Table 1.
Comparison of genotypic predictions of HIV-1 subtype D tropism with observed phenotypes
| Genotyping tool and TTT phenotype | TTT phenotype |
Performance of the genotyping tool |
|||
|---|---|---|---|---|---|
| R5 | X4 | % Sensitivity | % Specificity | % Concordance (kappa value)a | |
| G2P 10 | |||||
| R5 | 19 | 0 | 100 | 76 | 81 (0.55) |
| X4 | 6 | 6 | |||
| G2P 5 | |||||
| R5 | 20 | 0 | 100 | 80 | 84 (0.61) |
| X4 | 5 | 6 | |||
| G2P 2.5 | |||||
| R5 | 23 | 1 | 83 | 92 | 90 (0.70) |
| X4 | 2 | 5 | |||
| Combined D rule | |||||
| R5 | 24 | 2 | 67 | 96 | 90 (0.67) |
| X4 | 1 | 4 | |||
a
The kappa coefficient was measured by using MedCalc to assess the agreement between the genotypic algorithms and the phenotypic assay. The correlation between two tests is usually considered good when the kappa coefficient is greater than 0.60.