Table 4.
Summary of studies evaluating the malaria diagnostic accuracy of the Sysmex XE-2100 analyser.
| First author, year and country | Number of participants and diagnoses | Blinding | Index test criterion | Sensitivity % | Specificity % | |
|---|---|---|---|---|---|---|
| Huh, 2008, South Korea [54] | Total: 463, P. vivax: 144 | - | >5% pseudoeosinophilia and/or an abnormal DIFF scatter-plot† | 69.4 | 100 | |
| Yoo, 2010, South Korea [55]* | Total: 1801, P. vivax: 413 | - | 46.2 | 99.7 | ||
| Campuzano-Zuluaga, 2010, Colombia [51] | Total: 158, P. falciparum: 30, P. vivax: 65, 63 febrile patients Validation control group including healthy and febrile participants: 161 |
+ | Model¶ | Variables (Figure 4) | ||
| U-ODPv‡ | 'XE-2100 P. vivax pattern' | 96.9 | 93.6 | |||
| M-ODPv** | Number of granulocyte DIFF abnormalities ≥7 pixels in the WBC/BASO(III) |
95.4 | 98.4 | |||
| N-OD1Pv | ΔDIFF/WBC Plateletcrit LYMPH-Y |
94.3 | 95.1 | |||
| N-OD2Pv | PLT-O Pixels WBC/BASO(III) |
96.8 | 96.8 | |||
| N-OD1Pf | PLT-O RDW-SD LYMPH-Y |
93 | 81 | |||
| N-OD2Pf | PLT-O RDW-SD Pixels WBC/BASO(III) |
86 | 90 | |||
* All studies use microscopy as reference test for malaria diagnosis, except Yoo and colleagues study that also use real time quantitative PCR (RT-PCR). †An abnormal DIFF scatter-plot corresponds to extra blue, red or gray-coded groups in the DIFF scatter-plot (Figure 4). ¶ All N-OD models use continuous variables and are designed to compute a predicted probability of malaria obtained from the logistic regression analyses as shown in Figure 3. ‡The recognition of a 'general XE-2100 P. vivax pattern' seen in the DIFF, WBC/BASO and RET-EXT scatter-plots corresponds to the univariate observer-dependent model [U-ODPv]. M-ODPv: The multivariate observer-depend model, by means of a 'malaria score' quantifies several abnormalities seen in the U-ODPv. **P. vivax Malaria Score: '≥7 pixels in the WBC/BASO(III)' (3 points), 'number of granulocyte-coded DIFF abnormalities' (10 variables; 1 point per variable), with ≥4 points being diagnostic. N-OD1: Non-observer dependent models that use built-in XE-2100 variables, for P. vivax (Pv) and P. falciparum (Pf). N-OD2: Non-observer dependent models that use built-in XE-2100 variables and the WBC/BASO(III) pixel count (Figure 4), for P. vivax (Pv) and P. falciparum (Pf). PLT-O: Optic platelet count. RDW-SD: Red cell distribution width SD.