Clinical applications and availability of CD4+ T cell count testing in sub-Saharan Africa

Abstract

The absolute CD41 T cell count in adults and CD41 T cell percentage of lymphocytes (CD4%) in pediatrics compliment clinical history and physical examination to inform decisions about initiating antiretroviral therapy (ART). In addition, these immunologic markers predict host susceptibility to specific opportunistic infections, selected drug toxicities, and mortality. These benefits argue strongly for the availability of CD41 T cell testing capacity in all settings where HIV infection is treated. Several currently available flow cytometry-based devices, and novel CD41 T cell enumeration techniques such as the panleucogating CD4 are especially suitable for resource-constrained settings.At this time, unfortunately, the landscape of HIV care in sub-Saharan Africa is a mosaic characterized by large areas where CD41 T cell testing capacity is limited or unavailable, and small, but growing, pockets where the capacity exists. Routine HIV quantification is currently unaffordable and unsustainable in the great majority of the region; therefore, a reliance on CD41 T cell testing is inevitable for now. To this end, correcting the disparities in CD41 T cell testing capacity and defining the minimum laboratory requirements for the safe use of antiretroviral drugs through well-designed clinical studies are some of the most urgent priorities of the ongoing global scale-up of ART. q 2007 Clinical Cytometry Society

Evaluating Total Lymphocyte Counts and Other Hematological Parameters as a Substitute for CD4 Counts in the Management of HIV Patients in Northeastern Nigeria

“…Thus, a person with a low CD4 T cell count may show relatively high TLC if high amounts of B cells are expressed due to immune hyperactivation from exposure to the wide variety of circulating antigens consequent on varieties opportunistic infections in HIV patients with severe immunosuppression. 4 Our previous study indicated that most HIV patients in our setting present late with a varieties of opportunistic infections. 19 We observed good correlation between TLC and CD4 count using the Spearman's rank test (r = 0.632) in HAART-experienced and r = 0.494 in HAARTnaïve cohorts, similar to the value of 0.431 reported by Akinola.…”

“…Indeed, local resources for health care are already overstretched by HIV/AIDS and overlapping high-impact endemic diseases such as malaria, tuberculosis, and infant diarrheal illnesses. 4 Against this background, the World Health Organization (WHO) recommended the use of total lymphocyte count of less than 1.0-1.2 × 10 3 /µL in individuals with stage II or III disease as an indication to initiate antiretroviral therapy in the absence of knowing the CD4 count. 5 This recommendation was exclusively derived from studies conducted in developed countries.…”

Head to head comparisons in performance of CD4 point-of-care assays: a Bayesian meta-analysis (2000–2013)

“…CD4+ cells counts and measures of VL are surrogate biomarkers of disease progression that help to stage, initiate and monitor treatment. CD4+ cell counts provide an immunological measure of HIV progression; these counts are utilized in the care of HIV+ patients for staging infections and in assessing patients for ART eligibility [5][6][7][8]. Specialized laboratories use highly trained personnel and sophisticated flow cytometry techniques to perform CD4+ cell counts, as this is the current gold standard technique [6,9].…”

“…CD4+ cell counts provide an immunological measure of HIV progression; these counts are utilized in the care of HIV+ patients for staging infections and in assessing patients for ART eligibility [5][6][7][8]. Specialized laboratories use highly trained personnel and sophisticated flow cytometry techniques to perform CD4+ cell counts, as this is the current gold standard technique [6,9]. When ART is available, rapid staging, continual monitoring, and retention of individuals on ART become crucial to controlling HIV infection, but the availability of quality patient monitoring in all field settings remains a challenge [10].…”

Cyto 2011—Overview of the XXVI ISAC Congress Proceedings Issue of Cytometry

“…It is widely recognized that patient care in subSaharan Africa operates under conditions where HIV quantification is frequently unsustainable for the great majority of those affected in the region resulting in a focus on CD41 T cell testing (13). In this issue, the paper by Marinucci et al reports on the experience of decentralization of CD4 testing in resource limited settings-relating 7 years of experience in six African countries.…”