Minor variants in HIV-1 Minor variants in HIV-1 Why? Why? - - PowerPoint PPT Presentation

▶

Oct 29, 2023 184 likes •348 views

University of Cologne Institute of Virology Minor variants in HIV-1 Minor variants in HIV-1 Why? Why? University of Cologne Institute of Virology with the method of direct sequencing only virus populations 20% can be detected. it

SLIDE 1

University of Cologne Institute of Virology

Minor variants in HIV-1 Minor variants in HIV-1

SLIDE 2

University of Cologne Institute of Virology

Why? Why?

…with the method of direct sequencing only virus populations ≥ 20% can be detected. …it is important to detect mutations as soon as possible to avoid early virological failure … to know more about the evolution of viral strains under changing drug conditions (e.g treatment interruption or transmitted resistance). ….in drug classes with a low genetic barrier such as NNRTIs one mutation (e.g K103N) is enough for drug failure.

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) and Hance et al. (V82A)

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

What? What?

V82A

RT PR

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

K103N K103N

patients collective:

163 therapy naïve patients from the RESINA cohort 127 patients with HIV-1 subtype B 26 patients with HIV-1 non-B subtype Characteristics population based sequencing: no K103N detectable 11 patients with NRTI associated mutations (6,7%) 8 patients with a revertant at position 215 2 patients with NNRTI mutations (1,2%)

SLIDE 7

University of Cologne Institute of Virology

Results K103N Results K103N

Minority assay with a sensitivity of 0,2% proven shows:

163 pats 34 pats. K103N 129 pats. K103 wt

21% minority resistance

SLIDE 8

University of Cologne Institute of Virology

Results K103N Results K103N

Overall unexpected high prevalence of K103N in therapy- naïve patients Difference in HIV-1 subtypes? subtype B: 16% vs subtype non Bs: 40% Is this resistant minority relevant for the first line treatment? No data at the moment-further analysis could show this

SLIDE 9

University of Cologne Institute of Virology

V82A V82A

characteristics: protease mutation in combination with other protease mutations resistance associated for the following protease inhibitors: Indinavir (IDV), Lopinavir (LPV), Atazanavir (ATV)

SLIDE 10

University of Cologne Institute of Virology

V82A V82A

8. International Congress on Drug Therapy in HIV Infection, 12-16

November 2006 Glasgow,UK

Characteristics: african male newly diagnosed with HIV-1 first-line treatment: AZT, 3TC and LPV/r failed this therapy with a VL of 18724 copies/ml

WHY?

SLIDE 11

University of Cologne Institute of Virology

V82A V82A

3 samples available:

sample 1 :before therapy; date 04.04.03 sample 2 : short after starting therapy (VL 217 copies/ml); date 01.03.04 sample 3 : after virological failure; date 16.12.04

SLIDE 12

University of Cologne Institute of Virology

Population based sequencing Population based sequencing Genotypes:

1. sample: baseline genotype revertant RT T215C only
2. sample: negative result
3. sample: after failure - protease V82A and RT M41L,

T215C/Y and M184V could be detected treatment: AZT, 3TC, LPV/r

SLIDE 13

University of Cologne Institute of Virology

Results V82A Results V82A

Population based sequence no V82A no sequence V82A Minority assay 0,2% V82A 7% V82A 100% V82A sample 1 sample 2 sample 3

a transmitted resistance at position V82A could be detected and had an effect on the first therapy!

SLIDE 14

University of Cologne Institute of Virology

Summary Summary

verall unexpected high prevalence of K103N in therapy- naïve

patients of 21% was found difference in resistant minority populations K103N in HIV-1 subtype B (16%) vs. non B subtype (40%) case report of a therapy naïve patient failing his first line regimen with AZT, 3TC and LPV: Detection of a transmitted minority population with a V82A and assumed transmitted NRTI mutations M41L, T215Y and M184V lead to virological failure

SLIDE 15

University of Cologne Institute of Virology

Thank you

Rolf Kaiser Martin Däumer Saleta Sierra Dörte Hammerschmitt Ibrahim Boussaad Jens Verheyen Elena Litau Claudia Müller Nadine Sichtig Herbert Pfister Jürgen Rockstroh Gerd Fätkenheuer Mark Oette and colleagues Resina study group Stephanie Koch Arne Kroidl