While HAART allows for the reconstitution of immune functions in most treated HIV patients, failure to achieve a significant increase in circulating CD4+ T cells despite undetectable viremia occurs.

A retrospective study was conducted to evaluate the treatment outcome in a subgroup of 232 patients who after 3.1 years of treatment had not achieved desirable immune reconstitution despite a good virological response to HAART.

After a further 3.6±2.4 years of HAART, 82 (35.3%) patients achieved immune reconstitution (565.2±174.6 CD4 cells/μl), while 149 (64.2%) patients did not (268.8±91.1 cells/μl); the difference in the achieved CD4 counts between these subgroups was significant (P<0.01). One patient experienced treatment failure. Eleven patients died to the end of follow-up, of which 10 with a continuously dissociated response. Factors associated with immune recovery included clinical AIDS at HAART initiation (OR: 0.4, 95% CI: 0.24–0.81, P<0.01), usage of PIs and of drugs from all three classes (OR: 1.7, 95% CI: 1.0–3.0, P=0.046 and OR: 4.5, 95% CI: 1.15–18.19, P=0.03, respectively), and a rise in CD4 count to over 200 cells/μl after the first 3.1 years of treatment (OR: 5.3 95% CI: 2.6–11.0, P<0.01). Achievement of a rise in CD4 count to over 200 cells/μl after the first 3.1 years of treatment was an independent predictor of immune reconstitution in the following period.

If patients on HAART reach CD4 cell counts of above 200 cells/μl in the first 3 years, immune recovery is possible after at least 6 years of treatment.