Evaluation of the Alere Pima™ for CD4+ T lymphocytes counts in HIV-positive outpatients in Southern Brazil
International Journal of STD & AIDS: Clinical practice in sexual health
Published online on March 10, 2014
Abstract
CD4 + Lymphocyte counts are routinely ordered during the early phases of antiretroviral therapy and for prophylaxis of opportunistic infections in HIV-positive patients. Flow cytometry is the standard methodology for CD4 counts in Brazilian reference laboratories. However, these laboratories are located in large cities, frequently distant from patients, thus limiting patient access and delaying results. We compared a point-of-care test with flow cytometry for CD4+ T lymphocyte counts in HIV patients. We analysed 107 consecutive samples by both methods. Overall, the point-of-care test performed well, with excellent agreement between it and the standard method. Test results were concordant for patients with CD4+ T lymphocyte values above and below 200 cells/mm 3. The performance characteristics obtained were sensitivity 94% (IC 95% 89.5–98.5%), specificity 93% (IC 95% 88.2–97.8%), positive predictive value 86% (IC 95% 79.4–92.6%), and negative predictive value 97% (IC 95% 94–100%). The high sensitivity and specificity of the point-of-care test methodology suggest its utility as an alternative method for rapid measurement of CD4+ T lymphocyte in patients with limited access to reference laboratories, enabling prompt therapeutic intervention for patients at risk of progression to AIDS.