Objective: To assess the value of butyrylcholinesterase (BuChE) in the diagnosis of acute organophosphorus pesticide poisoning (AOPP), and to investigate the relationship between the activity of whole blood acetylcholinesterase (AChE) and plasma BuChE in patients of AOPP in order to re-evaluate the diagnostic value of BuChE.
Methods: An improved Ellman method was employed to determine the activity of AChE and BuChE in 21 AOPP inpatients due to different kinds of pesticides (from April to September in 2009) during the course of the illness, with 26 healthy volunteers as normal control. The relationship between BuChE activity and other clinical indicators of 113 inpatients (from January 2008 to April 2009) was also retrospectively analyzed.
Results: The normal value of AChE and BuChE were (105 + or - 33) U/Hb and (15 807 + or - 3 495) U/L . The inhibition levels of these two enzymes were different. When the AChE activity was lower than 50%, 30% or 20%, the activity of BuChE was lower than 20%, 10% or 5% correspondingly. The tendency of changes in the two enzymes was similar and coincided well with the clinical symptoms after poisoning. The results of sequential detection showed that a significant decrease or persistent inhibition of BuChE activity by less than 5% indicated a high level of organophosphorus pesticide in the body. However, an elevation of BuChE indicated a favorable outcome.
Conclusion: BuChE is one of the ideal diagnostic and classification criteria for AOPP. When the inhibition level of BuChE reaches 20%, AOPP is of moderate degree, when it reaches 10%, severe AOPP can be diagnosed, with different kinds of organophosphorus pesticides taken into consideration.