A cross-sectional study that involved secondary analysis of data collected from 681 pregnant women and 183 miners (94 men and 89 women; ratio of men to women, 1:0.95) in Jos, Nigeria, was carried out to determine the reference ranges for CD4؉ -cell counts in healthy HIV-negative adult Nigerians. The main results of interest were CD4؉ -cell counts and odds ratios (ORs) of low CD4 ؉ -cell counts, defined as below 350 cells per l.
15). The 95% confidence interval for CD4؉ -cell counts in healthy adult Nigerians is 547 to 1,327 cells per l, and this is the first time this has been determined.
CD4ϩ -cell counts, alongside other parameters, are of central importance in the monitoring of immune function. In Nigeria, although country-specific reference ranges for some hematologic measures have been determined earlier (1), CD4ϩ -cell reference values are not available from West African populations. Rather, values from textbooks and other publications based on studies in Western countries are largely employed for clinical decision making. However, there is evidence in the literature of significant geographical and racial differences in these parameters. For example, lower CD4 ϩ -cell counts have been recorded for Asians (10) than for Caucasians, and studies in African populations have shown mean CD4 ϩ -cell counts in healthy Ethiopians (16) that are markedly lower than those in Ugandans (17) and Tanzanians (11).The adult prevalence of human immunodeficiency virus (HIV) infection in Nigeria is currently estimated to be 5% (6), which translates to approximately 6 million infected persons in a country with a population of 120 million. Fortunately, both local and international efforts, especially the U.S. President's Emergency Plan for AIDS Relief and the Global Fund, have recently been directed towards the provision of antiretroviral therapy for the estimated 1.5 million AIDS cases in the country. As access to treatment increases, the need to determine local reference values for CD4 ϩ -cell counts and factors that may affect it, for accurate monitoring of responses to therapy and other treatment outcomes, becomes more urgent.This study involves secondary analysis of data obtained from two studies in collaboration with Plateau State Specialist Hospital. The objective is to describe CD4 ϩ -cell reference ranges for normal adult Nigerians, based on data obtained from 183 healthy HIV-negative adults and an additional 681 HIV-negative pregnant women.
MATERIALS AND METHODSStudy subjects. This cross-sectional study involved secondary analysis of data from two larger HIV surveillance studies aimed at determining the seroprevalence of HIV type 1 infection and the risk factors among high-risk groups in the population. Between October 2001 and April 2002, women attending the antenatal clinic at Plateau State Specialist Hospital in Jos, Nigeria, were asked to participate in the study, which involved HIV counseling, collection of basic information on HIV knowledge and behavior, and collection of biological specimens for HIV screening an...
