Diagnosis of Multisystem Inflammatory Syndrome in Children by a Whole-Blood Transcriptional Signature.

BACKGROUND: To identify a diagnostic blood transcriptomic signature that distinguishes multisystem inflammatory syndrome in children (MIS-C) from Kawasaki disease (KD), bacterial infections, and viral infections. METHODS: Children presenting with MIS-C to participating hospitals in the United Kingdom and the European Union between April 2020 and April 2021 were prospectively recruited. Whole-blood RNA Sequencing was performed, contrasting the transcriptomes of children with MIS-C (n = 38) to those from children with KD (n = 136), definite bacterial (DB; n = 188) and viral infections (DV; n = 138). Genes significantly differentially expressed (SDE) between MIS-C and comparator groups were identified. Feature selection was used to identify genes that optimally distinguish MIS-C from other diseases, which were subsequently translated into RT-qPCR assays and evaluated in an independent validation set comprising MIS-C (n = 37), KD (n = 19), DB (n = 56), DV (n = 43), and COVID-19 (n = 39). RESULTS: In the discovery set, 5696 genes were SDE between MIS-C and combined comparator disease groups. Five genes were identified as potential MIS-C diagnostic biomarkers (HSPBAP1, VPS37C, TGFB1, MX2, and TRBV11-2), achieving an AUC of 96.8% (95% CI: 94.6%-98.9%) in the discovery set, and were translated into RT-qPCR assays. The RT-qPCR 5-gene signature achieved an AUC of 93.2% (95% CI: 88.3%-97.7%) in the independent validation set when distinguishing MIS-C from KD, DB, and DV. CONCLUSIONS: MIS-C can be distinguished from KD, DB, and DV groups using a 5-gene blood RNA expression signature. The small number of genes in the signature and good performance in both discovery and validation sets should enable the development of a diagnostic test for MIS-C.

Vaccination against Community-Acquired Pneumonia in Spanish Adults: Practical Recommendations by the NeumoExperts Prevention Group.

In the adult population, community-acquired pneumonia (CAP) is a serious disease that is responsible for high morbidity and mortality rates, being frequently associated with multidrug resistant pathogens. The aim of this review is to update a practical immunization prevention guideline for CAP in Spain caused by prevalent respiratory pathogens, based on the available scientific evidence through extensive bibliographic review and expert opinion. The emergence of COVID-19 as an additional etiological cause of CAP, together with the rapid changes in the availability of vaccines and recommendations against SARS-CoV-2, justifies the need for an update. In addition, new conjugate vaccines of broader spectrum against pneumococcus, existing vaccines targeting influenza and pertussis or upcoming vaccines against respiratory syncytial virus (RSV) will be very useful prophylactic tools to diminish the burden of CAP and all of its derived complications. In this manuscript, we provide practical recommendations for adult vaccination against the pathogens mentioned above, including their contribution against antibiotic resistance. This guide is intended for the individual perspective of protection and not for vaccination policies, as we do not pretend to interfere with the official recommendations of any country. The use of vaccines is a realistic approach to fight these infections and ameliorate the impact of antimicrobial resistance. All of the recently available scientific evidence included in this review gives support to the indications established in this practical guide to reinforce the dissemination and implementation of these recommendations in routine clinical practice.

Immunisation schedule of the Spanish Association of Paediatrics: 2023 Recommendations.

As it does every year, the CAV-AEP publishes the update of its recommendations for the use of vaccines in children, adolescents and pregnant women residing in Spain. The 2 + 1 schedule is maintained in infants (at 2, 4 and 11 months), including preterm infants, with the hexavalent vaccine (DTaP-IPV-Hib-HB) and the pneumococcal 13-valent conjugate vaccine. A booster dose with DTaP-IPV is needed at 6 years for those who received the 2 + 1 series with hexavalent vaccine as infants, in addition to 1 dose of dTap in adolescence. Routine vaccination of pregnant women with a dose of dTap is recommended in each pregnancy, preferably between weeks 27 and 32 of gestation, although can be given from 20 weeks if there is risk of preterm delivery. All infants should receive the rotavirus vaccine (2-3 doses) and the 4CMenB vaccine (2 + 1 series). All children aged 6-59 months should be vaccinated against influenza each year. The MenACWY vaccine should be given routinely at 12 months of age and in adolescence between ages 12 and 18 years. The recommendations for the MMR vaccine (12 months and 3-4 years) and varicella vaccine (15 months and 3-4 years) also remain unchanged, using the MMRV vaccine for the second dose. Recommendations for the use of SARS-CoV-2 vaccines in the paediatric age group will be updated periodically on the CAV-AEP website. The HPV vaccine is indicated in all adolescents, regardless of sex, at age 12 years. Novelties include the recommendation of routine administration of nirsevimab to neonates and infants aged less than 6 months for passive immunization against RSV, and the recommendations regarding the hexavalent vaccine are consolidated in a single section.

Calendario de inmunizaciones de la Asociación Española de Pediatría: recomendaciones 2023

Resumen Como cada año, el Comité Asesor de Vacunas de la Asociación Española de Pediatría (CAV-AEP) actualiza sus recomendaciones de inmunización en niños, adolescentes y embarazadas residentes en España. Se mantiene el esquema 2+1 en lactantes (dos, cuatro y 11 meses), incluyendo prematuros, para vacunas hexavalentes (DTPa-VPI-Hib-HB) y neumocócica conjugada 13-valente. A los seis años de edad, refuerzo con DTPa-VPI a los que recibieron la pauta 2+1 con hexavalentes siendo lactantes, y, en la adolescencia, Tdpa, una dosis. En gestantes, Tdpa en cada embarazo, preferentemente entre las semanas 27 y 32, aunque si hay riesgo de parto pretérmino se puede desde la semana 20 de gestación. Todos los lactantes deben recibir vacunas contra rotavirus (dos o tres dosis) y meningococo B (2+1). Todos los niños de entre seis y 59 meses deben ser vacunados anualmente contra la gripe, además de los grupos de riesgo desde los 6 meses. MenACWY debe administrarse a los 12 meses de edad y a los adolescentes entre 12 y 18 años que no la hayan recibido. Se mantienen las recomendaciones sobre SRP (12 meses y tres a cuatro años) y varicela (15 meses y tres a cuatro años), procurando en la segunda dosis el uso de la vacuna tetravírica (SRPV). Las recomendaciones para el uso de las vacunas contra la COVID-19 en la edad pediátrica se actualizarán periódicamente en la web del CAV-AEP. Vacuna contra el virus del papiloma humanon (VPH) indicada para todos los adolescentes, independientemente del género, a los 12 años. Como novedades, se incluyen la recomendación de uso de nirsevimab sistemático en recién nacidos y lactantes menores de seis meses como inmunización pasiva contra el virus respiratorio sincitial (VRS), y se aglutinan las hexavalentes en un solo apartado. As it does every year, the CAV-AEP publishes the update of its recommendations for the use of vaccines in children, adolescents and pregnant women residing in Spain. The 2 + 1 schedule is maintained in infants (at 2, 4 and 11 months), including preterm infants, with the hexavalent vaccine (DTaP-IPV-Hib-HB) and the pneumococcal 13-valent conjugate vaccine. A booster dose with DTaP-IPV is needed at 6 years for those who received the 2 + 1 series with hexavalent vaccine as infants, in addition to 1 dose of dTap in adolescence. Routine vaccination of pregnant women with a dose of dTap is recommended in each pregnancy, preferably between weeks 27 and 32 of gestation, although can be given from 20 weeks if there is risk of preterm delivery. All infants should receive the rotavirus vaccine (2–3 doses) and the 4 CMenB vaccine (2 + 1 series). All children aged 6–59 months should be vaccinated against influenza each year, in addition to risk groups from 6 months. The MenACWY vaccine should be given routinely at 12 months of age and in adolescence between ages 12 and 18 years. The recommendations for the MMR vaccine (12 months and 3–4 years) and varicella vaccine (15 months and 3–4 years) also remain unchanged, using the MMRV vaccine for the second dose. Recommendations for the use of SARS-CoV-2 vaccines in the paediatric age group will be updated periodically on the CAV-AEP website. The HPV vaccine is indicated in all adolescents, regardless of sex, at age 12 years. Novelties include the recommendation of routine administration of nirsevimab to neonates and infants aged less than 6 months for passive immunization against RSV, and the recommendations regarding the hexavalent vaccine are consolidated in a single section.

Exome-wide association study to identify rare variants influencing COVID-19 outcomes: Results from the Host Genetics Initiative.

Host genetics is a key determinant of COVID-19 outcomes. Previously, the COVID-19 Host Genetics Initiative genome-wide association study used common variants to identify multiple loci associated with COVID-19 outcomes. However, variants with the largest impact on COVID-19 outcomes are expected to be rare in the population. Hence, studying rare variants may provide additional insights into disease susceptibility and pathogenesis, thereby informing therapeutics development. Here, we combined whole-exome and whole-genome sequencing from 21 cohorts across 12 countries and performed rare variant exome-wide burden analyses for COVID-19 outcomes. In an analysis of 5,085 severe disease cases and 571,737 controls, we observed that carrying a rare deleterious variant in the SARS-CoV-2 sensor toll-like receptor TLR7 (on chromosome X) was associated with a 5.3-fold increase in severe disease (95% CI: 2.75-10.05, p = 5.41x10-7). This association was consistent across sexes. These results further support TLR7 as a genetic determinant of severe disease and suggest that larger studies on rare variants influencing COVID-19 outcomes could provide additional insights.

Effectiveness of COVID-19 vaccine booster in the general population and in subjects with comorbidities. A population-based study in Spain.

BACKGROUND: Research on the effectiveness of COVID-19 booster-based vaccine schedule is ongoing and real-world data on vaccine effectiveness (VE) in comorbid patients are limited. We aimed to estimate booster dose VE against SARS-CoV-2 infection and COVID-19 severity in the general population and in comorbid patients. METHOD: A retrospective test-negative control study was undertaken in Galicia-Spain (December 2020-November 2021). VE and 95% confidence interval (CI) were estimated using multivariate logistic regression models. RESULTS: 1,512,415 (94.13%) negative and 94,334 (5.87%) positive SARS-CoV-2 test results were included. A booster dose of COVID-19 vaccine is associated with substantially higher protection against SARS-CoV-2 infection than vaccination without a booster [VEboosted = 87% (95%CI: 83%; 89%); VEnon-boosted = 66% (95%CI: 65%; 67%)]. The high VE was observed in all ages, but was more pronounced in subjects older than 65 years. VE against COVID-19 severity was analyzed in a mixed population of boosted and non-boosted individuals and considerable protection was obtained [VE: hospitalization = 72% (95%CI: 68%; 75%); intensive care unit administration = 83% (95%CI: 78%; 88%), in-hospital mortality = 66% (95%CI: 53%; 75%)]. Boosted comorbid patients are more protected against SARS-CoV-2 infection than those who were non-boosted. This was observed in a wide range of major diseases including cancer (81% versus 54%), chronic obstructive pulmonary disease (84% versus 61%), diabetes (84% versus 65%), hypertension (82% versus 65%) and obesity (91% versus 67%), among others. CONCLUSIONS: A booster dose of COVID-19 vaccine increases the protection against SARS-CoV-2 infection and COVID-19 severity in the general population and in comorbid patients.

Characterisation of the blood RNA host response underpinning severity in COVID-19 patients.

Infection with SARS-CoV-2 has highly variable clinical manifestations, ranging from asymptomatic infection through to life-threatening disease. Host whole blood transcriptomics can offer unique insights into the biological processes underpinning infection and disease, as well as severity. We performed whole blood RNA Sequencing of individuals with varying degrees of COVID-19 severity. We used differential expression analysis and pathway enrichment analysis to explore how the blood transcriptome differs between individuals with mild, moderate, and severe COVID-19, performing pairwise comparisons between groups. Increasing COVID-19 severity was characterised by an abundance of inflammatory immune response genes and pathways, including many related to neutrophils and macrophages, in addition to an upregulation of immunoglobulin genes. In this study, for the first time, we show how immunomodulatory treatments commonly administered to COVID-19 patients greatly alter the transcriptome. Our insights into COVID-19 severity reveal the role of immune dysregulation in the progression to severe disease and highlight the need for further research exploring the interplay between SARS-CoV-2 and the inflammatory immune response.

Evaluation of BNT162b2 Vaccine Effectiveness in Galicia, Northwest Spain.

Investigating vaccine effectiveness (VE) in real-world conditions is crucial, especially its variation across different settings and populations. We undertook a test-negative control study in Galicia (Northwest Spain) to assess BNT162b2 effectiveness against acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection as well as COVID-19 associated hospitalization, intensive care unit (ICU) admission and mortality. A total of 44,401 positive and 817,025 negative SARS-CoV-2 test results belonging to adults were included. Adjusted odds ratios of vaccination and their 95% confidence interval (CI) were estimated using multivariate logistic-regression models. BNT162b2 showed high effectiveness in reducing SARS-CoV-2 infections in all age categories, reaching maximum VE ≥ 14 days after administering the second dose [18-64 years: VE = 92.9% (95%CI: 90.2-95.1); 65-79 years: VE = 85.8% (95%CI: 77.3-91.9), and ≥80 years: VE = 91.4% (95%CI: 87.9-94.1)]. BNT162b2 also demonstrated effectiveness in preventing COVID-19 hospitalization for all age categories, with VE more pronounced for those aged ≥80 years [VE = 60.0% (95%CI: 49.4-68.3)]. Moreover, there was a considerable reduction in ICU admission [VE = 88.0% (95%CI: 74.6-95.8)] and mortality [VE = 38.0% (95%CI: 15.9-55.4)] in the overall population. BNT162b2 showed substantial protection against SARS-CoV-2 infections and COVID-19 severity. Our findings would prove useful for systematic reviews and meta-analysis on COVID-19 VE.

Evaluation of BNT162b2 Vaccine Effectiveness in Galicia, Northwest Spain

Investigating vaccine effectiveness (VE) in real-world conditions is crucial, especially its variation across different settings and populations. We undertook a test-negative control study in Galicia (Northwest Spain) to assess BNT162b2 effectiveness against acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection as well as COVID-19 associated hospitalization, intensive care unit (ICU) admission and mortality. A total of 44,401 positive and 817,025 negative SARS-CoV-2 test results belonging to adults were included. Adjusted odds ratios of vaccination and their 95% confidence interval (CI) were estimated using multivariate logistic-regression models. BNT162b2 showed high effectiveness in reducing SARS-CoV-2 infections in all age categories, reaching maximum VE ≥14 days after administering the second dose [18–64 years: VE = 92.9% (95%CI: 90.2–95.1);65–79 years: VE = 85.8% (95%CI: 77.3–91.9), and ≥80 years: VE = 91.4% (95%CI: 87.9–94.1)]. BNT162b2 also demonstrated effectiveness in preventing COVID-19 hospitalization for all age categories, with VE more pronounced for those aged ≥80 years [VE = 60.0% (95%CI: 49.4–68.3)]. Moreover, there was a considerable reduction in ICU admission [VE = 88.0% (95%CI: 74.6–95.8)] and mortality [VE = 38.0% (95%CI: 15.9–55.4)] in the overall population. BNT162b2 showed substantial protection against SARS-CoV-2 infections and COVID-19 severity. Our findings would prove useful for systematic reviews and meta-analysis on COVID-19 VE.

A multi-tissue study of immune gene expression profiling highlights the key role of the nasal epithelium in COVID-19 severity.

Coronavirus Disease-19 (COVID-19) symptoms range from mild to severe illness; the cause for this differential response to infection remains unknown. Unravelling the immune mechanisms acting at different levels of the colonization process might be key to understand these differences. We carried out a multi-tissue (nasal, buccal and blood; n = 156) gene expression analysis of immune-related genes from patients affected by different COVID-19 severities, and healthy controls through the nCounter technology. Mild and asymptomatic cases showed a powerful innate antiviral response in nasal epithelium, characterized by activation of interferon (IFN) pathway and downstream cascades, successfully controlling the infection at local level. In contrast, weak macrophage/monocyte driven innate antiviral response and lack of IFN signalling activity were present in severe cases. Consequently, oral mucosa from severe patients showed signals of viral activity, cell arresting and viral dissemination to the lower respiratory tract, which ultimately could explain the exacerbated innate immune response and impaired adaptative immune responses observed at systemic level. Results from saliva transcriptome suggest that the buccal cavity might play a key role in SARS-CoV-2 infection and dissemination in patients with worse prognosis. Co-expression network analysis adds further support to these findings, by detecting modules specifically correlated with severity involved in the abovementioned biological routes; this analysis also provides new candidate genes that might be tested as biomarkers in future studies. We also found tissue specific severity-related signatures mainly represented by genes involved in the innate immune system and cytokine/chemokine signalling. Local immune response could be key to determine the course of the systemic response and thus COVID-19 severity. Our findings provide a framework to investigate severity host gene biomarkers and pathways that might be relevant to diagnosis, prognosis, and therapy.

Immunization schedule of the Pediatric Spanish Association: 2022 recommendations.

After reviewing the best available scientific information, CAV-AEP publishes their new recommendations to protect pregnant women, children and adolescents living in Spain through vaccination. The same recommendations as the previous year regarding hexavalent vaccines, pneumococcal conjugate vaccine of 13 serotypes, booster with tetanus, diphtheria, pertussis and inactivated poliomyelitis (Tdpa-IPV) at 6 years and with tetanus, diphtheria and pertussis (Tdpa) at 12-14 years and pregnant women from week 27 (from week 20 if there is a high risk of preterm delivery). Also with rotavirus, tetraantigenic meningococcal B (2+1), meningococcal quadrivalent (MenACWY), MMR, varicella and human papillomavirus (HPV) vaccines, for both genders. As novelties this year the CAV-AEP recommends: Influenza vaccination from 6 to 59 months of age whenever feasible and does not harm the vaccination program aimed at people at higher risk. According to official national recommendations, the CAV-AEP recommends the systematic use of COVID mRNA vaccines since 5 years old.

Calendario de vacunaciones de la Asociación Española de Pediatría: Recomendaciones 2022

Resumen Tras la revisión de la mejor información científica disponible, el CAV-AEP publica las nuevas recomendaciones para proteger con vacunas a las embarazadas, los niños y los adolescentes residentes en España. Se mantienen las mismas recomendaciones que el año anterior en cuanto a las vacunas hexavalentes y a la vacuna neumocócica conjugada de 13 serotipos, al refuerzo con tétanos, difteria, tosferina y poliomielitis inactivada (Tdpa-VPI) a los seis años y con tétanos, difteria y tosferina (Tdpa) a los 12-14 años y a las embarazadas a partir de la semana 27 (desde la semana 20 si hay alto riesgo de parto pretérmino). Lo mismo sucede con las vacunas del rotavirus, del meningococo B tetraantigénica (2 + 1), de la vacuna meningocócica tetravalente (MenACWY), de la triple vírica, de la varicela y de la vacuna del virus del papiloma humano (VPH), en ambos géneros. Como novedades este año el CAV-AEP recomienda: La vacunación antigripal de seis a 59 meses de edad siempre que sea factible y no perjudique al programa vacunal dirigido a las personas de mayor riesgo. En consonancia con las recomendaciones oficiales nacionales, el CAV-AEP recomienda el uso sistemático a partir de los 5 años de las vacunas para la COVID-19 de ARNm. After reviewing the best available scientific information, CAV-AEP publishes their new recommendations to protect pregnant women, children and adolescents living in Spain through vaccination. The same recommendations as the previous year regarding hexavalent vaccines, pneumococcal conjugate vaccine of 13 serotypes, booster with tetanus, diphtheria, pertussis and inactivated poliomyelitis (Tdpa-IPV) at 6 years and with tetanus, diphtheria and pertussis (Tdpa) at 12–14 years and pregnant women from week 27 (from week 20 if there is a high risk of preterm delivery). Also with rotavirus, tetraantigenic meningococcal B (2+1), meningococcal quadrivalent (MenACWY), MMR, varicella and human papillomavirus (HPV) vaccines, for both genders. As novelties this year the CAV-AEP recommends:. Influenza vaccination from 6 to 59 months of age whenever feasible and does not harm the vaccination program aimed at people at higher risk. According to official national recommendations, the CAV-AEP recommends the systematic use of COVID mRNA vaccines since 5 years old.

Seroprevalence of SARS-CoV-2 Among Pediatric Healthcare Workers in Spain.

Spain is one of the countries most severely affected by the SARS-CoV-2 pandemic, with almost 190,000 cases as of April 18, 2020. As healthcare workers (HCW) are one of the groups hardest hit by the infection, it is important to know the seroprevalence of antibodies against SARS-CoV-2 in pediatric departments. We performed 175 immunoglobulin (Ig)M and IgG immunochromatographic rapid tests in the personnel working at the Pediatric Department of the Hospital Clínico Universitario of Santiago de Compostela (Spain), including pediatricians, residents, nurses, and other staff, on days 31-33 since the lockdown started. Seven out of the 175 tests were positive, including four for IgM and three for IgG, leading to a seroprevalence of 4.0% (95% CI: 1.1-6.9%). Only one of them had symptoms at the time of testing (sore throat). All seropositive cases yielded negative RT-PCR of the upper and lower respiratory tract. This is the first SARS-CoV-2 serological survey among HCWs reported in Spain. Notwithstanding the test limitations, our results reveal that personal protection policy and lockdown measures have been effective to limit population exposure. The low seroprevalence rate poses a significant challenge for the next strategic steps of pandemic control.

Acute onset supraclavicular lymphadenopathy coinciding with intramuscular mRNA vaccination against COVID-19 may be related to vaccine injection technique, Spain, January and February 2021.

Monitoring adverse reactions following immunisation is essential, particularly for new vaccines such as those against COVID-19. We describe 20 cases of acute onset of a single supraclavicular lymphadenopathy manifesting between 24 h and 9 days after ipsilateral intramuscular administration of an mRNA-based COVID-19 vaccine, referred to our WHO Collaborating Centre for Vaccine Safety. Our results indicate that the swelling of supraclavicular lymph nodes following immunisation may constitute a benign and self-limited condition, related to a higher than recommended injection site.

Maternal, Perinatal and Neonatal Outcomes With COVID-19: A Multicenter Study of 242 Pregnancies and Their 248 Infant Newborns During Their First Month of Life.

BACKGROUND: Our aim was to describe the clinical features of mothers with coronavirus disease 2019 (COVID-19) infection during gestation or delivery, and the potential vertical transmission. We also wish to evaluate the possible horizontal transmission after hospital discharge, by means of a follow-up of all the newborns included at 1 month of age. METHODS: This multicenter descriptive study involved 16 Spanish hospitals. We reviewed the medical records of 242 pregnant women diagnosed with COVID-19 from March 13 to May 31, 2020, when they were in their third trimester of pregnancy. They and their 248 newborn infants were monitored until the infant was 1 month old. RESULTS: Caesarean sections (C-sections) were performed on 63 (26%) women. The initial clinical symptoms were coughing (33%) and fever (29.7%). Mothers hospitalized due to COVID-19 pathology had a higher risk of ending their pregnancy via C-section (P = 0.027). Newborns whose mothers had been admitted due to their COVID-19 infection had a higher risk of premature delivery (P = 0.006). We admitted 115 (46.3%) newborn infants to the neonatal unit, of those, 87 (75.6%) were only admitted due to organizational circumstances. No infants died and no vertical or horizontal transmission was detected. Regarding type of feeding, 41.7% of the newborns received exclusive breast-feeding at discharge and 40.4% at 1 month. CONCLUSIONS: We did not detect COVID-19 transmission during delivery or throughout the first month of life in the newborns included in our study. Exclusive breast-feeding rates at discharge and at 1 month of age were lower than expected.

Increased Serum Levels of sCD14 and sCD163 Indicate a Preponderant Role for Monocytes in COVID-19 Immunopathology.

Background: Emerging evidence indicates a potential role for monocytes in COVID-19 immunopathology. We investigated two soluble markers of monocyte activation, sCD14 and sCD163, in COVID-19 patients, with the aim of characterizing their potential role in monocyte-macrophage disease immunopathology. To the best of our knowledge, this is the first study of its kind. Methods: Fifty-nine SARS-Cov-2 positive hospitalized patients, classified according to ICU or non-ICU admission requirement, were prospectively recruited and analyzed by ELISA for levels of sCD14 and sCD163, along with other laboratory parameters, and compared to a healthy control group. Results: sCD14 and sCD163 levels were significantly higher among COVID-19 patients, independently of ICU admission requirement, compared to the control group. We found a significant correlation between sCD14 levels and other inflammatory markers, particularly Interleukin-6, in the non-ICU patients group. sCD163 showed a moderate positive correlation with the time lapsed from admission to sampling, independently of severity group. Treatment with corticoids showed an interference with sCD14 levels, whereas hydroxychloroquine and tocilizumab did not. Conclusions: Monocyte-macrophage activation markers are increased and correlate with other inflammatory markers in SARS-Cov-2 infection, in association to hospital admission. These data suggest a preponderant role for monocyte-macrophage activation in the development of immunopathology of COVID-19 patients.

Role of Monocytes/Macrophages in Covid-19 Pathogenesis: Implications for Therapy.

Emerging studies from SARS-CoV-2-infected patients indicate a preponderant role of monocytes/macrophages in the pathogenesis of this viral infection, in a similar way to that previously observed in other coronavirus outbreaks (SARS and MERS). The clinical presentation of severe patients resembles viral-associated hemophagocytic syndrome, a rare condition previously seen during lethal influenza pandemics and during previous SARS and MERS coronavirus outbreaks. SARS-CoV-2 infection triggers an over-exuberant inflammatory response due to the development of a cytokine storm and the depletion of the adaptative immune compartment, which may prelude sepsis in many cases. The present review summarizes past evidence on the role of monocytes/macrophages in previous coronavirus outbreaks and the emerging knowledge on their role in COVID-19 pathogenesis. Treatment strategies incorporating the blockade of migration and differentiation of monocyte-macrophage, such as granulocyte macrophage-colony stimulating factor inhibitors, might enhance the promising results seen so far with selective cytokine blockade.