Sharma Supriya, Mishra Neelima, Valecha Neena, Anvikar Anupkumar R
National Institute of Malaria Research (ICMR), New Delhi, India.
J Vector Borne Dis. 2016 Oct-Dec;53(4):341-347.
BACKGROUND & OBJECTIVES: Antimalarial drug resistance is a serious challenge to malaria control worldwide. In vitro sensitivity assays provide an early indication of emerging drug resistance. In vitro susceptibility of field and culture adapted Plasmodium falciparum isolates to different antimalarials was compared using two Methods: World Health Organization (WHO) micro-test (MARK III) and histidine rich protein II (HRP II) based enzyme- linked immunosorbent assay (ELISA).
In total, 50 P. falciparum isolates were collected from five states, viz. Chhattisgarh, Meghalaya, Mizoram, Tripura and Odisha of India during December 2011-September 2014. The isolates were revived and evaluated for their susceptibility to chloroquine (CQ), monodesethylamodiaquine (AQ), mefloquine (MQ), quinine (QN) and artemisinin (ART) using the WHO micro-test (Mark III) and HRP II ELISA. The data were analyzed using non- linear regression analysis.
The geometric mean (GM) IC50 values of different antimalarials for WHO Mark III assay were comparatively lower than HRP II ELISA assay. The GM IC50 value for CQ was 59.5 nM (95% confidence interval [CI]: 49.35-71.73 nM) and 78.34 nM (95% CI: 64.57-95.03 nM) for Mark III and HRP II ELISA, respectively. Similarly, the values of GM IC50 for AQ, MQ, QN and ART by Mark III and HRP II ELISA were 13.31, 7.07, 146.4, 0.43 nM and 22.02, 11.46, 258.7, 1.00 nM, respectively. On analyzing statistically, the results of both assays were comparable (R2 = 0.96, p < 0.001; mean log difference at IC50= 0.037).
INTERPRETATION & CONCLUSION: The HRP II ELISA assay showed a reliable sensitivity in comparison to WHO Mark III micro-test complemented with distinguishing features such as high specificity, ease of performance, and notable consistency.
抗疟药物耐药性是全球疟疾防控面临的严峻挑战。体外敏感性测定可为新出现的耐药性提供早期迹象。采用两种方法比较了野外采集及适应性培养的恶性疟原虫分离株对不同抗疟药物的体外敏感性：世界卫生组织（WHO）微量检测法（MARK III）和基于富含组氨酸蛋白II（HRP II）的酶联免疫吸附测定（ELISA）。
2011年12月至2014年9月期间，从印度的恰蒂斯加尔邦、梅加拉亚邦、米佐拉姆邦、特里普拉邦和奥里萨邦这五个邦共收集了50株恶性疟原虫分离株。使用WHO微量检测法（Mark III）和HRP II ELISA对分离株进行复苏，并评估其对氯喹（CQ）、单去乙基氨喹啉（AQ）、甲氟喹（MQ）、奎宁（QN）和青蒿素（ART）的敏感性。采用非线性回归分析对数据进行分析。
WHO Mark III检测法中不同抗疟药物的几何平均（GM）IC50值比HRP II ELISA检测法的相对较低。Mark III检测法中CQ的GM IC50值为59.5 nM（95%置信区间[CI]：49.35 - 71.73 nM），HRP II ELISA检测法中为78.34 nM（95% CI：64.57 - 95.03 nM）。同样，Mark III检测法和HRP II ELISA检测法中AQ、MQ、QN和ART的GM IC50值分别为13.31、7.07、146.4、0.43 nM和22.02、11.46、258.7、1.00 nM。经统计学分析，两种检测方法的结果具有可比性（R2 = 0.96，p < 0.001；IC50处的平均对数差异 = 0.037）。
与WHO Mark III微量检测法相比，HRP II ELISA检测法显示出可靠的敏感性，且具有高特异性、操作简便和显著一致性等突出特点。
