1 HIV and Injection Drug Use HAIVN Harvard Medical School AIDS Initiative in Vietnam.
1 Treatment Failure HAIVN Harvard Medical School AIDS Initiative in Vietnam.
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Transcript of 1 Treatment Failure HAIVN Harvard Medical School AIDS Initiative in Vietnam.
1
Treatment Failure
HAIVNHarvard Medical School AIDS
Initiative in Vietnam
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Learning Objectives
By the end of this session, participants should be able to:
Identify the 3 types of treatment failure Explain how to diagnose treatment
failure based on clinical, immunological, and virological criteria
Explain the indications for viral load testing in Vietnam and interpret a viral load result
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Overview
Estimated frequency of treatment failure in Vietnam is 2-3% in first year of treatment, based on clinical and immunological criteria• Highest incidence among patients who took
ARVs before enrolling in free ARV program Changing treatment to second line on
basis of virological or immunological failure aims to prevent clinical progression
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Resistance Overview (1)
Low levels of drug (caused by nonadherence) or low drug potency (caused by previous resistance) allow viral replication, which generate mutations in viral RNA and DNA
New mutations arise and these mutations can confer resistance to current drug
Resistant virus will preferentially multiply, gradually leading to treatment failure
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Resistance Overview (2)
Pre-Treatment
Initial Response
ARV Treatment
Wild type HIV Resistant HIV
Adherence Problem
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Three Types of Treatment Failure
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Typical Order of Treatment Failure
ClinicalFailure
ImmunologicFailure
VirologicFailure
ClinicalFailure
Immunological Failure
Virological Failure
This is the only part that you “see” (without lab tests)
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Clinical Treatment Failure
MOH criteria:• New or recurrent WHO stage IV event
Note: • Must differentiate from IRIS• Some stage 4 conditions can occur even
with complete virological suppression and may not indicate treatment failure while some stage 3 conditions may indicate treatment failure
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Immunological Treatment Failure
MOH Criteria: (at least 2 CD4 measurements)• CD4 count falls to or below pre-treatment
value• CD4 count falls to or below 50% on-
treatment peak value• CD4 persistently below 100 cells/uL for 1
year Other causes of change in CD4 must be
considered
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CD4 Monitoring
Check CD4 every 3-6 months Develop a system for reviewing all
CD4 count to review and compare every test to previous results
The CD4 test is like a lottery ticket:
you only get a benefit if you check the numbers later!
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Virological Treatment Failure
MOH criteria: VL > 5.000 copies/ml Confirm virological failure with 2 VL
tests at least one month apart before switching to 2nd line ARV
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Viral Load (VL) Test
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Viral Load Test – Definition
HIV PCR (VL) test:• Number of HIV RNA copies per ml of
plasma• VL testing will be supported in some
provinces in Vietnam
Best test to assess treatment success or failure
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Viral Load Test - Best Test to Assess Treatment
Effectiveness 2008 HCMC study of ARV resistance in
patients with 1st-Line treatment failure 248 patients had VL testing June-
December 2007• 96% on 1st line regimens
(d4T/AZT + 3TC + NVP/EFV)• Results:
VL undetectable: 100 (41.5%) VL detectable: 148 (58.5%)
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Targeted Viral Load
Objectives:• Confirm suspected clinical or
immunological failure• Maximize clinical benefits of first-line
therapy• Reduce unnecessary switching to second-
line therapy WHO now recommends use of viral load
to confirm treatment failure A targeted viral load strategy will be
supported in Vietnam
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When to Do the VL test?
After you make sure that patient has:• Been on ARV > 6 months• Adequate adherence
Do the VL test if patient presents with one of the following:• Clinical treatment failure criteria• Immunological treatment failure criteria• Other conditions or risk factors suspecting
treatment failure
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Interpretation of Viral Load
The results of VL Test will be one of these:
Note: Depends on the machine used for VL test, the detectable level can be 250 or 48
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What to Do if VL Result Is Undetectable?
Interpretation: •VL suppressed•Treatment failure is not confirmed
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Interpretation: Detectable but below threshold for confirming treatment failure
What to Do if VL Result Is Low Detectable?
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What to Do if VL Result Is > 5000?
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3 Steps to Diagnose Treatment Failure
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Clinical Practice: 3 Steps to Diagnose Treatment Failure
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Clinical Practice: Step 1 (1)
If patient is not adherent? Counsel the patient on adherenceEvaluate the patient again after 3 months of good adherence:
• Clinical exam• Repeat CD4 and/or VL if available Consider switching to 2nd line only if
evidence of treatment failure persists while patient is taking ARV with good adherence
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Clinical Practice: Step 1 (2)
Does patient have an acute OI? Acute OI such as TB can temporarily
decrease the CD4 count Therefore, before considering
switching to second line ARV:• Treat the OI first• Then reassess the clinical and
immunological status of the patient.
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Clinical Practice: Step 2
Clinical failure
New or recurrence of stage 4 diseases or conditions
CD4
failure c
CD4 count returns to or falls below pre-therapy baseline level
50% decline from the on-treatment peak value since the initiation of ART (if known)
CD4 count < 100 cells/mm3 after a year without any increase
Virological failured
VL > 5,000/ml
Check patient based on MOH Criteria for Treatment Failure
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Clinical Practice: Step 3 – Making a Decision
CriteriaClinical Stage
1 - 2 3 4
CD4 failure(VL testing not available)
• Do not switch ARV regimen
• Follow for appearance of clinical manifestations of treatment failure
• Repeat CD4 after 3 months
Consider switching to 2nd line ARV
Switch to 2nd line ARV
CD4 and VL failure Switch to 2nd line ARV
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If Patient Is Confirmed with Treatment Failure, What to Do?
Before Switching to 2nd Line ARV: Repeat adherence counseling Treat any acute OI first Provide counseling and patient
education about the new regimen
Second line ARV is last-line ARV in Vietnam!
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Switching ARV Due toTreatment Failure
1st Line ARV 2nd Line ARV
TDF + 3TC + NVP/EFVAZT + 3TC
or ddI + ABC
+ LPV/rAZT/d4T + 3TC + NVP/EFV
TDF + 3TCor
ddI + ABC
AZT/d4T + 3TC +TDF/ABC EFV/NVP + ddI
Vietnam MOH, HIV/AIDS
Treatment Guidelines, 2009.
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CASE STUDY
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Key Points
Important to recognize resistance and treatment failure
Three types of treatment failure are: clinical, immunological, and virological
Always evaluate patient’s adherence before changing to second line ARV
Diagnose treatment failure through:• VL testing (most accurate)• If VL not available, use combination of
clinical and/or immunological criteria
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Thank you!
Questions?