TABLE 1.

Mutations in HIV-1 RT at codons associated with drug resistance in subjects interrupting RTI therapy, as assessed by population sequencing of plasma viruses

Subject or isolate	Treatment interrupted	Treatment continued	No. of weeks post-PTIa	Codonb
				41	62	67	69	70	103	118	181	184	190	210	215	219
Clade B consensus				M	A	D	T	K	K	V	Y	M	G	L	T	K
3005	ZDV/3TC	IDV/RTV	0	L	-	N	D	-	-	-	-	V	-	W	Y	-
			34	M/L	-	N	D	-	-	V/I	-	M/V	-	L/W	Y	-
			36	M	-	N	D	-	-	V/I	-	M/V	-	L/W	Y	-
			48	-	-	N	D	-	-	V/I	-	-	-	L/W	D/N/Y	-
3040	d4T/3TC	LPV/RTV	0	-	-	N	T/A	R	-	-	Y/C	V	-	-	T/S	Q
			12	-	-	N	T	R	-	-	-	V	-	-	-	Q
			16	-	-	N	-	R	-	-	-	V	-	-	-	Q
			22	-	-	N	-	R	-	-	-	M/V	-	-	-	Q
			24	-	-	N	-	R	-	-	-	M/V	-	-	-	Q
			36	-	-	N	-	R	-	-	-	-	-	-	-	Q
3057	d4T/3TC	IDV	0	L	V	-	T/A	K/R	-	-	-	V	-	-	-	K/Q
			7	L	V	-	-	-	-	-	-	V	-	-	-
			36	L	V	-	-	-	-	-	-	-	-	-	-	-
			48	L	V	-	-	-	-	-	-	-	-	-	-	-
3151	DDI/d4T/3TC/EFV	APV/RTV	0	L	-	N	D	R	-	I	C	V	S	W	F	Q
			16	L	-	N	D	R	-	I	C	V	S	L/W	F	Q
3167	ZDV/3TC	NFV	0	-	-	-	-	-	-	-	-	V	-	-	-	-
			4	-	-	-	-	-	-	-	-	V	-	-	-	-
			8	-	-	-	-	-	-	-	-	V	-	-	-	-
			12	-	-	-	-	-	-	-	-	M/V	-	-	-	-
3158	d4T/3TC	None	0	-	-	N	-	R	-	-	-	V	-	-	-	Q
			5	-	-	N	-	R	-	-	-	V	-	-	-	Q
			12	-	-	N	-	R	-	-	-	M/V	-	-	-	Q
			16	-	-	N	-	R	-	-	-	M/V	-	-	-	Q

^aPTI, partial treatment interruption.

^bAmino acid residues are indicated by single-letter abbreviations. The HIV-1 clade B consensus sequence is shown for comparison. Dashes indicate identity with the consensus sequence. ZDV, zidovudine; ddI, didanosine; EFV, efavirenz; IDV, indinavir; RTV, ritonavir; SQV, saquinavir; APV, amprenavir.