Table 3.

NRTI Mutation 74V Decreases Phenotypic Susceptibility to ABC, ddL, 3TC, and d4T and Increases Phenotypic Susceptibility to ZDV and TDF

	Phenotype (FC IC50)
	NRTI						NNRTI
Genotype	ABC	ddl	3TC	d4T	TDF	ZDV	DLV	EFV	NVP	RC%
Pt 19
101E, 190S	2.6	1.7	3	2.1	1.0	3.7	0.3	240	> >	100
41L, 74V, 215Y
101E, 190S	1.6	1.0	1.7	1.6	1.3	7.9	0.2	174	> >	56
41L, 215Y
101E, 190S	5.8	2.6	> >	1.4	0.4	1.0	0.1	95	220	41
41L, 74V, 184V, 215Y
101E, 190S	3.0	1.0	> >	1.0	0.4	1.5	0.1	51	104	4.9
41L, 184V, 215Y
101E, 190S	3.3	2.0	2.5	2.9	1.2	12	0.3	282	> >	117
41L, 74V, 210W, 215Y
101E, 190S	2.0	1.0	1.7	1.6	1.5	36	0.2	192	> >	49
41L, 210W, 215Y
101E, 190S	7.8	3.1	> >	1.6	0.5	1.0	0.1	92	161	29
41L, 74V, 184V, 210W, 215Y
101E, 190S	3.6	1.0	> >	1.0	0.6	1.9	0.1	49	93	5.4
41L, 184V, 210W, 215Y
NNRTI reverteda	6.3	2.5	> >	1.7	0.3	0.7	0.1	0.1	0.1	18
41L, 74V, 184V, 210W, 215Y
NNRTI reverted	3.8	1.2	> >	1.0	0.5	1.0	0.1	0.1	0.1	30
41L, 18V, 210W, 215Y
NNRTI reverted	2.0	1.5	2.7	2.0	0.6	1.8	0.1	0.2	0.2	39
41L, 74V, 210W, 215Y
Pt 8
41L, 210W, 215Y	2.7	1.3	2.1	2.3	3.3	197	0.5	0.4	0.7	51
41L, 74V, 210W, 215Y	3.0	1.7	2.8	2.4	1.6	24	0.2	0.3	0.3
41L, 67N, 210W, 215Y	2.6	1.6	4.6	2.8	2.7	> >b	0.2	0.3	0.4
41L, 67N, 74V, 210W, 215Y	2.9	1.8	4.1	2.1	1.2	11	0.2	0.2	0.2	—c
41L, 65R, 184V, 210W, 215Y	7.9	2.4	> >	1.2	1.0	0.8	0.1	0.2	0.2	13
41L, 74V, 184V, 210W, 215Ya	6.6	2.8	> >	1.6	0.6	3.8	0.2	0.3	0.3	91
41L, 65R	2.2	1.8	12	1.5	2.6	0.8	0.9	0.6	0.6	69
41L, 74V	1.5	1.6	1.2	1.1	0.8	0.7	0.9	0.6	0.6	97

^aIndicates NNRTI resistance mutations K101E and G190S have been modified to confer wild-type amino acids at these positions.

^bIndicates maximal limit of FC detected by phenotype assay, PhenoSense.

^cReplication capacity is low and cannot be reliably measured.