Page 250 - HIVMED_v21_i1.indb

Page 3 of 4 Scientific Letter

recommended 1-week tail of TDF/FTC after cessation of EFV sequenced, 37 (95%) had HIV-1 RNA < 40 copies/mL in the
and 42 (57%) stopped all treatment at once. Of 70 women with sample being tested.
viral load results at enrolment into the Mpepu study, 58 (83%)
had HIV-1 RNA < 40 copies/mL. At 4–6 weeks Discussion
post-EFV/FTC/TDF cessation, 44 (62%) of 71 women with A small proportion of women stopping EFV/FTC/TDF had
viral load result had HIV-1 RNA < 40 copies/mL. Thirty-three a major NNRTI resistance mutation detected in plasma taken
(47%) women had HIV-1 RNA < 40 copies/mL at delivery and
at the time of sample draw for genotyping (post-ARV cessation). a little more than a month after stopping treatment. Among
women receiving a 7-day tail of TDF/FTC after stopping EFV
where genetic resistance testing was able to be performed,
Mutations
none had detectable mutations. Our findings thus support
Thirty-five (47%) of 74 samples were successfully sequenced, the recommended staggered discontinuation of antiretrovirals
with 4 (11%) of 35 having a major drug resistance mutation: when an EFV/FTC/TDF regimen is being stopped. Our data
2 with K103N and 2 with V106M (Table 1). All four resistance support prior studies that evaluated the use of an NRTI tail
mutations occurred among women who did not receive when discontinuing EFV-based ART.
a TDF/FTC tail (4/42, 10%), whereas no mutations occurred
among 18 genotyped women who had received a TDF/FTC Our observation of prolonged viral suppression < 40
tail (p = 0.053). Eighteen (58%) of the 31 women who copies/mL for a median of 5 weeks in 62% of women post-
had a genotype result and no drug resistance mutation ART cessation was similar to findings from other studies
took a TDF/FTC tail. Of 39 samples that could not be which have demonstrated that it is not unusual for viral

TABLE 1: Characteristics of women with successful sequencing post-antiretroviral treatment cessation.
Age (years) Prior use of ART Prior use of ART Received Duration of ART Nadir CD4 Baseline Post ART cessation Mutation
for own health for PMTCT TDF/FTC tail use (weeks) (cell/UI) VL (copies/mL) VL (copies/mL)
27 No Yes Yes 31.6 518 < 40 42 166 E138A
27 No No Yes 38.4 570 < 40 < 40 E138A
23 No No Yes 40.7 710 < 40 13 120 K103N
25 No No Yes 10.1 572 < 40 1719 K103N
35 No No No 54.5 772 < 40 18 259 None
40 No Yes Yes 31.2 442 < 40 2658 None
36 No Yes No 20.4 963 < 40 < 40 None
25 No No No 20.2 611 < 40 857 None
35 No No No 11.4 430 < 40 - None
25 No No Yes 15.8 575 < 40 33 906 None
24 No No Yes 25.2 496 < 40 5688 None
26 No Yes No 25.6 460 < 40 2342 None
27 No Yes Yes 14.0 908 < 40 1805 None
29 No No Yes 23.1 436 58 379 None
42 No No Yes 27.8 533 < 40 < 40 None
40 No No No 13.5 361 52 250 None
33 Yes No Yes 10.8 796 < 40 < 40 None
30 No No No 21.1 616 - 9764 None
26 No No No 24.9 1037 < 40 554 None
27 No No Yes 16.1 601 < 40 3648 None
40 No No Yes 24.6 363 < 40 33 432 None
27 No No No 81.6 673 < 40 196 735 None
24 No No Yes 39.2 800 < 40 < 40 None
31 Yes No No 36.7 1236 < 40 - None
31 No Yes Yes 11.0 589 125 < 40 None
29 No No No 18.5 715 < 40 2261 None
26 No Yes No 96.2 612 <40 < 40 None
41 No No No 82.1 840 - 2229 None
35 No Yes No 45.8 960 < 40 4536 None
40 No Yes No 26.8 679 < 40 972 None
28 No No No 21.9 436 < 40 40 709 None
26 No No No 23.2 397 < 40 309 None
24 No No No 26.5 468 52 < 40 None
20 No No Yes 22.4 384 45 68† V106M
33 No Yes‡ Yes 23.8 468 < 40 145 392 V106M
ART, antiretroviral treatment; FTC, emtricitabine; TDF, tenofovir disoproxil fumarate; VL, viral load.
†, Genotypes were performed independent of the knowledge of the participants’ viral load; therefore, verification of the viral load on individual plasma sample was not performed.
‡, Previous exposure to zidovudine for prevention of mother-to-child transmission (PMTCT).

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