A Rapid, Simple, and Low-Cost CD4 Cell Count Sensor Based on Blocking Immunochromatographic Strip System.

Area of Science:

• Immunology
• Biotechnology
• Medical Diagnostics

Background:

• CD4+ T lymphocyte (CD4 cell) counting is crucial for assessing immune function in HIV and cancer patients.
• There is a clinical need for rapid, simple, accurate, and affordable CD4 cell counting methods.

Purpose of the Study:

• To design and develop a novel fluorescent immunochromatographic strips (ICS) system for CD4 cell counting.
• To evaluate the performance and clinical applicability of the developed ICS system.

Main Methods:

• Developed a fluorescent ICS system based on a blocking principle to indirectly measure CD4 cells.
• Quantified CD4 cells by measuring the fluorescence intensity of unbound fluorescent antibodies.
• Validated the system using peripheral blood mononuclear cells (PBMC) and whole blood samples.

Main Results:

• The CD4 count-ICS demonstrated a quasilinear response to logarithmic CD4 cell concentrations (50-1000 cells/μL) in PBMCs (R² = 0.96).
• The assay showed a linear correlation (R² = 0.976) for CD4 cell concentrations (100-800 cells/μL) in whole blood.
• Results from 54 blood samples showed high correlation (R² > 0.97) with flow cytometry (FCM) analysis.

Conclusions:

• The fluorescent ICS system provides a reliable method for CD4 cell counting.
• The system exhibits a high coincidence rate with FCM analysis.
• This CD4 count ICS system is a promising candidate for CD4 cell enumeration in resource-limited settings.