Variability of Loa loa microfilarial counts in successive blood smears and its potential implication in drug-related serious adverse events.

IF 3 2区医学 Q1 PARASITOLOGY

Parasites & Vectors Pub Date : 2024-11-08 DOI:10.1186/s13071-024-06494-0

Tristan M Lepage, Jérémy T Campillo, Frédéric Louya, Paul Bikita, François Missamou, Marlhand C Hemilembolo, Sébastien D S Pion, Michel Boussinesq, Cédric B Chesnais

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引用次数: 0

Abstract

Background: The standard method to diagnose Loa loa infection and quantify microfilarial density (MFD) is the microscopic examination of calibrated thick blood smears (TBSs). In 1950, it was noticed that successive L. loa MFD samples from a single capillary puncture could exhibit up to 20% variation. Although loiasis treatment allocation is based on MFD to prevent serious adverse events (SAEs), data on this variability are scarce. There are also no guidelines supporting the collection and analysis of one or two TBSs.

Methods: We assessed the variability of two successive L. loa MFD samples (MFD₁ and MFD₂), collected from 255 patients. We analyzed the influence of sex, age, weight, heart rate, arterial pressure, body temperature, and sampling time on MFD variability, as well the impact of MFD variability on MFD thresholds relevant to loiasis treatment protocols.

Results: The MFD₂ was found to have increased in 63% (1145/1826) of TBS pairs and to have decreased in 37% (681/1826) of TBS pairs. The MFD₂ were on average 28% higher than the MFD₁. These variations drove a total of 333 (17.4%) changes in MFD classes according to loiasis treatment protocol, including 210 (11.3%) class increases. TBSs generated from blood samples from subjects with lower MFD (1-1000 mf/ml) or lower mean arterial pressure (MAP; 55-80 mmHg), or from blood samples collected at an earlier hour time-point (10:00-10:59 a.m.) were more subject to MFD₂ variability in a multivariate analysis. The MFD relative change was not constant over time for a given person.

Conclusions: We observed a trend towards an increase in MFD₂ with an important variability between samples that may impact loiasis treatment allocation. We suggest that systematically sampling at least two successive TBSs might allow better MFD assessments to prevent post-treatment SAEs. Further studies are needed to verify this variability in larger samples as well as confirm the potential explanatory variables identified.

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连续血液涂片中 Loa loa 微丝蚴计数的变异性及其对药物相关严重不良事件的潜在影响。

背景：诊断 Loa loa 感染和量化微丝蚴密度（MFD）的标准方法是对校准的浓血涂片（TBS）进行显微镜检查。1950 年，人们注意到，从单个毛细血管穿刺中连续采集的 L. loa MFD 样本可显示出高达 20% 的差异。尽管为防止严重不良事件（SAE），菱形虫治疗的分配是基于 MFD，但有关这种变异性的数据却很少。目前也没有支持收集和分析一次或两次 TBS 的指南：我们评估了从 255 名患者身上连续采集的两个 L. loa MFD 样本（MFD1 和 MFD2）的变异性。我们分析了性别、年龄、体重、心率、动脉压、体温和采样时间对 MFD 变异性的影响，以及 MFD 变异性对与丝虫病治疗方案相关的 MFD 阈值的影响：结果发现，63%（1145/1826）的 TBS 对的 MFD2 上升，37%（681/1826）的 TBS 对的 MFD2 下降。MFD2 平均比 MFD1 高 28%。这些变化共导致 333 个（17.4%）MFD 等级根据丝虫病治疗方案发生变化，其中 210 个（11.3%）等级增加。在多变量分析中，MFD（1-1000 mf/ml）较低或平均动脉压（MAP；55-80 mmHg）较低的受试者的血样或在较早时间点（上午 10:00-10:59）采集的血样生成的 TBS 更受 MFD2 变化的影响。对于特定的人来说，MFD 的相对变化并非随着时间的推移而恒定不变：我们观察到 MFD2 呈上升趋势，但不同样本之间存在很大差异，这可能会影响丝虫病治疗的分配。我们建议至少连续两次系统性地采集 TBS 样本，以便更好地评估 MFD，防止治疗后 SAE 的发生。我们还需要进一步研究，以便在更大样本中验证这种变异性，并确认已确定的潜在解释变量。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Parasites & Vectors 医学-寄生虫学

CiteScore

6.30

自引率

9.40%

发文量

433

审稿时长

1.4 months

期刊介绍： Parasites & Vectors is an open access, peer-reviewed online journal dealing with the biology of parasites, parasitic diseases, intermediate hosts, vectors and vector-borne pathogens. Manuscripts published in this journal will be available to all worldwide, with no barriers to access, immediately following acceptance. However, authors retain the copyright of their material and may use it, or distribute it, as they wish. Manuscripts on all aspects of the basic and applied biology of parasites, intermediate hosts, vectors and vector-borne pathogens will be considered. In addition to the traditional and well-established areas of science in these fields, we also aim to provide a vehicle for publication of the rapidly developing resources and technology in parasite, intermediate host and vector genomics and their impacts on biological research. We are able to publish large datasets and extensive results, frequently associated with genomic and post-genomic technologies, which are not readily accommodated in traditional journals. Manuscripts addressing broader issues, for example economics, social sciences and global climate change in relation to parasites, vectors and disease control, are also welcomed.