Department of Immunology, National AIDS Research Institute, G-73, MIDC, Bhosari, Pune, 411 026, India.
AIDS Res Ther. 2012 Sep 21;9(1):26. doi: 10.1186/1742-6405-9-26.
In resource limited settings non-availability of CD4 count facility at the site could adversely affect the ART roll out programme. Point of care CD4 enumerating equipments can make the CD4 count available at the site of care and improve the patients' management considerably. This study is aimed at determining the utility of a Point of Care PIMA CD4 analyzer (Alere, Germany) in the field settings in India.
The blood samples were collected from 1790 participants at 21 ART centers from different parts of the country and tested using PIMA and the reference methods (FACSCalibur, FACSCount and CyFlow SL3). The paired finger prick and venous blood samples from 175 participants were tested by the PIMA CD4 Analyzer and then by FACSCalibur.
The CD4 counts obtained by PIMA CD4 analyzer showed excellent correlation with the counts obtained by the reference methods; for venous blood the Pearson's r was 0.921, p < 0.001 and the relative bias was 0.2% (range: -42 to 42%) and for finger prick samples, the Pearson's r was 0.856 and the relative bias was -9.1% (range: -46% to 27%). For CD4 ranges; <250, 251-350, 351-500 and >500 cells/mm3, the differences in the median CD4 counts obtained by the reference method and the PIMA analyzer were not significant (P > 0.05) and the relative bias were low (-7 to 5.1%). The Intermachine comparison showed variation within the acceptable limit of%CV of 10%.
In the field settings, the POC PIMA CD4 analyzer gave CD4 counts comparable to the reference methods for all CD4 ranges. The POC equipment could identify the patients eligible for ART in 91% cases. Adequate training is necessary for finger prick sample collection for optimum results. Decentralization of CD4 testing by making the CD4 counts available at primary health centers, especially in remote areas with minimum or no infrastructure would reduce the missed visits and improve adherence of the patients.
在资源有限的情况下，如果现场无法提供 CD4 计数设备，可能会对 ART 推广计划产生不利影响。即时检测 CD4 计数设备可以在护理现场提供 CD4 计数，并极大地改善患者的管理。本研究旨在确定在印度现场环境中使用即时检测 PIMA CD4 分析仪（德国 Alere）的效果。
从全国不同地区的 21 个 ART 中心采集了 1790 名参与者的血液样本，并使用 PIMA 和参考方法（FACSCalibur、FACSCount 和 CyFlow SL3）进行测试。对 175 名参与者的指尖和静脉血样本，先用 PIMA CD4 分析仪进行测试，然后再用 FACSCalibur 进行测试。
PIMA CD4 分析仪获得的 CD4 计数与参考方法获得的计数高度相关；对于静脉血，Pearson's r 为 0.921，p<0.001，相对偏差为 0.2%（范围：-42 至 42%），对于指尖血样本，Pearson's r 为 0.856，相对偏差为-9.1%（范围：-46%至 27%）。对于 CD4 范围<250、251-350、351-500 和>500 个细胞/mm3，参考方法和 PIMA 分析仪获得的中位数 CD4 计数差异无统计学意义（P>0.05），相对偏差较低（-7 至 5.1%）。仪器间比较显示，变异在 10%的可接受%CV 范围内。
在现场环境中，即时检测 PIMA CD4 分析仪提供的 CD4 计数与所有 CD4 范围的参考方法相当。即时检测设备可以识别出 91%符合 ART 条件的患者。为了获得最佳结果，需要对指尖采血进行充分的培训。通过将 CD4 计数在基层卫生中心（特别是在基础设施最少或没有的偏远地区）普及，实现 CD4 检测的去中心化，将减少漏诊，并提高患者的依从性。
