Table 3.
Infant drug resistance genotype and phenotype at 12 months.
| Genotype - DRMs |
Resistance level |
|||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Child | Age at blood draw (m) | Plasma viral load (HIV RNA copies per mL) | NNRTI | NRTI | PI | low | Intermediate | high | Subsequently suppressed? | Plasma ART detected |
| 1 | 36 | 17 000 | none | none | none | none | none | none | no | none |
| 15* | 9 | 15 000 | none | none | none | none | none | none | no | 3TC |
| 16 | 15 | 24 000 | none | none | none | none | none | none | no - LTFU | none |
| 17 | 6 | 410 000 | none | none | none | none | none | none | no - LTFU | none |
| 18 | 12 | 350 000 | K103N (88%) | none | none | none | none | EFV, NVP | yes | none |
| 19* | 9 | 2100 | none | M184V | none | ABC | none | 3TC | yes | LPVr, 3TC, ABC |
| 20 | 6 | 6500 | none | M184I (38%) | none | ABC | none | 3TC | yes | none |
| 21 | 9 | 520 000 | K103N (84%) | K65R (98%) M184V (97%) | none | none | none | 3TC, ABC, EFV, NVP | yes | 3TC |
| 9* | 15 | 88 000 | Y181C G190A |
M184V | none | ABC | EFV | 3TC, NVP | yes | none |
| 10 | 6 | 69 000 | K103N (98%) Y188C (16%) |
none | none | none | none | EFV, NVP | no | none |
| 22 | 6 | 7400 | K103N (87%) | none | none | none | none | EFV, NVP | yes | none |
| 23 | 15 | 6000 | none | M184I (96%) | none | ABC | none | 3TC | no | 3TC |
| 11 | 9 | 390 000 | A98G (98%) K103N (82%) |
M184V (98%) | none | ABC | none | 3TC, EFV, NVP | no | none |
| 14 | 12 | 50 000 | V106M (72%) G190A (12%) F227L (11%) |
none | none | none | EFV | NVP | no - LTFU | LPVr, 3TC, ABC |
| 24 | 12 | 330 000 | K103N (81%) | M184V (12%) | none | ABC | none | EFV, NVP ABC, 3TC | no - LTFU | none |
| 25 | 18 | 15 000 | V106M (91%) H221Y (98%) |
M184V (98%) | none | ABC | EFV | 3TC, NVP | no - LTFU | LPVr, 3TC, ABC |
HIV genotype was determined using Next-Generation Sequencing methods of a selection of infants with plasma viral load >1000 RNA copies per mL, subject to sample availability. Mutation prevalence shown in brackets. *Indicates samples that only underwent Sanger consensus sequencing. Resistance phenotypes for the ART drugs commonly used in South African children were determined from the Online Stanford Database. Plasma ART levels were quantified using high performance liquid chromatography and were considered negative if at very low levels or below the level of quantification. Median infant age was 12 months, IQR 8–15 months; median viral load 24 000 HIV RNA copies per mL. No protease inhibitor (PI) resistance mutations were found for any of the participants. NNRTI: non-nucleoside reverse transcriptase inhibitor, NRTI: nucleoside reverse transcriptase inhibitor, ABC: abacavir, 3TC: lamivudine, NVP: nevirapine, EFV: efavirenz, LPVr: ritonavir boosted lopinavir, LTFU: loss to follow-up.