Excessive IL-10 and IL-18 trigger hemophagocytic lymphohistiocytosis-like hyperinflammation and enhanced myelopoiesis.

BACKGROUND: Hyperinflammation is a life-threatening condition associated with various clinical disorders characterized by excessive immune activation and tissue damage. Multiple cytokines promote the development of hyperinflammation; however, the contribution of IL-10 remains unclear despite emerging speculations for a pathological role. Clinical observations from hemophagocytic lymphohistiocytosis (HLH), a prototypical hyperinflammatory disease, suggest that IL-18 and IL-10 may collectively promote the onset of a hyperinflammatory state. OBJECTIVE: We aimed to investigate the collaborative roles of IL-10 and IL-18 in hyperinflammation. METHODS: A comprehensive plasma cytokine profile for 87 secondary HLH patients was first depicted and analyzed. We then investigated the systemic and cellular effects of coelevated IL-10 and IL-18 in a transgenic mouse model and cultured macrophages. Single-cell RNA sequencing was performed on the monocytes/macrophages isolated from secondary HLH patients to explore the clinical relevance of IL-10/IL-18-mediated cellular signatures. The therapeutic efficacy of IL-10 blockade was tested in HLH mouse models. RESULTS: Excessive circulating IL-10 and IL-18 triggered a lethal hyperinflammatory disease recapitulating HLH-like phenotypes in mice, driving peripheral lymphopenia and a striking shift toward enhanced myelopoiesis in the bone marrow. IL-10 and IL-18 polarized cultured macrophages to a distinct proinflammatory state with pronounced expression of myeloid cell-recruiting chemokines. Transcriptional characterization suggested the IL-10/IL-18-mediated cellular features were clinically relevant with HLH, showing enhanced granzyme expression and proteasome activation in macrophages. IL-10 blockade protected against the lethal disease in HLH mouse models. CONCLUSION: Coelevated IL-10 and IL-18 are sufficient to drive HLH-like hyperinflammatory syndrome, and blocking IL-10 is protective in HLH models.

JAK inhibition as a new treatment strategy for patients with COVID-19.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemic continues to spread globally. The rapid dispersion of coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 drives an urgent need for effective treatments, especially for patients who develop severe pneumonia. The excessive and uncontrolled release of pro-inflammatory cytokines has proved to be an essential factor in the rapidity of disease progression, and some cytokines are significantly associated with adverse outcomes. Most of the upregulated cytokines signal through the Janus kinase-signal transducer and activator of transcription (JAK/STAT) pathway. Therefore, blocking the exaggerated release of cytokines, including IL-2, IL-6, TNF-α, and IFNα/ß/γ, by inhibiting JAK/STAT signaling will, presumably, offer favorable pharmacodynamics and present an attractive prospect. JAK inhibitors (JAKi) can also inhibit members of the numb-associated kinase (NAK) family, including AP2-associated kinase 1 (AAK1) and cyclin G-associated kinase (GAK), which regulate the angiotensin-converting enzyme 2 (ACE-2) transmembrane protein and are involved in host viral endocytosis. According to the data released from current clinical trials, JAKi treatment can effectively control the dysregulated cytokine storm and improve clinical outcomes regarding mortality, ICU admission, and discharge. There are still some concerns surrounding thromboembolic events, opportunistic infection such as herpes zoster virus reactivation, and repression of the host's type-I IFN-dependent immune repair for both viral and bacterial infection. However, the current JAKi clinical trials of COVID-19 raised no new safety concerns except a slightly increased risk of herpes virus infection. In the updated WHO guideline, Baricitinb is strongly recommended as an alternative to IL-6 receptor blockers, particularly in combination with corticosteroids, in patients with severe or critical COVID-19. Future studies will explore the application of JAKi to COVID-19 treatment in greater detail, such as the optimal timing and course of JAKi treatment, individualized medication strategies based on pharmacogenomics, and the effect of combined medications.

Ultrapotent neutralizing antibodies against SARS-CoV-2 with a high degree of mutation resistance.

Many SARS-CoV-2 neutralizing antibodies (nAbs) lose potency against variants of concern. In this study, we developed 2 strategies to produce mutation-resistant antibodies. First, a yeast library expressing mutant receptor binding domains (RBDs) of the spike protein was utilized to screen for potent nAbs that are least susceptible to viral escape. Among the candidate antibodies, P5-22 displayed ultrahigh potency for virus neutralization as well as an outstanding mutation resistance profile. Additionally, P14-44 and P15-16 were recognized as mutation-resistant antibodies with broad betacoronavirus neutralization properties. P15-16 has only 1 binding hotspot, which is K378 in the RBD of SARS-CoV-2. The crystal structure of the P5-22, P14-44, and RBD ternary complex clarified the unique mechanisms that underlie the excellent mutation resistance profiles of these antibodies. Secondly, polymeric IgG enhanced antibody avidity by eliminating P5-22's only hotspot, residue F486 in the RBD, thereby potently blocking cell entry by mutant viruses. Structural and functional analyses of antibodies screened using both potency assays and the yeast RBD library revealed rare, ultrapotent, mutation-resistant nAbs against SARS-CoV-2.

Airborne pathogenic microorganisms and air cleaning technology development: A review.

Transmission of pathogens through air is a critical pathway for the spread of airborne diseases, as airborne pathogenic microorganisms cause several harmful infections. This review summarizes the occurrence, transmission, and adverse impacts of airborne pathogenic microorganisms that spread over large distances via bioaerosols. Air cleaning technologies have demonstrated great potential to prevent and reduce the spread of airborne diseases. The recent advances in air cleaning technologies are summarized on the basis of their advantages, disadvantages, and adverse health effects with regard to the inactivation mechanisms. The application scope and energy consumption of different technologies are compared, and the characteristics of air cleaners in the market are discussed. The development of high-efficiency, low-cost, dynamic air cleaning technology is identified as the leading research direction of air cleaning. Furthermore, future research perspectives are discussed and further development of current air cleaning technologies is proposed.

Clinical and molecular characteristics of COVID-19 patients with persistent SARS-CoV-2 infection.

The characteristics of COVID-19 patients with persistent SARS-CoV-2 infection are not yet well described. Here, we compare the clinical and molecular features of patients with long duration of viral shedding (LDs) with those from patients with short duration patients (SDs), and healthy donors (HDs). We find that several cytokines and chemokines, such as interleukin (IL)-2, tumor necrosis factor (TNF) and lymphotoxin α (LT-α) are present at lower levels in LDs than SDs. Single-cell RNA sequencing shows that natural killer (NK) cells and CD14+ monocytes are reduced, while regulatory T cells are increased in LDs; moreover, T and NK cells in LDs are less activated than in SDs. Importantly, most cells in LDs show reduced expression of ribosomal protein (RP) genes and related pathways, with this inversed correlation between RP levels and infection duration further validated in 103 independent patients. Our results thus indicate that immunosuppression and low RP expression may be related to the persistence of the viral infection in COVID-19 patients.

Germline variants in UNC13D and AP3B1 are enriched in COVID-19 patients experiencing severe cytokine storms.

Critically ill coronavirus disease 2019 (COVID-19) is characterized by severe cytokine storms, a hyperinflammatory condition intimately related to the development of fatal outcomes. Why some individuals seem particularly vulnerable to severe cytokine storms is still unknown. Primary immunodeficiency (PID)-related genes are inherited factors that dysregulate host inflammatory responses to infection, especially hemophagocytic lymphohistiocytosis (HLH)-related genes, established as contributors to the development of excessive cytokine storms. We analyzed the association between PID gene variants with severe cytokine storms in COVID-19. We conducted whole-exome sequencing in 233 hospitalized COVID-19 patients and identified four PID gene (UNC13D, AP3B1, RNF168, DHX58) variants were significantly enriched in COVID-19 patients experiencing severe cytokine storms. The total percentage of COVID-19 patients with variants in UNC13D or AP3B1, two typical HLH genes, was dramatically higher in high-level cytokine group than in low-level group (33.3 vs. 5.7%, P < 0.001). Germline variants in UNC13D and AP3B1 were associated with the development of severe cytokine storms, fatal outcomes in COVID-19. These findings advance the understanding of individual susceptibility to severe cytokine storms and help optimize the current management of COVID-19.

Single-cell transcriptomes of peripheral blood cells indicate and elucidate severity of COVID-19.

The blood and immune system of coronavirus disease 2019 (COVID-19) infected patients are dysfunctional, and numerous studies have been conducted to resolve their characteristics and pathogenic mechanisms. Nevertheless, the variations of immune responses along with disease severity have not been comprehensively documented. Here, we profiled the single-cell transcriptomes of 96,313 peripheral blood mononuclear cells (PBMCs) derived from 12 COVID-19 patients (including four moderate, four severe and four critical cases) and three healthy donors. We showed that proliferative CD8 effector T cells with declined immune functions and cytotoxicity accumulated in the critical stage. By contrast, the quantity of natural killer (NK) cells was significantly reduced, while they exhibited enhanced immune activities. Notably, a gradually attenuated responseto COVID-19 along with disease severity was observed in monocytes, in terms of cellular composition, transcriptional discrepancy and transcription factor regulatory network. Furthermore, we identified immune cell-type dependent cytokine signatures distinguishing the severity of COVID-19 patients. In addition, cell interactions between CD8 effector T/NK cells and monocytes mediated by inflammatory cytokines were enhanced in moderate and severe stages, but weakened in critical cases. Collectively, our work uncovers the cellular and molecular players underlying the disordered and heterogeneous immune responses associated with COVID-19 severity, which could provide valuable insights for the treatment of critical COVID-19 patients.

Dynamics of Blood Viral Load Is Strongly Associated with Clinical Outcomes in Coronavirus Disease 2019 (COVID-19) Patients: A Prospective Cohort Study.

The prevalence and clinical relevance of viremia in patients with coronavirus disease 2019 (COVID-19) have not been well studied. A prospective cohort study was designed to investigate blood viral load and clearance kinetics in 52 patients (median age, 62 years; 31 [59.6%] male) and explore their association with clinical features and outcomes based on a novel one-step RT droplet digital PCR (RT-ddPCR). By using one-step RT-ddPCR, 92.3% (48 of 52) of this cohort was quantitatively detected with viremia. The concordance between the blood and oropharyngeal swab tests was 60.92% (53 of 87). One-step RT-ddPCR was tested with a 3.03% false-positive rate and lower 50% confidence interval of detection at 54.026 copies/mL plasma. There was no reduction in the blood viral load in all critical patients, whereas the general and severe patients exhibited a similar ability to clear the viral load. The viral loads in critical patients were significantly higher than those in their general and severe counterparts. Among the 52 study patients, 30 (58%) were discharged from the hospital. Among half of the 30 discharged patients, blood viral load remained positive, of which 76.9% (10 of 13) completely cleared their blood viral load at follow-up. Meanwhile, none of their close contacts had evidence of infection. Quantitative determination of the blood viral test is of great clinical significance in the management of patients with coronavirus disease 2019.

Asymptomatic Subclinical Cases of Coronavirus Disease 2019 without Viral Transmission in Three Independent Families.

PURPOSE: There is increasing evidence indicating that considerable fractions of cases of SARS-CoV-2 infection are asymptomatic. We traced three asymptomatic clusters to investigate the infectivity of subclinical cases of coronavirus disease 2019 (COVID-19). PATIENTS AND METHODS: Three medical staff who were asymptomatic were diagnosed with coronavirus disease 2019 by serological tests. Their close contacts were systematically evaluated based on COVID-19-related symptoms, nucleic acid tests, serological tests, and chest computed tomography (CT) as needed to determine if they were infected by SARS-CoV-2. RESULTS: None of the staff's close contacts, including 10 family members, were infected by the indexes, even though no protective measures were taken. CONCLUSION: The infectivity of asymptomatic subclinical infection patients of coronavirus disease 2019 seems to be low.

SARS-CoV-2 infection in immunocompromised patients: humoral versus cell-mediated immunity.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic placed unprecedented pressure on various healthcare systems, including departments that use immunotherapies such as chimeric antigen receptor (CAR) T-cell therapy and immunosuppression therapy in organ transplantation units. The true impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on immunocompromised CAR T-cell therapy recipients and kidney transplant recipients (KTRs) has not yet been established. CASE PRESENTATION: In this report, we compare two patients with severe COVID-19 pneumonia in either the humoral or cell-mediated immunodeficient states. The first patient was a man in his early 30s who was diagnosed with refractory multiple myeloma. He received fully humanized, anti-B-cell maturation antigen, CAR T-cell therapy before 4 months and achieved strict complete remission. He was infected with SARS-CoV-2 starting on January 26, 2019 and gradually progressed to severe pneumonia. Throughout the clinical progression of the disease, SARS-CoV-2 could not be cleared due to his humoral immunodeficient state. During this period of his severe COVID-19 pneumonia, elevated cytotoxic T-cells were observed in this patient's peripheral blood while elevated plasma levels of interleukin (IL)-2R, IL-6, tumor necrosis factor α, and ferritin were observed in his cytokine profiles. This patient eventually progressed into acute respiratory distress syndrome and recieved non-invasive ventilatory support. He failed to generate specific SARS-CoV-2 antibodies and died of respiratory failure on day 33 (d33). The second patient was a 52-year-old kidney transplant recipient (KTR) who took ciclosporin after renal transplantation for more than 7 years. He confirmed SARS-CoV-2 infection on January 20, 2019 and gradually progressed into severe pneumonia on d16 with a slightly elevated B-cell percentage and normal T-lymphocyte subsets. Viral clearance occurred together with the generation of specific anti-immunoglobulin G-SARS-CoV-2 antibodies after 2 weeks of treatment. He was symptom-free and discharged from the hospital on d42. CONCLUSION: We report a CAR T-cell therapy recipient diagnosed with COVID-19 for the first time. His virus clearance failure and life-threating cytokine storm during SARS-CoV-2 infection suggested that any decision to proceed CAR T-cell therapy during COVID-19 pandemics will require extensive discussion of potential risks and benefits. Immunosuppressant treatment based on ciclosporin could be relatively safe for KTRs diagnosed with COVID-19. TRIAL REGISTRATION NUMBER: ChiCTR-OPN-1800018137.

Recurrent pneumonia in a patient with new coronavirus infection after discharge from hospital for insufficient antibody production: a case report.

BACKGROUND: The rapid spread of coronavirus disease 2019 (COVID-19) was declared as an emerging public health threat by the World Health Organization. As various measures have been taken successfully to combat the epidemic caused by SARS-CoV-2, a growing number of fully recovered patients have been discharged from hospitals. However, some of them have relapsed. Little is known about the causes that triggered the relapse. CASE PRESENTATION: We report a case of a 40 years old man who suffered from recurrent pulmonary infection with progression of lesions on chest computed tomography (CT), elevated levels of ferritin and IL2R, reduced lymphocyte count and positive oropharyngeal swab test for SARS-CoV-2 again after 5 days discharge from hospital. The anti-SARS-CoV-2 antibody level of this patient was very low at the time of relapse, suggesting a weak humoral immune response to the virus. Total exon sequencing revealed mutations in TRNT1 gene, which may be responsible for B cell immunodeficiency. Therefore, uncleared SARS-CoV-2 at his first discharge was likely to lead to his recurrence. However, viral superinfection and non-infectious organizing pneumonia could not be completely excluded. CONCLUSION: COVID-19 relapse may occur in a part of discharged patients with low titers of anti-SARS-CoV-2 antibodies. These patients should be maintained in isolation for longer time even after discharge. A more sensitive method to detect SARS-CoV-2 needs to be established and serological testing for specific antibodies may be used as a reference to determine the duration of isolation.

Impact of COVID-19 epidemic on live online dental continuing education.

INTRODUCTION: This study aimed to assess live online dental continuing education during COVID-19 epidemic in China. METHODS: Twenty-one institutions providing live online dental courses in China during COVID-19 epidemic enrolled in this study. Their online and/or offline course provision before and during the epidemic was retrospectively inquired. If live online education was provided, the number of courses, duration and number of participants per week were further investigated. Time distributions of live online dental courses were recorded and classified as within working time and out of working time. The test period of COVID-19 epidemic was for two weeks between 16 February and 29 February 2020. The control period of pre-COVID-19 epidemic was for ten weeks between 01 November 2019 and 09 January 2020. RESULTS: The percentages of offline and online courses provided by 21 dental continuing education institutions before COVID-19 epidemic were 95.2% (20 out of 21) and 28.6% (6 out of 21), respectively. All the institutions suspended offline courses whilst providing two live online courses, on average, per week with 188 minutes duration and 7290 participants during the epidemic. The total number of online courses for 10 weeks before the epidemic was 33, and that for two weeks during the epidemic was 119. The proportion of courses provided within working time raised from 6.1% (2 out of 33) of pre-COVID-19 to 46.2% (55 out of 119) during COVID-19. There were significant differences between before and during the epidemic (P < .001). CONCLUSION: The dental continuing education transferred from offline to online dramatically, and live online dental continuing education increased significantly during COVID-19 epidemic in China.

Ruxolitinib in treatment of severe coronavirus disease 2019 (COVID-19): A multicenter, single-blind, randomized controlled trial.

BACKGROUND: Accumulating evidence proposed Janus-associated kinase (JAK) inhibitors as therapeutic targets warranting rapid investigation. OBJECTIVE: This study evaluated the efficacy and safety of ruxolitinib, a JAK1/2 inhibitor, for coronavirus disease 2019. METHODS: We conducted a prospective, multicenter, single-blind, randomized controlled phase II trial involving patients with severe coronavirus disease 2019. RESULTS: Forty-three patients were randomly assigned (1:1) to receive ruxolitinib plus standard-of-care treatment (22 patients) or placebo based on standard-of-care treatment (21 patients). After exclusion of 2 patients (1 ineligible, 1 consent withdrawn) from the ruxolitinib group, 20 patients in the intervention group and 21 patients in the control group were included in the study. Treatment with ruxolitinib plus standard-of-care was not associated with significantly accelerated clinical improvement in severe patients with coronavirus disease 2019, although ruxolitinib recipients had a numerically faster clinical improvement. Eighteen (90%) patients from the ruxolitinib group showed computed tomography improvement at day 14 compared with 13 (61.9%) patients from the control group (P = .0495). Three patients in the control group died of respiratory failure, with 14.3% overall mortality at day 28; no patients died in the ruxolitinib group. Ruxolitinib was well tolerated with low toxicities and no new safety signals. Levels of 7 cytokines were significantly decreased in the ruxolitinib group in comparison to the control group. CONCLUSIONS: Although no statistical difference was observed, ruxolitinib recipients had a numerically faster clinical improvement. Significant chest computed tomography improvement, a faster recovery from lymphopenia, and favorable side-effect profile in the ruxolitinib group were encouraging and informative to future trials to test efficacy of ruxolitinib in a larger population.

Clinical characteristics of hematological patients concomitant with COVID-19.

The rapid spread of coronavirus disease 2019 (COVID-19) represented the most serious issue to public health globally. Hematological patients as immunocompromised hosts are vulnerable to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. There is little information available regarding the clinical features of hematological patients concomitant with COVID-19. In this study, 9 concomitant patients were analyzed for their clinical manifestations, laboratory data, radiological findings, and immunologic features. The median age was 50 years (range, 17-68 years) and 6 patients were male. Seven patients were infected through hospital-associated transmission and other 2 through community-associated transmission. Onset of COVID-19 in all patients occurred during routine treatments for their hematological diseases. Eight patients were classified as moderate and 1 patient as critically ill COVID-19. Four patients died, 1 from leukemia progression, 2 from life-threatening secondary infection, and the other from respiratory failure caused by COVID-19. Abruptly elevated levels of cytokines were often correlated with progressive hematological disease or concurrent bacterial infections. Two patients had atypical computed tomography (CT) imaging findings of COVID-19. The median interval from the first CT scan imaging to improvement in survivors was 40 days (range, 14-51 days). Four of 5 survivors had negative serological tests 1 month after symptom onset. Positive viral load in 4 survivors lasted longer than 45 days. Our results indicated concomitant patients formed a distinct subgroup characterized by atypical clinical features, defective viral clearance, and lower level of SARS-CoV-2-specific Abs. Targeted therapies that impair host humoral immunity should be avoided. These findings will be helpful to tailor appropriate management for the concomitant patients.

CAR T-cell treatment during the COVID-19 pandemic: Management strategies and challenges.

The pandemic of coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is spreading rapidly across the world. Currently, the COVID-19 pandemic is affecting the continuity of essential routine healthcare services and procedures, including chimeric antigen receptor T-cell (CAR-T) therapy, a life-saving option for patients with relapsed/refractory (R/R) hematologic malignancies. Due to the rapid disease progression of hematological malignancies, there is an urgent need to manufacture and utilize CAR T-cells. However, CAR-T treatment has become extraordinarily challenging during this COVID-19 pandemic. Thus, many medical and technical factors must now be taken into consideration before, during, and after CAR-T therapy. The purpose of this review is to provide brief suggestions for rational decision-making strategies in evaluating and selecting CAR T-cell treatment and appropriate CAR T-cell products, and protective strategies for medical staff and patients to prevent infection in the midst of the current COVID-19 pandemic.