Isotope ratio mass spectrometry (IRMS) versus laser-assisted ratio analyzer (LARA): a comparative study using two...

Area of Science:

• Medical Diagnostics
• Microbiology
• Gastroenterology

Background:

• Helicobacter pylori infection is a major cause of upper gastrointestinal diseases.
• Accurate diagnosis is crucial for effective treatment and eradication.
• Traditional diagnostic methods like isotope-ratio mass spectrometry (IRMS) can be expensive.

Purpose of the Study:

• To compare the diagnostic accuracy and measurements of the LARA system against the traditional IRMS for H. pylori detection.
• To evaluate the performance of both systems using different [13C]urea doses and test meals.
• To assess the utility of the LARA system in pre- and post-treatment H. pylori diagnosis.

Main Methods:

• A total of 354 dyspeptic patients undergoing upper gastrointestinal endoscopy were included.
• Breath samples were collected at baseline, 30, and 60 minutes after ingesting [13C]urea with either Ensure or citric acid.
• H. pylori infection was confirmed by CLO-test and histology; eradication was defined by negative biopsy results.

Main Results:

• Excellent agreement was observed between LARA and IRMS measurements for both [13C]urea dosages.
• Both systems showed high sensitivity (90-100%) and specificity (90-97%) for H. pylori detection before and after treatment.
• Reliable results were obtained as early as 30 minutes post-ingestion, making the 60-minute sample unnecessary.

Conclusions:

• The LARA system is a cost-effective and valid alternative to IRMS for diagnosing H. pylori infection.
• The [13C]urea Breath Test (UBT) using 75 mg [13C]urea with citric acid provides accurate results.
• The LARA system is effective for both initial diagnosis and post-therapy monitoring of H. pylori eradication.