IgG antispike persistence and immunophenotype in children infected by SARS-CoV-2.

AIM: The immune status of children recovering from SARS-CoV-2 infection is not completely understood. We describe IgG antispike persistence in children infected during the first two pandemic waves. In addition, we compared with healthy controls their leukocyte populations and CD64 expression. METHODS: Cross-sectional study. Carried out from October 2021 to February 2022 in nonreinfected and nonvaccinated children with SARS-CoV-2 in 2020. The presence of antispike IgG was studied using chemiluminescent immunoassay. Leukocyte populations were analysed using flow cytometry and marked for CD45, CD4, CD8 and CD64. Statistical minor than 0.05 was considered significant. RESULTS: One hundred and eighty-three control and 77 patients were included. IgG antispike determinations were performed after a median of 501 days (262-464); 52 of 77 children were positive. Cases showed significantly higher percentages of monocytes, lymphocytes, CD8+ and CD4+ . In addition, CD64 expression was higher in monocytes and neutrophils. The presence of IgG antispike was accompanied by a higher percentage of CD64+ neutrophils. CONCLUSION: In our series, the SARS-CoV-2 IgG antispike protein was usually positive beyond 1 year after infection. Furthermore, leukocyte populations from cases differ from controls, with higher CD64 expression on neutrophils and monocytes. Prospective clinical observations are required to confirm the implications of these findings.

Multisystem Inflammatory Syndrome in Children in Western Countries? Decreasing Incidence as the Pandemic Progresses?: An Observational Multicenter International Cross-sectional Study.

BACKGROUND: SARS-CoV-2 variations as well as immune protection after previous infections and/or vaccination may have altered the incidence of multisystemic inflammatory syndrome in children (MIS-C). We aimed to report an international time-series analysis of the incidence of MIS-C to determine if there was a shift in the regions or countries included into the study. METHODS: This is a multicenter, international, cross-sectional study. We collected the MIS-C incidence from the participant regions and countries for the period July 2020 to November 2021. We assessed the ratio between MIS-C cases and COVID-19 pediatric cases in children <18 years diagnosed 4 weeks earlier (average time for the temporal association observed in this disease) for the study period. We performed a binomial regression analysis for 8 participating sites [Bogotá (Colombia), Chile, Costa Rica, Lazio (Italy), Mexico DF, Panama, The Netherlands and Catalonia (Spain)]. RESULTS: We included 904 cases of MIS-C, among a reference population of 17,906,432 children. We estimated a global significant decrease trend ratio in MIS-C cases/COVID-19 diagnosed cases in the previous month ( P < 0.001). When analyzing separately each of the sites, Chile and The Netherlands maintained a significant decrease trend ( P < 0.001), but this ratio was not statistically significant for the rest of sites. CONCLUSIONS: To our knowledge, this is the first international study describing a global reduction in the trend of the MIS-C incidence during the pandemic. COVID-19 vaccination and other factors possibly linked to the virus itself and/or community transmission may have played a role in preventing new MIS-C cases.

PIMS-TS immunophenotype: description and comparison with healthy children, Kawasaki disease and severe viral and bacterial infections.

BACKGROUND: A new clinical syndrome named Paediatric Inflammatory Multisystem Syndrome Temporally Associated with SARS-CoV-2 (PIMS-TS) has been described. This new disease is a leading cause of hospital and paediatric intensive care unit (PICU). It has been related to immunity dysregulation. METHODS: Prospective-retrospective observational study to describe the innate cell signature and immunophenotype of children admitted to PICU because of PIMS-TS (from March 2020 to September 2020). The immunophenotype was done through the expression analysis of these proteins of mononuclear cells: CD64, CD18, CD11a and CD11b. They were compared with previous healthy controls and children admitted to PICU because of bacterial infection, viral infection and Kawasaki disease (KD). Two hundred and forty-seven children were studied: 183 healthy controls, 25 viral infections, 20 bacterial infections, 6 KD and 13 PIMS-TS. RESULTS: PIMT-TS showed the lowest percentage of lymphocytes and monocytes with higher relative numbers of CD4+ (p = .000). Monocytes and neutrophils in PIMS-TS showed higher levels of CD64 expression (p = .000). Also, CD11a and CD11b were highly expressed (p =,000). CONCLUSION: We observed a differential cell innate signature in PIMS-TS. These findings are consistent with a proinflammatory status (CD64 elevated expression) and lymphocyte trafficking to tissues (CD11a and CD11b). More studies should be carried out to confirm our results.

Spanish consensus document on diagnosis, stabilisation and treatment of pediatric multisystem inflammatory syndrome related to SARS-CoV-2 (SIM-PedS).

A new paediatric multisystem inflammatory syndrome, linked to SARS-CoV-2 (MIS-Paed), has been described. The clinical picture is variable and is associated with an active or recent infection due to SARS-CoV-2. A review of the existing literature by a multidisciplinary group of paediatric specialists is presented in this document. Later, they make recommendations on the stabilisation, diagnosis, and treatment of this syndrome.

Se ha descrito un nuevo síndrome inflamatorio multisistémico pediátrico vinculado a SARS-CoV-2 (SIM-PedS). Este cuadro presenta una expresividad clínica variable y se asocia a infección activa o reciente por SARS-CoV-2. En este documento se revisa la literatura existente por parte de un grupo multidisciplinar de especialistas pediátricos. Posteriormente se realizan recomendaciones sobre estabilización, diagnóstico y tratamiento de este síndrome.

The COVID-19 puzzle: deciphering pathophysiology and phenotypes of a new disease entity.

The zoonotic SARS-CoV-2 virus that causes COVID-19 continues to spread worldwide, with devastating consequences. While the medical community has gained insight into the epidemiology of COVID-19, important questions remain about the clinical complexities and underlying mechanisms of disease phenotypes. Severe COVID-19 most commonly involves respiratory manifestations, although other systems are also affected, and acute disease is often followed by protracted complications. Such complex manifestations suggest that SARS-CoV-2 dysregulates the host response, triggering wide-ranging immuno-inflammatory, thrombotic, and parenchymal derangements. We review the intricacies of COVID-19 pathophysiology, its various phenotypes, and the anti-SARS-CoV-2 host response at the humoral and cellular levels. Some similarities exist between COVID-19 and respiratory failure of other origins, but evidence for many distinctive mechanistic features indicates that COVID-19 constitutes a new disease entity, with emerging data suggesting involvement of an endotheliopathy-centred pathophysiology. Further research, combining basic and clinical studies, is needed to advance understanding of pathophysiological mechanisms and to characterise immuno-inflammatory derangements across the range of phenotypes to enable optimum care for patients with COVID-19.

Bridging animal and clinical research during SARS-CoV-2 pandemic: A new-old challenge.

Many milestones in medical history rest on animal modeling of human diseases. The SARS-CoV-2 pandemic has evoked a tremendous investigative effort primarily centered on clinical studies. However, several animal SARS-CoV-2/COVID-19 models have been developed and pre-clinical findings aimed at supporting clinical evidence rapidly emerge. In this review, we characterize the existing animal models exposing their relevance and limitations as well as outline their utility in COVID-19 drug and vaccine development. Concurrently, we summarize the status of clinical trial research and discuss the novel tactics utilized in the largest multi-center trials aiming to accelerate generation of reliable results that may subsequently shape COVID-19 clinical treatment practices. We also highlight areas of improvement for animal studies in order to elevate their translational utility. In pandemics, to optimize the use of strained resources in a short time-frame, optimizing and strengthening the synergy between the preclinical and clinical domains is pivotal.

Severe manifestations of SARS-CoV-2 in children and adolescents: from COVID-19 pneumonia to multisystem inflammatory syndrome: a multicentre study in pediatric intensive care units in Spain.

BACKGROUND: Multisystem inflammatory syndrome temporally associated with COVID-19 (MIS-C) has been described as a novel and often severe presentation of SARS-CoV-2 infection in children. We aimed to describe the characteristics of children admitted to Pediatric Intensive Care Units (PICUs) presenting with MIS-C in comparison with those admitted with SARS-CoV-2 infection with other features such as COVID-19 pneumonia. METHODS: A multicentric prospective national registry including 47 PICUs was carried out. Data from children admitted with confirmed SARS-CoV-2 infection or fulfilling MIS-C criteria (with or without SARS-CoV-2 PCR confirmation) were collected. Clinical, laboratory and therapeutic features between MIS-C and non-MIS-C patients were compared. RESULTS: Seventy-four children were recruited. Sixty-one percent met MIS-C definition. MIS-C patients were older than non-MIS-C patients (p = 0.002): 9.4 years (IQR 5.5-11.8) vs 3.4 years (IQR 0.4-9.4). A higher proportion of them had no previous medical history of interest (88.2% vs 51.7%, p = 0.005). Non-MIS-C patients presented more frequently with respiratory distress (60.7% vs 13.3%, p < 0.001). MIS-C patients showed higher prevalence of fever (95.6% vs 64.3%, p < 0.001), diarrhea (66.7% vs 11.5%, p < 0.001), vomits (71.1% vs 23.1%, p = 0.001), fatigue (65.9% vs 36%, p = 0.016), shock (84.4% vs 13.8%, p < 0.001) and cardiac dysfunction (53.3% vs 10.3%, p = 0.001). MIS-C group had a lower lymphocyte count (p < 0.001) and LDH (p = 0.001) but higher neutrophil count (p = 0.045), neutrophil/lymphocyte ratio (p < 0.001), C-reactive protein (p < 0.001) and procalcitonin (p < 0.001). Patients in the MIS-C group were less likely to receive invasive ventilation (13.3% vs 41.4%, p = 0.005) but were more often treated with vasoactive drugs (66.7% vs 24.1%, p < 0.001), corticosteroids (80% vs 44.8%, p = 0.003) and immunoglobulins (51.1% vs 6.9%, p < 0.001). Most patients were discharged from PICU by the end of data collection with a median length of stay of 5 days (IQR 2.5-8 days) in the MIS-C group. Three patients died, none of them belonged to the MIS-C group. CONCLUSIONS: MIS-C seems to be the most frequent presentation among critically ill children with SARS-CoV-2 infection. MIS-C patients are older and usually healthy. They show a higher prevalence of gastrointestinal symptoms and shock and are more likely to receive vasoactive drugs and immunomodulators and less likely to need mechanical ventilation than non-MIS-C patients.

Shock and Myocardial Injury in Children With Multisystem Inflammatory Syndrome Associated With SARS-CoV-2 Infection: What We Know. Case Series and Review of the Literature.

BACKGROUND: Multisystem inflammatory syndrome associated with SARS-CoV-2 infection can lead to myocardial injury and shock in children, likely the result of a severe inflammatory state, and can mimic Kawasaki disease. OBJECTIVE: To describe the characteristics of shock and myocardial injury in children with confirmed or suspeted COVID-19 during the SARS-CoV-2 pandemic in Spain, including clinical presentation, laboratory and imaging findings, treatment, disease course, and outcome. An extensive literature review is provided. METHODS: Retrospective case series including all children (age 1 month-18 years) admitted to a pediatric intensive care unit in Madrid, Spain, between March 15 and April 30, 2020 with suspected or confirmed SARS-CoV-2 infection and shock. RESULTS: Twelve previously healthy patients with shock, age 5 to 14 years, were included. All required volume resuscitation and 75% required vasoactive/inotropic support. Distributive shock was present on admission in 67% (n = 8), and 4 patients (33%) showed features of cardiogenic shock. Myocardial injury was diagnosed in 67% (n = 8) and ventricular dysfunction in 33% (n = 4). The most common symptoms on presentation were fever (100%), anorexia (100%), diarrhea (75%), and vomiting (75%). Five patients showed signs of Kawasaki disease but none met the criteria for the classic form. Laboratory findings revealed lymphopenia (83%), thrombocytopenia (83%), and increased inflammatory markers (100%). Respiratory status was not significantly impacted. Chest X-ray showed bilateral alveolar infiltrates in 7 (58%) and bilateral pneumonia in 3 (25%). COVID-19 was confirmed in 11 cases (92%). All received empirical therapy against COVID-19, thromboprophylaxis and immunomodulation. Median stay in the PICU and inpatient ward was 4.5 and 10 days, respectively. No patients died. CONCLUSION: Multisystem inflammatory syndrome in children with COVID-19 can mimic Kawasaki disease and lead to a combination of distributive and cardiogenic shock, probably secondary to a hyperinflammatory state that remains to be precisely defined. Treatment strategies include hemodynamic support, empirical therapies against COVID-19, thromboprophylaxis, and immunomodulation.

[Spanish consensus document on diagnosis, stabilisation and treatment of pediatric multisystem inflammatory syndrome related to SARS-CoV-2 (SIM-PedS)]. / Documento español de consenso sobre diagnóstico, estabilización y tratamiento del síndrome inflamatorio multisistémico pediátrico vinculado a SARS-CoV-2 (SIM-PedS).

A new paediatric multisystem inflammatory syndrome, linked to SARS-CoV-2, has been described. The clinical picture is variable and is associated with an active or recent infection due to SARS-CoV-2. A review of the existing literature by a multidisciplinary group of paediatric specialists is presented in this document. Later, they make recommendations on the stabilisation, diagnosis, and treatment of this syndrome.

Narrative review of the immune response against coronavirus: An overview, applicability for SARS-COV-2, and therapeutic implications.

The new coronavirus (SARS-CoV-2) that causes a severe acute respiratory syndrome emerges in Wuhan, China, in December 2019. It produces the aforementioned disease due to coronavirus 2019 (COVID-19), and has led to a declaration of a world public health emergency by the World Health Organisation. This new SARS-CoV-2 virus could share characteristics and an immune response similar to those described for other coronavirus. Given its activity on the interferon pathway, and the manner in which it dysregulates innate immunity, the use of treatments directed at modulating or containing this could be of interest. A narrative review was made of the current evidence about immunity against coronavirus and its applicability to SARS-CoV-2. The physiopathogenesis is also described, along with the underlying leucocyte activity, with the intention of clarifying the possible usefulness of inflammatory biomarkers and the development of personalised treatments.

El nuevo coronavirus (SARS-CoV-2) productor de síndrome respiratorio agudo severo surge en Wuhan, China, en diciembre de 2019. Genera la denominada enfermedad por coronavirus 2019 (COVID-19) y ha llevado a la declaración de emergencia de salud pública global a la Organización Mundial de la Salud. Este nuevo virus SARS-CoV-2 podría compartir características y respuesta inmune a las descritas para otros coronavirus. Dada su actividad sobre la vía del interferón y el modo en el que disregula la inmunidad innata, el uso de tratamientos dirigidos a modular o contener esta pueden ser de interés. Se realiza una revisión narrativa de la evidencia actual acerca de la inmunidad sobre coronavirus y su aplicabilidad para SARS-CoV-2. Se describe también la fisiopatogenia y la actividad leucocitaria subyacente, con intención de clarificar la posible utilidad de biomarcadores inflamatorios y el desarrollo de tratamientos personalizados.