Assessment of the beryllium lymphocyte proliferation test using statistical process control

Area of Science:

• Occupational Health
• Toxicology
• Immunology

Background:

• Chronic beryllium disease (CBD) diagnosis relies on the beryllium blood lymphocyte proliferation test (BeBLPT) for beryllium sensitization (BeS).
• Understanding the dose-response relationship between beryllium exposure and BeS or subclinical CBD has been limited.
• Potential BeBLPT variability may lead to misclassification of BeS, impacting diagnostic accuracy.

Purpose of the Study:

• To assess the reliability and performance of the BeBLPT across four laboratories.
• To evaluate the impact of test variations on the diagnosis of beryllium sensitization.
• To determine if statistical process control (SPC) can improve BeBLPT quality management.

Main Methods:

• Utilized a 10-year dataset (1992-2001) from a medical surveillance program involving beryllium-exposed workers.
• Employed statistical process control (SPC) charts to analyze temporal patterns of the stimulation index (cell reactivity to beryllium).
• Conducted correlation analysis and assessed the impact of missing test results on SPC findings.

Main Results:

• All laboratories demonstrated significant variations in BeBLPT results beyond chance, suggesting systematic issues.
• Test result patterns indicated instability in BeBLPT performance over time.
• Missing data influenced the observed variations and SPC outcomes.

Conclusions:

• The BeBLPT exhibits significant variability, questioning its current reliability for diagnosing beryllium sensitization.
• Systematic variations in test performance necessitate improved quality management strategies.
• Implementing statistical process control (SPC) is recommended for laboratories performing BeBLPT and similar immunological assays to enhance reliability.