Table 5.
NRTI Resistance Mutations and Estimated NRTI Resistance Levels
| SID | Sanger and NGS | Sanger alone | NGS alone | Sanger score → NGS score |
|||
|---|---|---|---|---|---|---|---|
| FTC/3TC | ABC | AZT | TDF | ||||
| Samples for which NGS reported higher levels of drug resistance for one or more NRTIs | |||||||
| 30_PR,RT | K65KE (10.5%) | 1 | 1 → 2 | 1 | 1 → 2 | ||
| 34_PR,RT | M41L (99.2%), D67N (90.9%), M184MV (50.1%), L210W (96.9%), T215Y (96.2%) | 1 → 5 | 1 → 5 | 1 → 5 | 1 → 4 | ||
| 104_PR,RT | D67DN (7.8%) | 1 | 1 | 1 → 3 | 1 | ||
| 111_PR,RT | T215TS (5.6%) | 1 | 1 | 1 → 3 | 1 | ||
| 154_PR,RT | M41ML | M184MV (6.8%) | 1 → 5 | 1 → 3 | 3 → 1 | 1 | |
| 183_PR,RT | K65KE (4.4%) | 1 | 1 → 2 | 1 | 1 → 2 | ||
| 184_PR,RT | L210LW (6.8%) | 1 | 1 | 1 → 3 | 1 | ||
| 254_PR,RT | D67DN (5.4%) | 1 | 1 | 1 → 3 | 1 | ||
| Samples for which Sanger reported higher levels of drug resistance for one or more NRTIs | |||||||
| 31_PR,RT | K219KR | 1 | 1 | 2 → 1 | 1 | ||
| 50_PR,RT | T215TA | 1 | 1 | 3 → 1 | 1 | ||
| 88_PR,RT | T215TILP | 1 | 1 | 3 → 1 | 1 | ||
| 121_PR,RT | T215TADN | 1 | 1 | 3 → 1 | 1 | ||
| 154_PR,RT | M41ML | M184MV (6.8%) | 1 → 5 | 1 → 3 | 3 → 1 | 1 | |
| Samples for which Sanger or NGS detected different DRMs, but for which levels of NRTI resistance were the same | |||||||
| 83_PR,RT | M41ML | T69D | T69DN (86.1%; 10.6%) | 1 | 2 | 4 | 2 |
| 103_PR,RT | M184V | D67DN (5.0%) | 5 | 3 | 1 | 1 | |
| 105_PR,RT | A62AV (5.9%) | 1 | 1 | 1 | 1 | ||
| 123_PR,RT | M41L,T215E | K65KE (3.4%) | 1 | 3 | 4 | 3 | |
| 157_PR,RT | M184IV | M184I (99.3%) | 5 | 3 | 2 | 1 | |
| 214_PR,RT | M184I | K70Q | K70NQ (27.2%; 70.1%) | 5 | 4 | 1 | 3 |
| 281_PR,RT | M184V | M184IV (4.3%; 91.4%) | 5 | 3 | 1 | 1 | |
Predicted levels of drug resistance according to the HIVdb genotypic resistance interpretation system: susceptible, 1; potential low-level resistance, 2; low-level resistance, 3; intermediate resistance, 4; high-level resistance, 5. Percent mixtures are shown in parentheses. All samples listed in this table are subtype B.
ABC, abacavir; AZT, azidothymidine; DRM, drug resistance mutation; FTC/3TC, emtricitabine/lamivudine; NGS, next-generation sequencing; NRTI, nucleoside reverse transcriptase inhibitor; PR, protease; RT, reverse transcriptase; SID, sample ID; TDF, tenofovir.