Table 2.
Major IAS Resistance Mutations Accumulated on first-line ART
| PI- low |
PI- higher |
NNRTI- low |
NNRTI- higher |
Poisson P-value* |
|
|---|---|---|---|---|---|
| Total children | 67 | 64 | 67 | 65 | |
| Number requiring tests** | 34 | 22 | 26 | 25 | |
| Number with test results | 28 | 17 | 20 | 22 | |
| Included in analysis* | 61 | 59 | 61 | 62 | |
| NRTI resistance | |||||
| 1 or 2 mutations | 11 (18%) | 7 (12%) | 12 (20%) | 12 (19%) | any difference <0.001 |
| ≥3 mutations | 0 (0%) | 1 (2%) | 0 (0%) | 7 (11%) | |
| PI or NNRTI resistance | |||||
| 1 or 2 mutations | 10 (16 %) | 4 (7%) | 13 (21%) | 12 (19%) | PI versus |
| ≥3 mutations | 0 (0%) | 0 (0%) | 1 (2%) | 5 (8%) | NNRTI <0.001 |
| ABC+3TC |
3TC+ ZDV/d4T |
Other (mainly ZDV+ddI) |
Poisson P-value* |
||
| Total children | 62 | 166 | 35 | ||
| Number requiring tests | 15 | 67 | 25 | ||
| Number with test results | 9 | 59 | 19 | ||
| Included in analysis* | 56 | 158 | 29 | ||
| NRTI resistance | |||||
| 1 or 2 mutations | 4 (7%) | 32 (20%) | 6 (21%) | any difference <0.01 |
|
| ≥3 mutations | 1 (2%) | 7 (4%) | 0 (0%) | ||
| Thymidine analogue mutations (TAMs) | |||||
| 1 or 2 TAMs | 0 (0%) | 6 (4%) | 6 (21%) | ||
| ≥3 TAMs | 0 (0%) | 4 (3%) | 0 (0%) | ||
| K65R | 1 (2%) | 0 (0%) | 0 (0%) | ||
| L74R | 1 (2%) | 1 (1%) | 0 (0%) | ||
| Y115F | 1 (2%) | 0 (0%) | 0 (0%) | ||
| M184V/I | 5 (9%) | 39 (25%) | 0 (0%) | ||
Analysis assumes those not requiring tests were not resistant, and excludes those with unavailable resistance results.
Resistance tests were required on first-line, while children were on ART, at 1) the last sample with RNA ≥1000c/ml before switch, 2) the last sample after confirmed RNA ≥1000c/ml (e.g. if not switched because ‘30000 criteria' not met and RNA re-suppressed to <1000c/ml), and 3) samples with RNA ≥1000c/ml at 4 years or trial end. IAS major resistance mutations were accumulated across multiple tests per child on first-line, where appropriate. The table displays number of children requiring tests and the number of children with test results, rather than the absolute number of tests performed.
Children are displayed in 4 groups defined by the class of ART initiated as first-line (PI-based versus NNRTI-based) and their randomized switch threshold (low=1000c/ml, higher=30000c/ml). IAS = International AIDS Society-USA, ART = antiretroviral therapy, PI = protease inhibitor, NNRTI = non-nucleoside reverse transcriptase inhibitor, NRTI = nucleoside reverse transcriptase inhibitor, ABC = abacavir, 3TC = lamivudine, ZDV = zidovudine, d4T = stavudine, ddI = didanosine