Rapid decline of anti-SARS-CoV-2 antibodies in patients on haemodialysis: the COVID-FRIAT study.

BACKGROUND: Coronavirus disease 2019 (COVID-19) patients on haemodialysis (HD) have high mortality. We investigated the value of reverse transcription polymerase chain reaction (RT-PCR) and the dynamic changes of antibodies (enzyme-linked immunosorbent assay immunoglobulin M (IgM) + IgA and/or IgG) in a large HD cohort. METHODS: We conducted a prospective observational study in 10 Madrid HD centres. Infection rate, anti-SARS-CoV-2 antibody dynamics and the incidence of asymptomatic SARS-CoV-2 infection (defined by positive RT-PCR, IgM + IgA and/or IgG) were assessed. RESULTS: From 1 March to 15 April 2020, 136 of 808 (16.8%) HD patients were diagnosed with symptomatic COVID-19 by RT-PCR of nasopharyngeal swabs and 42/136 (31%) died. In the second fortnight of April, RT-PCR and anti-SARS-CoV-2 antibodies were assessed in 763 of the surviving patients. At this point, 69/91 (75.8%) symptomatic COVID-19 patients had anti-SARS-CoV-2 antibodies. Four weeks later, 15.4% (10/65) of initially antibody-positive patients had become negative. Among patients without prior symptomatic COVID-19, 9/672 (1.3%) were RT-PCR positive and 101/672 patients (15.0%) were antibody positive. Four weeks later, 62/86 (72.1%) of initially antibody-positive patients had become negative. Considering only IgG titres, serology remained positive after 4 weeks in 90% (54/60) of patients with symptomatic COVID-19 and in 52.5% (21/40) of asymptomatic patients. The probability of an adequate serologic response (defined as the development of anti-SARS-CoV-2 antibodies that persisted at 4 weeks) was higher in patients who had symptomatic COVID-19 than in asymptomatic SARS-CoV-2 infection {odds ratio [OR) 4.04 [95% confidence interval (CI) 2.04-7.99]} corrected for age, Charlson comorbidity index score and time on HD. Living in a nursing home [OR 5.9 (95% CI 2.3-15.1)] was the main risk factor for SARS-CoV-2 infection. CONCLUSIONS: The anti-SARS-CoV-2 antibody immune response in HD patients depends on clinical presentation. The antibody titres decay earlier than previously reported for the general population. This inadequate immune response raises questions about the efficacy of future vaccines.

Serology in the xxi century: is it still of interest? / Serología en el siglo xxi: ¿continúa teniendo interés?

Serological techniques have developed in recent years, and are now more sensitive, automated and easier to interpret. However, serology in often being replaced by direct diagnosis based on molecular biology, essentially PCR (polymerase chain reaction) techniques. Nevertheless, in some cases, serology continues to be an essential feature in the routine work of microbiology laboratories, such as in screening pregnant wo-men, studies of transplant donors and recipients, diagnosis of certain viruses and bacteria, and epidemiological and prevalence studies. The improved speed, sensitivity and specificity of direct diagnostic methods will probably continue to decrease antibody-based diagnosis. Thus, serology will not be relevant in the management of acute patient infections; however, it will continue to be relevant in population-based studies and in certain syndromic studies, with more automated and more sensitive, specific and cheap methods. Supplement information: This article is part of a supplement entitled «SEIMC External Quality Control Programme. Year 2016¼, which is sponsored by Roche, Vircell Microbiologists, Abbott Molecular and Francisco Soria Melguizo, S.A. © 2019 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosasy Microbiología Clínica. All rights reserved.

Serología en el siglo xxi: ¿continúa teniendo interés? / Serology in the xxi century: is it still of interest?

Las técnicas serológicas han evolucionado en los últimos años, pues son más sensibles, automatizables y de más fácil interpretación. Sin embargo, la serología en muchos casos está siendo desplazada por el diagnóstico directo que ofrece la biología molecular, fundamentalmente la amplificación de ácidos nucleicos (reacción en cadena de la polimerasa), aunque continúa siendo básica en la práctica diaria del laboratorio de microbiología clínica asistencial en algunas situaciones, como en el cribado en la mujer embarazada, los estudios a donantes y receptores en un trasplante, el diagnóstico de determinados virus y bacterias, y en estudios epidemiológicos y de prevalencia. La mejora en la rapidez, sensibilidad, especificidad y costes de los métodos diagnósticos directos moleculares representará, probablemente, la progresiva disminución en el diagnóstico basado en anticuerpos. Así, no es probable que la serología tenga relevancia en el tratamiento de infecciones del paciente agudo, pero continuará siendo relevante en los estudios poblacionales y en determinados estudios sindrómicos, con métodos más automatizables, más sensibles, específicos y baratos. Información sobre el suplemento: este artículo forma parte del suplemento titulado "Programa de Control de Calidad Externo SEIMC. Año 2016", que ha sido patrocinado por Roche, Vircell Microbiologists, Abbott Molecular y Francisco Soria Melguizo, S.A

Serological techniques have developed in recent years, and are now more sensitive, automated and easier to interpret. However, serology in often being replaced by direct diagnosis based on molecular biology, essentially PCR (polymerase chain reaction) techniques. Nevertheless, in some cases, serology continues to be an essential feature in the routine work of microbiology laboratories, such as in screening pregnant women, studies of transplant donors and recipients, diagnosis of certain viruses and bacteria, and epidemiological and prevalence studies. The improved speed, sensitivity and specificity of direct diagnostic methods will probably continue to decrease antibody-based diagnosis. Thus, serology will not be relevant in the management of acute patient infections; however, it will continue to be relevant in population-based studies and in certain syndromic studies, with more automated and more sensitive, specific and cheap methods. Supplement information: This article is part of a supplement entitled "SEIMC External Quality Control Programme. Year 2016", which is sponsored by Roche, Vircell Microbiologists, Abbott Molecular and Francisco Soria Melguizo, S.A

[Molecular diagnosis of parasitic and fungal infections]. / El diagnóstico molecular en las infecciones parasitarias y fúngicas.

Conventional microbiological diagnosis of fungal infections and parasitic diseases has been characterized by low diagnostic sensitivity, laboriousness, and the need for expert microscopists. Consequently, diagnostic methods based on the detection of nucleic acids are a magnificent alternative to overcome these problems, but have not yet provided a satisfactory response in all situations. The molecular methods used are varied and most are based on techniques of nucleic acid amplification. These techniques have proved useful for mycological and parasitological diagnosis, for epidemiological and taxonomic studies, and for monitoring the response to different treatments and detection of resistance. The introduction of these techniques in developing countries may be hampered by their higher cost but molecular diagnostic methods are already beginning to spread in clinical microbiology laboratories and are competing successfully with traditional methods. The present article reviews the current status of molecular methods in the diagnosis of fungal and parasitic infections.

El diagnóstico molecular en las infecciones parasitarias y fúngicas / Molecular diagnosis of parasitic and fungal infections

El diagnóstico microbiológico convencional de lasinfecciones fúngicas y parasitarias se ha caracterizado por su escasa sensibilidad diagnóstica, su laboriosidad y la necesidad de microscopistas experimentados. Frente aellos, los métodos diagnósticos basados en la detección de ácidos nucleicos son una alternativa magnífica parasuperar estos problemas, aunque todavía no han dadorespuesta satisfactoria a todas las situaciones. Losmétodos moleculares utilizados son variados, la mayoríabasados en técnicas de amplificación de ácidos nucleicos,y han demostrado ser útiles para los diagnósticosmicológico y parasitológico, los estudios epidemiológicosy taxonómicos, y para el seguimiento de la respuesta a los diferentes tratamientos y la detección de resistencias. Es posible que su implantación presente dificultades en los países en vías de desarrollo, debido a su mayor coste; pero los métodos de diagnóstico molecular ya comienzan a extenderse en los laboratorios de microbiología clínica y rivalizan, con éxito, con los métodos clásicos. En este trabajo, nos proponemos revisar la situación actual de los métodos moleculares en el diagnóstico de las infecciones fúngicas y parasitarias

Conventional microbiological diagnosis of fungalinfections and parasitic diseases has been characterized by low diagnostic sensitivity, laboriousness, and the need for expert microscopists. Consequently, diagnostic methods based on the detection of nucleic acids are a magnificent alternative to overcome these problems, but have not yet provided a satisfactory response in all situations. The molecular methods used are varied and most are based on techniques of nucleic acid amplification. These techniques have proved useful for mycological and parasitological diagnosis, for epidemiological and taxonomic studies, andfor monitoring the response to different treatments anddetection of resistance. The introduction of thesetechniques in developing countries may be hampered bytheir higher cost but molecular diagnostic methods arealready beginning to spread in clinical microbiologylaboratories and are competing successfully withtraditional methods. The present article reviews thecurrent status of molecular methods in the diagnosis offungal and parasitic infections

El diagnóstico molecular en las infecciones parasitarias y fúngicas / Molecular diagnosis of parasitic and fungal infections

El diagnóstico microbiológico convencional de las infecciones fúngicas y parasitarias se ha caracterizado por su escasa sensibilidad diagnóstica, su laboriosidad y la necesidad de microscopistas experimentados. Frente a ellos, los métodos diagnósticos basados en la detección de ácidos nucleicos son una alternativa magnífica para superar estos problemas, aunque todavía no han dado respuesta satisfactoria a todas las situaciones. Los métodos moleculares utilizados son variados, la mayoría basados en técnicas de amplificación de ácidos nucleicos, y han demostrado ser útiles para los diagnósticos micológico y parasitológico, los estudios epidemiológicos y taxonómicos, y para el seguimiento de la respuesta a los diferentes tratamientos y la detección de resistencias. Es posible que su implantación presente dificultades en los países en vías de desarrollo, debido a su mayor coste; pero los métodos de diagnóstico molecular ya comienzan a extenderse en los laboratorios de microbiología clínica y rivalizan, con éxito, con los métodos clásicos. En este trabajo, nos proponemos revisar la situación actual de los métodos moleculares en el diagnóstico de las infecciones fúngicas y parasitarias(AU)

Conventional microbiological diagnosis of fungal infections and parasitic diseases has been characterized by low diagnostic sensitivity, laboriousness, and the need for expert microscopists. Consequently, diagnostic methods based on the detection of nucleic acids are a magnificent alternative to overcome these problems, but have not yet provided a satisfactory response in all situations. The molecular methods used are varied and most are based on techniques of nucleic acid amplification. These techniques have proved useful for mycological and parasitological diagnosis, for epidemiological and taxonomic studies, and for monitoring the response to different treatments and detection of resistance. The introduction of these techniques in developing countries may be hampered by their higher cost but molecular diagnostic methods are already beginning to spread in clinical microbiology laboratories and are competing successfully with traditional methods. The present article reviews the current status of molecular methods in the diagnosis of fungal and parasitic infections(AU)