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More Than an Association: Latent Toxoplasmosis Might Provoke a Local Oxidative Stress That Triggers the Development
Mohammed A Afifi1,2, Asif A Jiman-Fatani1, Mohammed W Al-Rabia1
1Department of Medical Microbiology and Parasitology, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia.
Introduction:
Toxoplasma gondii, a common parasitic infection, has a special affinity to the brain. It has a lifelong existence without an apparent clinical disease. While the etiology of bipolar disorder (BD) remains unclear, epidemiological studies suggest a role for infections. Central nervous system is particularly susceptible to oxidative stress (OS) because of its high metabolic rate and its low levels of antioxidant defenses. OS is a contributor to the initiation and progression of many neurological illnesses. OS injury is a constantly and compelling finding associated with BD and toxoplasmosis.
Aim:
This cross-sectional study has investigated a possible role of toxoplasma-induced OS in the development of BD.
Methods:
Healthy controls and BD patients were examined for anti-Toxoplasma immunoglobulin-G (IgG) and two protein (3-nitrotyrosine) and DNA (8-hydroxy-2' deoxyguanosine [8-OHdG]) OS markers.
Results:
Toxoplasma positivity was higher (40%) among BD patients compared to controls (12%). Significantly higher levels of anti-Toxoplasma IgG were detected in BD patients compared to controls. Nitrotyrosine (796.7 ± 106.28) and especially 8-OHdG (20.31 ± 8.38) were significantly higher among toxo-positive BD compared to toxo-negative BD (675.97 ± 144.19 and 7.44 ± 2.86) and healthy controls (464.02 ± 134.6 and 4.17 ± 1.43).
Conclusion:
These findings might indicate a role for Toxoplasma infection in the development of BD, possibly through creating a highly oxidative brain environment.
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