Immunomodulation for ARDS:Insights From Proteomics in COVID-19

Background: The success of targeted immunomodulation in COVID-19 underscores its potential for ARDS resulting from other causes. However, it is important to understand both its targeted and broader impacts on the inflammatory host response. To guide future ARDS studies, we explored this in patients with COVID-19 using targeted proteomics.Research Question: How do different immune modulators affect the immune profiles of patients who are critically ill with COVID-19-related ARDS? Study Design and Methods: In this multicenter cohort study, we used 2 Dutch biorepositories to compare patients with COVID-19 with acute respiratory failure treated with: no immunotherapy (n = 18), corticosteroids (n = 21), anakinra plus corticosteroids (n = 9), or tocilizumab plus corticosteroids (n = 22). Plasma proteins related to inflammation and cardiovascular injury were measured using proximity extension assays on ICU days 0 through 1, ICU days 2 through 4 (T3), and ICU days 6 through 8 (T7) after treatment initiation. Results: We observed lower expression of inflammatory biomarkers immediately after tocilizumab administration and from T3 onward after anakinra administration. After treatment with corticosteroids alone, fewer inflammatory biomarkers were suppressed, and only at T3. Multivariate analyses at T3 identified tumor necrosis factor-related apoptosis-inducing ligand, IL-1 receptor-like 2, and tumor necrosis factor β as markedly increased and proto-oncogene tyrosine-protein kinase (SRC) and serine/threonine kinase 4 (STK4) as decreased, solely after tocilizumab. At T7, lower concentrations of 2,4-dienoyl-CoA reductase 1, signaling lymphocytic activation molecule family member 7, SRC, and STK4 were observed in patients treated with tocilizumab or anakinra, whereas interferon γ, chemokine (C-X-C motif) ligand 9, and chemokine (C-C motif) ligand 19 were decreased only after anakinra treatment. Interpretation: In this exploratory study, adding tocilizumab or anakinra to corticosteroids triggered a much broader immunoregulatory response than can be explained by their receptor-specific actions. The response after tocilizumab occurred more rapidly than that after anakinra, offering a potential advantage in the time-sensitive ICU setting. Additionally, tocilizumab preserved the interferon pathway, crucial for antiviral defense, whereas anakinra suppressed it.</p

Immunobiological effects of tocilizumab across respiratory subphenotypes in COVID-19 ARDS

Background: Two distinct longitudinal respiratory subphenotypes have recently been described in COVID-19-related acute respiratory distress syndrome (ARDS). These subphenotypes exhibit dynamic immunobiological changes that may help guide immunomodulatory interventions. However, the extent to which the immune response is determined by respiratory subphenotype in the presence of concurrent immunomodulatory treatment remains unclear. We investigated the independent and combined effects of respiratory subphenotype and tocilizumab on inflammatory response and clinical outcomes. Methods: We analyzed patients from existing COVID-19 biobanks who were consecutively admitted to the ICU and received more than 4 days of invasive mechanical ventilation between March 2020 and May 2022. Patients were classified into two previously described longitudinal respiratory subphenotypes—characterized by mechanical power, minute volume and ventilatory ratio—referred to as ‘low-power’ and ‘high-power’ subphenotypes. We analyzed how tocilizumab treatment and respiratory subphenotype were associated with endothelial and inflammatory plasma biomarkers on days 0, 4 and 7, as well as with mortality. Results: 720 patients were included, of whom 464 (64%) and 256 (36%) were assigned to the low- and high-power subphenotypes, respectively. 108 (23%) of the low-power subphenotype patients received tocilizumab, and 43 (17%) of the high-power subphenotype. 427 patients had plasma samples available. The high-power subphenotype was associated with slightly higher SP-D, thrombomodulin and TNF-RI plasma concentrations on the day of intubation compared to the low-power subphenotype, along with a more rapid increase in IL-6 and TNF-RI levels in subjects who had received tocilizumab treatment (β = 0.14 log ng/ml, p = 0.022, and β = 0.06 log ng/ml, p = 0.014, respectively). Tocilizumab treatment accounted for four times more variance in IL-6 and angiopoietin-2 levels than subphenotype, while subphenotype explained only a small proportion of the variance and slightly more than tocilizumab for TNF-RI and thrombomodulin. Subphenotype did not modify the association between tocilizumab and mortality (IPTW adjusted hazard ratio 1.18; 95%CI 0.60–2.33). Conclusion:Respiratory subphenotypes showed varying TNF-RI and IL-6 responses to tocilizumab, but these differences were only minor compared to the drug’s overall immunobiological effect. This suggests that respiratory subphenotype should not determine tocilizumab treatment decisions.</p

Longitudinal assessment of immunoglobulin response and disease progression in critically ill patients with community acquired pneumonia

Background: Low endogenous immunoglobulin(Ig)-levels are common in critically ill patients with sepsis, but it is unknown whether low Ig-levels are associated with poor outcome, and in which patients Ig-replacement therapy (IgRT) improves outcome. Given the crucial role of immunoglobulins in eliminating certain encapsulated pathogens, we examined the relationship between serial Ig-levels and disease course in critically ill patients with community acquired pneumonia (sCAP) caused by encapsulated or other pathogens. Methods: We included a cohort of consecutive critically ill patients with CAP, and PaO2/FiO2-ratio < 200 with or without septic shock, from an existing biorepository where microbiological causes of infection had been adjudicated in a protocolized manner. We used generalized linear mixed models to assess the association between IgG and IgM (measured on admission days 1, 3 and 7) and disease course (Sequential Organ Failure Assessment (SOFA)-score on day 2, 4, and 8) for all-cause sCAP and for episodes caused by Streptococcus (S.) pneumoniae or Haemophilus (H.) influenzae. Results: We included 255 eligible patients admitted with CAP, of which 82 (32%) episodes were caused by S. pneumoniae or H. influenzae. 151 (59%) patients had low IgG (< 7.0 g/L), 77 (30%) had low IgM (< 0.4 g/L), and 56 (22%) had both. A lower IgG-level was related to a slightly higher SOFA-score at admission (β = − 0.07 per 1 g/L IgG, p = 0.029), but an IgG-level decline over time was not associated with a SOFA-score increase (β = − 0.04, p = 0.564). IgM-levels were not associated with changes in SOFA-score over time. Neither association was affected by the presence or absence of S. pneumoniae and H. influenzae. Conclusion: In critically ill patients with CAP, IgG and IgM dynamics in the first week of ICU stay are not associated with clinically relevant changes in disease course, regardless of the causative pathogen

Prognostic Value of [¹⁸F]FDG PET Radiomics to Detect Peritoneal and Distant Metastases in Locally Advanced Gastric Cancer—A Side Study of the Prospective Multicentre PLASTIC Study

Aim: To improve identification of peritoneal and distant metastases in locally advanced gastric cancer using [18F]FDG-PET radiomics. Methods: [18F]FDG-PET scans of 206 patients acquired in 16 different Dutch hospitals in the prospective multicentre PLASTIC-study were analysed. Tumours were delineated and 105 radiomic features were extracted. Three classification models were developed to identify peritoneal and distant metastases (incidence: 21%): a model with clinical variables, a model with radiomic features, and a clinicoradiomic model, combining clinical variables and radiomic features. A least absolute shrinkage and selection operator (LASSO) regression classifier was trained and evaluated in a 100-times repeated random split, stratified for the presence of peritoneal and distant metastases. To exclude features with high mutual correlations, redundancy filtering of the Pearson correlation matrix was performed (r = 0.9). Model performances were expressed by the area under the receiver operating characteristic curve (AUC). In addition, subgroup analyses based on Lauren classification were performed. Results: None of the models could identify metastases with low AUCs of 0.59, 0.51, and 0.56, for the clinical, radiomic, and clinicoradiomic model, respectively. Subgroup analysis of intestinal and mixed-type tumours resulted in low AUCs of 0.67 and 0.60 for the clinical and radiomic models, and a moderate AUC of 0.71 in the clinicoradiomic model. Subgroup analysis of diffuse-type tumours did not improve the classification performance. Conclusion: Overall, [18F]FDG-PET-based radiomics did not contribute to the preoperative identification of peritoneal and distant metastases in patients with locally advanced gastric carcinoma. In intestinal and mixed-type tumours, the classification performance of the clinical model slightly improved with the addition of radiomic features, but this slight improvement does not outweigh the laborious radiomic analysis.</p

Thrombosis pathways in COVID-19 vs. influenza-associated ARDS: a targeted proteomics approach

Background: Pulmonary embolism (PE) occurs in one-third of critically-ill COVID-19 patients. Although prior studies identified several pathways contributing to thrombogenicity, it is unknown whether this is COVID-19-specific or also occurs in ARDS patients with another infection. Objective: To compare pathway activity among patients having COVID-19 with PE (C19PE+), COVID-19 without PE (C19PE-), and influenza-associated ARDS (IAA) using a targeted proteomics approach. Methods: We exploited an existing biorepository containing daily plasma samples to carefully match C19PE+ cases to C19PE- and IAA controls on mechanical ventilation duration, PEEP, FiO2, and cardiovascular-SOFA (n = 15 per group). Biomarkers representing various thrombosis pathways were measured using proximity extension- and ELISA-assays. Summed z-scores of individual biomarkers were used to represent total pathway activity. Results: We observed no relevant between-group differences among 22 biomarkers associated with activation of endothelium, platelets, complement, coagulation, fibrinolysis or inflammation, except sIL-1RT2 and sST2, which were lower in C19PE- than IAA (log2-Foldchange −0.67, p =.022 and −1.78, p =.022, respectively). However, total pathway analysis indicated increased activation of endothelium (z-score 0.2 [−0.3–1.03] vs. 0.98 [−2.5–−0.3], p =.027), platelets (1.0 [−1.3–3.0] vs. −3.3 [−4.1–−0.6], p =.023) and coagulation (0.8 [−0.5–2.0] vs. −1.0 [−1.6–1.0], p =.023) in COVID-19 patients (C19PE+/C19PE- groups combined) compared to IAA. Conclusion: We observed only minor differences between matched C19PE+, C19PE-, and IAA patients, which suggests individual biomarkers mostly reflect disease severity. However, analysis of total pathway activity suggested upregulation of some distinct processes in COVID-19 could be etiologically related to increased PE-risk

Clinical subtypes in critically ill patients with sepsis: validation and parsimonious classifier model development

Background: The application of sepsis subtypes to enhance personalized medicine in critically ill patients is hindered by the lack of validation across diverse cohorts and the absence of a simple classification model. We aimed to validate the previously identified SENECA clinical sepsis subtypes in multiple large ICU cohorts, and to develop parsimonious classifier models for δ-type adjudication in clinical practice. Methods: Data from four cohorts between 2008 and 2023 were used to assign α, β, γ and δ-type in patients fulfilling the Sepsis-3 criteria using clinical variables: (I) The Molecular diAgnosis and Risk stratification of Sepsis (MARS, n = 2449), (II) a contemporary continuation of the MARS study (MARS2, n = 2445) (III) the Dutch National Intensive Care Evaluation registry (NICE, n = 28,621) and (IV) the Medical Information Mart for Intensive Care including (MIMIC-IV, n = 18,661). K-means clustering using clinical variables was conducted to assess the optimal number of classes and compared to the SENECA subtypes. Parsimonious models were built in the SENECA derivation cohort to predict subtype membership using logistic regression, and validated in MARS and MIMIC-IV. Results: Among 52.226 patients with sepsis, the subtype distribution in MARS, MARS2 and NICE was 2–6% for the α-type, 1–5% for the β-type, 49–65% for the γ-type and 26–48% for the δ-type compared to 33%, 27%, 27% and 13% in the original SENECA derivation cohort, whereas subtype distribution in MIMIC-IV was more similar at 25%, 24%, 27% and 25%, respectively. In-hospital mortality rates were significantly different between the four cohorts for α, γ and δ-type (p < 0.001). Method-based validation showed moderate overlap with the original subtypes in both MARS and MIMIC-IV. A parsimonious model for all four subtypes had moderate to low accuracy (accuracy 62.2%), while a parsimonious classifier model with 3 variables (aspartate aminotransferase, serum lactate, and bicarbonate) had excellent accuracy in predicting the δ-type patients from all other types in the derivation cohort and moderate accuracy in the validation cohorts (MARS: area under the receiver operator characteristic curve (AUC) 0.93, 95% CI [0.92–0.94], accuracy 85.5% [84.0–86.8%]; MIMIC-IV: AUC 0.86 [0.85–0.87], accuracy 82.9% [82.4–83.4%]). Conclusions: The distribution and mortality rates of clinical sepsis subtypes varied between US and European cohorts. A three-variable model could accurately identify the δ-type sepsis patients

Prognostic Value of [18F]FDG PET Radiomics to Detect Peritoneal and Distant Metastases in Locally Advanced Gastric Cancer-A Side Study of the Prospective Multicentre PLASTIC Study.

AIM: To improve identification of peritoneal and distant metastases in locally advanced gastric cancer using [ 18F]FDG-PET radiomics. METHODS: [ 18F]FDG-PET scans of 206 patients acquired in 16 different Dutch hospitals in the prospective multicentre PLASTIC-study were analysed. Tumours were delineated and 105 radiomic features were extracted. Three classification models were developed to identify peritoneal and distant metastases (incidence: 21%): a model with clinical variables, a model with radiomic features, and a clinicoradiomic model, combining clinical variables and radiomic features. A least absolute shrinkage and selection operator (LASSO) regression classifier was trained and evaluated in a 100-times repeated random split, stratified for the presence of peritoneal and distant metastases. To exclude features with high mutual correlations, redundancy filtering of the Pearson correlation matrix was performed (r = 0.9). Model performances were expressed by the area under the receiver operating characteristic curve (AUC). In addition, subgroup analyses based on Lauren classification were performed. RESULTS: None of the models could identify metastases with low AUCs of 0.59, 0.51, and 0.56, for the clinical, radiomic, and clinicoradiomic model, respectively. Subgroup analysis of intestinal and mixed-type tumours resulted in low AUCs of 0.67 and 0.60 for the clinical and radiomic models, and a moderate AUC of 0.71 in the clinicoradiomic model. Subgroup analysis of diffuse-type tumours did not improve the classification performance. CONCLUSION: Overall, [ 18F]FDG-PET-based radiomics did not contribute to the preoperative identification of peritoneal and distant metastases in patients with locally advanced gastric carcinoma. In intestinal and mixed-type tumours, the classification performance of the clinical model slightly improved with the addition of radiomic features, but this slight improvement does not outweigh the laborious radiomic analysis

Effect of Hydrocortisone on Mortality and Organ Support in Patients With Severe COVID-19: The REMAP-CAP COVID-19 Corticosteroid Domain Randomized Clinical Trial.

Importance: Evidence regarding corticosteroid use for severe coronavirus disease 2019 (COVID-19) is limited. Objective: To determine whether hydrocortisone improves outcome for patients with severe COVID-19. Design, Setting, and Participants: An ongoing adaptive platform trial testing multiple interventions within multiple therapeutic domains, for example, antiviral agents, corticosteroids, or immunoglobulin. Between March 9 and June 17, 2020, 614 adult patients with suspected or confirmed COVID-19 were enrolled and randomized within at least 1 domain following admission to an intensive care unit (ICU) for respiratory or cardiovascular organ support at 121 sites in 8 countries. Of these, 403 were randomized to open-label interventions within the corticosteroid domain. The domain was halted after results from another trial were released. Follow-up ended August 12, 2020. Interventions: The corticosteroid domain randomized participants to a fixed 7-day course of intravenous hydrocortisone (50 mg or 100 mg every 6 hours) (n = 143), a shock-dependent course (50 mg every 6 hours when shock was clinically evident) (n = 152), or no hydrocortisone (n = 108). Main Outcomes and Measures: The primary end point was organ support-free days (days alive and free of ICU-based respiratory or cardiovascular support) within 21 days, where patients who died were assigned -1 day. The primary analysis was a bayesian cumulative logistic model that included all patients enrolled with severe COVID-19, adjusting for age, sex, site, region, time, assignment to interventions within other domains, and domain and intervention eligibility. Superiority was defined as the posterior probability of an odds ratio greater than 1 (threshold for trial conclusion of superiority >99%). Results: After excluding 19 participants who withdrew consent, there were 384 patients (mean age, 60 years; 29% female) randomized to the fixed-dose (n = 137), shock-dependent (n = 146), and no (n = 101) hydrocortisone groups; 379 (99%) completed the study and were included in the analysis. The mean age for the 3 groups ranged between 59.5 and 60.4 years; most patients were male (range, 70.6%-71.5%); mean body mass index ranged between 29.7 and 30.9; and patients receiving mechanical ventilation ranged between 50.0% and 63.5%. For the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively, the median organ support-free days were 0 (IQR, -1 to 15), 0 (IQR, -1 to 13), and 0 (-1 to 11) days (composed of 30%, 26%, and 33% mortality rates and 11.5, 9.5, and 6 median organ support-free days among survivors). The median adjusted odds ratio and bayesian probability of superiority were 1.43 (95% credible interval, 0.91-2.27) and 93% for fixed-dose hydrocortisone, respectively, and were 1.22 (95% credible interval, 0.76-1.94) and 80% for shock-dependent hydrocortisone compared with no hydrocortisone. Serious adverse events were reported in 4 (3%), 5 (3%), and 1 (1%) patients in the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively. Conclusions and Relevance: Among patients with severe COVID-19, treatment with a 7-day fixed-dose course of hydrocortisone or shock-dependent dosing of hydrocortisone, compared with no hydrocortisone, resulted in 93% and 80% probabilities of superiority with regard to the odds of improvement in organ support-free days within 21 days. However, the trial was stopped early and no treatment strategy met prespecified criteria for statistical superiority, precluding definitive conclusions. Trial Registration: ClinicalTrials.gov Identifier: NCT02735707

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570