Assessment of two POC technologies for CD4 count in Morocco

Abstract

Background: In the era of "test and treat strategy", CD4 testing remains an important tool for monitoring HIVinfected individuals. Since conventional methods of CD4 count measurement are costly and cumbersome, POC CD4 counting technique are more affordable and practical for countries with limited resources. Before introducing such methods in Morocco, we decided to assess their reliability. Methods: In this study 92 blood samples from HIV-infected patients, were tested by PIMA and FACSPresto to derive CD4 count. Flow cytometry using FacsCalibur, was used as reference method for CD4 count comparison. Linear regression, Bland-Altman analysis were performed to assess correlation and agreement between these POC methods and the reference method. In addition, sensitivity and specificity, positive predictive value (PPV), negative predictive value (NPV) and misclassification percentage at 350 and 200 CD4 count thresholds; were also determined. Finally, because FACSPresto can also measure hemoglobin (Hb) concentration, 52 samples were used to compare FACSPresto against an automated hematology analyzer. Results: The coefficient of determination R 2 was 0.93 for both methods. Bland-Altman analysis displayed a mean bias of − 32.3 and − 8.1 cells/µl for PIMA and FACSPresto, respectively. Moreover, with a threshold of 350 CD4 count,

Peripheral blood lymphocyte immunophenotyping (TBNK) – a comparison of BD FACSCanto II and BD FACSLyric flow cytometry analysers

“…The results of both studies indicated the good consistency between these two analysers. It is in agreement with two separate, analogous studies by Elharti et al [23] and Sagnia et al [24] that produced the same results. However, the results obtained by Bwana et al suggest that despite the sufficient…”

“…It is in agreement with two separate, analogous studies by Elharti et al . [ 23 ] and Sagnia et al . [ 24 ] that produced the same results.…”

Assessment of POC CD4 Detecting Mode in District or County Labs — Jiangsu Province, China, 2021

“…It can ultimately help PLWH get their CD4 count test results faster and facilitate their timely initiation into or adjustment to antiviral treatment regimens (9-10). In some countries, studies have shown that adopting POC CD4 detection instruments can meaningfully improve the timeliness of initiating antiviral therapies (6,(11)(12). Timeliness plays a vital role in the care and therapeutic evaluation of HIV patients; this is especially witnessed in mobile HIV testing services (HTS) delivery, which patients are often more willing to use (11).…”

“…However, the time and frequency of detection are limited as flow cytometry techniques, which require more time, are the primary means of follow-up detection for PLWH in most areas of China (3)(4)(5). In comparison, some recent studies have shown point of care (POC) technology to positively affect timely treatment and assessment of therapeutic efficacy for HIV (6)(7).…”

A Simple Approach for Counting CD4+ T Cells Based on a Combination of Magnetic Activated Cell Sorting and Automated Cell Counting Methods

“…Additionally, at this threshold MACS-Countess had PPV and NPV of 96.3% and 85.7%, respectively. The PIMA system has either lower or similar upward misclassification values (0-10.4%) with a sensitivity of 89.6 to 100% [29,30], whereas it has a lower PPV at 91.2% and a higher NPV at 92.3% [31,32]. As the cut-off increases to 500 cells/µL, the specificity of MACS-Countess decreases to 88.9%, whereas the sensitivity remains 89.7%, which are not much different from those of PIMA, which are 95.5% and 84.2%, respectively [30].…”