Characteristics of lymphocyte subsets in a normal Afro-Caribbean population and the implications in HIV management

The Caribbean relies on normal lymphocyte subsets ranges established in other geographical locations and from different racial ethnic groups for the basis of the clinical management of HIV and AIDS with Highly Active Anti Retroviral Therapy (HAART). Normal ranges of these parameters have not been previously established in an Afro-Caribbean population. So we set out to determine how the normal lymphocyte subset ranges compare to those reported in other, races and geographical locations. A prospective study was done on 112 healthy Afro-Caribbean clients who attended the Blood Collection Unit, Queen Elizabeth Hospital, Barbados from July 15th to November 12th 2004. Analysis for lymphocyte subsets was done by flow cytometry, which allows simultaneous identification and enumeration of total T Helper, cytotoxic T, natural killer and B lymphocyte cells. HIV-1, Hepatitis B and C, HTLV-1 and full blood count test were done as part of the normal screening routine of all blood donors. Absolute white blood cell counts and percentage lymphocytes for males and females were not significantly different, and the absolute and percentage of the T-Helper CD4 positive lymphocyte cells were not significantly higher in females than in males. Absolute Cytotoxic T cell CD8 positive lymphocyte cells were higher in males than in females. CD56 Natural Killer cells absolute and percentage counts were higher in males than females however CD19 B Lympocyte absolute and percentage counts were not different between the two sexes in this sample population. Compared to published normal ranges published by the WHO and CDC, there were no significantly differences observed in any of the lymphocyte subsets. These finding are very similar to what has been reported in previous studies. We conclude that WHO/CDC recommendations established for the treatment and monitoring of HIV/AIDS patients based on CD4 levels can be safely utilized in our population.