TRYPTOPHAN CONCENTRATIONS INCREASE IN CEREBROSPINAL-FLUID AND BLOOD AFTER ZIDOVUDINE TREATMENT IN PATIENTS WITH HIV TYPE-1 INFECTION

Cerebrospinal fluid (CSF) and blood concentrations of indoleamines and catecholamines were analyzed in 14 HIV-1-seropositive individuals bef ore antiviral treatment,vith zidovudine, after 3-14 months of treatmen t, and, in 8 of the patients, also after 14-30 months. The median pret reatment concentrations of tryptophan in CSF and blood were low (224 n g/ml and 6.0 mu g/ml, respectively), but an increase in these values b y an average of 40% in CSF and 23% in blood was seen after 3-14 months of zidovudine treatment (p < 0.01) and remained undiminished after 14 -30 months of treatment. No significant change was observed in the 5-h ydroxytryptamine (5-HT, serotonin) level in blood or in the CSF concen trations of the 5-HT metabolite 5-hydroxyindoleacetic acid (5-HIAA) an d the dopamine metabolite homovanillic acid (HVA). The CSF concentrati ons of the noradrenalin metabolite 3-methoxy-4-hydroxyphenylglycol (MH PG) had decreased by 12% on average (p < 0.01) by the time of the seco nd follow-up, that is, after 14-30 months of zidovudine treatment. A d ecrease in neopterin during antiretroviral treatment correlated with a n increase in tryptophan (p < 0.01). The data suggest that an associat ion between decreased immune stimulation and reduced tryptophan degrad ation in patients treated with zidovudine.