Sequential dysregulated plasma levels of angiopoietins (ANG-2 and ratios of ANG-2/ANG-1) are associated with malaria severity and mortality among hospital admitted cases in South Bastar Region of Chhattisgarh, Central India

Cerebral malaria (CM) is one of the most severe forms of P. falciparum infection, with an associated high case-fatality rate. Angiopoietins (ANG‐1 and ANG‐2) are important biomarkers of endothelial activation and dysfunction. This study was carried out in Maharani Hospital and associated Medical College, Jagdalpur, CG, Central India from 2010 to 2014. Based on the treatment recovery patterns, cases (n = 65) were classified as mild malaria with rapid recovery (MM-RR), n= 14; non-cerebral severe malaria with moderately fast recovery (NCSM‐MFR), n= 9; CM survivors with slow recovery (CMS-SR), n= 36 and deteriorated CM non-survivors (Det‐CMNS), n= 6. Plasma levels (pg/ml) of ANG-1 and ANG-2 were measured by ELISA in all the samples at the time of hospital admission and 48 hours of treatment. Levels were also measured in available samples at the third time point (time of discharge for survivors or 72 hours post-treatment in fatal cases). Data analysis was done by appropriate statistical tests using Stata 11.0 and SPSS 25.0 software. At the time of admission, ANG-2 and ratios of ANG-2/ANG-1 significantly distinguished Det‐CMNS cases from MM-RR and NCSM‐MFR cases with good AUC scores (0.8‐0.9). Further, Det-CMNS cases could also be distinguished from MM-RR, NCSM-MFR, and CMS-SR cases by ANG-2 (AUC scores 0.9) and ratios of ANG‐2/ANG-1 (AUC: 0.8‐0.9) at 48 hours of treatment. Paired analysis of sequential measurement of angiopoietins revealed that compared to admission levels, the ratios of ANG-2/ANG-1 significantly declined 48 hours after treatment in MM-RR (p= 0.041), NCSM-MFR (p= 0.050), and CMS-SR (p= 0.0002) cases but not in cases of Det-CMNS (p= 0.916). In conclusion, plasma levels of ANG-2 and ratios of ANG-2/ANG-1 may serve as good biomarkers to distinguish the malaria severity at the time of hospital admission and recovery patterns upon treatment in Central India

脑型疟疾（Cerebral malaria, CM）是恶性疟原虫（Plasmodium falciparum, P. falciparum）感染最严重的类型之一，伴随极高的病死率。血管生成素（Angiopoietins, ANG-1和ANG-2）是内皮细胞激活与功能异常的重要生物标志物。本研究于2010至2014年在印度中部恰蒂斯加尔邦贾格布尔市的玛哈瑞妮医院及其附属医学院开展。根据治疗康复模式，将65例病例分为四组：快速康复型轻度疟疾（MM-RR）14例、中速康复型非脑型重症疟疾（NCSM-MFR）9例、缓慢康复型脑型疟疾存活者（CMS-SR）36例，以及病情恶化的脑型疟疾死亡者（Det-CMNS）6例。所有受试者入院时及治疗48小时后的血浆样本均采用酶联免疫吸附试验（ELISA）检测ANG-1与ANG-2的血浆水平（单位：pg/ml）；部分存活者出院时、死亡病例治疗72小时后的剩余样本，同样完成了上述指标检测。数据分析采用Stata 11.0与SPSS 25.0软件，通过合适的统计学检验完成。入院时，ANG-2水平及ANG-2/ANG-1比值可有效区分Det-CMNS组与MM-RR、NCSM-MFR组，受试者工作特征曲线下面积（Area Under the Curve, AUC）为0.8~0.9，区分效果良好。治疗48小时时，ANG-2水平（AUC=0.9）与ANG-2/ANG-1比值（AUC=0.8~0.9）同样可有效区分Det-CMNS组与MM-RR、NCSM-MFR及CMS-SR组。对血管生成素的连续检测结果进行配对分析显示：与入院水平相比，MM-RR组（p=0.041）、NCSM-MFR组（p=0.050）及CMS-SR组（p=0.0002）患者的ANG-2/ANG-1比值在治疗48小时后显著下降，而Det-CMNS组无明显变化（p=0.916）。综上，血浆ANG-2水平及ANG-2/ANG-1比值可作为良好的生物标志物，用于区分印度中部地区疟疾的严重程度，以及评估治疗后的康复模式。