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An In Vitro Model for Measuring Immune Responses to Malaria in the Context of HIV Co-infection
Published on: October 6, 2015
Lymphocyte subsets in human immunodeficiency virus type 1-infected and uninfected children in Nairobi
J Embree1, J Bwayo, N Nagelkerke
1Department of Medical Microbiology, University of Manitoba, Winnepeg, Canada. embree@ms.umanitoba.ca
Insights
Reference lymphocyte subset values for African children differ from other populations. Perinatally HIV-1 infected infants show distinct CD4+ and CD8+ lymphocyte percentages by 3 months, aiding diagnosis.
Area of Science:
- Immunology
- Pediatrics
- Infectious Diseases
Background:
- Establishing reference lymphocyte subset values for African children is crucial.
- Existing data often lacks representation from this demographic.
- This study addresses this gap by documenting normal values and alterations in HIV-1 exposed children.
Purpose of the Study:
- To document reference lymphocyte subset values in African children.
- To analyze alterations associated with perinatal and postnatal HIV-1 transmission.
- To investigate immune responses in HIV-1 exposed but uninfected children.
Main Methods:
- Lymphocyte subsets were analyzed in HIV-1 seronegative controls and HIV-1 infected/uninfected children born to HIV-1 seropositive mothers in Kenya.
- Data was collected across various age groups from birth to 10 years.
- Statistical analysis included determining mean, median, and percentile values for CD4+ and CD8+ lymphocyte counts and percentages.
Main Results:
- African children exhibit distinct lymphocyte subset counts and percentages compared to other populations, with higher absolute counts and lower percentages than adults.
- Perinatally HIV-1 infected children showed significant differences in CD4+ and CD8+ percentages by 3 months of age.
- Differences between HIV-1 exposed uninfected and control children diminished after one year of age.
Conclusions:
- Normal lymphocyte subset values in African children differ significantly from other populations.
- Early detection of CD4+ and CD8+ lymphocyte percentage changes in perinatally infected infants can aid diagnosis.
- Transient immune variations in HIV-1 exposed uninfected infants may indicate a robust immune response.
Background:
Reference lymphocyte subset values for African children are lacking. This study documents these values as well as their alterations associated with perinatal and postnatal HIV-1 transmission and with protection from HIV-1 infection.
Methods:
Lymphocyte subsets were determined for HIV-1-seronegative nonpregnant women and their children (controls) and for uninfected, perinatally infected and postnatally infected children born to HIV-1-seropositive mothers in Nairobi, Kenya. The mean, median and 5th and 95th percentile values for CD4+ and CD8+ lymphocyte counts and percentages were determined and compared at the age ranges birth to 3 months, 4 months to 1 year, yearly from 1 to 5 years and from 6 to 10 years of age.
Results:
Among control children counts differed from published values of other populations. In all age ranges, whereas the absolute values were significantly higher than adult values, the percentages were significantly lower. Children perinatally infected with HIV-1 had clearly distinguishable differences in lymphocyte subset percentages by 3 months of age, when the median CD4+ percentage was 27.9% (5th to 95th percentile, 25.7 to 30.1%) for infected vs. 35.9% (33.3 to 38.7%) for uninfected and 39.9% (37.8 to 42.2%) for control children, P < 0.001; whereas the median CD8+ percentage was 37.0% (33.1 to 41.0%) for infected vs. 27.5% (24.2 to 30.8%) for uninfected and 27.5% (24.2 to 30.8%) for control children, P = 0.001. Differences between uninfected and control children disappeared after 1 year of age.
Conclusions:
Normal lymphocyte subset values among African children differ from those in other populations. Significant differences are detectable by 3 months of age in CD4+ and CD8+ lymphocyte percentages among perinatally infected infants, which may be useful as an adjunct in diagnosis. Transient differences observed among HIV-1-exposed but uninfected infants could reflect a successful immune response to HIV-1 challenge.

