Innovative diagnostics for HIV, HBV and HCV Dan Otelea National Institute for Infectious Diseases Bucharest, Romania
Disclaimer No conflicts of interest
Innovative diagnostics for HIV, HBV and HCV - is there a need? Dan Otelea National Institute for Infectious Diseases Bucharest, Romania
HIV HCV HBV Genome RNA RNA DNA Mutation Rate 10-4 10-5 10-5 10-5 Virus copies/day 10 10 10 12 10 13 Reservoir Integrated proviral DNA None cccdna
Testing requirements: Sensitivity:
Testing requirements: Sensitivity Discrimination
Testing requirements: Sensitivity Discrimination See all viral subpopulations Quantify all viral subpopulations
Accepted PLOS ONE
What is expected of us?
What is expected of us?
Management of virological failure (VF) If HIV-VL > 50 and < 500-1000 copies/ml: Check for adherence Check HIV-VL 1 to 2 months later If genotype not possible, consider changing regimen based on past treatment and resistance history If HIV-VL confirmed > 500 copies/ml: Change regimen as soon as possible. What to change will depend on the resistance testing results: If no resistance mutations found: re-check for adherence, perform TDM If resistance mutations found: switch to a suppressive regimen based on drug history; multidisciplinary expert discussion advised Goal of new regimen: HIV-VL < 50 copies/ml within 6 months
2016 Recommendations of the International Antiviral Society USA Panel Management of Low-Level Viremia Although any detectable virus has been associated with viral rebound in some studies, measurable HIV RNA between 20 and 50 copies/ml did not increase the risk of virologic failure in 1 study. Data are inconsistent about long-term effects of persistent HIV RNA between 50 and 200 copies/ml, and current data are insufficient to guide clinical management. Such patients should be reassessed for causes of virologic failure, evaluated again within 4 weeks, and monitored closely (evidence rating BIII). Decisions to change therapy should be individualized based on ART options, resistance history, and clinical circumstances. Treatment should be changed in patients with persistent HIV RNA above 200 copies/ml.
BHIVA VL 50 200 copies/ml INVESTIGATIONS VL 50 200 copies/ml VL >200 copies/ml If the repeat is <50 copies/ml, continue routine monitoring. This is considered a single blip. If the initial viral load measurement is below 200 copies/ml and subsequent measurement again between 50 and 200 copies/ml, check adherence and possible drug interactions. Do a resistance test 3 4 monthly viral load follow-ups of individuals with stable unsuppressed (<200 copies/ml) viral loads if they are managed as low level viraemic patients Genotypic resistance testing should be attempted and acted upon especially if there is a gradual increase in viral load No need for repeat genotypic resistance testing at a frequency greater than once a year if the viral load is stable and there is no need for routine TDM
BHIVA Action is taken if a second repeat viral load is above 200 copies/ml and if both measurements are above 200 copies/ml, refer to BHIVA treatment guidelines Careful assessment of patients with frequent blips and/or one measurement above 200 copies/ml as these can sometimes be associated with viral rebound and virological fail
HCV RNA detection and quantification should be made by a sensitive assay with a lower limit of detection of 15 IU/ml (A1). If HCV RNA testing is not available or not affordable, HCV core antigen detection and quantification by EIA can be used as a surrogate marker of HCV replication (A1).
Tools: First generation: end point PCR (obsolete) Second generation: real time PCR = SOC; productivity vs. flexibility Third generation: digital droplet PCR (cure)
The vast majority of HIV resides in the lymphoid organs, most of it assumed to be in CD4+ T cells, but the macrophage-rich tissues are understudied? (HIV+ cells/gram tissue) 10 4 10 3 10 (kidney) 10 6 (large bowel) 1 0 10 5 (spleen) 10 6-7 (LN) 10 5 (small bowel) From SG Deeks, MD at San Antonio, Texas, August 21-23, 2017, Ryan White HIV/AIDS Program Clinical Conference, IAS USA.
Viral resistance to treatment
2016 Recommendations of the International Antiviral Society USA Panel Genotypic resistance testing should occur at the time of confirmed virologic failure, although amplification may not be successful for HIVRNA levels below 500 to 1000 copies/ml; proviral DNA assays to estimate archived resistance may be considered. With CC chemokinereceptor 5 inhibitors, tropism testing is recommended at the time of virologic failure (evidence rating AIa).
BHIVA VL 50 200 copies/ml INVESTIGATIONS VL 50 200 copies/ml VL >200 copies/ml If the repeat is <50 copies/ml, continue routine monitoring. This is considered a single blip. If the initial viral load measurement is below 200 copies/ml and subsequent measurement again between 50 and 200 copies/ml, check adherence and possible drug interactions. Do a resistance test 3 4 monthly viral load follow-ups of individuals with stable unsuppressed (<200 copies/ml) viral loads if they are managed as low level viraemic patients Genotypic resistance testing should be attempted and acted upon especially if there is a gradual increase in viral load No need for repeat genotypic resistance testing at a frequency greater than once a year if the viral load is stable and there is no need for routine TDM
BHIVA Action is taken if a second repeat viral load is above 200 copies/ml and if both measurements are above 200 copies/ml, refer to BHIVA treatment guidelines Careful assessment of patients with frequent blips and/or one measurement above 200 copies/ml as these can sometimes be associated with viral rebound and virological fail
Tools: Sanger sequencing (SOC) Next generation sequencing
Li et al JAMA 2011
Our results NS3 188_2014 54S, 156S 1b (NS3) 290_2014 117H, 132V 1b (NS3) 305_2014 132V, 168E 1b (NS3) 557_2014 170A, 132V 1b (NS3) 646_2014 36V, 117H, 132V, 170V 1b (NS3) 681_2014 36V, 117H, 170V 1b (NS3) 766_2014 36V, 41H, 117H, 170V 1b (NS3) 7_2015 36V, 117H, 132V, 170V 1b (NS3) 107_2015 36V, 54S, 156S, 170V 1b (NS3) 234_2014 54S, 155K, 132V 1b (NS3) 780_2014 36V,54S, 55I,122T, 132V 1b (NS3) 803_2014 36V, 80L, 117H,132V 1b (NS3) 537_2015 36V, 168A, 174F 1b (NS3) 939_2015 36V, 80L, 168E,170V 1b (NS3) NS5A 1696_2015 Y93H 651_2016 Y93H 666_2016 Y93H 687_2016 Y93H 1033_2016 Y93H 114_2017 Y93H 236_2017 Y93H 256_2017 Y93H 419_2017 Y93H 529_2017 Y93H 595_2017 Y93H
ddpcr + NGS: Entering the clinical laboratory Higher throughput Optimized costs Higher precision Improved sensitivity