Agreement between local and central anti-synthetase antibodies detection: results from the Classification Criteria of Anti-Synthetase Syndrome project biobank.

OBJECTIVES: The CLASS (Classification Criteria of Anti-Synthetase Syndrome) project is a large international multicentre study that aims to create the first data-driven anti-synthetase syndrome (ASSD) classification criteria. Identifying anti-aminoacyl tRNA synthetase antibodies (anti-ARS) is crucial for diagnosis, and several commercial immunoassays are now available for this purpose. However, using these assays risks yielding false-positive or false-negative results, potentially leading to misdiagnosis. The established reference standard for detecting anti-ARS is immunoprecipitation (IP), typically employed in research rather than routine autoantibody testing. We gathered samples from participating centers and results from local anti-ARS testing. As an "ad-interim" study within the CLASS project, we aimed to assess how local immunoassays perform in real-world settings compared to our central definition of anti-ARS positivity. METHODS: We collected 787 serum samples from participating centres for the CLASS project and their local anti-ARS test results. These samples underwent initial central testing using RNA-IP. Following this, the specificity of ARS was reconfirmed centrally through ELISA, line-blot assay (LIA), and, in cases of conflicting results, protein-IP. The sensitivity, specificity, positive likelihood ratio and positive and negative predictive values were evaluated. We also calculated the inter-rater agreement between central and local results using a weighted κ co-efficient. RESULTS: Our analysis demonstrates that local, real-world detection of anti-Jo1 is reliable with high sensitivity and specificity with a very good level of agreement with our central definition of anti-Jo1 antibody positivity. However, the agreement between local immunoassay and central determination of anti-non-Jo1 antibodies varied, especially among results obtained using local LIA, ELISA and "other" methods. CONCLUSIONS: Our study evaluates the performance of real-world identification of anti-synthetase antibodies in a large cohort of multi-national patients with ASSD and controls. Our analysis reinforces the reliability of real-world anti-Jo1 detection methods. In contrast, challenges persist for anti-non-Jo1 identification, particularly anti-PL7 and rarer antibodies such as anti-OJ/KS. Clinicians should exercise caution when interpreting anti-synthetase antibodies, especially when commercial immunoassays test positive for non-anti-Jo1 antibodies.

Enfermedad de Chagas crónica: ausencia de Triatoma infestans intradomiciliario y persistencia de Trypanosoma cruzi circulante post-terapia / Chronic Chagas disease: absence of intradomiciliary Triatomatoma infestans and persistence of circulating post-therapy Trypanosoma cruzi

En el año 1999, se certificó en Chile la interrupción de la transmisión vectorial de la enfermedad de Chagas. Por otra parte, el desarrollo de políticas habitacionales, que incluyen zonas rurales endémicas, han logrado importantes avances en grupos humanos que presentaban graves deficiencias de habitabilidad. En esta situación epidemiológica, se estudió 10 años después de la terapia, a 37 chagásicos crónicos procedentes de zonas rurales de la IV Región, mediante encuesta epidemiológica (pre y post-terapia) y evaluación parasitológica (post-terapia). La encuesta incluyó: conocimiento del vector, triatominos en el domicilio actual, antecedentes de haber sido picado por triatominos y material de la construcción de la vivienda. La evaluación parasitológica se realizó mediante xenodiagnóstico (XD) (37 casos) y Reacción en Cadena de la Polimerasa (PCR) en sangre periférica (34 casos). Los resultados de la encuesta epidemiológica evidenciaron cambios importantes en la calidad de la vivienda rural de los chagásicos tratados, mientras que, en relación a la parasitemia, se detectó Trypanosoma cruzi circulante en el 89,2 por ciento de los casos (37,8 por ciento y 88,2 por ciento, mediante XD y PCR, respectivamente). Se concluye que la persistencia del parásito en condiciones post-terapia, no está relacionada con la presencia de Triatoma infestans intradomiciliario.

Variaciones epidemiológicas en el Servicio de Otorrinolaringología del Hospital Clínico de la Universidad de Chile y su influencia en la docencia de postgrado / Epidemiologic variations in Othorhinolaringology Service of Clinical Hospital of University of Chile and and its influence in postgraduate teaching

Evaluar en el Servicio de Otorrinolaringología del Hospital Clínico de la Universidad de Chile HCUCH, si junto con el aumento en las cirugías durante los últimos años, disminuyeron las de mayor complejidad, afectando la calidad docente. Y determinar si existieron cambios epidemiológicos en el tipo de procedimientos, y si la cantidad de éstos, es suficiente para capacitar a los alumnos de postgrado. Se analizaron los años 1990, 1999 y 2003 para el total y el detalle de las intervenciones quirúrgicas, y las consultas. Se clasificaron las operaciones según complejidad 1999 y 2003. Para evaluar el número mínimo de procedimientos necesarios para cumplir los objetivos terminales del programa se compararon los datos del HCUCH, con datos nacionales e internacionales. Aumentaron 53 por ciento las consultas y 148 por ciento las cirugías 1990-2003. Esto no significó disminuir proporcionalmente la cantidad de cirugías de mediana y mayor complejidad. Han disminuido cirugías, han aumentado y aparecido nuevas técnicas quirúrgicas. El número de procedimientos realizados por los residentes está sobre los requerimientos mínimos encontrados.

[Spondylodiscitis. Analysis of 25 cases]. / Espondilodiscitis. Análisis de una serie de 25 casos.

BACKGROUND: Spondylodiscitis is a rare but prolonged inflammation of two adjacent vertebral bodies and the disk in between. AIM: To report the clinical features of a series of patients with spondylodiscitis. MATERIAL AND METHODS: A retrospective analysis of medical records of patients with spondylitis, identified between 1989 and 2002. RESULTS: A total of 25 cases were identified, 15 female, aged 49.8 years as a mean. Their mean evolution before admission was 4.3 months. Main complaints were back or radicular pain. Mild anemia was present in most patients. Mean erythrocyte sedimentation rate and C reactive protein values were 66 mm/h and 60 mg/L, respectively. Forty four percent of patients had neurological complications. Vertebral computed tomography and scintigraphic studies were done in 72% of patients, but magnetic resonance imaging was done only in 4 (16%). In 18 patients, a tissue sample for pathological and microbiological analysis, was obtained by imaging guiding or surgically. Tuberculosis, diagnosed on pathology, was the leading cause of spondylitis in nine cases (36%), followed by Staphylococcus aureus infection in five (20%). Other agents found were E coli and group D Streptococcus (one each). Age, symptoms, evolution time and different laboratory parameters did not differ between patients with tuberculosis and patients with other causes. A microbiological cause was not established in 36% of cases. Most patients evolved satisfactorily and recovered from neurological complications (88%). One patient with tuberculosis did not improve after prolonged treatment and 2 patients infected with S aureus died (8%). CONCLUSIONS: Spondylodiscitis is associated to a diversity of microbial agents and in most cases has a favorable prognosis.

Loxoscelismo y latrodectismo en una paciente: caso clínico / Loxoscelism and latrodectism in the same patient

We report a 51 years old, woman, who live in a rural zone of Llolleo, San Antonio, V Región of Chile. Her dewelling is near a wheat ground sown. In november 1999 during the cleaning of her house she felt a "bug" in her head, but did not find it. She started immediatly with itching, hypoesthesia of arms and legs, dispnea, thoracic pain, vomiting, 40§C fever, myalgias in right arm, thorax, and hypogastric zone, trembling, plantiful sweating, and rapidly lost consciousness. She recovered consciousness 1 hour later and asked for help. A neighbour saw and captured a spider going out of her clothes. She was taken to the emergency room, where she received sera and oxigen, and was discharged two days later with a prescription of antihistaminics, glucosteroids, a muscle relaxing agend and diuretics. During six months se was controled in the out patient clinic of the hospital. The spider was identified by entomologist as Latrodectus mactans. In june 2002 when she was sleeping, felt a wounding lancet pain in the middle finger of the right hand. Afterwards a black plate with yellow vesicles in his center appeared in that same zone. The right arm become edematous and paresthetic; the patient complained of an important asthenia. She was hospitalized receiving intravenous steroids. In this ocassion the patients couldnït keep the spider, but when she describes it to the entomologist of the National Science and Arqueological Museum of San Antonio, the specimen was identified as an exemplar of Loxosceles laeta . Latrodectism is usually a day out door accident, during agricultural activities. Loxoscelism is in general a night in door accident. In this excepcional case the patient lives near a wheat ground sown and the absence of routinary cleaning of her dewelling, could explain both accidents. We couldïnt find publications of accidents of both spiders affecting the same person. For this reason we consider important to comunicate this case