IFCC interim guidelines on rapid point-of-care antigen testing for SARS-CoV-2 detection in asymptomatic and symptomatic individuals.

With an almost unremittent progression of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections all around the world, there is a compelling need to introduce rapid, reliable, and high-throughput testing to allow appropriate clinical management and/or timely isolation of infected individuals. Although nucleic acid amplification testing (NAAT) remains the gold standard for detecting and theoretically quantifying SARS-CoV-2 mRNA in various specimen types, antigen assays may be considered a suitable alternative, under specific circumstances. Rapid antigen tests are meant to detect viral antigen proteins in biological specimens (e.g. nasal, nasopharyngeal, saliva), to indicate current SARS-CoV-2 infection. The available assay methodology includes rapid chromatographic immunoassays, used at the point-of-care, which carries some advantages and drawbacks compared to more conventional, instrumentation-based, laboratory immunoassays. Therefore, this document by the International Federation for Clinical Chemistry and Laboratory Medicine (IFCC) Taskforce on COVID-19 aims to summarize available data on the performance of currently available SARS-CoV-2 antigen rapid detection tests (Ag-RDTs), providing interim guidance on clinical indications and target populations, assay selection, and evaluation, test interpretation and limitations, as well as on pre-analytical considerations. This document is hence mainly aimed to assist laboratory and regulated health professionals in selecting, validating, and implementing regulatory approved Ag-RDTs.

B cell subset alteration and the expression of tissue homing molecules in dengue infected patients.

BACKGROUND: B cells play an essential role during dengue viral infection. While a major expansion of antibody secreting cells (ASCs) was observed, the importance of these increased frequencies of ASCs remains unclear. The alteration of B cell subsets may result from the expression of tissue specific homing molecules leading to their mobilization and distribution to different target organs during acute dengue viral infection. METHODS: In this study, whole blood samples were obtained from thirty pediatric dengue-infected patients and ten healthy children and then stained with fluorochrome-conjugated monoclonal antibodies against CD3, CD14, CD19, CD20, CD21, CD27, CD38, CD45, CD138 and homing molecules of interest before analyzed by polychromatic flow cytometry. B cell subsets were characterized throughout acute infection period. RESULTS: Data shows that there were no detectable differences in frequencies of resting, activated and tissue memory cells, whereas the frequency of ASCs was significantly increased and associated with the lower frequency of naïve cells. These results were found from patients with both dengue fever and dengue hemorrhagic fever, suggesting that such change or alteration of B cells was not associated with disease severity. Moreover, several homing molecules (e.g., CXCR3 and CCR2) were found in ASCs, indicating that ASCs may distribute to inflamed tissues and various organs. CONCLUSIONS: Findings from this study provide insight into B cell subset distribution. Furthermore, organ mobilization according to homing molecule expression on different B cell subsets during the course of dengue viral infection also suggests they are distributed to inflamed tissues and various organs.

La enfermedad de Castleman: entidad poco frecuente en pediatría y de presentación variable / Castleman’s disease: a rare entity and variable presentation in children

La enfermedad de Castleman (EC) es un trastorno linfoproliferativo infrecuente. Su etiología es desconocida, pero se cree que en ella pueden estar implicados procesos autoinmunes, inflamaciones crónicas, infecciones e inmunodeficiencias. Afecta a pacientes jóvenes y se diferencian clínicamente dos formas, una localizada, que se presenta como una masa única, asintomática, de buen pronóstico, más prevalente en pediatría, y otra multicéntrica, con afectación sistémica y peor pronóstico. Histológicamente, existen dos variantes: la hialinovascular, que suele corresponder a las formas localizadas, y la de células plasmáticas, que suele ser multicéntrica. La resección es curativa en las formas localizadas; sin embargo, en las formas multicéntricas se ha ensayado multitud de tratamientos sin éxito. Presentamos el caso de un paciente de 7 años de edad con una forma localizada de EC en la región cervical, en la que la resección quirúrgica resultó ser diagnóstica y terapéutica. Tras 2 años de seguimiento, se mantiene asintomático (AU)

Castleman's disease (CD) is an uncommon lymphoproliferative disorder. The etiology is unknown, but autoimmune processes, chronic inflammations, infections and immunodeficiencies are postulated to be involved. CD usually affects young patients and is classified into two clinical groups: a localized variant, the more frequent type in children, presented as a solitary asymptomatic mass, with good prognosis; and the multicentric variant, associated with systemic symptoms and a more aggressive clinical evolution. There are two histological variants, the hyaline-vascular type, which usually appears as localized forms, and the plasma-cell type, which is often multicentric. Resection is curative in localized forms; however, several treatments have been tried in multicentric forms without success. We report the case of a 7-year-old boy with the localized form of CD in the neck, in which the excision was both diagnostic and therapeutic. He remains asymptomatic after 2 years of follow-up (AU)

Association of NAFLD with subclinical atherosclerosis and coronary-artery disease: meta-analysis

BACKGROUND: Recent studies have associated non-alcoholic fatty liver disease (NAFLD) with increased risk of cardiovascular disease, using tests of subclinical atherosclerosis. AIM: To evaluate the influence of NAFLD on subclinical atherosclerosis and coronary artery disease (CAD). METHODS: We reviewed Pubmed and EMBASE. According to inclusion and exclusion criteria, we selected 14 studies and were classified in two groups. Ten studies aimed the presence of subclinical atherosclerosis and four studies the presence of coronary artery disease. To assess subclinical atherosclerosis, we selected studies with pathological carotid intima-media thickness (CIMT) and with presence of carotid plaques. We considered coronary artery disease when patients showed at least 50 % stenosis at one or more major coronary arteries. NAFLD was assessed by ultrasound (US) and liver biopsy. RESULTS: NAFLD showed a higher prevalence of pathological CIMT [35.1 % (351/999) vs. 21.8 % (207/948); p < 0.0001], with OR 2.04 (95 % CI: 1.65-2.51). Similarly, the presence of carotid plaques was higher in NAFLD diagnosed by US [34.2 % (101/295) vs. 12.9 % (51/394); p < 0.0001] [OR 2.82 (95 % CI: 1.87-4.27)] and diagnosed by liver biopsy [64.8 % (70/108) vs. 31.3 % (59/188); p < 0.0001] [OR 4.41 (95 % CI: 2.63- 7.40)]. On the other hand, four studies assessed CAD in patients underwent coronary angiogram. Subjects with NAFLD showed 80.4 % (492/612) of CAD, while it was detected in 60.7 % (356/586) (p < 0.0001) in patients without NAFLD. Therefore, NAFLD was associated with a remarkably higher likelihood of CAD, using random effects model [OR 3.31 (95 % CI: 2.21-4.95)] or fixed effects model [OR 3.13 (95 % CI: 2.36-4.16)]. CONCLUSIONS: NAFLD increases the risk of subclinical atherosclerosis and coronary artery disease. The right management of these patients could modify the natural history both liver and cardiovascular disease

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Assessing the welfare impact of foot disorders in dairy cattle by a modeling approach.

Foot disorders are the main cause of dairy cow lameness and are considered to have a major impact on the welfare of dairy cattle. This study adopts a modeling approach, using a dynamic stochastic model, to provide more insight into the welfare impact of different types of foot disorders, both clinical and subclinical. The impact of specific foot disorders on welfare was assessed by simulating the incidence and duration of foot disorders and the pain associated with them. Pain assessment was based on locomotion scores, with underlying knowledge obtained from scientific literature and experts. The results demonstrated the seriousness of the welfare impact of foot disorders. The negative welfare impact was measured on a scale from 0 to 60, where the maximum outcome represents a cow having very severe pain during the whole year. On average, each cow achieves a welfare impact score of 12, which is 20% of the maximum welfare impact score. This welfare score equals having severe pain for a period of 3 months, indicating a serious impact on welfare. On average, digital dermatitis impacts most on welfare, which is caused by a high incidence of the painful clinical stage, followed by sole hemorrhages (SoH) and interdigital dermatitis and heel horn erosion (IDHE). The combination of a high incidence and long duration of SoH and IDHE causes this relatively high welfare impact of foot disorders that occur mostly subclinically. On average, over 1 year, 46% of the welfare impact due to foot disorders is caused by clinical foot disorders. The fact that subclinical foot disorders contribute more or less equally to the effects on welfare as clinical ones, indicates that farmers may readily underestimate the welfare impact by a factor two. Modeling welfare impact at cow level, individual cases of foot disorders, stresses the importance of pain intensity, indicating the importance of clinical foot disorders. This study demonstrated the serious welfare impact of foot disorders in dairy cattle and pointed out the considerable impact of subclinical foot disorders. Furthermore, the approach of welfare assessment, for example herd v. cow level, influenced the ranking of foot disorders for their impact on animal welfare. Potentially, this leads to different prioritization of specific solution strategies for dairy farmers, for example, focusing on cow comfort, hygiene or preventive medical treatments, foot trimming and/or health monitoring. The findings in this study support in raising awareness about this welfare issue.