Value of Laboratory Testing in The Care and Treatment of HIV Patients

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Value of Laboratory Testing in The Care and
Treatment of HIV Patients

• Francis Kasolo, MBChB, MSc, Ph.D, DTM H.
• Consultant Virologist.

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Presentation Outline

• HIV infection is Zambia
• laboratory involvement in the care of PLWHA
• Way forward
• Conclusion

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Background Information
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HIV The Zambian Situation

• HIV is a leading cause of deaths among Zambians.
• At the end of 2001, 1.2 million Zambians were
  estimated to be living with HIV/AIDS.
• Over half of these infections are in women.
• An estimated 20,000 Zambians died of AIDS in
  2001- Underestimate.

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HIV The Zambian Situation

• In the 2001-2002 DHS reported that
• HIV prevalence is almost twice as high in urban
  as in rural areas.
• 17.8 women aged 15-46 were HIV positive.
• 12.9 men of the same age were HIV positive.
• Sentinel populations show significant increases
  in infection rates over time.
• In Lusaka and Ndola, HIV prevalence among women
  attending antenatal clinics increased from 5 in
  1985 to 27 in 1994.
• This rate then dropped to 18 in 2001.

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Remember Labs role in the Continuum of Care For
HIV/AIDS
Community
Traditional leaders Religious leaders
Schoolteachers Parents Youths Men/Women Vulnerable
people
BCC
IEC/BCC
BCC
BCC
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Role of Laboratory In the Management of PLWHA

• Laboratories are involved at several levels of
  HIV/AIDS Care and treatment.
• Initiation of therapy.
• Monitoring of Therapy.
• Monitoring of Side effects.
• Monitoring of Drug resistance.
• Investigating Emergence of New OI While on ARVS.

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What Laboratory Tests Are We Talking About?

• Virological tests
• Immunological tests
• Haematology assessment
• Clinical chemistry assessment
• Opportunistic infection screening
• Bacteriology, parasitology, mycology etc

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Initiation of Therapy
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Laboratory Diagnosis for HIV Infection
Antibody Assay (Serial Testing)-OMS II
Negative
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HIV Viral Load Estimation. Quantitative
methodologies

• Abbott LCx HIV Quantitative RNA Assay (LCx)
• Bayer(formerly Chiron) Quantiplex HIV RNA bDNA
• Assay version 3.0 (bDNA)
• Organon Teknika NASBA NucliSens HIV-1 QT
• Assay(Nuclisens)
• P24 antigen assays as alternative to viral load
• Roche Amplicor HIV-1 Monitor Assay version 1.5
• (Monitor)

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CD4 Estimation.

• Flow cytometry Technology
• Microscopy based Technology I.e. Dynabead
  technology
• ELISA based Technology

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Additional Investigations

• Hematological assessment
• e.g. Hgb, WBC,
• Bio-Chemical assessment
• Liver enzymes
• Renal funcition
• Hepatitis screen
• (HCV, HBV)
• Screen for opportunistic infections/Malignacies
• Tuberculosis, PCP, Histology for KS, CACx

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When Should We Start Therapy-laboratory
Perspective
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Where Comprehensive Lab Facilities Are Available
and Affordable
Symptomatic Phase Treatment
Asymptomatic Phase
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WHO Recommendation on Initiation of Therapy (In
Resource Poor Countries).

• If CD 4 testing unavailable
• WHO stage IV disease irrespective of total
  lymphocyte count
• WHO stage II or III disease with a total
  lymphocyte count lt1,200 /mm (1,200 lymphocytes
  approx.200 CD4 /?l)
• WHO stage I delay initiation of therapy

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Monitoring Response to ARV Therapy
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Monitoring Response to ARV Therapy

• Frequency 0, 1, 3, 6, 9, 12
• Hematological monitoring
• Hgb, WBC
• Bio-Chemical monitoring
• Liver Renal
• Immunological Virological monitoring
• Viral Load, CD4 Drug Resistance testing

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Monitoring Side Effects Attributable to ARV Drugs
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• Monitoring Side Effects Attributable to ARV Drugs

NARTI Lactic acidosis AZT Zidovudine
Bone marrow inhibition 3TC Lamivudine d4T
Stavudine Neuritis ddI Didanosine Diarrhea dd
C Zalcitavine ABC Abacavir Anaphylaxis NNART
I NVP Nevirapine Hepatitis, Rash EFV
Efavirenz Central nerves system DLV
Nelavirdine PI SQV Saquinavir RTV
Ritonavir Liver obstruction IDV
Indinavir Urolithiasis (kidney stones), NFV
Nelfinavir Diarrhea APV Amprenavir Rash LPV/r
Lopinavir/ritonavir
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Monitoring Possible Emergence of ARV Drug
Resistance
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When Should One Suspect Emergence of ARV Drug
Resistance?

• CD4 lymphocyte decrease
• Increase in VL from undetectable
• levels despite compliance
• Clinical failure e.g. emergence of new
• OI un-explained loss of weight

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Mutated Position of Reverse Transcriptase by RT
Inhibitor Treatment (amino acid position)
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Investigating Emergence of New OI While on ARVS

• It is important to remember that Laboratories are
  critical in investigating emergence of OI e.g TB,
  PCP, etc

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What Is the Way Forward?

• Acceptance of the fact that not all our
  facilities will perform all the required
  investigations need to support ART
• Creation of a three level laboratory network

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What Is the Way Forward?

• Primary level- Minimum requirements to initiate
  monitor therapy (e.g. Hgb, WBC, LFT, U/E) /-
  Microscopy based CD4 testing.
• Secondary level- Primary level plus simpler
  technologies for CD4 estimation.
• Tertiary level- Comprehensive laboratory
  facilities (Viral load, resistance
  testing-Centers of excellence).
• Ensure a coordinated QA/QC system that will
  guarantee quality HIV testing and ART monitoring.

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Conclusion

• The laboratories are a key component in the
  management of patients on ARV.
• However.
• Comprehensive laboratory support in the
  management of patients on ARV is expensive
  (Approx. 200 US plus/year).

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Conclusion

• This will affect the way therapy is monitored
  esp. in Zambia.
• Highly technical investigations e.g. drug
  resistance testing, are not available in all
  facilities.
• There is need to establish a national laboratory
  network to support ART.

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Since this picture was taken there has been a new
addition-Thank You