ValueValue of Laboratory of Laboratory Testing Testing in in The The Care and Treatment of HIV Care and Treatment of HIV PatiePatie

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Francis Kasolo, MBChB, MSc, Ph.D, DTM& H.

Consultant Virologist.

Presentation Outline

• HIV infection is Zambia• laboratory involvement in the care

of PLWHA• Way forward• Conclusion

Background Information

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.

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.

Medical & Health CareCommunity

+

-

KA+ people

People positivelyliving withHIV/AIDS

A+

BCC

BCC

BCC

A+

Remember Labs role in the Remember Labs role in the Continuum oContinuum of Care For HIV/AIDSf Care For HIV/AIDS

Spiritual Support

Social Support

Economic Support

Psychological S/C

Legal Support

Clinical Care(O.I. Treatment)

Basic health care / nutrition advice

Home-based Care

MTCT Prevention

ARV Drug Treatment

Vaccine Trial

Confidential/Anonymous

VCTVCTIP+

People

Traditional leadersReligious leaders SchoolteachersParentsYouthsMen/WomenVulnerable people

IEC/BCC

Role of Laboratory In the Management of Role of Laboratory In the Management of PLWHAPLWHA

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.

What Laboratory Tests Are What Laboratory Tests Are

We Talking About?We Talking About?

• Virological tests • Immunological tests• Haematology assessment• Clinical chemistry assessment• Opportunistic infection screening

Bacteriology, parasitology, mycology etc

1.1. Initiation of TherapyInitiation of Therapy

Laboratory Diagnosis for HIV Laboratory Diagnosis for HIV InfectionInfection

Screening Test

Negative Positive

Positive-Confirm +ve

2nd Test

3rd Test

IndeterminatePositive Negative

Antibody Assay (Serial Testing)-OMS II

Negative

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 loadRoche Amplicor HIV-1 Monitor Assay version 1.5 (Monitor)

HIV Viral Load Estimation.HIV Viral Load Estimation.Quantitative methodologiesQuantitative methodologies

CD4 Estimation.CD4 Estimation.

Flow cytometry Technology Microscopy based Technology I.e. Dynabe

ad technologyELISA based Technology

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

When Should We Start Therapy-laboratory Perspective

HIV (copies/ml)

200

350

55,000

CD4(/ml)

Treatment

Recommend treatment

Observeprocess

Observe process orrecommend treatment

Where Comprehensive Lab Where Comprehensive Lab Facilities Are Available and Facilities Are Available and

AffordableAffordableSymptomatic Phase: Treatment

Asymptomatic Phase:

WHO WHO Recommendation on Recommendation on Initiation of Initiation of Therapy Therapy (In Resource (In Resource

Poor Countries).Poor Countries).

• If CD 4 testing unavailable:WHO stage IV disease irrespective of

total lymphocyte countWHO stage II or III disease with a total

lymphocyte count <1,200 /mm (1,200 lymphocytes approx.200 CD4 /l)

WHO stage I delay initiation of therapy

2.2. Monitoring Response Monitoring Response to ARV Therapyto ARV Therapy

2.2. Monitoring Response to Monitoring Response to ARV TherapyARV Therapy

• Frequency 0, 1, 3, 6, 9, 12 • Hematological monitoringHgb, WBC• Bio-Chemical monitoring Liver & Renal• Immunological & Virological

monitoringViral Load, CD4 & Drug Resistance

testing

3.3. Monitoring Monitoring Side Effects AttributaSide Effects Attributable to ARV Drugsble to ARV Drugs

3.3.Monitoring Monitoring Side Effects AttributablSide Effects Attributable to ARV Drugse to ARV Drugs

NARTI Lactic acidosisLactic acidosisAZT: Zidovudine Bone marrow inhibition3TC: Lamivudine d4T: Stavudine NeuritisddI: Didanosine DiarrheaddC: ZalcitavineABC: Abacavir AnaphylaxisNNARTINVP: Nevirapine Hepatitis, RashEFV: Efavirenz Central nerves systemDLV: NelavirdinePISQV: SaquinavirRTV: Ritonavir Liver obstructionIDV: Indinavir Urolithiasis (kidney stones), NFV: Nelfinavir DiarrheaAPV: Amprenavir RashLPV/r: Lopinavir/ritonavir

4. Monitoring Possible 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

When Should One Suspect When Should One Suspect EmerEmergence of ARV Drug Resistancegence of ARV Drug Resistance??

Mutated Position of Reverse Mutated Position of Reverse Transcriptase by RT Inhibitor Transcriptase by RT Inhibitor Treatment Treatment (amino acid position)(amino acid position)

Drugs Mutated position

ZDV M41L D67N K70R L210W T215F/Y K219E/Q

ddI M41L K65R D67N T69A/S K70R L74V V75T M184V/I L210W T215Y K219Q

ddC K65R T67D L74V V75T M184V/I T215C

3TC E44D V118I P157S M184I/T/V

d4T M41L I50T D67N V75T I178M T215Y K219Q

ABC M41L K65R D67N K70R L74V Y115F M184V L210W T215F/Y K219Q

NVP A98G L100I K103N V108I Y181C/I Y188C/L/H G190A

DLV K103N/T Y181C P236L

EFV A98G L100I K101E K103N V108I V179D Y181C Y188L G190S P225H

5.5. Investigating Emergence Investigating Emergence of New OI While on ARVSof New OI While on ARVS

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

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

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 Ensure a coordinated QA/QC system that

will guarantee quality HIV testing and will guarantee quality HIV testing and ART monitoring.ART monitoring.

Conclusion

• The laboratories are a key component in the management of patients on ARV.However.However.

• Comprehensive laboratory support in the management of patients on ARV is expensive (Approx. 200 US$ plus/year).

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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