Acta Pharm. 51 (2001) 289-296

Original scientific paper  

Interlaboratory study into the proficiency of attribution of human serum butyrylcholinesterase phenotypes: Reference values of activities and inhibitor numbers


1Institute for Medical Research and Occupational Health, P.O. Box 291, Zagreb, Croatia
2Leeds, UK
Received October 11, 2001      Accepted December 5, 2001

Correct recognition of butyrylcholinesterase (E.C. variants in human serum is essential if patients susceptible to a prolonged reaction following treatment with short acting muscle relaxants are to be successfully identified. They can then be given appropriate advice, along with any relatives who may be similarly affected. In order to assess the ability of clinical laboratories to perform this task, a proficiency programme was organised, which extended over four and a half years. Serum specimens of serum were taken from selected sensitive and non-sensitive patients, previously examined in the reference laboratory. The reference values for the activities and inhibitor numbers of human serum butyrylcholinesterase phenotypes were thus obtained and are presented in this paper. Of 1035 samples distributed, 983 reports were returned. Correct conclusion was drawn in 83% of the reports, 11% were incorrect, and in 6% no phenotype was attributed or no definitive interpretation could be made. On average, twenty-nine laboratories participated in each of the 36 runs. In the second half of the programme, a noticeable improvement in performance was observed, primarily associated with a smaller number of cases in which no phenotype was ascribed.

Keywords: cholinesterase phenotypes, butyrylcholinesterase phenotyping, quality control, evaluation of performance, activity measurement, inhibition by dibucaine, sodium fluoride and Ro 02-0683, reference values of activities and inhibitor numbers