Interferon-α2 Auto-antibodies in Convalescent Plasma Therapy for COVID-19.

PURPOSE: To study the effect of interferon-α2 auto-antibodies (IFN-α2 Abs) on clinical and virological outcomes in critically ill COVID-19 patients and the risk of IFN-α2 Abs transfer during convalescent plasma treatment. METHODS: Sera from healthy controls, cases of COVID-19, and other respiratory illness were tested for IFN-α2 Abs by ELISA and a pseudo virus-based neutralization assay. The effects of disease severity, sex, and age on the risk of having neutralizing IFN-α2 Abs were determined. Longitudinal analyses were performed to determine association between IFN-α2 Abs and survival and viral load and whether serum IFN-α2 Abs appeared after convalescent plasma transfusion. RESULTS: IFN-α2 neutralizing sera were found only in COVID-19 patients, with proportions increasing with disease severity and age. In the acute stage of COVID-19, all sera from patients with ELISA-detected IFN-α2 Abs (13/164, 7.9%) neutralized levels of IFN-α2 exceeding physiological concentrations found in human plasma and this was associated with delayed viral clearance. Convalescent plasma donors that were anti-IFN-α2 ELISA positive (3/118, 2.5%) did not neutralize the same levels of IFN-α2. Neutralizing serum IFN-α2 Abs were associated with delayed viral clearance from the respiratory tract. CONCLUSIONS: IFN-α2 Abs were detected by ELISA and neutralization assay in COVID-19 patients, but not in ICU patients with other respiratory illnesses. The presence of neutralizing IFN-α2 Abs in critically ill COVID-19 is associated with delayed viral clearance. IFN-α2 Abs in COVID-19 convalescent plasma donors were not neutralizing in the conditions tested.

Multiplex Autoantibody Detection in Patients with Autoimmune Polyglandular Syndromes.

The diagnosis of autoimmune polyglandular syndrome (APS) types 1/2 is difficult due to their rarity and nonspecific clinical manifestations. APS-1 development can be identified with assays for autoantibodies against cytokines, and APS-2 development with organ-specific antibodies. In this study, a microarray-based multiplex assay was proposed for simultaneous detection of both organ-specific (anti-21-OH, anti-GAD-65, anti-IA2, anti-ICA, anti-TG, and anti-TPO) and APS-1-specific (anti-IFN-ω, anti-IFN-α-2a, and anti-IL-22) autoantibodies. Herein, 206 serum samples from adult patients with APS-1, APS-2, isolated autoimmune endocrine pathologies or non-autoimmune endocrine pathologies and from healthy donors were analyzed. The prevalence of autoantibodies differed among the groups of healthy donors and patients with non-, mono- and multi-endocrine diseases. APS-1 patients were characterized by the presence of at least two specific autoantibodies (specificity 99.5%, sensitivity 100%). Furthermore, in 16 of the 18 patients, the APS-1 assay revealed triple positivity for autoantibodies against IFN-ω, IFN-α-2a and IL-22 (specificity 100%, sensitivity 88.9%). No anti-cytokine autoantibodies were found in the group of patients with non-APS-1 polyendocrine autoimmunity. The accuracy of the microarray-based assay compared to ELISA for organ-specific autoantibodies was 88.8-97.6%. This multiplex assay can be part of the strategy for diagnosing and predicting the development of APS.

Autoantibodies against type I IFNs in patients with life-threatening COVID-19.

Interindividual clinical variability in the course of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is vast. We report that at least 101 of 987 patients with life-threatening coronavirus disease 2019 (COVID-19) pneumonia had neutralizing immunoglobulin G (IgG) autoantibodies (auto-Abs) against interferon-ω (IFN-ω) (13 patients), against the 13 types of IFN-α (36), or against both (52) at the onset of critical disease; a few also had auto-Abs against the other three type I IFNs. The auto-Abs neutralize the ability of the corresponding type I IFNs to block SARS-CoV-2 infection in vitro. These auto-Abs were not found in 663 individuals with asymptomatic or mild SARS-CoV-2 infection and were present in only 4 of 1227 healthy individuals. Patients with auto-Abs were aged 25 to 87 years and 95 of the 101 were men. A B cell autoimmune phenocopy of inborn errors of type I IFN immunity accounts for life-threatening COVID-19 pneumonia in at least 2.6% of women and 12.5% of men.

Interferon Alpha 2a and 2b in Ophthalmology: A Review.

Interferon alpha (IFN-α) is a glycoprotein with antitumor, antiviral, and immunomodulatory activity, used widely in the treatment of viral infections (hepatitis B and C, condylomata acuminata, herpes zoster, etc.), hematological disorders (leukemia, multiple myeloma, T cell lymphoma, and essential thrombocythemia), and solid tumors (clear cell carcinoma in the metastatic stage, melanoma, hepatocellular carcinoma, and cervical neoplasia). Studies have proven the effectiveness of IFN-α in the treatment of ophthalmic disorders involving the anterior segment of the eye (conjunctival papilloma, squamous neoplasia, conjunctival mucosa-associated lymphoid tissue, Mooren's ulcer, and vernal keratoconjunctivitis) and the posterior segment of the eye (serpiginous choroidopathy, posterior uveitis, pseudophakic and diabetic cystoid macular edema, and proliferative diabetic retinopathy). The therapy with IFN-α remains a promising alternative in cases of a failing response to conventional therapy, helping to maintain or improve visual acuity, prevent vision loss, and ameliorate the prognosis of the patient. However, clinicians who decide to use IFN-α in their patients must be aware of general and ophthalmological side effects and inform their patients to undergo a systemic evaluation such as a physical examination, blood and serological tests, and a chest X-ray before the beginning of treatment. This review presents the current knowledge of the use of IFN-α, its efficacy, and properties in ophthalmological diseases, and thus may encourage clinicians to administer this drug as a treatment modality in ophthalmological diseases in the future.

Evaluation of nasal levels of interferon and clinical severity of influenza in children.

BACKGROUND: Experimental data show that type I interferon has a key role in innate immune response against influenza infection. OBJECTIVE: We compared nasal levels of interferon-α2 and ß among inpatients and outpatients with influenza. STUDY DESIGN: Children younger than 5 years of age with influenza-like illness seeking care at the emergency department within the first 72 h of disease onset were prospectively included. Clinical and demographic data and secretions through nasal wash were obtained. Influenza infection was assessed through reverse-transcription polymerase chain reaction and nasal levels of interferon-α2 and ß were measured by enzyme-linked immunosorbent assay. All patients followed until the end of the disease. RESULTS: One hundred patients were included, of which 24 had confirmed influenza infection, and 5 of them were hospitalized. Subtypes A (H3N2) and B were confirmed in 10 and 14 patients, respectively. Seventy-six patients without influenza, including 48% of outpatients, were recruited as controls. All hospitalized patients were significantly younger regardless of influenza status (age <6 months in 59% vs. 23.2%, p < 0.001). All other data were similar among the groups. Comparing median levels of interferon-α2 among children with influenza, levels were significantly higher in outpatients than in hospitalized patients and were 263.2 pg/mL (25-75 interquartile range: 58.3-634) and detectable in only one patient (90 pg/mL), respectively. The levels of interferon-α2 in controls and those of interferon-ß in all groups were not detected. CONCLUSIONS: Higher levels of interferon-α2 in patients with less severe influenza reinforce experimental evidence about the protective role of interferon-α2 against influenza infection.

Parallel adaptation of rabbit populations to myxoma virus.

In the 1950s the myxoma virus was released into European rabbit populations in Australia and Europe, decimating populations and resulting in the rapid evolution of resistance. We investigated the genetic basis of resistance by comparing the exomes of rabbits collected before and after the pandemic. We found a strong pattern of parallel evolution, with selection on standing genetic variation favoring the same alleles in Australia, France, and the United Kingdom. Many of these changes occurred in immunity-related genes, supporting a polygenic basis of resistance. We experimentally validated the role of several genes in viral replication and showed that selection acting on an interferon protein has increased the protein's antiviral effect.

The heterogeneity of autoimmune polyendocrine syndrome type 1: Clinical features, new mutations and cytokine autoantibodies in a Brazilian cohort from tertiary care centers.

Autoimmune polyendocrine syndrome type 1 (APS1) is characterized by multiorgan autoimmunity. We aim at characterizing a multi-center Brazilian cohort of APS1 patients by clinical evaluation, searching mutation in the AIRE gene, measuring serum autoantibodies, and investigating correlations between findings. We recruited patients based on the clinical criteria and tested them for AIRE mutations, antibodies against interferon type I and interleukins 17A, 17F and 22. We identified 12 unrelated families (13 patients) with typical signs of APS1 in the proband, and the screening of relatives recognized an asymptomatic child. Candidiasis was present in all cases, and 19 other manifestations were observed. All patients carried one of 10 different mutations in AIRE, being 3 new ones, and were positive for anti-interferon type I serum antibody. Anti-interleukin-17A levels inversely correlated with the number of manifestations in each patient. This negative correlation may suggest a protective effect of anti-interleukin-17A with a potential therapeutic application.

Life-threatening influenza pneumonitis in a child with inherited IRF9 deficiency.

Life-threatening pulmonary influenza can be caused by inborn errors of type I and III IFN immunity. We report a 5-yr-old child with severe pulmonary influenza at 2 yr. She is homozygous for a loss-of-function IRF9 allele. Her cells activate gamma-activated factor (GAF) STAT1 homodimers but not IFN-stimulated gene factor 3 (ISGF3) trimers (STAT1/STAT2/IRF9) in response to IFN-α2b. The transcriptome induced by IFN-α2b in the patient's cells is much narrower than that of control cells; however, induction of a subset of IFN-stimulated gene transcripts remains detectable. In vitro, the patient's cells do not control three respiratory viruses, influenza A virus (IAV), parainfluenza virus (PIV), and respiratory syncytial virus (RSV). These phenotypes are rescued by wild-type IRF9, whereas silencing IRF9 expression in control cells increases viral replication. However, the child has controlled various common viruses in vivo, including respiratory viruses other than IAV. Our findings show that human IRF9- and ISGF3-dependent type I and III IFN responsive pathways are essential for controlling IAV.

Interferon α2 and interferon γ induce the degranulation independent production of VEGF-A and IL-1 receptor antagonist and other mediators from human mast cells.

BACKGROUND: Mast cells are resident immune effector cells, often studied in the context of allergic disease. Found in substantial numbers at sites of potential infection they are increased at sites of angiogenesis and can be pivotal for the sensing and clearance of a variety of pathogens. Interferons (IFNs) are cytokines that are critical for host defence against intracellular pathogens. Increased levels of IFNs are observed during viral infection and in autoimmune diseases. IFNs are also widely used therapeutically and have been examined in the therapy of severe asthma. OBJECTIVE: To define the selective human mast cell cytokine and chemokine response following activation with type I or type II IFN's. METHODS: The ability of both IFNα2 and IFNγ to induce cytokine production by human cord blood-derived mast cells was examined in vitro. Cytokine and chemokine production at 6 and 24 h was assessed by multiplex protein analysis. Degranulation was assessed by ß-hexosaminidase release. Mast cells were also treated with reovirus or respiratory syncytial virus and their production of CXCL10, IL-1 receptor antagonist (IL-1Ra), and vascular endothelial growth factor (VEGF) examined after 24 h. RESULTS: In addition to increased expression of classical IFN response genes, such as CXCL10, small but significant increases in CCL5 and IL-17 production were observed following IFN activation. Notably, human mast cells produced both VEGF and IL-1Ra in a dose dependent manner. These responses occurred in the absence of mast cell degranulation by a mechanism consistent with classical IFN signaling. Both reovirus and respiratory syncytial virus infection of mast cells, were also associated with IFN-dependent IL-1Ra expression. CONCLUSION AND CLINICAL RELEVANCE: Our findings demonstrate that IFNs have profound impact on cytokine and chemokine expression by human mast cells, alone or in the context of viral infection. Mast cell VEGF and IL-1Ra responses to IFNs could impact the regulation of local inflammatory responses and subsequent tissue remodeling.