Maclennan Calman A, Dzumani Felix, Namarika Alinane, Moons Peter, Senga Edward, Molyneux Malcolm E, Drayson Mark T, Bunn James E G
Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi.
Cytometry B Clin Cytom. 2008;74 Suppl 1(Suppl 1):S90-7. doi: 10.1002/cyto.b.20411.
Rapid expansion of antiretroviral therapy in Malawi has occurred in the relative absence of suitable pediatric CD4 counting facilities. We have recently validated in adults a simplified affordable flow cytometric CD4 counting method, the Blantyre count. There is a need for this technology to transfer to government laboratories run by local staff, and to be validated in children, where %CD4/lymphocyte values are required.
We assessed agreement of %CD4/lymphocyte values determined by the Blantyre count and Panleucogate methods on an EPICS XL-MCL flow cytometer on 113 venous blood samples from HIV-seropositive children in Blantyre, Malawi. All assays were performed by two Malawian laboratory technicians.
Overall bias between the two methods was -0.13% (95% CI -0.37 to 0.11) and limits of agreement were -2.69 to 2.43% (95% CI -3.11 to -2.27 and 2.01 to 2.85). Limits of agreement were within -3.00 and 3.00 for each laboratory technician. Coefficient of variation for the Blantyre count assay was 2.0% and samples showed good stability over 5 days.
The Blantyre count method can accurately determine %CD4/lymphocyte values in blood of HIV-seropositive children on an EPIC XL-MCL flow cytometer at a reagent cost of US $0.21 per test or less. The assay can be competently carried out by local laboratory technicians.
在马拉维，抗逆转录病毒疗法迅速推广，而合适的儿科CD4计数设施相对匮乏。我们最近在成人中验证了一种简化且经济实惠的流式细胞术CD4计数方法——布兰太尔计数法。需要将这项技术传授给由当地工作人员管理的政府实验室，并在需要%CD4/淋巴细胞值的儿童中进行验证。
我们在马拉维布兰太尔对113份HIV血清阳性儿童的静脉血样本，评估了用EPICS XL-MCL流式细胞仪通过布兰太尔计数法和全白细胞门控法测定的%CD4/淋巴细胞值的一致性。所有检测均由两名马拉维实验室技术人员进行。
两种方法之间的总体偏差为-0.13%（95%置信区间为-0.37至0.11），一致性界限为-2.69至2.43%（95%置信区间为-3.11至-2.27以及2.01至2.85）。每位实验室技术人员的一致性界限均在-3.00和3.00以内。布兰太尔计数法检测的变异系数为2.0%，样本在5天内显示出良好的稳定性。
布兰太尔计数法能够在EPIC XL-MCL流式细胞仪上准确测定HIV血清阳性儿童血液中的%CD4/淋巴细胞值，每次检测的试剂成本为0.21美元或更低。该检测可由当地实验室技术人员熟练完成。
