Background: Organophosphorus compounds (OPC) poisoning leads to several neurotoxic 
disorders in humans. Glial Fibrillary Acidic Protein (GFAP) released in response to neuronal cell 
injury and has been used as a sensitive and specific indicator of several neurotoxic conditions, 
there is no human studies focused on the diagnostic and prognostic value of GFAP in OPC 
toxicity. Thus, there is a need for studying its role in OPC poisoning. Objectives: This study 
aimed to assess the usefulness of GFAP as early predictor of OPC related neurotoxic disorders 
both in acute poisoning and chronic exposure and to correlate levels of GFAP with severity of 
acute OPC poisoning. Methods: This is a prospective clinical study that was conducted in 
Poison Control Center, Ain Shams University Hospitals. The study included 4 groups, control 
group (23 healthy volunteers), group II acute moderate OPC patients (19 patients), group III 
acute severe OPC patients (25 patients), and group IV chronic group (41 farmers). All 
participants were subjected to measurement of GFAP, serum acetylcholine (ACh), serum pseudo 
cholinesterase (PChE), serum glucose, potassium, serum lactate ,lactate dehydrogenase (LDH), 
and serum creatine phosphokinase (CPK). Results: Serum GFAP and ACh were significantly 
high in all patient groups compared to the control group, but no significant difference was found 
between acute moderate and acute severe groups. Also serum PChE had no significant difference 
between patients of acute moderate and severe groups. Serum glucose, lactate, LDH and CPK
were highly significant in acute severe group when compared to acute moderate group.
Conclusion: Glial Fibrillary Acidic Protein, a biomarker of neurotoxicity, can be used in 
patients with acute and chronic OPC poisoning as early predictor of OP induced brain cell injury. 
Serum glucose, lactate, LDH and CPK could be used as simple tools in prediction of severity in
acute OP poisoning.
Received in original form: 14 September 2022 Accepted in final form: 31 January 2023