SLIDE 1
University of Cologne Institute of Virology
University of Cologne Institute of Virology
Influence of the K103N minor variants in Influence of the K103N - - PowerPoint PPT Presentation
Influence of the K103N minor variants in Influence of the K103N - - PowerPoint PPT Presentation
University of Cologne Institute of Virology Influence of the K103N minor variants in Influence of the K103N minor variants in therapy-nave HIV-1 infected patients on therapy-nave HIV-1 infected patients on clinical outcome clinical
SLIDE 2
SLIDE 3
University of Cologne Institute of Virology
How? How?
…with a real time assay on the LightCycler 2.0 (Roche)
with Taqman- probes two different specific primerpairs
modified method after Lecossier et al. (K103N)
K103N and K103
X
amplification first primerpair: equal amplification of mutant and wt second primerpair: amplification of mutant and no amplification of wt
K103N
X
amp.
K103
X
no amp.
X
quantification of the two different products with standard plasmids
Calculation proportion of mutant (%)= (amount of mutant / general amount) x 100
SLIDE 4
University of Cologne Institute of Virology
K103N
RT
What? What?
SLIDE 5
University of Cologne Institute of Virology
K103N K103N
characteristics:
common reverse transcriptase mutation against non-nucleosidic-reverse-transcriptase inhibitors (NNRTI) for this drug class with a very low genetic barrier one mutation is sufficient to cause drug failure reported by Lecossier et al. a minority population with a K103N can get dominant under a treatment with EFV or NVP and leads to inefficacy of these drugs
SLIDE 6
University of Cologne Institute of Virology
Patients´ characteristics Patients´ characteristics
159 therapy naïve patients from the RESINA cohort 127 patients with HIV-1 subtype B, 32 non-B subtype 130 male, 29 female median time since infection: 0.25 years (range 0-18) VL 12 week after start of therapy available from 121 patients
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University of Cologne Institute of Virology
2 4 6 8 10 12 14 16 18 NRTI-mutants M41L 118 C, F, G, V 75 I, A 210 W 67 N 69 S 219 Q revertant RT 215 NNRTI-mutants 101 E 103 R 108 I 181 C 230 T
resistance associated mutations number of mutations
Population based sequencing Population based sequencing
no K103N detectable 17 patients with NRTI associated mutations (10.7 %) 10 patients with a revertant at position 215 6 patients with NNRTI mutations (3.8%)
SLIDE 8
University of Cologne Institute of Virology
K103N Minority Assay K103N Minority Assay
Minority assay with a sensitivity of 0.2 % proven shows:
159 pats 32 pats. K103N 127 pats. K103 wt
20% minority resistance
SLIDE 9
University of Cologne Institute of Virology
Minority K103N Minority K103N
Higher frequency in non B subtypes 40.6% (13/32) Frequency in B subtype 15% (19/127)
Prevalence of non-B subtypes
2 4 6 8 10 12
S u b t y p A S u b t y p C C R F _ A E C R F _ A G S u b t y p G S u b t y p D S u b t y p J C R F _ C P X
Subtypen
patients
total minority
SLIDE 10
University of Cologne Institute of Virology
Clinical outcome Clinical outcome
121 patients were treated
(38 patients no therapy or lost in follow up)
NRTI backbone
(64% AZT+ 3TC 26% TDF+ FTC 10% other)
NNRTI 66%
(80 pats.)
34%
(41 pats.)
Non NNRTI treatment
fail success
min K103N no min K103N
24% (4 pats.) 68%
(23 pats.)
21%
(17 pats.)
79%
(63 pats.)
fail success fail succ 32% (13 pats.) 76% (13 pats.) 15% (9 pats.) 85% (54 pats.)
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University of Cologne Institute of Virology
Patient nr. Proportion minority % Treatment failure 14 0.20 23 0.20 + 25 0.20 8 0.21 17 0.21 32 0.21 18 0.22 24 0.22 + 6 0.23 10 0.23 21 0.23 1 0.23 28 0.24 2 0.25 4 0.26 11 0.30 5 0.31 Patient nr. Proportion minority % Treatment failure 29 0.32 26 0.33 9 0.33 12 0.33 30 0.33 13 0.34 31 0.34 15 0.36 + 27 0.41 7 0.47 22 0.52 20 2.41 16 3.20 3 8.62 19 13.00 +
Threshold of failure? Threshold of failure?
no threshold for a minority amount and therapy failure can be found
SLIDE 12
University of Cologne Institute of Virology
Summary Summary
- verall unexpected high prevalence of K103N in therapy- naïve
patients of 20% was found Population based sequencing:
10.7 % NRTI mutations 3.8% NNRTI mutations
no patient with minority harboured another major mutation difference in resistant minority populations K103N in HIV-1 subtype B (15%) vs. non B subtype (41%) Higher therapy failure rate in NNRTI-treated patients with minority than without minority (24% vs.15%), not significant No threshold of K103N minority and therapy failure could be found
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University of Cologne Institute of Virology