Occup Environ Med

Objective Agricultural pesticide handlers are at an elevated risk for overexposure to organophosphate (OP) pesticides, but symptoms can be difficult to recognize, making biomarkers invaluable for diagnosis. Occupational monitoring programs for cholinesterase depression generally rely on measuring activity of either of two common blood cholinesterases which serve as proxy measurements for nervous-system acetylcholinesterase activity: red blood cell acetylcholinesterase (AChE) and plasma butyrylcholinesterase (BChE). These biomarkers, however, may be affected differentially by some OPs and the relationship between them has not been well characterized. We aim to determine the association between blood acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activity levels and assess whether they produce comparable classifications of clinical cholinesterase depression among organophosphate pesticide handlers. Methods Using blood samples from 215 participants of the Washington State Cholinesterase Monitoring Program, we quantified changes in AChE and BChE activity from before and after exposure to OP pesticides and calculated Pearson correlation statistics for correlation of AChE and BChE changes in activity, as well as weighted Kappa statistics for agreement of classification of clinical cholinesterase depression based on AChE versus BChE measurements. Results AChE and BChE activity measurements are weakly negatively correlated in our study population. Reaching a clinical threshold for diagnosis of cholinesterase depression based on the AChE marker did not correlate with reaching clinical depression based on the BChE marker. Conclusions Both AChE and BChE should be measured in monitoring programs because they may both give potentially important but disparate classifications of clinical cholinesterase depression.

25189163

PMC4224972

CDC Public Access