Abnormal cholinesterase activity: understanding and interpretation.

Abnormal acetylcholinesterase and cholinesterase activity may occur due to a) various physiological and pathological conditions, b) genetic factors or c) interaction with drugs and cholinesterase inhibitors. This paper reviews and discusses such conditions in which both cholinesterases show abnormal activity focusing on better understanding and interpretation of laboratory results. In particular, the mechanism of interaction of both cholinesterases with their inhibitors such as organophosphorus and carbamate compounds is discussed. Some practical recommendations concerning sampling and preparation of samples for enzyme assay are given in order to avoid errors that may affect laboratory findings.