Abstract

For some twenty years, the beryllium induced lymphocyte proliferation test (BeLPT) has been used as an early screening test. It demonstrates sensitization to beryllium metal (BeS), which would precede the appearance of chronic beryllium disease. While it is considered effective for identifying subjects at risk of developing this disease, it nevertheless remains controversial since it can produce discordant findings, depending on how the laboratories consider the many analytical variables. This report summarizes work aiming to harmonize the method used by two laboratories to measure diagnostic agreement, identify sources of variation, and document the longitudinal follow-up of repeated tests on workers in the same laboratory. The simultaneous analysis of the samples collected from beryllium-exposed workers, using the BeLPT, led to the determination of an interlaboratory precision of close to 88% when the methods were harmonized and the results were studied by calculating the “SI” stimulation index. This agreement dropped to less than 64% when another method (Least Absolute Value) was used. To maintain interlaboratory agreement, the authors recommend implementing a quality assurance program to compare interlaboratory results, establishing a duplicate verification sequence, as well as having a recognized organization conduct a regular audit of the laboratories.