RESUMO
Low concentrations of type-I interferon (IFN) in blood seem to be associated with more severe forms of Coronavirus disease 2019 (COVID-19). However, following the type-I interferon response (IR) in early stage disease is a major challenge. We evaluated detection of a molecular interferon signature on a FilmArray® system, which includes PCR assays for four interferon stimulated genes. We analyzed three types of patient populations: (i) children admitted to a pediatric emergency unit for fever and suspected infection, (ii) ICU-admitted patients with severe COVID-19, and (iii) healthcare workers with mild COVID-19. The results were compared to the reference tools, that is, molecular signature assessed with Nanostring® and IFN-α2 quantification by SIMOA® (Single MOlecule Array). A strong correlation was observed between the IR measured by the FilmArray®, Nanostring®, and SIMOA® platforms (r-Spearman 0.996 and 0.838, respectively). The FilmArray® panel could be used in the COVID-19 pandemic to evaluate the IR in 45-min with 2 min hand-on-time at hospitalization and to monitor the IR in future clinical trials.
Assuntos
COVID-19/sangue , Interferon-alfa/sangue , Reação em Cadeia da Polimerase/métodos , SARS-CoV-2/imunologia , Adulto , Idoso , COVID-19/imunologia , Criança , Feminino , Pessoal de Saúde , Humanos , Interferon Tipo I/sangue , Interferon Tipo I/genética , Interferon-alfa/genética , MasculinoRESUMO
BACKGROUND: Aicardi-Goutières syndrome (AGS) is an inflammatory disorder caused by mutations in any of six genes (TREX1, RNASEH2A, RNASEH2B, RNASEH2C, SAMHD1, and ADAR). The disease is severe and effective treatments are urgently needed. We investigated the status of interferon-related biomarkers in patients with AGS with a view to future use in diagnosis and clinical trials. METHODS: In this case-control study, samples were collected prospectively from patients with mutation-proven AGS. The expression of six interferon-stimulated genes (ISGs) was measured by quantitative PCR, and the median fold change, when compared with the median of healthy controls, was used to create an interferon score for each patient. Scores higher than the mean of controls plus two SD (>2·466) were designated as positive. Additionally, we collated historical data for interferon activity, measured with a viral cytopathic assay, in CSF and serum from mutation-positive patients with AGS. We also undertook neutralisation assays of interferon activity in serum, and looked for the presence of autoantibodies against a panel of interferon proteins. FINDINGS: 74 (90%) of 82 patients had a positive interferon score (median 12·90, IQR 6·14-20·41) compared with two (7%) of 29 controls (median 0·93, IQR 0·57-1·30). Of the eight patients with a negative interferon score, seven had mutations in RNASEH2B (seven [27%] of all 26 patients with mutations in this gene). Repeat sampling in 16 patients was consistent for the presence or absence of an interferon signature on 39 of 41 occasions. Interferon activity (tested in 147 patients) was negatively correlated with age (CSF, r=-0·604; serum, r=-0·289), and was higher in CSF than in serum in 104 of 136 paired samples. Neutralisation assays suggested that measurable antiviral activity was related to interferon α production. We did not record significantly increased concentrations of autoantibodies to interferon subtypes in patients with AGS, or an association between the presence of autoantibodies and interferon score or serum interferon activity. INTERPRETATION: AGS is consistently associated with an interferon signature, which is apparently sustained over time and can thus be used to differentiate patients with AGS from controls. If future studies show that interferon status is a reactive biomarker, the measurement of an interferon score might prove useful in the assessment of treatment efficacy in clinical trials. FUNDING: European Union's Seventh Framework Programme; European Research Council.
Assuntos
Adenosina Desaminase/genética , Doenças Autoimunes do Sistema Nervoso/metabolismo , Exodesoxirribonucleases/genética , Regulação da Expressão Gênica , Interferon Tipo I/fisiologia , Proteínas Monoméricas de Ligação ao GTP/genética , Malformações do Sistema Nervoso/metabolismo , Fosfoproteínas/genética , Ribonuclease H/genética , Adolescente , Adulto , Autoanticorpos/sangue , Doenças Autoimunes do Sistema Nervoso/genética , Biomarcadores , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Heterogeneidade Genética , Genótipo , Humanos , Lactente , Interferon Tipo I/sangue , Interferon Tipo I/líquido cefalorraquidiano , Interferon Tipo I/imunologia , Masculino , Mutação , Malformações do Sistema Nervoso/genética , Testes de Neutralização , Estudos Prospectivos , RNA Mensageiro/biossíntese , Proteínas de Ligação a RNA , Proteína 1 com Domínio SAM e Domínio HD , Regulação para Cima , Adulto JovemRESUMO
Hundred and fifty-four samples of heparinized blood from patients with chronic toxoplasmosis, chronic brucellosis, lung diseases, psychiatric affective disorders, healthy individuals and neonates, were obtained. The experimental material included also 14 bone marrow samples from patients with hematological diseases or lung cancer. The whole cell populations were treated with several classical IFN inducers and supernatants were assayed for IFN activity in human lung adenocarcinoma cell line A 549 using VSV or EMC viruses as challenge. The response of WBC to NDV or PHA + PMA was high and remarkably stable in majority of cases except listed below. The levels of IFN induced by LPS were low. The response of WBMC to IFN inducers closely resembled the response of WBC. Low IFN levels in samples of stimulated WBMC from some hematological patients were connected with low cellularity. WBC from psychiatric patients with affective disorders weakly responded to stimulation with NDV. This suggested an existence of deficiency of IFN alpha production connected with affective disorders. Also WBC from cord blood failed to react to PHA + PMA and were poorly responsive to NDV.