Outline. Role of POC CD4 in the conenuum of care. How does POC CD4 compare with Lab based tests. Issues of sampling: venous vs capillary sampling

Transcription

1 Role of Point of Care CD4 in TasP Sikhulile Moyo Laboratory Manager, Clinical Trials Botswana- Harvard AIDS InsEtute Partnership Botswana- Harvard HIV Reference Laboratory Gaborone, Botswana May 1, 2014

2 Outline Role of POC CD4 in the conenuum of care How does POC CD4 compare with Lab based tests Issues of sampling: venous vs capillary sampling ImplementaEon Issues Product pipelines Summary 2

3 Role of POC CD4 in conenuum of care There is a recognized need for improving the care pathway from HIV diagnosis to Emely aneretroviral therapy (ART) inieaeon several recent studies highligheng substaneal losses in the conenuum of care from HIV teseng to ART inieaeon 3

4 Role of POC CD4 in conenuum of care Point- of- care teseng for CD4 cell count is considered one of the promising ways of: reducing the,me to eligibility assessment for an,retroviral therapy (ART) increasing reten,on in care prior to treatment ini,a,on 4

5 Many lab tests are performed but results are never delivered to patients, compounding low coverage of essential HIV diagnostics CD4 In sub- Saharan Africa 46% of CD4 test results were NOT received by the paeent 1,2,3,4 HIV diagnosis in infants Based on UNICEF Stocktaking report, 51% of posieve EID test results are NOT received by the paeent 5 54% 46% Results not received Results received 49% 51% Roughly half of laboratory- based CD4 and EID results are never delivered to paeents, due to loss- to- follow- up associated with long wait Emes and the need for frequent clinic visits Sources: 1 NaEonal volumes for Mozambique, Malawi and South Africa based on CHAI data; 2 LTFU esemated based on Jani et al (2011); 3 MOH Malawi; 4 Larson et al (2011); 5 December 2008 Stocktaking Report, UNICEF CHAI data 5

6 POC Tes6ng Accelerates and Eases ART Ini6a6on HIV Diagnosis 1 Primary opportunity for interveneon (POC CD4) Enrollment in HIV care 2 Blood draw 3 Same day testing to CD4 result Test performed Result received 4 5 Clinical consulta6on 6 ART ini6a6on 7 Follow- up 8 POC CD4 combines a number of steps required pre- ART inieaeon making it less burdensome for paeents 6

7 POC Tes6ng at 6me of tes6ng Accelerates access to care and staging Primary opportunity for interveneon (POC CD4) HIV Diagnosis 1 Blood draw 2 Same day testing to CD4 result Test performed Result received 3 4 Enrollment in HIV care 5 Clinical consulta6on 6 ART ini6a6on 7 Follow- up 8 POC CD4 can further accelerates enrollment in TasP by providing result at HIV diagnosis 7

8 POC CD4 is effeceve at reducing paeent loss to follow- up and reducing Eme to inieaeon Reduction in the median time to complete CD4 staging: from 33 days to 3 days Ilesh V Jani, Nádia E Sitoe et al: Effect of point- of- care CD4 cell count tests on reteneon of paeents and rates of aneretroviral therapy inieaeon in primary health clinics: an observaeonal cohort study. Lancet 2011; 378:

9 How does POC CD4 compare with Lab based Tests?

10 EvaluaEon Studies The PIMA has been evaluated in South Africa, Zimbabwe, Mozambique and Uganda Performs well compared to gold standard FACS analysis. South African mobile VCT clinic semng 1) venous POC vs Flow cytometry mean difference (Bland Altman) = 12 cells/μl, (95% CI 23 to 1), 94% sensievity, 98% specificity, 84% PPV]. 2) finger- seck blood vs Flow Cytometry mean difference = 15 cells/μl, (95% CI 9 to 39), 100% sensievity, 98% specificity, 67% PPV]. 10

11 EvaluaEon Studies: Lab techs versus Nurses Alere PIMA (Lab Techs) vs. BD FACSCalibur Alere PIMA (Nurses) vs. BD FACSCalibur Limits of Agreement -314 to +257 Limits of Agreement -249 to

12 Use of capillary blood sampling tubes improves peformance of Alere PIMA CD4 (Mochudi Study) Alere PIMA Capillary EDTA Blood) vs. BD FACSCalibur Alere PIMA Capillary Finger- S6ck) vs. BD FACSCalibur Difference (pima_cd4 - flow_cd4) Identity Average 12

13 EvaluaEon Studies: Summary Recent data suggests improvements in capillary sampling improves performance of POC Blade vs needle lancets Sampling techniques Training, competence assessment and monitoring Variable precision of Pima is amributable to variable capillary sampling. Stringent ameneon to capillary blood colleceon technique is therefore imperaeve if technologies like Pima are used in the field sengngs. Our data suggests that using capillary sampling using EDTA microtube performs bemer than finger seck when compared to flow cytometer 13

14

15 Connec6vity

16 Alere Pima controls in Levey- Jennings plot

17 Combina6on of POC Devices Can we couple a combinaeon of POC Devices: PIMA (CD4), HemoCue (hemoglobin), Reflotron (alanine aminotransferase, creaenine).

18 Summary POC TesEng POC TesEng Accelerates and Eases ART IniEaEon accelerates and Eases ART IniEaEon Coupling with other tests such as LFTs, CreaEnine and Lactate monitoring may further accelerate ART inieaeon and reduce LTFU Recent data shows improvements in the performance of finger seck versus flow cytometry, amributed to improvements in training and capillary sampling Using capillary EDTA sampling tubes shows bemer performance than finger seck capillary sampling. Training on colleceon techniques is key

19 Acknowledgements Botswana- Harvard Partnership Botswana- Harvard HIV Reference Laboratory Harvard School of Public Health Mochudi PrevenEon Project Clinton Health Access IniEaEve [Dr Trevor Francis Peters UNITAID

20

21 Monitoring HIV Pa6ents Device- based POC CD4 Company PointCare/Human Partec Alere Daktari Plarorm Name HumaCount CD4 NOW Partec CyFlow mini POC Alere Pima CD4 Test Daktari CD4 Counter Type Desk top; ~26 lbs [11kgs] Bench top portable; ~11 lbs [5kgs] Bench top portable; ~5.5 lbs (2.5Kgs) Bench top portable; ~5.5 lbs [2.5] Output Absolute & %CD4, WBC, Hb, total lymphocytes Absolute & %CD4, WBC, total lymphocytes Absolute CD4 Absolute CD4 Specimen Type 40 µl venous blood 20 µl venous blood 16 µl fingerseck blood 16 µl fingerseck blood Cost/test ~$10.00 per test, including controls ~$3.96 per test; high volume discounts $ $12.00 ~$8.00 per test; lower with volume discounts Number of samples/run ~40 50 samples per day; TAT 8 minutes; no batching Up to 250 tests/day; TAT seconds per test ayer 15 minutes incubaeon Maximum of ~20 samples per day; TAT minutes per test ~40 50 samples per day; TAT 8 minutes; no batching Equipment Cost ($US) ~$25,000 ~$9,380; point- of- care package at lower effeceve cost $6,500 to $12,000 ~$1,000

22 Monitoring HIV Pa6ents Device- based and Disposable POC CD4 Company MBio BD Zyomyx Omega Diagnos6cs/ Burnet Plarorm Name Mbio CD4 System BD Point of Care CD4 System Type Bench top portable; ~6.6 lbs Bench top; ~11 lbs Output Absolute CD4 Absolute CD4, %CD4 & Hb Specimen Type 10 µl fingerseck blood 16 µl fingerseck blood Zyomyx CD4 Counter Disposable cartridge with mechanical mixer/ spinner (less than 11 lbs) Absolute CD4 Omega Diagnos6cs CD4 Counter Disposable cartridge with reader (~14 ounces) Absolute CD4 100 µl fingerseck blood 40 µl fingerseck blood Cost/test TBD TBD <$8.00 per test $2.00 per test esemated Number of samples/ run Equipment Cost ($US) ~100 samples per day; TAT 20 minutes (17 minutes in cartridge; 3 minutes instrument reading) Maximum of ~25-30 samples per day; TAT 2-5 minutes plus 20 minutes of incubaeon ~40 samples per day; TAT 10 minutes; batch processing TBD TBD TBD ~$200 for mixer/spinner; may be included in cost per test with TBD volume of test cartridges ~120 samples per day; TAT ~40 minutes, including incubaeon ~1,200 for reader, expected to go to $400