Studying Outcomes after Steroid-Sparing Immunosuppressive Agent vs. Steroid-Only Treatment for Immune-Related Adverse Events in Non-Small-Cell Lung Cancer (NSCLC) and Melanoma: A Retrospective Case-Control Study.

BACKGROUND: The effects of steroid-sparing immunosuppressive agents (SSIAs), used for the treatment of immune-related adverse events (irAEs), on immune checkpoint inhibitor (ICI) antitumor activity is not well known. We compared tumor outcomes of patients who received corticosteroid monotherapy (CS) versus a corticosteroid plus SSIA (CS-SSIA) for irAE treatment, using statistical methods to address immortal time bias. METHODS: We conducted a retrospective case-control study on patients ≥ 18 years with melanoma or non-small-cell lung cancer (NSCLC) treated with ≥1 ICI at a quaternary care center between 1 January 2016 and 11 January 2021. Patients were divided into two cohorts: CS or CS-SSIA. We used propensity score nearest-neighbor matching to match on tumor type, stage, and prior lines of therapy. Primary outcomes were progression-free survival (PFS) and overall survival (OS). Secondary outcomes included the time from the start of the irAE treatment to the irAE resolution. Hazard ratios (HRs) for PFS and OS were calculated using the Cox proportional hazard regression method with both (1) the time to the steroid and SSIA as time-varying covariates and (2) a binary exposure classification not accounting for the time to the treatment. RESULTS: A total of 167 patients were included after matching (132 in the CS cohort and 35 in the CS-SSIA cohort). Sixty-six percent of all the patients had melanoma. The most common irAEs requiring treatment were gastroenterocolitis and hepatitis. In an adjusted analysis not accounting for immortal time bias, there were no significant differences in PFS (HR 0.75, 95% CI [0.46-1.23]) or OS (HR 0.82, 95% CI [0.46-1.47]). In analyses using a time-varying treatment indicator, there was a trend toward improved PFS in patients treated with SSIAs (HR 0.54, CI 0.26-1.10). There was no difference in OS (HR 1.11, CI 0.55-2.23). Patients with melanoma who specifically received infliximab had improved PFS compared to patients with CS only, after adjusting for immortal time bias (HR 0.32, CI 0.24-0.43). CONCLUSIONS: The use of SSIAs with CS did not have worse outcomes than CS monotherapy. In melanoma, our findings showed improved PFS for the use of infliximab versus steroid monotherapy for irAEs. Large, prospective, randomized controlled trials are needed to confirm these findings and guide the optimal treatment of irAEs.

Effects of immune-related adverse events (irAEs) and their treatment on antitumor immune responses.

Immune checkpoint inhibitors (ICIs) are potentially life-saving cancer therapies that can trigger immune-related adverse events (irAEs). irAEs can impact any organ and range in their presentation from mild side effects to life-threatening complications. The relationship between irAEs and antitumor immune responses is nuanced and may depend on the irAE organ, the tumor histology, and the patient. While some irAEs likely represent an immune response against antigens shared between tumor cells and healthy tissues, other irAEs may be entirely unrelated to antitumor immune responses. Clinical observations suggest that low-grade irAEs have a positive association with responses to ICIs, but the correlation between severe irAEs and clinical benefit is less clear. Currently, severe irAEs are typically treated by interrupting or permanently discontinuing ICI treatment and administering empirically selected systemic immunosuppressive agents. However, these interventions could potentially diminish the antitumor effects of ICIs. Efforts to understand the mechanistic relationship between irAEs and the tumor microenvironment have yielded meaningful insights and nominated therapeutic targets for irAE management that may preserve or even boost ICI efficacy. We explore the clinical and molecular relationship between irAEs and antitumor immunity as well as the role that irAE treatments may play in shaping antitumor immune responses.

STK11 Inactivation Predicts Rapid Recurrence in Inoperable Early-Stage Non-Small-Cell Lung Cancer.

PURPOSE: Molecular factors predicting relapse in early-stage non-small-cell lung cancer (ES-NSCLC) are poorly understood, especially in inoperable patients receiving radiotherapy (RT). In this study, we compared the genomic profiles of inoperable and operable ES-NSCLC. MATERIALS AND METHODS: This retrospective study included 53 patients with nonsquamous ES-NSCLC (stage I-II) treated at a single institution (University of Chicago) with surgery (ie, operable; n = 30) or RT (ie, inoperable; n = 23) who underwent tumor genomic profiling. A second cohort of ES-NSCLC treated with RT (Stanford, n = 39) was included to power clinical analyses. Prognostic gene alterations were identified and correlated with clinical variables. The primary clinical end point was the correlation of prognostic genes with the cumulative incidence of relapse, disease-free survival, and overall survival (OS) in a pooled RT cohort from the two institutions (N = 62). RESULTS: Although the surgery cohort exhibited lower rates of relapse, the RT cohort was highly enriched for somatic STK11 mutations (43% v 6.7%). Receiving supplemental oxygen (odds ratio [OR] = 5.5), 20+ pack-years of tobacco smoking (OR = 6.1), and Black race (OR = 4.3) were associated with increased frequency of STK11 mutations. In the pooled RT cohort (N = 62), STK11 mutation was strongly associated with inferior oncologic outcomes: 2-year incidence of relapse was 62% versus 20% and 2-year OS was 52% versus 85%, remaining independently prognostic on multivariable analyses (relapse: subdistribution hazard ratio = 4.0, P = .0041; disease-free survival: hazard ratio, 6.8, P = .0002; OS: hazard ratio, 6.0, P = .022). STK11 mutations were predominantly associated with distant failure, rather than local. CONCLUSION: In this cohort of ES-NSCLC, STK11 inactivation was associated with poor oncologic outcomes after RT and demonstrated a novel association with clinical hypoxia, which may underlie its correlation with medical inoperability. Further validation in larger cohorts and investigation of effective adjuvant systemic therapies may be warranted.

Association Between Rheumatic Autoantibodies and Immune-Related Adverse Events.

BACKGROUND: Side effects of immune checkpoint inhibitors (ICIs), called immune-related adverse events (irAEs), closely resemble primary autoimmune or rheumatic diseases. We aimed to understand the clinical utility of rheumatic autoantibodies (rhAbs) for diagnosing irAEs. PATIENTS AND METHODS: Patients without pre-existing autoimmune disease (pAID) who had cancer treated with ICI(s) treatment from 1/1/2011 to 12/21/2020 and a rhAb checked were retrospectively identified. Logistic regression assessed associations between autoantibodies and irAEs, cancer outcome, and survival. Specificity, sensitivity, and positive/negative predictive values (PPV, NPV) were estimated for key rhAbs and ICI-arthritis. Kaplan-Meier analyzed objective response rate (ORR) and overall survival (OS). RESULTS: A total of 2662 patients were treated with≥1 ICIs. One hundred and thirty-five without pAID had ≥ 1 rhAb tested. Of which 70/135(52%) were female; median age at cancer diagnosis was 62 years with most common cancers: melanoma (23%) or non-small cell lung cancer (21%), 96/135 (75%) were anti-PD1/PDL1 treated. Eighty had a rhAb ordered before ICI, 96 after ICI, and 12 before and after. Eighty-two (61%) experienced an irAE, 33 (24%) with rheumatic-irAE. Pre-ICI RF showed significant association with rheumatic-irAEs (OR = 25, 95% CI, 1.52-410.86, P = .024). Pre- and post-ICI RF yielded high specificity for ICI-arthritis (93% and 78%), as did pre- and post-ICI CCP (100% and 91%). Pre-ICI RF carried 93% NPV and pre-ICI CCP had 89% PPV for ICI-arthritis. No variables were significantly correlated with ORR. Any-type irAE, rheumatic-irAE and ICI-arthritis were all associated with better OS (P = .000, P = .028, P = .019). CONCLUSIONS: Pre-ICI RF was associated with higher odds of rheumatic-irAEs. IrAEs had better OS; therefore, clinical contextualization for rhAbs is critical to prevent unnecessary withholding of lifesaving ICI for fear of irAEs.

Insights from a Rapidly Implemented COVID-19 Biobank Using Electronic Consent and Informatics Tools.

Biobanking during the COVID-19 pandemic presented unique challenges regarding patient enrollment, sample collection, and experimental analysis. This report details the ways in which we rapidly overcame those challenges to create a robust database of clinical information and patient samples while maintaining clinician and researcher safety. We developed a pipeline using REDCap (Research Electronic Data Capture) to coordinate electronic informed consent, sample collection, immunological assay execution, and data analysis for biobanking samples from patients with COVID-19. We then integrated immunological assay data with clinical data extracted from the electronic health record to link study parameters with clinical readouts. Of the 193 inpatients who participated in this study, 138 consented electronically and 56 provided paper consent. We collected and banked blood samples to measure circulating cytokines and chemokines, peripheral immune cell composition and activation status, anti-COVID-19 antibodies, and germline gene polymorphisms. In addition, we collected DNA and RNA from nasopharyngeal swabs to assess viral titer and microbiome composition by 16S sequencing. The rapid spread and contagious nature of COVID-19 required special considerations and innovative solutions to biobank samples quickly while protecting researchers and clinicians. Overall, this workflow and computational pipeline allowed for comprehensive immune profiling of 193 inpatients infected with COVID-19, as well as 89 outpatients, 157 patients receiving curbside COVID-19 testing, and 86 healthy controls. We describe a novel electronic framework for biobanking and analyzing patient samples during COVID-19, and present insights and strategies that can be applied more broadly to other biobank studies.

Severe COVID-19 induces autoantibodies against angiotensin II that correlate with blood pressure dysregulation and disease severity.

Patients infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can experience life-threatening respiratory distress, blood pressure dysregulation, and thrombosis. This is thought to be associated with an impaired activity of angiotensin-converting enzyme 2 (ACE2), which is the main entry receptor of SARS-CoV-2 and which also tightly regulates blood pressure by converting the vasoconstrictive peptide angiotensin II (AngII) to a vasopressor peptide. Here, we show that a significant proportion of hospitalized patients with COVID-19 developed autoantibodies against AngII, whose presence correlates with lower blood oxygenation, blood pressure dysregulation, and overall higher disease severity. Anti-AngII antibodies can develop upon specific immune reaction to the SARS-CoV-2 proteins Spike or receptor-binding domain (RBD), to which they can cross-bind, suggesting some epitope mimicry between AngII and Spike/RBD. These results provide important insights on how an immune reaction against SARS-CoV-2 can impair blood pressure regulation.

Checkpoint Blockade-Induced Dermatitis and Colitis Are Dominated by Tissue-Resident Memory T Cells and Th1/Tc1 Cytokines.

Immune checkpoint blockade is therapeutically successful for many patients across multiple cancer types. However, immune-related adverse events (irAE) frequently occur and can sometimes be life threatening. It is critical to understand the immunologic mechanisms of irAEs with the goal of finding novel treatment targets. Herein, we report our analysis of tissues from patients with irAE dermatitis using multiparameter immunofluorescence (IF), spatial transcriptomics, and RNA in situ hybridization (RISH). Skin psoriasis cases were studied as a comparison, as a known Th17-driven disease, and colitis was investigated as a comparison. IF analysis revealed that CD4+ and CD8+ tissue-resident memory T (TRM) cells were preferentially expanded in the inflamed portion of skin in cutaneous irAEs compared with healthy skin controls. Spatial transcriptomics allowed us to focus on areas containing TRM cells to discern functional phenotype and revealed expression of Th1-associated genes in irAEs, compared with Th17-asociated genes in psoriasis. Expression of PD-1, CTLA-4, LAG-3, and other inhibitory receptors was observed in irAE cases. RISH technology combined with IF confirmed expression of IFNγ, CXCL9, CXCL10, and TNFα in irAE dermatitis, as well as IFNγ within TRM cells specifically. The Th1-skewed phenotype was confirmed in irAE colitis cases compared with healthy colon.

Lymphatic coagulation and neutrophil extracellular traps in lung-draining lymph nodes of COVID-19 decedents.

Clinical manifestations of severe COVID-19 include coagulopathies that are exacerbated by the formation of neutrophil extracellular traps (NETs). Here, we report that pulmonary lymphatic vessels, which traffic neutrophils and other immune cells to the lung-draining lymph node (LDLN), can also be blocked by fibrin clots in severe COVID-19. Immunostained tissue sections from COVID-19 decedents revealed widespread lymphatic clotting not only in the lung but also in the LDLN, where the extent of clotting correlated with the presence of abnormal, regressed, or missing germinal centers (GCs). It strongly correlated with the presence of intralymphatic NETs. In mice, tumor necrosis factor α induced intralymphatic fibrin clots; this could be inhibited by DNase I, which degrades NETs. In vitro, TNF-α induced lymphatic endothelial cell upregulation of ICAM-1 and CXCL8, among other neutrophil-recruiting factors, as well as thrombomodulin downregulation; in decedents, lymphatic clotting in LDLNs. In a separate cohort of hospitalized patients, serum levels of Myeloperoxidase-DNA (MPO-DNA, a NET marker) inversely correlated with antiviral antibody titers, but D-dimer levels, indicative of blood thrombosis, did not correlate with either. Patients with high MPO-DNA but low D-dimer levels generated poor antiviral antibody titers. This study introduces lymphatic coagulation in lungs and LDLNs as a clinical manifestation of severe COVID-19 and suggests the involvement of NETosis of lymphatic-trafficking neutrophils. It further suggests that lymphatic clotting may correlate with impaired formation or maintenance of GCs necessary for robust antiviral antibody responses, although further studies are needed to determine whether and how lymphatic coagulation affects adaptive immune responses.

Antibody and T cell responses to COVID-19 vaccination in patients receiving anticancer therapies.

BACKGROUND: Patients with cancer were excluded from phase 3 COVID-19 vaccine trials, and the immunogenicity and side effect profiles of these vaccines in this population is not well understood. Patients with cancer can be immunocompromised from chemotherapy, corticosteroids, or the cancer itself, which may affect cellular and/or humoral responses to vaccination. PD-1 is expressed on T effector cells, T follicular helper cells and B cells, leading us to hypothesize that anti-PD-1 immunotherapies may augment antibody or T cell generation after vaccination. METHODS: Antibodies to the SARS-CoV-2 receptor binding domain (RBD) and spike protein were assessed in patients with cancer (n=118) and healthy donors (HD, n=22) after 1, 2 or 3 mRNA vaccine doses. CD4+ and CD8+ T cell reactivity to wild-type (WT) or B.1.617.2 (delta) spike peptides was measured by intracellular cytokine staining. RESULTS: Oncology patients without prior COVID-19 infections receiving immunotherapy (n=36), chemotherapy (n=15), chemoimmunotherapy (n=6), endocrine or targeted therapies (n=6) and those not on active treatment (n=26) had similar RBD and Spike IgG antibody titers to HDs after two vaccinations. Contrary to our hypothesis, PD-1 blockade did not augment antibody titers or T cell responses. Patients receiving B-cell directed therapies (n=14) including anti-CD20 antibodies and multiple myeloma therapies had decreased antibody titers, and 9/14 of these patients were seronegative for RBD antibodies. No differences were observed in WT spike-reactive CD4+ and CD8+ T cell generation between treatment groups. 11/13 evaluable patients seronegative for RBD had a detectable WT spike-reactive CD4+ T cell response. T cells cross-reactive against the B.1.617.2 variant spike peptides were detected in 31/59 participants. Two patients with prior immune checkpoint inhibitor-related adrenal insufficiency had symptomatic hypoadrenalism after vaccination. CONCLUSIONS: COVID-19 vaccinations are safe and immunogenic in patients with solid tumors, who developed similar antibody and T cell responses compared with HDs. Patients on B-cell directed therapies may fail to generate RBD antibodies after vaccination and should be considered for prophylactic antibody treatments. Many seronegative patients do develop a T cell response, which may have an anti-viral effect. Patients with pre-existing adrenal insufficiency may need to take stress dose steroids during vaccination to avoid adrenal crisis.

Severe COVID-19 infection is associated with aberrant cytokine production by infected lung epithelial cells rather than by systemic immune dysfunction.

The mechanisms explaining progression to severe COVID-19 remain poorly understood. It has been proposed that immune system dysregulation/over-stimulation may be implicated, but it is not clear how such processes would lead to respiratory failure. We performed comprehensive multiparameter immune monitoring in a tightly controlled cohort of 128 COVID-19 patients, and used the ratio of oxygen saturation to fraction of inspired oxygen (SpO2 / FiO2) as a physiologic measure of disease severity. Machine learning algorithms integrating 139 parameters identified IL-6 and CCL2 as two factors predictive of severe disease, consistent with the therapeutic benefit observed with anti-IL6-R antibody treatment. However, transcripts encoding these cytokines were not detected among circulating immune cells. Rather, in situ analysis of lung specimens using RNAscope and immunofluorescent staining revealed that elevated IL-6 and CCL2 were dominantly produced by infected lung type II pneumocytes. Severe disease was not associated with higher viral load, deficient antibody responses, or dysfunctional T cell responses. These results refine our understanding of severe COVID-19 pathophysiology, indicating that aberrant cytokine production by infected lung epithelial cells is a major driver of immunopathology. We propose that these factors cause local immune regulation towards the benefit of the virus.

SARS-CoV-2 infection induces cross-reactive autoantibodies against angiotensin II.

Patients infected with the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) can experience life-threatening respiratory distress, blood pressure dysregulation and thrombosis. This is thought to be associated with an impaired activity of angiotensin-converting enzyme-2 (ACE-2), which is the main entry receptor of SARS-CoV-2 and which also tightly regulates blood pressure by converting the vasoconstrictive peptide angiotensin II (AngII) to a vasopressor peptide. Here, we show that a significant proportion of hospitalized COVID-19 patients developed autoantibodies against AngII, whose presence correlates with lower blood oxygenation, blood pressure dysregulation, and overall higher disease severity. Anti-AngII antibodies can develop upon specific immune reaction to the SARS-CoV-2 proteins Spike or RBD, to which they can cross-bind, suggesting some epitope mimicry between AngII and Spike/RBD. These results provide important insights on how an immune reaction against SARS-CoV-2 can impair blood pressure regulation.

CDKN2A loss-of-function predicts immunotherapy resistance in non-small cell lung cancer.

Immune checkpoint blockade (ICB) improves outcomes in non-small cell lung cancer (NSCLC) though most patients progress. There are limited data regarding molecular predictors of progression. In particular, there is controversy regarding the role of CDKN2A loss-of-function (LOF) in ICB resistance. We analyzed 139 consecutive patients with advanced NSCLC who underwent NGS prior to ICB initiation to explore the association of CDKN2A LOF with clinical outcomes. 73% were PD-L1 positive (≥ 1%). 48% exhibited high TMB (≥ 10 mutations/megabase). CDKN2A LOF was present in 26% of patients and was associated with inferior PFS (multivariate hazard ratio [MVA-HR] 1.66, 95% CI 1.02-2.63, p = 0.041) and OS (MVA-HR 2.08, 95% CI 1.21-3.49, p = 0.0087) when compared to wild-type (WT) patients. These findings held in patients with high TMB (median OS, LOF vs. WT 10.5 vs. 22.3 months; p = 0.069) and PD-L1 ≥ 50% (median OS, LOF vs. WT 11.1 vs. 24.2 months; p = 0.020), as well as in an independent dataset. CDKN2A LOF vs. WT tumors were twice as likely to experience disease progression following ICB (46% vs. 21%; p = 0.021). CDKN2A LOF negatively impacts clinical outcomes in advanced NSCLC treated with ICB, even in high PD-L1 and high TMB tumors. This novel finding should be prospectively validated and presents a potential therapeutic target.

Sensitive detection and quantification of SARS-CoV-2 in saliva.

Saliva has significant advantages as a test medium for detection of SARS-CoV-2 infection in patients, such as ease of collection, minimal requirement of supplies and trained personnel, and safety. Comprehensive validation in a large cohort of prospectively collected specimens with unknown SARS-CoV-2 status should be performed to evaluate the potential and limitations of saliva-based testing. We developed a saliva-based testing pipeline for detection of SARS-CoV-2 nucleic acids using real-time reverse transcription PCR (RT-PCR) and droplet digital PCR (ddPCR) readouts, and measured samples from 137 outpatients tested at a curbside testing facility and 29 inpatients hospitalized for COVID-19. These measurements were compared to the nasal swab results for each patient performed by a certified microbiology laboratory. We found that our saliva testing positively detects 100% (RT-PCR) and 93.75% (ddPCR) of curbside patients that were identified as SARS-CoV-2 positive by the Emergency Use Authorization (EUA) certified nasal swab testing assay. Quantification of viral loads by ddPCR revealed an extremely wide range, with 1 million-fold difference between individual patients. Our results demonstrate for both community screening and hospital settings that saliva testing reliability is on par with that of the nasal swabs in detecting infected cases, and has potential for higher sensitivity when combined with ddPCR in detecting low-abundance viral loads that evade traditional testing methods.

Neutrophil-to-Lymphocyte Ratio Is a Predictive Biomarker in Patients with Epidermal Growth Factor Receptor (EGFR) Mutated Advanced Non-Small Cell Lung Cancer (NSCLC) Treated with Tyrosine Kinase Inhibitor (TKI) Therapy.

BACKGROUND: First-line treatment for patients with non-small cell lung cancer (NSCLC) with a sensitizing epidermal growth factor receptor (EGFR) mutation is a tyrosine kinase inhibitor (TKI). Despite higher response rates and prolonged progression free survival (PFS) compared with platinum doublet chemotherapy, a subset of these patients do not receive prolonged benefit from these agents. We investigate if the neutrophil-to-lymphocyte ratio (NLR) and other markers of cachexia and chronic inflammation correlate with worse outcomes in these patients. METHODS: This study is a retrospective review of 137 patients with advanced EGFR-mutated NSCLC treated with TKIs at Rush University Medical Center and University of Chicago Medicine from August 2011 to July 2019, with outcomes followed through July 2020. The predictive value of NLR and body mass index (BMI) was assessed at the start of therapy, and after 6 and 12 weeks of treatment by univariable and multivariable analyses. RESULTS: On univariable analysis, NLR ≥ 5 or higher NLR on a continuous scale were both associated with significantly worse PFS and overall survival (OS) at treatment initiation, and after 6 or 12 weeks of treatment. On multivariable analysis, NLR ≥ 5 was associated with increased risk of death at 12 weeks of therapy (HR 3.002, 95% CI 1.282-7.029, p = 0.011), as was higher NLR on a continuous scale (HR 1.231, 95% CI 1.063-1.425, p = 0.0054). There was no difference in PFS and OS and amongst BMI categories though number of disease sites and Eastern Cooperative Oncology Group (ECOG) performance status was associated with worse PFS and OS. CONCLUSIONS: Patients with NLR ≥ 5 have a worse median PFS and median OS than patients with NLR < 5. NLR may have value as a predictive biomarker and may be useful for selecting patients for therapy intensification in the front-line setting either at diagnosis or after 12 weeks on therapy. NLR needs to be validated prospectively.

COVIDOSE: A Phase II Clinical Trial of Low-Dose Tocilizumab in the Treatment of Noncritical COVID-19 Pneumonia.

Interleukin-6 (IL-6)-mediated hyperinflammation may contribute to the mortality of coronavirus disease 2019 (COVID-19). The IL-6 receptor-blocking monoclonal antibody tocilizumab has been repurposed for COVID-19, but prospective trials and dose-finding studies in COVID-19 have not yet fully reported. We conducted a single-arm phase II trial of low-dose tocilizumab in nonintubated hospitalized adult patients with COVID-19, radiographic pulmonary infiltrate, fever, and C-reactive protein (CRP) ≥ 40 mg/L. We hypothesized that doses significantly lower than the emerging standards of 400 mg or 8 mg/kg would resolve clinical and laboratory indicators of hyperinflammation. A dose range from 40 to 200 mg was evaluated, with allowance for one repeat dose at 24 to 48 hours. The primary objective was to assess the relationship of dose to fever resolution and CRP response. Thirty-two patients received low-dose tocilizumab, with the majority experiencing fever resolution (75%) and CRP decline consistent with IL-6 pathway abrogation (86%) in the 24-48 hours following drug administration. There was no evidence of a relationship between dose and fever resolution or CRP decline over the dose range of 40-200 mg. Within the 28-day follow-up, 5 (16%) patients died. For patients who recovered, median time to clinical recovery was 3 days (interquartile range, 2-5). Clinically presumed and/or cultured bacterial superinfections were reported in 5 (16%) patients. Low-dose tocilizumab was associated with rapid improvement in clinical and laboratory measures of hyperinflammation in hospitalized patients with COVID-19. Results of this trial provide rationale for a randomized, controlled trial of low-dose tocilizumab in COVID-19.

Sensitive detection and quantification of SARS-CoV-2 in saliva.

Saliva has significant advantages as a test medium for detection of SARS-CoV-2 infection in patients, such as ease of collection, minimal requirement of supplies and trained personnel, and safety. Comprehensive validation in a large cohort of prospectively collected specimens with unknown SARS-CoV-2 status should be performed to evaluate the potential and limitations of saliva-based testing. We developed a saliva-based testing pipeline for detection of SARS-CoV-2 nucleic acids using real-time reverse transcription PCR (RT-PCR) and droplet digital PCR (ddPCR) readouts, and measured samples from 137 outpatients tested at a curbside testing facility and 29 inpatients hospitalized for COVID-19. These measurements were compared to the nasal swab results for each patient performed by a certified microbiology laboratory. We found that our saliva testing positively detects 100% (RT-PCR) and 93.75% (ddPCR) of curbside patients that were identified as SARS-CoV-2 positive by the Emergency Use Authorization (EUA) certified nasal swab testing assay. Quantification of viral loads by ddPCR revealed an extremely wide range, with 1 million-fold difference between individual patients. Our results demonstrate for both community screening and hospital settings that saliva testing reliability is on par with that of the nasal swabs in detecting infected cases, and has potential for higher sensitivity when combined with ddPCR in detecting low-abundance viral loads that evade traditional testing methods.

COVIDOSE: Low-dose tocilizumab in the treatment of Covid-19.

Background Interleukin-6 (IL-6)-mediated hyperinflammation may contribute to the high mortality of coronavirus disease 2019 (Covid-19). Tocilizumab, an IL-6 receptor blocking monoclonal antibody, has been repurposed for Covid-19, but prospective trials and dose-finding studies in Covid-19 are lacking. Methods We conducted a phase 2 trial of low-dose tocilizumab in hospitalized adult patients with Covid-19, radiographic pulmonary infiltrate, fever, and C-reactive protein (CRP) >= 40 mg/L who did not require mechanical ventilation. Dose cohorts were determined by a trial Operations Committee, stratified by CRP and epidemiologic risk factors. A range of doses from 40 to 200 mg (low-dose tocilizumab) was evaluated, with allowance for one repeat dose at 24-48 hours. The primary objective was to assess the relationship of dose to fever resolution and CRP response. Outcomes were compared with retrospective controls with Covid-19. Correlative studies evaluating host antibody response were performed in parallel. Findings A total of 32 patients received low-dose tocilizumab. This cohort had improved fever resolution (75.0% vs. 34.2%, p = 0.001) and CRP decline (86.2% vs. 14.3%, p < 0.001) in the 24-48 hours following drug administration, as compared to the retrospective controls (N=41). The probabilities of fever resolution or CRP decline did not appear to be dose-related in this small study (p=0.80 and p=0.10, respectively). Within the 28-day follow-up, 5 (15.6%) patients died. For patients who recovered, median time to clinical recovery was 3 days (IQR, 2-5). Clinically presumed and/or cultured bacterial superinfections were reported in 5 (15.6%) patients. Correlative biological studies demonstrated that tocilizumab-treated patients produced anti-SARS-CoV-2 antibodies comparable to controls. Interpretation Low-dose tocilizumab was associated with rapid improvement in clinical and laboratory measures of hyperinflammation in hospitalized patients with Covid-19. Results of this trial and its correlative biological studies provide rationale for a randomized, controlled trial of low-dose tocilizumab in Covid-19.

Comparative Transcriptomic Analysis Identifies a Range of Immunologically Related Functional Elaborations of Lymph Node Associated Lymphatic and Blood Endothelial Cells.

Lymphatic and blood vessels are formed by specialized lymphatic endothelial cells (LEC) and blood endothelial cells (BEC), respectively. These endothelial populations not only form peripheral tissue vessels, but also critical supporting structures in secondary lymphoid organs, particularly the lymph node (LN). Lymph node LEC (LN-LEC) also have been shown to have important immunological functions that are not observed in LEC from tissue lymphatics. LN-LEC can maintain peripheral tolerance through direct presentation of self-antigen via MHC-I, leading to CD8 T cell deletion; and through transfer of self-antigen to dendritic cells for presentation via MHC-II, resulting in CD4 T cell anergy. LN-LEC also can capture and archive foreign antigens, transferring them to dendritic cells for maintenance of memory CD8 T cells. The molecular basis for these functional elaborations in LN-LEC remain largely unexplored, and it is also unclear whether blood endothelial cells in LN (LN-BEC) might express similar enhanced immunologic functionality. Here, we used RNA-Seq to compare the transcriptomic profiles of freshly isolated murine LEC and BEC from LN with one another and with freshly isolated LEC from the periphery (diaphragm). We show that LN-LEC, LN-BEC, and diaphragm LEC (D-LEC) are transcriptionally distinct from one another, demonstrating both lineage and tissue-specific functional specializations. Surprisingly, tissue microenvironment differences in gene expression profiles were more numerous than those determined by endothelial cell lineage specification. In this regard, both LN-localized endothelial cell populations show a variety of functional elaborations that suggest how they may function as antigen presenting cells, and also point to as yet unexplored roles in both positive and negative regulation of innate and adaptive immune responses. The present work has defined in depth gene expression differences that point to functional specializations of endothelial cell populations in different anatomical locations, but especially the LN. Beyond the analyses provided here, these data are a resource for future work to uncover mechanisms of endothelial cell functionality.