Preclinical Assessment of a Cartridge-Based Flow-Through Assay for Determination of Adult CD4 T-Cell Count

Simon Bystryak1, *
, Chitrangada Acharya1
, Kyle Dobiszewski1, #
, Hongying Zhu1
, Rajiv P. Bandwar1

1 Department of R&D, Allied Innovative Systems, LLC, Watchung Avenue, Suite 102, Chatham, NJ 07928, USA

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Creative Commons License
© 2020 Bystryak et al.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Address correspondence to this author at the Department of R&D Allied Innovative Systems, LLC, 13 Watchung Avenue, Suite 102, Chatham, NJ 07928, USA; Tel: 1-908-904-1100; Fax: 1-908-904-1130; E-mail:

# Present Address: Albert Dorman Honors College; New Jersey Institute of Technology; Newark, NJ, USA.



Despite the emphasis on viral load testing, current HIV testing guidelines consider CD4 T-cell count measurement as an important criterion for assessing disease progression, making decisions about anti-retroviral therapy regime changes, and treating HIV infected individuals with opportunistic infections. The CD4 counting by established methods (e.g., flow cytometry) presents challenges not only in resource-scarce settings due to cost and lack of skilled technicians but also in resource-rich areas where it is limited to centralized facilities.


Current options for Point-Of-Care (POC) CD4 enumeration are few and labor-intensive, prompting the need for newer technological methods that can overcome the aforementioned challenges.


The novel and patented flow-through cell counting assay (FTCA) described previously (Bystryak et al., 2019) was developed further into a point-of-care CD4 testing system using a disposable cartridge device and a portable imaging instrument. A pilot study with ~100 samples using this device was conducted to assess the validity of FTCA as a POC test for the measurement of CD4 count.


The FTCA signal was found to be linear over a wide range (17 - 1540 cells/μL) of CD4 T-cell concentration. The FTCA method also exhibits a strong agreement with flow cytometry, with very low bias (− 7 cells/μL) towards CD4 count measurement.


The cartridge-based FTCA method has great potential to be a fully quantitative method with low complexity, portability, low-cost, and wide applicability in clinical practice.

Keywords: CD4 count, HIV monitoring, HIV rapid test, Flow-through assay, Cartridge, Imaging system, Point-of-care.