Immune profiling is an essential method for quantifying changes in immune population numbers and states over time in health and disease. A cornerstone in translational and clinical research, it is frequently used to investigate chronic inflammation, infectious disease, autoimmune diseases, and cancer. The diversity of immune populations demands a high‑parameter approach to fully and efficiently quantify changes. Mass cytometry, which utilizes CyTOF® technology, is a single-cell analysis platform that has used as many as 50 metal-tagged antibodies1 to resolve discrete cell populations, all in a single tube of sample. It is an ideal solution for routine enumeration of immune cell populations.
We developed a sample-to-answer solution for human immune profiling using mass cytometry: the Maxpar® Direct™ Immune Profiling System. It includes an optimized 30-marker immune profiling panel provided in a single-tube format, validated SOPs for human whole blood and PBMC staining, an instrument data acquisition template, instructions for data acquisition on a Helios™ system, and automated Maxpar Pathsetter™ software for data analysis.
Here we present analytical validation data on repeatability, reproducibility, software precision / accuracy, and site-to-site reproducibility. The repeatability of eight identical donor samples acquired on a single Helios instrument resulted in CVs <12% for whole blood and <9% for PBMC for all major populations (>5% in frequency). Reproducibility of three identical samples acquired on three different Helios instruments resulted in CVs <10% for whole blood and <20% for PBMC for all major populations. We also performed Deming regression to test differences in results obtained by manual gating and Maxpar Pathsetter. For all major populations analyzed, 95% confidence interval of the correlation coefficient contained the value of 1, suggesting no proportional difference between the two methods of analysis. Finally, a multi-site study of whole blood from a single donor stained and analyzed at five institutions independently resulted in CVs of <10% for populations ≥5% in frequency, demonstrating that the Maxpar Direct Immune Profiling System shows a high degree of inter-site reproducibility.
We conclude that this assay provides a robust solution for broad immune profiling using mass cytometry, reducing sources of variability and subjectivity in sample preparation and data analysis.