Clinical phenotypes from fatal cases of acute respiratory distress syndrome caused by pneumonia

Autopsy analysis reveals increased macrophage infiltration and cell apoptosis in COVID-19 patients with severe pulmonary fibrosis

Clinical data indicates that SARS-CoV-2 infection-induced respiratory failure is a fatal condition for severe COVID-19 patients. However, the pathological alterations of different types of respiratory failure remained unknown for severe COVID-19 patients. This study aims to evaluate whether there are differences in the performance of various types of respiratory failure in severe COVID-19 patients and investigate the pathological basis for these differences. The lung tissue sections of severe COVID-19 patients were assessed for the degree of injury and immune responses. Transcriptome data were used to analyze the molecular basis in severe COVID-19 patients. Severe COVID-19 patients with combined oxygenation and ventilatory failure presented more severe pulmonary fibrosis, airway obstruction, and prolonged disease course. The number of M2 macrophages increased with the degree of fibrosis in patients, suggesting that it may be closely related to the development of pulmonary fibrosis. The co-existence of pro-inflammatory and anti-inflammatory cytokines in the pulmonary environment could also participate in the progression of pulmonary fibrosis. Furthermore, the increased apoptosis in the lungs of COVID-19 patients with severe pulmonary fibrosis may represent a critical factor linking sustained inflammatory responses to fibrosis. Our findings indicate that during the extended phase of COVID-19, antifibrotic and antiapoptotic treatments should be considered in conjunction with the progression of the disease.

Clinical efficacy and safety of multipotent adult progenitor cells (invimestrocel) for acute respiratory distress syndrome (ARDS) caused by pneumonia: a randomized, open-label, standard therapy-controlled, phase 2 multicenter study (ONE-BRIDGE)

BACKGROUND

Acute respiratory distress syndrome (ARDS) is a life-threatening inflammatory lung injury with high mortality; no approved medication exists. Efficacy and safety of bone marrow-derived, allogeneic, multipotent adult progenitor cells (invimestrocel) plus standard treatment in patients with ARDS caused by pneumonia was evaluated.

METHODS

A randomized, open-label, standard therapy-controlled, phase 2 study (January 2019-September 2021) conducted in 29 centers in Japan. Patients with ARDS caused by pneumonia, with extensive early fibroproliferation on high-resolution computed tomography and low risk of systemic organ failure identified by an Acute Physiology and Chronic Health Evaluation (APACHE II) score were included. Patients were randomized 2:1 to receive a single intravenous infusion of 9.0 × 108 cells of invimestrocel (administered at a rate of up to 10 mL/min over 30-60 min by free flow) plus standard treatment (N = 20) or standard treatment (N = 10) consistent with the clinical practice guidelines of the Japanese Respiratory Society for the management of ARDS. Primary endpoint was ventilator-free days (VFDs) through day 28 after study treatment. Analysis of covariance was performed with treatment group, age, partial pressure arterial oxygen/fraction of inspired oxygen ratio, and APACHE II score as covariates.

RESULTS

Median (interquartile range) number of VFDs was numerically higher in the invimestrocel group versus standard group (20.0 [0.0-24.0] vs 11.0 [0.0-14.0]) but was not statistically significantly different (least square [LS] means [95% confidence interval (CI)]: invimestrocel group, 11.6 [6.9-16.3]; standard group, 6.2 [- 0.4 to 12.8]; LS mean difference [95% CI], 5.4 [- 1.9 to 12.8]; p = 0.1397). Ventilator weaning rate at day 28 was 65% (13/20) versus 30% (3/10), and mortality rate was 21% (4/19) versus 29% (2/7) at day 28 and 26% (5/19 patients) versus 43% (3/7 patients) at day 180, for the invimestrocel and standard groups, respectively. No allergic or serious adverse reactions were associated with invimestrocel.

CONCLUSIONS

In Japanese patients with ARDS caused by pneumonia, invimestrocel plus standard treatment resulted in no significant difference in the number of VFDs but may result in improved survival compared with standard treatment. Invimestrocel was well tolerated.

TRIAL REGISTRATION

ClinicalTrials.gov, Identifier: NCT03807804; January 8, 2019; https://clinicaltrials.gov/ct2/show/NCT03807804 .

Analysis of clinical characteristics and prognostic factors of ARDS caused by community-acquired pneumonia in people with different immune status

BACKGROUND

The purpose of this study is to describe the clinical characteristics and prognostic risk factors of acute respiratory distress syndrome (ARDS) caused by community-acquired pneumonia under different immune states.

METHODS

The patients were divided into immunocompetent and immunocompromised groups according to their immune status. The basic clinical data of the two groups were collected and statistically analyzed, and the clinical characteristics and prognostic factors of ARDS caused by community-acquired pneumonia under different immune states were summarized.

RESULTS

128 patients with ARDS caused by community-acquired pneumonia were enrolled. The chest High-Resolution Computed Tomography (HRCT) scores of patients with immunosuppression were higher (236.0 ± 55.0 vs. 207.5 ± 49.6, p < 0.05) and the score of APACHE II was higher (17.3 ± 4.8 vs. 15.1 ± 5.4, p < 0.05). The 28-day intensive care unit (ICU) mortality was higher in the immunocompromised group (54.5% vs. 34.7%, p = 0.045). The 28-day in-hospital mortality in the immunocompetent group was mainly related to NLR and the oxygenation index. The 28-day in-hospital mortality in the immunocompromised group was mainly related to LDH and APACHE II.

CONCLUSION

There are differences in clinical characteristics and mortality of ARDS patients caused by community-acquired pneumonia under different immune states.