CORRELATION BETWEEN HIV1 MOLECULAR CHARACTERISTICS AND RESPONSE TO HAART IN PEDIATRIC POPULATION FRO

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CORRELATION BETWEEN HIV-1 MOLECULAR
CHARACTERISTICS AND RESPONSE TO HAART IN
PEDIATRIC POPULATION FROM SAO PAULO, BRAZIL
Cristina Mendes de Oliveira, Rosangela
Rodrigues, Carla M P Vazquez, Maria do Socorro
Carneiro Ferrão, Alexandre Campeas, Márcia
Crozatti, Silvia Marques, Luis Fernando de Macedo
Brígido.
Laboratório de Retrovírus, Instituto Adolfo Lutz,
São Paulo, Brasil Instituto de Infectologia
Emílio Ribas, são Paulo, Brasil
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• Decision on when to start ARV therapy is a
  matter of controversy even for adults
• Children pose additional challenges even in
  virological failure due to specific issues,
  including
• Potential interference with normal growth and
  development
• Toxicity Pharmaco-dynamics
• Limited ARV options posology limitations
• Adherence

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What is the contribution of molecular information
to the management of children living with
HIV/AIDS

• ARV drug resistance test were the fist molecular
  characterization brought into clinical practice
  routine, subsidizing salvage ARV therapy.
• Additional molecular characteristics of HIV-1
  that provide surrogate markers do determine when
  and how to treat HIV infected children can be
  useful in subsidizing decision on starting as
  well as changing ARV therapy.

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Methodology

• Inclusion criteria
• Informed consent from parents or gardian and
  additional informal consent for older children
  at inclusion visit
• Naïve samples collected before
  initiation of ARV (2001-2006)
• Treated children or adolescent using EFV
  or LPV based HAART
  (collected from 6 / 2005 to 11 / 2006 )
• Viral load bDNA (Bayer) TCD4 ( BD),
• performed at certified National Network
  Laboratory
• HIV sequencing
• performed at Retrovirus Laboratory, Adolfo
  Lutz Institute

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Samples collected at baseline

• EDTA blood collected at service and processed
  within 6 hs
• Cell lysade and plasma maintained at -70 C
• Extraction plasma RNA and/or Cell DNA
  (Qiagem/GFX)
• RNA retrotranscrition (Superscript II,
  Invitrogen, USA)
• Nested PCR
• Sequencing (ABI 3100) with Big Dye chemistry
  (ABI,USA)
• Edition Sequencher (Gene codes corp.,USA)
• Phylogeny REGA, NCBI, SIMPLOT, PAUP
• Drug Resistance Mutations (DRM), Stanford HIV
  Database

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Baseline Characteristics

• Naïve
  Treated
• n16
  n79
• Age (mean years) 3.6
  9.4
• Gender ( males) 44
  54
• Mean number of
• ARV regimens 0
  5.7
• TCD4 ( cels/mm3) 1108
  650
• Plasma Viremia (log) 4.91
  4.08
• undetectable 0
  24

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Clinical outcome of ARV treated cases

• 78 cases with follow up information
• 79.5 Asymptomatic
• 7 Bacterial Pneumonia
• 4 TB
• Other complications
• One death (adenocarcinoma)
• One loss to follow up (change town)

• - Citopenias in 6
• - Pancreatitis
• - CMV

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Outcome categories defined based on

• Viral load at last observation (end 2007- first
  semester of 2008)
• Clinical observation (patients pediatrician) at
  last documented visit
• and
• TCD4 cell counts (cells / mm3) at last
  observation
• GOOD RESPONDERS
• TCD4 counts over 350 and clinically asymptomatic
• POOR RESPONDERS
• TCD4 counts under 350 or clinical Aids related
  condition

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Viral Load and TCD4 outcome
At baseline

• TCD4 mean 650 cels/mm3
• TCD4 mean 691cels/mm3
• 61 with TCD4 over 500
• 27 200 - 500
• 12 below 200

24 aviremic - among viremic Log10 4.54
35 aviremic - among viremic
Log10 3.91
At last visit
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Treatment at last evaluation NNRTIs EFV and/or
LPV based HAART
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Baseline characteristics by Virological outcome
Plt 0.002
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Presence of DRMs by virological strata
Mean number of DRM at RT and PT
Virgt4 x Avir P 0.43
p0.14 p0.9
Plt0.001 plt0.05
plt0.01
DRM Drug Resistance Mutations RT reverse
transcriptase gene PT Protease gene Tam
-Tymidine Analogue mutations NRTI -Nucleoside
analogue ARV class NNRTI - Non analogue ARV
class PI -Protease inhibitor class Sec/acc
-Secondary/accessory mutations Major- Principal
mutations to PI
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Proportion of DRM to NRTI class in ARV resistance
codons at Reverse transcriptase (RT) by treatment
outcome
PR poor response GR good response
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Proportion of DRM to NNRTI class in ARV
resistance codons at Reverse transcriptase (RT)
by treatment outcome
PR poor response GR good response
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Proportion of DRM to Protease Inhibitors (PI) at
ARV resistance codon at PROTEASE by treatment
outcome
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Proportion of DRM to Protease Inhibitors (PI) at
ARV resistance codon at PROTEASE by treatment
outcome
PR poor response GR good response
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Proportion of DRM to Protease Inhibitors (PI) at
ARV resistance codon at PROTEASE by clinical
outcome
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Impact of DRM on treatment outcome
Proportion of selected major DRM at PR
plt0.0052 P0.067
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Impact of DRM on treatment outcome Among cases
currently using LPV based HAART
Mean number of DRM at RT and PT BY outcome
Plt0.0082 p0.2
GR Good responders PR Poor responders
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Impact of DRM on treatment outcome among cases
using EFV based HAART
Mean number of DRM at RT and PT
GR Good responders PR Poor responders
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Protease polimorphisms by pol clade
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V3 loop signatures among naïve and treated
cases stratified by poor responders (PR) and good
responders (GR)
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GR
PR

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Recombination patterns at gag (903-1920), pol
(2252-3251) and env (7077-7609), positions
related to HXB2 ( K03455).
HIV-1 B
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HIV-1 clades by virological outcome and clinical
outcome
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Predicted HIV tropism by virological and clinical
outcome
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V3 loop AA alignment of paired cell and plasma
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Impact V3 mixtures on treatment outcome
Most sequences ( 51 among GR and 54 among PR)
do not show mixtures at V3
Mean number of Mixtures at V3 by outcome
Plt0.031
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DIVERSIDADE - DIVERGENCIA intra-hospedeiro
Arts et al. 2007
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Conclusions

• Albeit treated for over a mean of 449 weeks (8.6
  years) over one third of these children had
  viral loadlt 50 c/ml at last evaluation
• Protease inhibitors mutations, both major as well
  as accessory/ Secondary DRM, correlated to
  viremia and poor clinical outcome some
  polymorphisms common among naïve cases and may
  have an impact in resistance evolution
• Presence of mixtures at V3 codons were
  associated to good clinical outcome

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