Background: Baseline (BL) CD4 cell count is a major factor in outcome of highly active antiretroviral therapy (HAART); treatment induced immune recovery and viral response can modulate this outcome.
Aim: To evaluate the association between baseline CD4 cell count and outcome during the first HAART regimen.
Material and methods: Prospective study in 2,050 patients on first HAART with a follow up (f/u) ofat least 1 year. All had BL CD4 and viral load (VL) counts which were repeated at least twice a year. Patients were grouped according to BL CD4 (cells/mm(3)) in <100 (Gl), 100-199 (G2) and > or = (G3). Groups were further divided according to immune and virological response at 1 year in CD4 > or < 200 and VL detectable or undetectable (<80 copies/mL). Outcome measures were death, ALUS defining events (ADE) and, as a surrogate marker of immune recovery reaction, herpes zoster (HZ).
Results: During the first year of follow up, 113 patients (10.8%) died in Gl (n =1,044), 17 (2.5%) in G2 (n =675) (Gl-2 p <0.05) and 9 (2.7%) in G3 (n =331) (G2-3 p NS). One hundred twenty five of 919 (13.6%) patients alive at 1 year had ADE in Gl, 55/643 (8.5%) in G2 (p <0.05) and 20/320 (5.2%) in G3 (G2-3 p NS). ADEs with follow up CD4 >vs< 200 were: 25/274 (9.1%) vs 100/643 (15 7%) in Gl (p <0.005); 28/404 (6.9%) vs 27/235 (11.2%) in G2 (p NS) and 18/281 (6.4%) vs 2/41 (4.8%) in G3 respectively (p NS). Detectable VL was an additional risk for ADE only in Gl without CD4 recovery. HZ was seen in 6.6% of Gl vs 4% in G2 (p <0.05) and 4.3% in G3. HZ rate was higher in all groups reaching a follow up CD4 >200 than those who did not, with a statistically significant difference at p <0.05 only in Gl (9.5% vs 5.3%).
Conclusions: The occurrence of death and ADE during the first year of HAART was significantly higher in patients with aBL CD4 <100, but no statistically significant difference was observed from BL CD4 >100 upwards. Immune recovery during f/u in the more immunosuppressed group greatly improved the outcome. The group with lowest BL CD4 and greater immune recovery showed the highest rate of immune recovery reaction.