This is a Phase 1, open label, evaluation of a 13C-urea breath test for the detection of urease-producing bacteria in patient with pneumonia in the emergency department.
This is a Phase 1, open-label evaluation of an inhaled 13C-urea breath test in the identification of urease positive bacteria in patients diagnosed with pneumonia in the emergency department (ED). This study will enroll up to 75 adult male and female subjects in two cohorts. Adult subjects will be screened for participation in two dosing cohorts to be enrolled sequentially. Cohort A will enroll 15 subjects presenting to the ED with clinical concern for pneumonia and plan for outpatient treatment. Following enrollment and review of the safety of dosing in Cohort A, subjects receiving a diagnosis of pneumonia in the ED that are planned for admission will be screened for enrollment in Cohort B. Eligible subjects will provide informed consent, medical history, and samples for laboratory testing (including pregnancy testing for females of childbearing potential) during screening. Subjects will be evaluated for their CURB-65 Pneumonia Severity Score, and Community-Acquired Pneumonia Severity Index (PSI) where required data are available. Prior to breath test administration, subjects will provide a sputum sample for bacterial culture; sample may be induced, or collected as part of initial ED workup if appropriate culture has been ordered. Subjects will undergo breath test with collection of baseline breath samples (up to 6), followed by complete nebulization of 13C-urea solution. Immediately following the end of nebulization, breath collection bag samples will be collected at up to 6 time points with at least 1 minute intervals within 10 minutes post-nebulization. Exhaled breath bags will be centrally processed to determine the change in exhaled 13CO2 levels. Vital signs, including resting blood pressure, resting pulse, respiratory rate, peripheral oxygen saturation, and temperature will be collected prior to, and following completion of, nebulization treatment. In the event of bronchospasm, during or following nebulization, albuterol rescue will be available for treatment at the discretion of the investigator. Once required tests are complete, the subject will be treated/followed according to standard institutional protocol/practice. The subjects' clinical course will be followed for at least 24 hours, where possible, to document the final diagnosis and outcome.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
DIAGNOSTIC
Masking
SINGLE
Enrollment
75
Subjects will undergo 13C-urea breath test involving collection of baseline breath samples, nebulization of 13C-urea, and collection of post-nebulization breath samples
Henry Ford Health System
Detroit, Michigan, United States
Adverse Events
Any untoward medical occurrence associated with the use of a drug in humans, whether or not considered drug related.
Time frame: Within 24-48 hours of breath test
Serious Adverse Events
Death, disability, incapacitation, escalation of level of care, prolongation of hospitalization, birth defect, or intervention to prevent the above.
Time frame: Within 24-48 hours of breath test
Suspected Adverse Reaction
Any adverse event for which there is a reasonable possibility that the adverse event was caused by the study drug.
Time frame: Within 24-48 hours of breath test
Serious Suspected Adverse Reaction
Any Suspected Adverse Reaction that is determined to be serious, based on the outcomes of a Serious Adverse Event; i.e. death, life-threatening, causes or prolongs inpatient hospitalization, causes a persistent of significant incapacity or substantial disruption of the ability to conduct normal life functions, or a congenital abnormality/birth defect.
Time frame: Within 24-48 hours of breath test
Exhaled 13CO2 Concentration
We recorded change in 13CO2/12CO2 ratio (delta over baseline or ΔOB, in units of ‰) between pre- and post-nebulization samples
Time frame: Collected at 6 minutes after nebulization and measured within 7 days of collection
Number of Participants With ¹³CO₂/¹²CO₂ Ratio Correlated (ρ > 0.75) to Bacterial RNAseq Counts
We recorded change in 13CO2/12CO2 ratio (delta over baseline or ΔOB, in units of ‰) between pre- and post-nebulization samples and compared with subject's causative pathogen based upon sputum or blood culture results
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Time frame: Collected at 6 minutes after nebulization and measured within 7 days of collection
Number of Participants With ¹³CO₂/¹²CO₂ Ratio Correlated (ρ > 0.75) to CURB-65 Score in Urease-Positive Pneumonia
Number of participants With ¹³CO₂/¹²CO₂ Ratio Correlated (ρ \> 0.75) to CURB-65 Score in Urease-Positive Pneumonia
Time frame: Collected at 6 minutes after nebulization and measured within 7 days of collection
Number of Participants With ¹³CO₂/¹²CO₂ Ratio Correlated (ρ > 0.75) to Pneumonia Severity Index in Urease-Positive Pneumonia.
Number of Participants With ¹³CO₂/¹²CO₂ Ratio Correlated (ρ \> 0.75) to Pneumonia Severity Index in Urease-Positive Pneumonia.
Time frame: Collected at 6 minutes after nebulization and measured within 7 days of collection
Number of Participants Meeting Sensitivity Criterion of ¹³C-Urea Breath Test for Urease-Producing Pathogens
This exploratory outcome was designed to assess whether the ¹³C-urea breath test (Δ¹³CO₂) is associated with the presence of urease-producing pathogens. Correlation between exhaled ¹³CO₂ levels and pathogen abundance (based on RNAseq bacterial counts) was to be evaluated using Spearman's correlation, with a pre-defined significance threshold of ρ \> 0.75.
Time frame: Collected at 6 minutes after nebulization and measured within 7 days of collection
Number of Participants Meeting Specificity Criterion of ¹³C-Urea Breath Test for Urease-Producing Pathogens
This exploratory outcome was designed to assess the specificity of the ¹³C-urea breath test (Δ¹³CO₂) for detecting urease-producing pathogens. Specificity was defined as the proportion of participants without urease-producing pathogens (based on RNAseq bacterial profiles) who also did not meet the predefined breath test threshold. The planned analysis used Spearman correlation (ρ) between ¹³CO₂ enrichment and bacterial abundance, with ρ \< 0.75 indicating a negative test result.
Time frame: Collected at 6 minutes after nebulization and measured within 7 days of collection
Number of Participants With Breath Test Positive and Confirmed Urease-Producing Pathogen (PPV Criterion)
This exploratory outcome measured the number of participants who met the criteria for positive predictive value of the ¹³C-urea breath test. A participant was considered to meet the PPV criterion if they had a positive breath test result (Spearman ρ \> 0.75 between Δ¹³CO₂ and bacterial abundance) and also had RNAseq-confirmed presence of at least one urease-producing pathogen.
Time frame: Collected at 6 minutes after nebulization and measured within 7 days of collection
Number of Participants Meeting Negative Predictive Value Criterion of ¹³C-Urea Breath Test for Urease-Producing Pathogens
This exploratory outcome was designed to evaluate the number of participants meeting the negative predictive value (NPV) criterion of the ¹³C-urea breath test for detecting urease-producing pathogens. A participant was considered to meet the NPV criterion if they had a negative breath test result defined as a Spearman correlation coefficient (ρ) ≤ 0.75 between Δ¹³CO₂ and bacterial abundance and RNAseq-confirmed absence of urease-producing pathogens.
Time frame: Collected at 6 minutes after nebulization and measured within 7 days of collection