Tetrahydrobiopterin deficiency in human rabies

Area of Science:

• Neuroscience
• Virology
• Biochemistry

Background:

• Rabies is a fatal viral encephalitis with unclear pathological mechanisms.
• Previous research suggested rabies virus might alter neurotransmission.
• The Milwaukee protocol is an experimental rabies treatment.

Observation:

• Three rabies patients exhibited tetrahydrobiopterin (BH(4)) deficiency.
• Dopaminergic and serotoninergic neurotransmission was pathologically decreased in these patients.
• CSF levels of BH(4) and neurotransmitter metabolites increased after supplementation in two patients.

Findings:

• Rabies is associated with BH(4) deficiency, leading to reduced brain dopamine and serotonin turnover.
• Neuronal nitric oxide synthase, dependent on BH(4), may be involved in rabies pathogenesis.
• Cerebrovascular insufficiency might be a consequence of altered neurotransmission in rabies.

Implications:

• This study identifies a metabolic derangement in rabies pathogenesis.
• Findings support a novel, metabolically targeted enteral therapy for rabies.
• Further research in animal models and future patients is crucial for validation.