Background: The automatic hematology analyzer XN-30 (Sysmex Corporation) leverages the flow cytometry technology, and it can count and calculate MI-RBC# and MI-RBC%. MI-RBC# represents the number of red blood cells containing nucleic acids such as malaria parasite, and MI-RBC% represents the ratio of them. These results can be reported in about 1 minute. Furthermore, XN-30 simultaneously provides the reference information to distinguish P. falciparum or other malaria species.
Aim: Clarify the analytical performance of XN-30.
Methods: The following tests were conducted: The repeatability test, the examination of Limit of blank (LoB), limit of detection (LoD), and limit of quantitation (LoQ) and the correlation test (vs microscopy) .Each examination was carried out by using cultured malaria. After preparation of specimen, XN-30 measurement was performed using 3 analysis modes, which are the Whole Blood mode (WB mode), the Pre Dilution mode (PD mode) and the Low Malaria mode (LM mode). The LM mode is high-sensitive mode which provides an accurate MI-RBC# value suitable for analyzing low parasitemia (%) samples. The PD mode is used for analyzing the small amount of whole blood.
Results: The calculated repeatability of MI-RBC# was 10.2% in the LM mode (N=10). LoB, LoD, and LoQ of the analyzer were calculated, and the results of each limit was 4/μL, 11/μL, 20/μL respectively in the LM mode. Correlation coefficient between MI-RBC% obtained through XN-30 measurement and parasitemia (%) obtained through microscopy was calculated at R =0.9918.
Conclusions: XN-30 has demonstrated high-repeatability, high-sensitivity and high-correlation with microscopy, owing to its automated mechanism.