Table 3.

Elevated plasma Trx is associated with impaired survival

Variable†	Survival* (subjects with CD4 T cell counts below 200/μl blood)
	0–400 days		0–800 days
	P	Relative risk of dying‡	P	Relative risk of dying
Elevated plasma Trx (>30 ng/ml)	0.0001	2.7 (1.6–5.2)	0.0002	2.2 (1.4–3.3)
NAC treated§	0.0004	0.3 (0.06–0.6)	0.002	0.5 (0.3–0.8)
CD4 T cell GSH (FACS GSB)¶	0.04	0.1 (0.02–0.9)	0.01	0.1 (0.02–0.6)
CD4 T cell count (/μl blood)	0.3	NS	0.005	0.8 (0.7–0.9)

^*Survival analysis (proportional hazard) computed from baseline until the indicated time. Whole model fit, P < 0.0001; χ² = 32 and 33 for 400 and 800 days, respectively. The model is computed on the basis of a total of 64 subjects, with 38 subjects in the group with <30 ng/ml and 26 subjects in the group with ≥30 ng/ml. None of the other variables listed in Table 1 showed significant effects. Reverse transcriptase inhibitor usage was similar for subjects in all groups and did not show a significant effect on survival when entered as a covariate in the above model. Since protease inhibitors were introduced after the end of the monitoring period, none of the subjects received protease inhibitors during the observation period shown here. 

^† Baseline values representing the average of 2–3 measurements taken within 1 month for each subject. CD4 T cell counts and CD4 T cell GSH levels were entered into the model as continuous variables; plasma Trx and NAC treatment were entered as categorical variables. 

^‡ Relative risk of dying (risk ratio); 95% confidence interval is shown in parentheses. Risk ratios shown for CD4 T cells are computed per increase in 20 T cells/μl blood. 

^§ Twenty-two of 64 subjects in this study were treated with NAC during the 8-week placebo-controlled and/or the 6-month open-label segments of the NAC trial. Among the subjects not treated with NAC (n = 42), 8 were in the placebo trial arm and did not elect open label NAC, 34 were screened for trial entry but either entered and rapidly withdrew (n = 3) or did not enter. Only 6/31 subjects in this latter No-NAC group were refused trial entry for medical cause, i.e., because they had protocol-defined exclusions such as elevated liver enzymes or hematologic deficiencies. We include these 6 subjects in data reported in the table. There was very little difference in the values obtained when significance and other table entries were computed with these 6 subjects excluded. 

^¶ B cell GSB was significant at the 0.04 level at 400 days and not significant at 800 days.