Daily Respiratory Research Analysis
Three advances stand out today: a CRISPR/Cas13a assay (CasTDR) enabling 30-minute, single-nucleotide–resolved detection of viral RNA; a pooled European analysis showing climate change attenuates air-quality and greenness benefits on lung function; and a large ICU study linking invasive mechanical ventilation to higher risk and delayed timing of severe AKI requiring RRT, especially in COVID-19.
Summary
Three advances stand out today: a CRISPR/Cas13a assay (CasTDR) enabling 30-minute, single-nucleotide–resolved detection of viral RNA; a pooled European analysis showing climate change attenuates air-quality and greenness benefits on lung function; and a large ICU study linking invasive mechanical ventilation to higher risk and delayed timing of severe AKI requiring RRT, especially in COVID-19.
Research Themes
- Point-of-care viral diagnostics with single-nucleotide resolution
- Exposome (air pollution–greenness–temperature) impacts on lung function under climate change
- Mechanical ventilation and renal outcomes (RRT) in critical respiratory illness including COVID-19
Selected Articles
1. Topologically constrained DNA-mediated one-pot CRISPR assay for rapid detection of viral RNA with single nucleotide resolution.
The CasTDR platform pairs a topologically constrained DNA ring with Cas13a to accelerate post-amplification detection, achieving 0.1 aM sensitivity and single-nucleotide variant discrimination within 30 minutes. Engineered crRNAs with synthetic mismatches and hairpins enable robust differentiation of SARS-CoV-2 variants, demonstrated on clinical samples.
Impact: This method offers a rapid, ultra-sensitive, and SNV-specific point-of-care assay, potentially transforming variant-resolved diagnostics for respiratory viruses.
Clinical Implications: Enables near-patient identification of viral variants to inform isolation, targeted therapies, and outbreak surveillance, especially where lab capacity is limited.
Key Findings
- Engineered topologically constrained DNA rings accelerate Cas13a trans-cleavage, enabling rapid post-isothermal amplification readout.
- Achieved 0.1 aM analytical sensitivity and single-nucleotide specificity in 30-minute sample-to-answer workflows.
- crRNA designs with synthetic mismatches and hairpin structures robustly discriminated SARS-CoV-2 variants in clinical samples.
Methodological Strengths
- Innovative molecular design integrating constrained DNA topology with CRISPR/Cas13a.
- Demonstrated single-nucleotide discrimination on clinical samples with rapid turnaround.
Limitations
- External multicenter validation and head-to-head comparisons with established NAATs are not reported.
- Operational performance in true point-of-care settings and varied sample types requires evaluation.
Future Directions: Prospective multicenter diagnostic accuracy studies, cost-effectiveness analyses, and extension to other RNA pathogens and resistance markers.
BACKGROUND: The widespread and evolution of RNA viruses, such as the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), highlights the importance of fast identification of virus subtypes, particularly in non-laboratory settings. Rapid and inexpensive at-home testing of viral nucleic acids with single-base resolution remains a challenge. METHODS: Topologically constrained DNA ring is engineered as substrates for the trans-cleavage of Cas13a to yield an accelerated post isothermal amplification. The capacity of CRISPR/Cas13a for discriminating single nucleotide variant (SNV) in viral genome is leveraged by designing synthetic mismatches and hairpin structure in CRISPR RNA (crRNA), enabling robust discrimination of different SARS-CoV-2 variants. Via optimisation of CasTDR
2. Lung function-associated exposome profile in the era of climate change: Pooled analysis of 8 population-based European cohorts within the EXPANSE project.
Across eight European cohorts (N≈10,776), elastic net modeling revealed that air pollution, greenness, and ambient temperature interactively relate to FEV1, with stronger, more stable effects in adults. Cleaner air and increased greenness are associated with better lung function, but climate change scenarios predict FEV1 declines and attenuate benefits of air-quality and greenness improvements.
Impact: Provides policy-relevant evidence that climate change can erode gains from air-quality and greenness interventions on lung function, informing urban and climate-health planning.
Clinical Implications: Clinicians should anticipate climate-related respiratory risk, particularly for adults with impaired lung function, and advocate for environmental interventions alongside patient-level prevention.
Key Findings
- Elastic net identified multiple non-zero interaction terms among air pollution, greenness, and temperature for FEV1, particularly in adults.
- Scenarios improving air quality or greenness predicted FEV1 gains, whereas climate change (warmer summers, colder winters) predicted FEV1 declines.
- Benefits of improved air quality/greenness on FEV1 were attenuated under climate change conditions.
Methodological Strengths
- Large multi-cohort pooled analysis with elastic net regression capturing interactions and non-linearities.
- Scenario-based interpretation linking statistical outputs to policy-relevant environmental changes.
Limitations
- Cross-sectional analysis limits causal inference and may be affected by residual confounding.
- Exposure assignment based on residential address may not reflect individual mobility or indoor exposures.
Future Directions: Longitudinal modeling with repeated lung function and exposure updates, vulnerable subgroup analyses, and integration with climate adaptation strategies.
BACKGROUND: The independent and interrelated long-term effects of the exposome such as air pollution, greenness, and ambient temperature on lung function are not well understood, yet relevant in the light of climate change. METHODS: Pre-bronchodilation FEV1 from five mature birth cohorts (N = 4724) and three adult cohorts (N = 6052) from five European countries were used to assess cross-sectional associations with air pollution, greenness, and ambient temperature, assigned to their residential address. All two-way interactions and square terms were a priori included in building the final elastic net regression model. Elastic net regression results were put into the context of different environmental scenarios such as improvement of air quality, improvement of greenness, climate change, or their combinations. RESULTS: Elastic net regression of FEV1 z-scores identified non-zero coefficients for many interaction terms, indicating the importance of joint effects of exposure to air pollution, greenness, and temperature. The non-zero coefficients were bigger and more stable in adults than in children. Upon exploring lung function benefits for different environmental scenarios, an improvement of FEV1 was expected in the scenario of improving air quality or greenness. In contrast, negative changes in FEV1 z-scores were expected in the scenario of climate change, characterized by daily temperature increase in summer and decrease in winter. The beneficial FEV1 effects of improving air pollution or greenness were attenuated in the presence of climate change. CONCLUSION: Complex exposome profiles of long-term exposure to air pollution, greenness, and temperature showed associations with FEV1 in European adults, and to less extent in children and adolescents. Climate change seems to have a negative impact on lung function and modifies the association of air pollution and greenspace with lung function.
3. Impact of mechanical ventilation on severe acute kidney injury in critically ill patients with and without COVID-19 - a multicentre propensity matched analysis.
In 8,678 ICU patients, invasive mechanical ventilation (IMV) was associated with increased risk of RRT initiation across all time intervals, with COVID-19 patients showing a significantly longer IMV-to-RRT interval (median 5 vs 2 days) and higher ICU mortality among those receiving RRT. Early (days 1–2) RRT initiation was less likely in COVID-19, but risk reversed after day 7.
Impact: Clarifies the temporal relationship between IMV and severe AKI requiring RRT in COVID-19 and non-COVID critical illness, informing ventilatory strategies and renal monitoring.
Clinical Implications: Heightened vigilance for kidney injury in mechanically ventilated patients is warranted, with early preventive strategies and nephrology involvement, especially in COVID-19 where IMV-to-RRT delays occur.
Key Findings
- Among 8,678 ICU patients, 12.8% required RRT in both COVID-19 and non-COVID groups.
- IMV increased the risk of RRT initiation throughout ICU stay; in COVID-19 this association was statistically significant.
- Median time from IMV to RRT was longer in COVID-19 (5 days [IQR 2–11]) than non-COVID (2 days [IQR 1–5]).
- Among RRT recipients, IMV was associated with higher ICU mortality compared with non-IMV.
Methodological Strengths
- Large multicentre cohort with propensity methods and time-interval analyses.
- Direct comparison of COVID-19 and non-COVID-19 critical illness.
Limitations
- Observational design cannot establish causality; residual confounding (ventilator settings, fluid balance) possible.
- Changes in ICU practices over the pandemic may influence temporal patterns.
Future Directions: Mechanistic studies on ventilator–kidney interactions, trials of kidney-protective ventilator strategies, and predictive models integrating respiratory and renal trajectories.
BACKGROUND: Acute kidney injury (AKI) is common in critically ill patients and is associated with increased morbidity and mortality. Its complications often require renal replacement therapy (RRT). Invasive mechanical ventilation (IMV) and infections are considered risk factors for the occurrence of AKI. The use of IMV and non-invasive ventilation (NIV) has changed over the course of the pandemic. Concomitant with this change in treatment a reduction in the incidences of AKI and RRT was observed. We aimed to investigate the impact of IMV on RRT initiation by comparing critically ill patients with and without COVID-19. Furthermore, we wanted to investigate the rates and timing of RRT as well as the outcome of patients, who were treated with RRT. RESULTS: A total of 8,678 patients were included, of which 555 (12.8%) in the COVID-19 and 554 (12.8%) in the control group were treated with RRT. In the first week of ICU stay the COVID-19 patients showed a significantly lower probability for RRT initiation (day 1: p < 0.0001, day 2: p = 0.021). However, after day 7 a reversed HR was found. In mechanically ventilated patients the risk was significantly higher for the initiation of RRT over the entire stay. While in non-COVID-19 patients this was a non-significant trend, in COVID-19 patients the risk for RRT was significantly increased. The median delay between initiation of IMV and requirement of RRT was observed to be longer in COVID-19 patients (5 days [IQR: 2-11] vs. 2 days [IQR: 1-5]). The analysis restricted to patients with RRT showed a significantly higher risk for ICU death in patients requiring IMV compared to patients without IMV. CONCLUSION: The analysis demonstrated that IMV as well as COVID-19 are associated with an increased risk for initiation of RRT. The association between IMV and risk of RRT initiation was given for all investigated time intervals. Additionally, COVID-19 patients showed an increased risk for RRT initiation during the entire ICU stay within patients admitted to an ICU due to respiratory disease. In COVID-19 patients treated with RRT, the risk of death was significantly higher compared to non-COVID-19 patients.