AEGiS-15IAC: Total lymphocyte count as an age-dependent surrogate for CD4 lymphocyte count in HIV-infected children 12 years of a age and younger.

15th International AIDS Conference

Bangkok, Thailand - July 11-16, 2004

Total lymphocyte count as an age-dependent surrogate for CD4 lymphocyte count in HIV-infected children 12 years of a age and younger.

Int Conf AIDS 2004 Jul 11-16; 15:(abstract no. TuOrB1150)

Fisher KA, Weiner J, Farley J, Nesheim S, Palumbo P, Bulterys M, Abrams EJ
Columbia Univrersity, New York City, United States

BACKGROUND: Current WHO guidelines suggest consideration of total lymphocyte count (TLC) as a substitute for CD4 lymphocyte count in resource-limited settings. In adults, investigators recently proposed a clinical algorithm combining TLC and hemoglobin (Hg). The age-dependent relationships between TLC, Hb, and CD4 have not been carefully examined in children.

METHODS: Data from the PACTS-HOPE cohort of 363 perinatally HIV-infected children followed from birth in 4 cities in the United States (US) were used to develop TLC and Hg levels predictive of age-adjusted severe immunosuppression according to CDC immunologic criteria (<12 months<750 cells/muL, 1-5 years<500 cells/muL, 6-12 years<200 cells/muL). Overall accuracy in predicting CD4 and CD4% was measured by Receiver Operating Characteristic (ROC) area under the curve (AUC) values. AUC values were generated for a range of TLC to select the optimal level for predicting immunosuppression: TLC with the highest AUC and positive predictive value were selected.

RESULTS: The optimal TLC level for each age group was determined to be:< 1 year, 3500 cells/muL; 1-5 years, 2500 cells/muL; and 6-12 years, 1200 cells/muL. When Hg<10g/dl was added into the model, TLC/Hg levels were more effective in predicting CD4 levels. TLC/Hg as a predictor varied by gender and prior diagnosis of a Class C category illness, but was unaffected by year of birth. TLC/Hg was not effective in predicting CD4%. Lower TLC levels than those selected in the Table increased positive predictive values but decreased sensitivity. [table: see text]

CONCLUSIONS: Total lymphocyte count, combined with hemoglobin level, appears to be useful as an inexpensive and simple alternative to CD4 lymphocyte count predicting advanced immunosuppression in HIV-infected children.

Keywords: AEGIS, CD4 Lymphocyte Count, HIV, Acquired Immunodeficiency Syndrome, HIV Seropositivity, Lymphocyte Count, HIV Infections, Antigens, CD4, Anti-HIV Agents, HIV Protease Inhibitors, Sensitivity and Specificity, United States, Child, Aged, Humans, Adult, immunology

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TuOrB1150