conclusions: in this cohort of SLE patients with confirmed SARS-CoV-2 infection, most had a symptomatic course, 22.1% were hospitalized, and 5% required mechanical ventilation. Mortality was close to 3%. The diagnosis of APS, having high blood pressure, and the use of glucocorticoids were significantly associated with severe COVID-19.

Lupus en Argentina. Pacientes no respondedores al tratamiento estándar y belimumab como posible opción. Datos del registro RELESSAR / Lupus in Argentina. Non-responders to standard treatment and belimumab as a possible option. RELESSAR record data

Introducción: el lupus es una enfermedad compleja y varias veces de difícil abordaje. Alcanzar la remisión es uno de los objetivos, incorporando opciones terapéuticas. Objetivos: describir las características generales de los pacientes según el estado de la enfermedad y el uso de belimumab. Materiales y métodos: estudio de corte transversal, registro RELESSAR. Se definió el estado de la enfermedad como: remisión: SLEDAI=0 y sin corticoides; baja actividad de la enfermedad: SLEDAI >0 y ≤4 y sin corticoides; control no óptimo: SLEDAI >4 y cualquier dosis de corticoides. Resultados: se incluyeron 1.277 pacientes, 23,4% en remisión, 12,6% en baja actividad y 63,8% con control no óptimo. En este último grupo eran más jóvenes y con menor duración de la enfermedad; presentaban mayores índices de actividad y cronicidad, y mayor empleo de inmunosupresores. Solo el 22,3% de los pacientes con criterio potencial de uso de belimumab (lupus eritematoso sistémico activo a pesar del tratamiento estándar) lo recibía en ese momento. Las variables asociadas a hospitalizaciones fueron: terapia con corticoides, ciclofosfamida y mayor SLICC. Conclusiones: se refleja la complejidad del manejo de estos pacientes y se visualizan aspectos estructurales como la desigualdad. El uso del belimumab resultaría beneficioso en los pacientes seleccionados.

Introduction: lupus is a complex disease and often difficult to approach. Achieving remission is one of the objectives, incorporating therapeutic options. Objectives: to describe the characteristics of the patients and the use of belimumab, according to the status of the disease. Materials and methods: cross-sectional study. Patients of the RELESSAR registry. Stratification: Remission: SLEDAI=0 and without corticosteroids. Low disease activity SLEDAI> 0 and ≤4 and without corticosteroids and non-optimal control: SLEDAI> 4 and any dose of corticosteroids. Results: a total of 1,277 patients were included, 23.4% in remission, 12.6% in low disease activity and 63.8% in non-optimal control. The last group was younger and had a shorter duration of the disease. They had higher activity and chronicity indices and greater use of immunosuppressants. Only 22.3% of the patients with potential criteria for the use of belimumab (activity disease despite standard treatment) were receiving it. The variables associated with hospitalizations were: corticosteroids, cyclophosphamide and higher SLICC. Those associated with severe infection: mycophenolate mofetil, azathioprine, corticosteroids, and higher SLICC. Conclusions: the complexity of the management of these patients is reflected, visualizing structural aspects such as inequality. The use of belimumab could be beneficial in selected patients.

Relapsing polychondritis or relapsing polychondritis-like symptoms associated with IgG4-RD. Case reports and review of the literature.

Relapsing polychondritis (RP) is a rare systemic disorder characterised by recurrent, widespread chondritis of the auricular, nasal, and tracheal cartilages. Immunoglobulin G4-related disease (IgG4-RD) is a systemic immune-mediated disease characterised by the infiltration of IgG4-bearing plasma cells into systemic organs. However, 25-35% of patients with RP have a concurrent autoimmune disease. The coexistence of RP and IgG4 is rare considering that, to the best of our knowledge, there are only four previous reports of RP or RP-like symptoms associated with IgG4-RD. We herein report two cases which could be RP or RP-like symptoms associated with IgG4-RD.

Réplica al artículo «Comparación de datos demográficos, presentación clínica, tratamiento y desenlace de pacientes lúpicos tratados en un centro público y otro privado de salud en Santa Fe, Argentina» / Reply to the article “Comparing demographics, clinical presentation, treatments and outcome between sle patients treated in a public and private health system in Santa Fe, Argentina”

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Comparación de datos demográficos, presentación clínica, tratamiento y desenlace de pacientes con lupus eritematoso sistémico tratados en un centro público y otro privado de salud en Santa Fe, Argentina / Comparing demographics, clinical presentation, treatments and outcome between systemic lupus erythematosus patients treated in a public and private health system in Santa Fe, Argentina

Se identificó a 159 pacientes con lupus eritematoso sistémico (LES) vistos entre 1987 y 2011. Ciento dieciséis fueron tratados en el sistema público de salud y 43 en el sistema privado. Ambos grupos fueron comparados, observando que los primeros tenían menor edad al momento de la primera consulta y al inicio del LES y menor duración de la enfermedad al momento de producirse la nefropatía de manera estadísticamente significativa. También mostraron mayor actividad del LES (medido por Systemic Lupus Erythematosus Activity Index), con presencia de fiebre, menor nivel de C4 y elevado valor de eritrosedimentación globular. La ciclofosfamida fue administrada con mayor frecuencia a los pacientes del sistema público, si bien no hubo diferencias en los hallazgos histológicos renales. En 20 pacientes se realizó una segunda biopsia renal debido a la presencia de proteinuria persistente, edema periférico y cilindros en orina, o por tener una mala muestra renal previa. La supervivencia a 10 años fue del 78% en los pacientes atendidos en el sistema público vs. el 91% de aquellos atendidos en el sistema privado. No se hallaron diferencias estadísticamente significativas cuando la sobrevida se evaluó a 15 años (log rank test: 0,65). Ambos grupos de pacientes (tanto los del sistema público como los del sector privado) fueron atendidos por especialistas, quienes realizaron un diagnóstico temprano de la enfermedad, con un cuidadoso seguimiento (AU)

The study includes 159 SLE patients seen between 1987 and 2011, of whom 116 were treated in the public health system and 43 in private practice. In the comparison between both groups, it was shown that patients in the public health system were younger at first consultation and at the onset of SLE, and that the mean duration of their disease prior to nephropathy was statistically significantly shorter. They also presented with more SLE activity (measured by Systemic Lupus Erythematosus Activity Index) such as fever, lower levels of C4, and elevated erythrocyte sedimentation rate. Although cyclophosphamide was administered more frequently to patients in the public health system group, there were no statistically significant differences in renal histological findings. A second renal biopsy was performed on 20 patients due to the presence of persistent proteinuria, peripheral edema, urinary casts, or because of previous defective renal specimens. The overall 10-year survival of the patients in the public health system was 78% compared to a survival rate of 91% for the patients in private practices. When survival was evaluated at 15 years, however, no differences were found (log rank test: 0.65). Patients from both public and private groups attended medical specialist practices and received early diagnoses and close follow-ups (AU)

Comparing demographics, clinical presentation, treatments and outcome between systemic lupus erythematosus patients treated in a public and private health system in Santa Fe, Argentina.

The study includes 159 SLE patients seen between 1987 and 2011, of whom 116 were treated in the public health system and 43 in private practice. In the comparison between both groups, it was shown that patients in the public health system were younger at first consultation and at the onset of SLE, and that the mean duration of their disease prior to nephropathy was statistically significantly shorter. They also presented with more SLE activity (measured by Systemic Lupus Erythematosus Activity Index) such as fever, lower levels of C4, and elevated erythrocyte sedimentation rate. Although cyclophosphamide was administered more frequently to patients in the public health system group, there were no statistically significant differences in renal histological findings. A second renal biopsy was performed on 20 patients due to the presence of persistent proteinuria, peripheral edema, urinary casts, or because of previous defective renal specimens. The overall 10-year survival of the patients in the public health system was 78% compared to a survival rate of 91% for the patients in private practices. When survival was evaluated at 15 years, however, no differences were found (log rank test: 0.65). Patients from both public and private groups attended medical specialist practices and received early diagnoses and close follow-ups.

Association of the yeast RNA-binding protein She2p with the tubular endoplasmic reticulum depends on membrane curvature.

Localization of mRNAs contributes to the generation and maintenance of cellular asymmetry in a wide range of organisms. In Saccharomyces cerevisiae, the so-called locasome complex with its core components Myo4p, She2p, and She3p localizes more than 30 mRNAs to the yeast bud tip. A significant fraction of these mRNAs encodes membrane or secreted proteins. Their localization requires, besides the locasome, a functional segregation apparatus of the cortical endoplasmic reticulum (ER), including the machinery that is involved in the movement of ER tubules into the bud. Colocalization of RNA-containing particles with these tubules suggests a coordinated transport of localized mRNAs and the cortical ER to the bud. Association of localized mRNAs to the ER requires the presence of the locasome component She2p. Here we report that She2p is not only an RNA-binding protein but can specifically bind to ER-derived membranes in a membrane curvature-dependent manner in vitro. Although it does not contain any known curvature recognizing motifs, the protein shows a binding preference for liposomes with a diameter resembling that of yeast ER tubules. In addition, membrane binding depends on tetramerization of She2p. In an in vivo membrane-tethering assay, She2p can target a viral peptide GFP fusion protein to the cortical ER, indicating that a fraction of She2p associates with the ER in vivo. Combining RNA- and membrane-binding features makes She2p an ideal coordinator of ER tubule and mRNA cotransport.

Manifestaciones y evolución clínica de pacientes con LES en un hospital de referencia / Clinical manisfestations and evolution of SLE patientes in a reference center

Se revisaron las historias clínicas de 159 pacientes con LES (criterios ACR 1982), 91% mujeres, con una edad media a la primera consulta: 30 años y un tiempo medio de seguimiento de 73 meses. El 51% presentó compromiso musculoesquelético, el 50% compromiso renal y el 44% presentó rash malar fotosensible. AAN (+) se determinó en 59% de los pacientes, consumo de complemento en 49% y linfopenia en 34.5%. 94/100 pacientes en quienes estuvo disponible el SLEDAI estaban en la primera consulta (media: 8). Durante la evolución, 70% de los pacientes fueron tratados con antipalúdicos y esteroides V.O. 80% de los pacientes permanecían vivos en al última consulta; la mortalidad fue del 17% debido principalmente a infecciones, hemorragía pulmonar e insuficiencia respiratoria.

Manifestaciones y evolución clínica de pacientes con LES en un hospital de referencia / Clinical manisfestations and evolution of SLE patientes in a reference center

Se revisaron las historias clínicas de 159 pacientes con LES (criterios ACR 1982), 91% mujeres, con una edad media a la primera consulta: 30 años y un tiempo medio de seguimiento de 73 meses. El 51% presentó compromiso musculoesquelético, el 50% compromiso renal y el 44% presentó rash malar fotosensible. AAN (+) se determinó en 59% de los pacientes, consumo de complemento en 49% y linfopenia en 34.5%. 94/100 pacientes en quienes estuvo disponible el SLEDAI estaban en la primera consulta (media: 8). Durante la evolución, 70% de los pacientes fueron tratados con antipalúdicos y esteroides V.O. 80% de los pacientes permanecían vivos en al última consulta; la mortalidad fue del 17% debido principalmente a infecciones, hemorragía pulmonar e insuficiencia respiratoria.(AU)

Infección diseminada por Strongyloides stercoralis en pacientes con enfermedades reumáticas / Disseminated strongiloidiasis in patients with rheumatic diseases

La infección por Strongyloides stercoralis puede desarrollarse de manera asintomática, sobre todo en aquellos individuos portadores de una enfermedad reumática o que estén bajo tratamiento inmunosupresor.Describimos 24 pacientes con enfermedades reumáticas (lupus eritematoso sistémico, artritis reumáticas, dermatomiositis, polimiositis) que se presentaron con síntomas que imitaron un brote de la enfermedad de base (fiebre, artritis, artralgias, serositis, compromiso renal, dolor abdominal, etc.), presentando solo 6 de ellos eosinofilia periférica. También presentamos otro paciente que concurrió a la consulta con síntomas que imitaron una enfermedad del tejido conectivo (derrame pleural y peritoneal, etc.), anemia, plaquetopenia y p-ANCA (+). El parásito se halló en los exámenes de materia fecal en la mayoría de ellos y en otros en biopsia duodenal. De los 25 pacientes, 4 fallecieron.

Strongyloides stercoralis infection may develop in individuals with asymptomaticinfection, being carriers of a rheumatic disease or receivingimmunosuppressive treatment.We describe twenty-four patients with rheumatic diseases (systemic lupuserythematosus, rheumatoid arthritis, polymyositis, dermatomyositis,etc.) presenting symptoms that mimicked a flare of the rheumatic disease(fever, arthritis, arthralgia, serous and renal involvement, abdominalpain). Only six of them showed increased peripheral eosinophils.There was another patient who came with symptoms that mimicked aconnective tissue disease, such as pleural and peritoneal effusion, andlaboratory test that showed the presence of anemia, thrombocytopeniaand positive p-ANCA. Strongyloides stercoralis was found in the majorityof them and in the other by duodenal intubation and biopsy. Four out of25 patients died.

Infección diseminada por Strongyloides stercoralis en pacientes con enfermedades reumáticas / Disseminated strongiloidiasis in patients with rheumatic diseases

La infección por Strongyloides stercoralis puede desarrollarse de manera asintomática, sobre todo en aquellos individuos portadores de una enfermedad reumática o que estén bajo tratamiento inmunosupresor.Describimos 24 pacientes con enfermedades reumáticas (lupus eritematoso sistémico, artritis reumáticas, dermatomiositis, polimiositis) que se presentaron con síntomas que imitaron un brote de la enfermedad de base (fiebre, artritis, artralgias, serositis, compromiso renal, dolor abdominal, etc.), presentando solo 6 de ellos eosinofilia periférica. También presentamos otro paciente que concurrió a la consulta con síntomas que imitaron una enfermedad del tejido conectivo (derrame pleural y peritoneal, etc.), anemia, plaquetopenia y p-ANCA (+). El parásito se halló en los exámenes de materia fecal en la mayoría de ellos y en otros en biopsia duodenal. De los 25 pacientes, 4 fallecieron.(AU)

Strongyloides stercoralis infection may develop in individuals with asymptomaticinfection, being carriers of a rheumatic disease or receivingimmunosuppressive treatment.We describe twenty-four patients with rheumatic diseases (systemic lupuserythematosus, rheumatoid arthritis, polymyositis, dermatomyositis,etc.) presenting symptoms that mimicked a flare of the rheumatic disease(fever, arthritis, arthralgia, serous and renal involvement, abdominalpain). Only six of them showed increased peripheral eosinophils.There was another patient who came with symptoms that mimicked aconnective tissue disease, such as pleural and peritoneal effusion, andlaboratory test that showed the presence of anemia, thrombocytopeniaand positive p-ANCA. Strongyloides stercoralis was found in the majorityof them and in the other by duodenal intubation and biopsy. Four out of25 patients died.(AU)

A cytoplasmic complex mediates specific mRNA recognition and localization in yeast.

In eukaryotes, hundreds of mRNAs are localized by specialized transport complexes. For localization, transcripts are recognized by RNA-binding proteins and incorporated into motor-containing messenger ribonucleoprotein particles (mRNPs). To date, the molecular assembly of such mRNPs is not well understood and most details on cargo specificity remain unresolved. We used ASH1-mRNA transport in yeast to provide a first assessment of where and how localizing mRNAs are specifically recognized and incorporated into mRNPs. By using in vitro-interaction and reconstitution assays, we found that none of the implicated mRNA-binding proteins showed highly specific cargo binding. Instead, we identified the cytoplasmic myosin adapter She3p as additional RNA-binding protein. We further found that only the complex of the RNA-binding proteins She2p and She3p achieves synergistic cargo binding, with an at least 60-fold higher affinity for localizing mRNAs when compared to control RNA. Mutational studies identified a C-terminal RNA-binding fragment of She3p to be important for synergistic RNA binding with She2p. The observed cargo specificity of the ternary complex is considerably higher than previously reported for localizing mRNAs. It suggests that RNA binding for mRNP localization generally exhibits higher selectivity than inferred from previous in vitro data. This conclusion is fully consistent with a large body of in vivo evidence from different organisms. Since the ternary yeast complex only assembles in the cytoplasm, specific mRNA recognition might be limited to the very last steps of mRNP assembly. Remarkably, the mRNA itself triggers the assembly of mature, motor-containing complexes. Our reconstitution of a major portion of the mRNA-transport complex offers new and unexpected insights into the molecular assembly of specific, localization-competent mRNPs and provides an important step forward in our mechanistic understanding of mRNA localization in general.

Nuclear transit of the RNA-binding protein She2 is required for translational control of localized ASH1 mRNA.

Cytoplasmic localization and localized translation of messenger RNAs contribute to asymmetrical protein distribution. Recognition of localized mRNAs by RNA-binding proteins can occur in the cytoplasm or, alternatively, co- or post-transcriptionally in the nucleus. In budding yeast, mRNAs destined for localization are bound by the She2 protein before their nuclear export. Here, we show that a specific transcript, known as ASH1 mRNA, and She2 localize specifically to the nucleolus when their nuclear export is blocked. Nucleolar She2 localization is enhanced in a She2 mutant that cannot bind to RNA. A fusion protein of the amino terminus of She3 and She2 (She3N-She2) fails to enter the nucleus, but does not impair ASH1 mRNA localization. Instead, these cells fail to distribute Ash1 protein asymmetrically, which is caused by a defective translational control of ASH1 mRNA. Our results indicate that the nucleolar transit of RNA-binding proteins such as She2 is necessary for the correct assembly of translationally silenced localizing messenger ribonucleoproteins.

Simultaneous transport of different localized mRNA species revealed by live-cell imaging.

Intracellular mRNA localization is a common mechanism to achieve asymmetric distributions of proteins. Previous studies have revealed that in a number of cell types, different mRNA species are localized by the same transport machinery. However, it has been unclear if these individual mRNA species are specifically sorted into separate or common ribonucleoprotein (RNP) particles before or during transport. Using budding yeast as a model system, we analyzed the intracellular movement of individual pairs of localized mRNA in live cells. Yeast cells localize more than 20 different mRNAs to the bud with the help of the Myo4p/She3p/She2p protein complex. For live cell imaging, mRNA pairs were tagged with tandem repeats of either bacteriophage MS2 or lambda boxB RNA sequences and fluorescently labeled by fusion protein constructs that bind to the RNA tag sequences. Using three-dimensional, single-particle tracking with dual-color detection, we have tracked the transport of two different localized mRNA species in real time. Our observations show that different localized mRNAs are coassembled into common RNP particles and cotransported in a directional manner to the target site. Nonlocalized mRNAs or mutant mRNAs that lack functional localization signals form separate particles that are not transported to the bud. This study reveals a high degree of co-ordination of mRNA trafficking in budding yeast.

Membrane association is a determinant for substrate recognition by PMT4 protein O-mannosyltransferases.

Protein O-mannosylation represents an evolutionarily conserved, essential posttranslational modification with immense impact on a variety of cellular processes. In humans, O-mannosylation defects result in Walker-Warburg syndrome, a severe recessive congenital muscular dystrophy associated with defects in neuronal migration that produce complex brain and eye abnormalities. In mouse and yeasts, loss of O-mannosylation causes lethality. Protein O-mannosyltransferases (PMTs) initiate the assembly of O-mannosyl glycans. The evolutionarily conserved PMT family is classified into PMT1, PMT2, and PMT4 subfamilies, which mannosylate distinct target proteins. In contrast to other types of glycosylation, signal sequences for O-mannosylation have not been identified to date. In the present study, we identified signals that determine PMT4-dependent O-mannosylation. Using specific model proteins, we demonstrate that in yeast Pmt4p mediates O-mannosylation of Ser/Thr-rich membrane-attached proteins. The nature of the membrane-anchoring sequence is nonrelevant, as long as it is flanked by a Ser/Thr-rich domain facing the endoplasmic reticulum lumen. Our work shows that, in contrast to several other types of glycosylation, PMT4 O-mannosylation signals are not just linear protein's primary structure sequences but rather are highly complex. Based on these findings, we performed in silico analyses of the Saccharomyces cerevisiae proteome and identified previously undescribed Pmt4p substrates. This tool for proteome-wide identification of O-mannosylated proteins is of general interest because several of these proteins are major players of a wide variety of cellular processes.

Why cells move messages: the biological functions of mRNA localization.

RNA localization is a widespread mechanism that allows cells to spatially control protein function by determining their sites of synthesis. In embryos, localized mRNAs are involved in morphogen gradient formation or the asymmetric distribution of cell fate determinants. In somatic cell types, mRNA localization contributes to local assembly of protein complexes or facilitates protein targeting to organelles. Long-distance transport of specific mRNAs in plants allows coordination of developmental processes between different plant organs. In this review, we will discuss the biological significance of different patterns of mRNA localization.