An automated haematology analyzer XN-30 distinguishes developmental stages of falciparum malaria parasite cultured in vitro

• Main Authors: Takahiro Tougan, Yuhgi Suzuki, Sawako Itagaki, Munehisa Izuka, Yuji Toya, Kinya Uchihashi, Toshihiro Horii
• Format: Article
• Language: English
• Published: BMC 2018-02-01
• Series: Malaria Journal
• Subjects: Plasmodium falciparum; in vitro culture; Blood stage; Flow cytometry; XN-30 analyzer
• Online Access: http://link.springer.com/article/10.1186/s12936-018-2208-6

Abstract Background The automated haematology analyzer XN-30 (Sysmex, Kobe, Japan) easily and rapidly detects malarial parasites in clinical blood samples using flow cytometry. The XN-30 analyzer is able to distinguish each developmental stage by measuring DNA content and cell size. Thus, it was expected to be capable of quantifying the developmental stages of cultured falciparum parasite. To achieve this requirement, a modified algorithm was tested for its validity and reliability using in vitro cultured falciparum parasite. Results The XN-30 analyzer automatically measured each developmental stage as well as total parasitaemia. Comparison of the parasitaemia obtained using the XN-30 analyzer equipped with the modified algorithm with that obtained using microscopy examination of Giemsa-stained smears revealed the greater sensitivity and reproducibility of the former. The XN-30 analyzer also detected free merozoites and purified gametocytes. Conclusions The XN-30 analyzer allows the precise recognition and enumeration of total and each developmental stages of cultured falciparum parasites, and permits the sensitive and reproducible calculation of parasitaemia. The results indicate the potential of the XN-30 analyzer for basic research on malarial biology, anti-malarial drug discovery, and evaluation of drug efficacy.