Neopterin Production, Degradation of Tryptophan and Neurologic Impairment in Human Immunodeficiency Virus Infection

Immune activation and neuropsychiatric symptoms in human immunodeficiency virus type 1 infection

“…72 Interestingly, neopterin concentrations in serum have been found to correlate significantly with brain tissue loss, as reflected by the ventricle brain ratio, according to computed tomography results. 16 Similar observations were made when brain tissue loss was compared with quinolinic acid concentrations in the CSF. 44 Higher serum neopterin concentrations also correlated inversely with the cognitive performance of patients as determined by scores on the Structured Interview for the Diagnosis of Alzheimer Dementia and dementia of other etiology.…”

“…44 Higher serum neopterin concentrations also correlated inversely with the cognitive performance of patients as determined by scores on the Structured Interview for the Diagnosis of Alzheimer Dementia and dementia of other etiology. 16 All these findings indicate that immune activation and immune activation-induced biochemical alterations are involved in the precipitation of neuropsychiatric symptoms in patients infected with HIV-1. However, immune activation and inflammatory responses may not only be involved in irreversible loss of brain tissue, but may also cause metabolic disturbances, the reversibility of which is more likely when, eg, HAART is successfully administered.…”

“…However, neopterin concentrations in serum are more closely related to the extent of brain lesions and the cognitive impairment than CSF levels, as determined by the Structured Interview for the Diagnosis of Alzheimer Dementia score. 16 From such data, it appears that systemic chronic immune stimulation in HIV-1 infection plays a greater role in neurological damage than local CNS phenomena. A more relevant role of systemic metabolic disturbances on the origin of HIV-1-associated neurological impairment might exist, which is probably in addition to local effects of HIV-1 on brain tissue.…”

“…[13][14][15] In patients with HIV-1 infection, signs of immune activation were found to relate to neuropsychiatric disturbances. 16 Higher neopterin concentrations in cerebrospinal fluid (CSF) were found in HIV-infected patients with neurological/psychiatric symptoms in comparison with patients without neurological/psychiatric symptoms. 17 In addition to other parameters, like immune-mediated catabolism of the essential amino acid tryptophan, which may impair the synthesis of abnormal neurotransmitters like 5-hydroxytryptamine (serotonin), dopamine and/or noradrenaline metabolism might influence quality of life in HIV-patients.…”