Protease-Anti-Protease Compartmentalization in SARS-CoV-2 ARDS: Therapeutic Implications

Rationale Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is characterised by an IL-6 driven cytokinemia, associated with a rapidly developing acute respiratory distress syndrome (ARDS). A blunted AAT response to IL-6 in SARS-CoV-2 has been associated with increased morbidity and mortality. One of the main functions of IL-6 is regulation of acute-phase proteins such as alpha-1 antitrypsin (AAT), a key lung anti-protease. We investigated the proteaseanti- protease balance in the circulation and pulmonary compartments in SARS-CoV-2 acute respiratory distress syndrome (ARDS). In addition, we investigated the effect of anti-IL-6 therapy on anti-protease defence. Methods Levels and activity of AAT and neutrophil elastase (NE) were measured in plasma (n=20), airway tissue (n=8) and tracheal secretions (n=13) of people with severe SARS-CoV-2 infection. AAT and IL-6 levels were also evaluated over time in people with moderate SARS-CoV-2 infection who received standard of care +/- tocilizumab (n=30). Results AAT plasma levels doubled in severe SARS-CoV-2 ARDS patients (329g/L +/- 08 g/L as compared to baseline levels 174g/L +/- 011 g/L, P<0001). In lung parenchyma AAT levels were increased. Despite no increase in neutrophils, an increased percentage of neutrophils involved in NET formation were observed in the alveoli. A protease-anti-protease imbalance was detected in tracheal aspirates (TA). NE was active and AAT inactivated, reflecting cleavage and complexation with NE. The major airway anti-protease, secretory leukoprotease inhibitor (SLPI) was decreased in SARS-CoV-2-infected lungs and cleaved in TAs. Induction of AAT in SARS-CoV-2 infection occurred mainly through IL-6 signalling. Tocilizumab (IL-6 receptor antagonist) down-regulated AAT during infection (13g/L+/-0225 from 2469 g/L+/-0197, P<00001) while IL-6 remained elevated (NS=0.0998) as reflected by the IL-6/AAT ratio (P=0046). Conclusion This study shows that the AAT response to SARS-CoV-2 infection is compartmentalized with an appropriate increase in plasma and alveoli but an inadequate response in airways. This underlines a significant, but potentially treatable, protease-antiprotease imbalance in SARS-CoV-2 ARDS as well as highlighting IL-6's importance in SARS-CoV-2 pathology not only as a pro-inflammatory cytokine but as an anti-inflammatory regulator. In conclusion there is unopposed NE activity in the airways of people with SARS-CoV-2 ARDS which could be amenable to AAT therapy. Our data suggest caution in the use of IL-6 blocking therapies in SARS-CoV-2-infected individuals.

The clinical impact of maternal COVID-19 on mothers, their infants, and placentas with an analysis of vertical transfer of maternal SARS-CoV-2-specific IgG antibodies.

INTRODUCTION: The effect of SARS-CoV-2 severity or the trimester of infection in pregnant mothers, placentas, and infants is not fully understood. METHODS: A retrospective, observational cohort study in Chapel Hill, NC of 115 mothers with SARS-CoV-2 and singleton pregnancies from December 1, 2019 to May 31, 2021 via chart review to document the infants' weight, length, head circumference, survival, congenital abnormalities, hearing loss, maternal complications, and placental pathology classified by the Amsterdam criteria. RESULTS: Of the 115 mothers, 85.2% were asymptomatic (n = 37) or had mild (n = 61) symptoms, 13.0% had moderate (n = 9) or severe (n = 6) COVID-19, and 1.74% (n = 2) did not have symptoms recorded. Moderate and severe maternal infections were associated with increased C-section, premature delivery, infant NICU admission, and were more likely to occur in Type 1 (p = 0.0055) and Type 2 (p = 0.0285) diabetic mothers. Only one infant (0.870%) became infected with SARS-CoV-2, which was not via the placenta. Most placentas (n = 63, 54.8%) did not show specific histologic findings; however, a subset showed mild maternal vascular malperfusion (n = 26, 22.6%) and/or mild microscopic ascending intrauterine infection (n = 28, 24.3%). The infants had no identifiable congenital abnormalities, and all infants and mothers survived. DISCUSSION: Most mothers and their infants had a routine clinical course; however, moderate and severe COVID-19 maternal infections were associated with pregnancy complications and premature delivery. Mothers with pre-existing, non-gestational diabetes were at greatest risk of developing moderate or severe COVID-19. The placental injury patterns of maternal vascular malperfusion and/or microscopic ascending intrauterine infection were not associated with maternal COVID-19 severity.

Low Incidence of COVID-19 Infection in Patients with Acute Myeloid Leukemia Undergoing Reduced Intensity/Venetoclax Based Treatment: Initial Results of the PACE Prospective Clinical Study from the UK Trials Acceleration Program

The impact of Coronavirus disease 2019 (COVID-19) on outcomes in patients with cancer remains unclear. Acute Myeloid Leukemia (AML)/high-risk myelodysplasia (MDS) are common hematological malignancies resulting in profound immunosuppression, which is exacerbated by intensive and less-intensive chemotherapy. Importantly, venetoclax based regimens have been increasingly used during the pandemic as a strategy to reduce patient hospitalization however, there is little information concerning the impact of such regimens on COVID-19 infection rates. We therefore opened a prospective clinical study (PACE), at the start of the current pandemic in April 2020 to characterize the risk of COVID-19 infection in patients with AML/MDS-EB2 receiving intensive or non-intensive treatment, including patients treated with venetoclax-based regimens. The primary aim was to determine the incidence of COVID-19 in patients with AML /MDS-EB2 including both, prior to study entry and during treatment until 4 weeks after the last cycle of treatment. Secondary aims were to: characterize the presentation of COVID-19;define the severity and type of both non-COVID-19 and COVID-19 infections;and undertake an exploratory analysis to quantify the incidence of COVID-19 infection in patients receiving (less-intensive) venetoclax based regimens. All analysis conducted to date has been descriptive. 211/230 recruited patients had full treatment histories available, of whom 116 patients received intensive chemotherapy and 95 low intensity regimens. 48 patients received a venetoclax-based regimen. The median age of the non-intensive treatment arm was 72 years;(range 19.1-86.5) and of the intensive arm was 59 years (range 16.1-76.1). There were more cases of secondary AML and relapsed disease in the non-intensive arm as compared to the intensive arm. 25/226 evaluable patients tested positive for COVID-19 as defined by positive SARS-CoV2 PCR test, 10 with a prior diagnosis at study entry and 15 tested positive during the study. The incidence of COVID-19 infection for patients with AML/MDS-EB2 was 11.1% (90%CI: 7.8%-15.1%) (Table). A lower proportion of patients (n=6/91 6.6%) undergoing non-intensive treatment suffered COVID-19 as compared to those undergoing more intensive chemotherapy regimens (n=19/116, 16.4%). Specifically, only 3/48 (6.3%) patients undergoing a venetoclax regimen were infected with SARS-CoV2. The most common presenting symptoms of COVID-19 in this study, regardless of the intensity of chemotherapy, was fever and cough with 6/25 patients asymptomatic. The risk of death at 30 days following study entry in patients who had prior COVID-19 infection or who contracted COVID-19 during this period was 13.6%, compared to 3.9% in the overall cohort without COVID-19 infection. There was a lower incidence of non-COVID-19 related infections in patients receiving venetoclax-based regimens, n=43 infections in 24 (50.0%) of patients;with 313 infections in 94 (81%) of intensively treated patients. The overall occurrence of non-COVID-19 infection in the non-intensive arm was 87 infections in 50 (54.9%) patients. Our multi-center study provides real-world estimates for the incidence and presentation of COVID-19 infection in a cohort of patients with AML/MDS-EB2, and indicates a higher risk of death at 30 days in patients with prior COVID-19 infection prior to, or during treatment. Venetoclax based, and other non-intensive, regimens, increasingly implemented during the pandemic, to minimize patient exposure and reduce usage of hospital beds, appeared to be associated with a low incidence of COVID-19. Further follow-up will be required to understand the long-term impact of this strategy. Analysis of immune responses to COVID-19 infection and vaccination is on-going. Acknowledgments: This study was funded by Cure Leukaemia under the Trials Acceleration Program (TAP), and grants from BMS and Blood Cancer UK. [Formula presented] Disclosures: Loke: Novartis: Other: Travel;Janssen: Honoraria;Amgen: Honoraria;Pfizer: Honoraria;Daichi Sankyo: Other: Travel. K apper: Pfizer: Consultancy, Speakers Bureau;Astellas: Ended employment in the past 24 months, Speakers Bureau;Jazz: Consultancy, Speakers Bureau;Novartis: Consultancy, Research Funding, Speakers Bureau. Khan: Abbvie: Honoraria;Astellas: Honoraria;Takeda: Honoraria;Jazz: Honoraria;Gilead: Honoraria;Novartis: Honoraria. Dillon: Amgen: Other: Research support (paid to institution);Astellas: Consultancy, Other: Educational Events, Speakers Bureau;Menarini: Membership on an entity's Board of Directors or advisory committees;Novartis: Membership on an entity's Board of Directors or advisory committees, Other: Session chair (paid to institution), Speakers Bureau;Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: educational events;Jazz: Other: Education events;Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Research Support, Educational Events;Shattuck Labs: Membership on an entity's Board of Directors or advisory committees. Culligan: AbbVie Ltd: Honoraria, Speakers Bureau;Celgene Ltd: Honoraria, Speakers Bureau;Gilead: Honoraria, Speakers Bureau;Jazz Pharma: Honoraria, Speakers Bureau;Takeda UK Ltd: Honoraria, Speakers Bureau. McMullin: Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees, Other: clinical trial support, Research Funding;Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau;AbbVie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau;Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau;AOP Orphan: Research Funding, Speakers Bureau. Murthy: Abbvie: Other: support to attend educational conferences. Craddock: Novartis Pharmaceuticals: Other: Advisory Board;Celgene/BMS: Membership on an entity's Board of Directors or advisory committees, Research Funding.

African americans have lower COVID-19 mortality risk than caucasians in CKD

Background: In the general population, African Americans have increased mortality risk with COVID-19. However, this has not been well-studied in CKD population. Methods: We analyzed a national Veteran cohort using data from the VA COVID-19 Shared Data Resource for COVID-positive patients (N=196,269) from 3/1/2020 -3/9/2021. Diagnosis of COVID-19 was defined as a confirmed positive laboratory test result. Index date was defined as the date of first positive COVID-19 test or the first negative test for patients who never tested positive for COVID-19. Baseline eGFR was defined as at least one outpatient serum creatinine measurement obtained within two years before the index date or the average of the two closest serum creatinine measurements obtained within two years before the index date. We identified 58,743 patients with valid eGFR measurements. Of this cohort, 51,002 were African American or Caucasian. Mortality data were available for 50,830 patients. We used Cox regression models to compare COVID-19 mortality in African Americans versus Caucasians based on pre-COVID eGFR stratification. Results: Of the COVID-positive patients with available eGFR and mortality data, baseline mean age was 60 ± 17 years, 24% African American, 76% Caucasian, and 21% with eGFR <60. There were 627 deaths among African Americans and 2,480 deaths among Caucasians. Average follow-up duration was 0.5 ± 0.3 years in African Americans and 0.4 ± 0.2 years in Caucasians. While there was no difference in mortality risk between African American and Caucasian Veterans without CKD, African Americans had lower mortality risk when compared to Caucasians in the CKD subgroup (Table 1). Conclusions: In the CKD subgroup, African Americans have lower COVID-19 mortality than Caucasians. The reasons for this observation are unclear.

Proteome Characterictics of Endotracheal Tube Washes from COVID-19 ICU Patients: Assessing the Host Response and Understanding the Pathways Involved in Generation of Severe Disease

RATIONALE There is a great need to understand the pathogenesis of COVID-19, to predict the host responses to COVID-19 infection, and to efficiently assess clinical trial data for effectiveness. Data describing the sequence and predictability of progression of COVID-19 lung disease are not available, nor are biomarkers available to estimate lung damage. Using a proteomic approach, we measured the composition of tracheal aspirate of intubated COVID-19 positive subject and compared to COVID-19 negative ARDS subjects. METHODS EndoTracheal Tube (ETT) washes from critically ill 20 COVID-19+ patients and from 13 COVID19 negative ARDS patients were obtained from UNC COVID-19 Biospecimens Core. This BSL2+ facility obtained ICU samples and treated them with 8M urea to sterilize pathogens and solubilize the samples. Samples were normalized by total biomolecular concentration by SEC-MALLS dRI and prepared with filter aided sample preparation for mass spectrometry based label free quantiative proteome analyses. Proteins were quantified using Scaffold software (normalized total precursor intensity). Unpaired, non-parametric, Mann-Whitney test was performed in GraphPad Prism 9.0.0. RESULTS More than 1,200 proteins were identified. Of these, 209 were unique to COVID-19 samples. Of 823 proteins common to disease controls, the level of 32 proteins were decreased, and 10 proteins incresased in the in COVID-19 samples comparing to non-COVID controls (p value <0.05). Proteins significantly reduced in COVID-19 were mostly in the innate immune category including SFTPA1, BPIB1, PIGRS, and ezrin. Acute-phase proteins (alpha 1 acid glycoprotein 1, prothrombin), proteins related to iron homeostasis (serotransferrin, hemopexin), and complement pathway proteins (Complement C9 and vitronectin) were significantly increased in the COVID-19 lung. Pathways analysis indicated that acute phase signalling and LXR/RXR pathway were activated, while the glycolysis I pathway was inhibited in the COVID-19 group CONCLUSIONS These data reveal several important aspects of COVID-19-induced lung injury: 1) TNF-alpha and/or IL-6 pathways are involved;2) the pulmonary epithelia are severely injured as acute phase serum components including albumin and serotransferrin, are excessively leaking into the lung from serum;3) Activation of LXR/RXR pathways in the macrophages and the inhibition of glycolysis pathway could be an important pathological outcome of the severe form of COVID-19. These data help elucidate cell-type-specific host responses and identify these pathways and their roles in generation of disease sequelae useful in the development of new therapies to reduce virus-relate injury and/or improve resolution of injury.