Day N P, Pham T D, Phan T L, Dinh X S, Pham P L, Ly V C, Tran T H, Nguyen T H, Bethell D B, Nguyan H P, Tran T H, White N J
Centre for Tropical Diseases, Cho Quan Hospital, Ho Chi Minh City, Vietnam.
Blood. 1996 Dec 15;88(12):4694-700.
In tropical areas, where unsupervised use of antimalarial drugs is common, patients with an illness consistent clinically with severe malaria but with negative blood smears pose a management dilemma. Malaria pigment is evident in peripheral blood leukocytes in greater than 90% of patients with severe malaria. To characterize the clearance kinetics of parasitized erythrocytes and malaria pigment-containing leukocytes, sequential peripheral blood and intradermal smears were assessed in 27 adult Vietnamese patients with severe falciparum malaria. The clearance of parasitized erythrocytes and pigment-containing monocytes (PCMs) followed first order kinetics. The elimination of pigment-containing neutrophils (PCNs) was first order initially, but deviated from this when counts were low. Clearance of peripheral blood PCMs (median clearance time, 216 hours; range, 84 to 492 hours) was significantly slower than that of parasitized erythrocytes (median, 96 hours; range, 36 to 168 hours) or PCNs (median, 72 hours; range, 0 to 168 hours; P < .0001). Intradermal PCM clearance times were the longest of all (median, 12 days; range, 6 to 23 days; significantly longer than peripheral blood PCM clearance, P < .001). Twenty-one (88%) patients still had signs, symptoms, or laboratory features of severe malaria after parasite clearance but before phagocyte pigment clearance. Sixteen of the 23 surviving patients (70%; 95% confidence interval, 50% to 87%) still had intraleukocytic malaria pigment on peripheral blood films 72 hours after parasite clearance. Thus, by determining the distribution of malaria pigment in peripheral blood and intradermal phagocytes, the time since effective antimalarial treatment started can be estimated. Microscopy for intraleukocytic pigment is valuable in the differential diagnosis of severe febrile illnesses in malarious areas where uncontrolled use of antimalarial drugs is widespread.
在热带地区，无监督使用抗疟药物的情况很常见，临床上患有与严重疟疾相符的疾病但血涂片呈阴性的患者面临着管理难题。在超过90%的严重疟疾患者的外周血白细胞中可明显见到疟色素。为了描述被寄生红细胞和含疟色素白细胞的清除动力学，对27名患有严重恶性疟的成年越南患者进行了连续外周血和皮内涂片评估。被寄生红细胞和含色素单核细胞（PCM）的清除遵循一级动力学。含色素中性粒细胞（PCN）的清除最初是一级动力学，但在计数较低时偏离了这一规律。外周血PCM的清除（中位清除时间为216小时；范围为84至492小时）明显慢于被寄生红细胞（中位时间为96小时；范围为36至168小时）或PCN（中位时间为72小时；范围为0至168小时；P <.0001）。皮内PCM的清除时间是所有清除时间中最长的（中位时间为12天；范围为6至23天；明显长于外周血PCM的清除时间，P <.001）。21名（88%）患者在寄生虫清除后但在吞噬细胞色素清除前仍有严重疟疾的体征、症状或实验室特征。23名存活患者中的16名（70%；95%置信区间为50%至87%）在寄生虫清除72小时后外周血涂片上仍有白细胞内疟色素。因此，通过确定疟色素在外周血和皮内吞噬细胞中的分布，可以估计自有效抗疟治疗开始后的时间。在抗疟药物使用无节制的疟疾流行地区，白细胞内色素的显微镜检查在严重发热性疾病的鉴别诊断中很有价值。
