CD4+ T-lymphocyte count/CD8+ T-lymphocyte count ratio: surrogate for HIV infection in infants?
BACKGROUND
Early diagnosis and treatment is necessary to prevent HIV-infected infants progressing to AIDS. Antibody testing is not confirmatory before the age of 18 months and PCR not widely available in resource-poor settings. We studied the accuracy of CD4(+) T-lymphocyte count, CD4% and CD4/CD8 ratio as surrogate markers of infant HIV infection.


METHODS
Two hundred and fifty-eight HIV-exposed Indian infants at a median age of 5 months (range 1-18) had DNA PCR and CD4, CD8 counts performed.


RESULTS
Fifty five infants tested positive by HIV-1 DNA PCR whereas 203 were negative. Median CD4 count, CD4% and CD4/CD8 ratio were significantly lower in DNA PCR+ infants. Overall sensitivity and specificity of CD4/CD8 ratio <1.0 in predicting HIV was 91 and 92% with a negative predicted value (NPV) and positive predicted value (PPV) of 97 and 76%, respectively.


CONCLUSIONS
CD4/CD8 ratio <1.0 is a more sensitive surrogate marker of HIV infection in Indian infants than a CD4 count <1500 cells/µl or CD4% <25%.
National Institute for Research in Tuberculosis, Indian Council of Medical Research, Chennai, India.
Poorana Ganga Devi
PG
Navaneethapandian
Ramesh
R
Karunaianantham
Sudha
S
Subramanyan
Ponnuraja
P
Chinnayan
Padmapriyadarsini
P
Chandrasekaran
Soumya
S
Swaminathan
D019380:Anti-HIV Agents / Q000627:therapeutic use; D015415:Biomarkers / Q000097:blood; D016516:CD4-CD8 Ratio; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D015658:HIV Infections / Q000097:blood / Q000175:diagnosis / Q000276:immunology* / Q000821:virology; D015497:HIV-1; D006801:Humans; D007194:India; D007223:Infant; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical; D018655:Lymphocyte Count; D008297:Male; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D017678:Sex Distribution
D019380:Anti-HIV Agents; D015415:Biomarkers