Confocal backscattering-based detection of leukemic cells in flowing blood samples

Area of Science:

• Biomedical Engineering
• Hematology
• Analytical Chemistry

Background:

• Assessing minimal residual disease (MRD) in leukemia is crucial for prognosis, but current methods like flow cytometry and PCR are costly and complex.
• Existing techniques require expensive equipment, extensive cell processing, and highly trained personnel, limiting accessibility.

Purpose of the Study:

• To explore the potential of light scattering at multiple wavelengths for detecting leukemic cells.
• To develop and evaluate cell classification algorithms based on light scattering properties for leukemia detection.

Main Methods:

• Utilized three wavelengths (405, 488, 633 nm) to analyze light scattering intensities of leukemic cells (Nalm-6) and various white blood cells (PBMCs, PMNs).
• Developed algorithms to classify cells based on distinct light scattering distributions.
• Validated algorithm performance using simultaneous light scattering and fluorescence flow cytometry data.

Main Results:

• Distinct light scattering patterns were identified for Nalm-6 cells, PBMCs, PMNs, and red blood cells.
• Prospective analysis of PBMC and leukemic cell mixtures yielded 99.6% specificity and 45.2% sensitivity.
• Analysis of mixtures including PMNs showed 91.6% specificity and 39.5% sensitivity.
• Estimated blood volumes of 42-71 μL are sufficient for 80% power detection of 0.01% leukemia.

Conclusions:

• Light scattering in a microfluidic platform offers a cost-effective, portable, and minimally invasive method for leukemia detection and monitoring.
• This approach holds significant promise for improving leukemia care, particularly for pediatric patients and in resource-limited settings.