TABLE 2.
Comparison of the isotopic and pLDH ELISA measurements for clinical isolates of P. falciparum tested against four drugs
| Drug | No. of isolates | Isotopic assay
|
pLDH ELISA
|
Pb | ||
|---|---|---|---|---|---|---|
| Geometric mean (range) IC50 (nmol/liter) | R/Sa | Geometric mean (range) IC50 (nmol/liter) | R/S | |||
| Chloroquine | 79 | 118 (20.1-465) | 49/30 | 158 (20.8-759) | 49/30 | <0.0001 |
| md-amod | 61 | 33.6 (8.5-115) | 4/57 | 39.6 (13.1-193) | 7/54 | 0.0003 |
| Lumefantrine | 42 | 10.8 (2.0-34.7) | 0/42 | 15.3 (2.3-60.3) | 0/42 | <0.0001 |
| dh-artem | 40 | 0.75 (0.25-4.1) | 0/40 | 0.97 (0.3-3.8) | 0/40 | 0.061 |
a
R/S, number of resistant isolates/number of susceptible isolates for each drug, according to the defined IC50 cutoff for chloroquine resistance (100 nM) or the estimated cutoffs of decreased susceptibility for the other drugs (see text).
b
P value of the paired t test for comparison of paired IC50s determined by the two methods.