(P166) MANUAL WHOLE BLOOD SEPARATION FOR POINT-OF-CARE HIV-1 VIRAL LOAD TESTING

Background:
Monitoring viral suppression and adherence to antiretroviral therapy is done by measuring the viral load (VL) in patient blood plasma. Bringing this testing to the point-of-care (POC) enables treatment decisions to be made within a single patient visit, without having to send the sample to a centralized lab. With operation simplicity and equipment cost in mind, we investigated an alternative to other expensive and inadequately sensitive tests that streamlines whole blood separation for rapid and sensitive VL detection in a portable PCR instrument.

Methods:
Custom 3D-printed blood separation modules facilitated manually operated immunomagnetic red blood cell depletion and subsequent white blood cell filtration. Automated magnetic processing of the filtered blood plasma with viral particles enabled capture of RNA from the lysed viral particles to be amplified through rapid qPCR to estimate VL. An MS2 bacteriophage control was multiplexed with HIV RNA extraction and amplification to confirm successful sample extraction and PCR.

Results:
With our blood separation module, automated downstream sample processing and qPCR, HIV VL was quantified from whole blood in less than 30 minutes. Compatible with fingerstick and venipuncture collection methods, the manual blood separation process was completed in less than 5 minutes. From 250 µL of whole blood we observed a VL detection down to 1000 copies/mL. The blood separation module was designed for a capacity of up to 500 µL of whole blood for potential further improvement in sensitivity.

Conclusion:
It is critical that POC VL tests are both adequately sensitive and universally accessible for maintained viral suppression and the global eradication of HIV. We propose our blood separation method, in combination with our rapid PCR platform under development, as an alternative to other more costly and less sensitive POC VL tests. Future work will ensure our platform sensitivity meets the CDC defined threshold of <200 copies/mL for viral suppression.