Should absolute lymphocyte count be used as a surrogate marker for CD4+ count in patients with HIV/AIDS?

Abstract

The World Health Organization (WHO) has recommended the use of absolute lymphocyte count (ALC) as a potential marker for immunosuppression where CD4+ count is unavailable. However, there are conflicting reports on the usefulness of ALC as a surrogate marker for CD4+ counts in patients with HIV/AIDS, more so. in patients with HIV-associated tuberculosis (TB). To evaluate the usefulness of ALC as an alternative to CD4+ counts and to see whether TB affects the correlation of ALC with CD4+ counts in patients with HIV-associated TB. A total of 66 consecutive patients (33 with and 33 without TB) with a diagnosis of HIV infection were recruited into the study as cases. Another group of 66 subjects (33 subjects each) age- and sex-matched HIV-negative controls were recruited as controls and stratified in to two: a) HIV-negative PTB patients, b) apparently healthy HIV and PTB negative individuals. The age range was from 15-60 years (median: 32 years). The highest percentage (39%) of subjects fell in the age range of 25-29 years. The mean ALC for HIV-associated PTB was 3906 ± 1092 cells/µl and for patients with HIV infection only. 4755 ± 1049 cells/µl. There was no significant difference in mean ALC between males and females in both groups (P>9.05). Patients with dual infection by M. tuberculosis and HIV had the lowest mean ALC (3906 ± 1092cells/µl). Healthy controls had mean ALC (±SD) of 5249±101 cells/µl. There was significant difference between the healthy controls and the other three groups. The observed difference was more in patients with HIV/ TB co-infection (P<0.05)