CD3+ T-lymphocyte percentage

Method

CD3-positive cells expressed as a percentage of total gated lymphocytes by flow cytometry.

The method is part of the endpoint identity. Studies measuring the same quantity by a different method are held as separate endpoints.

Notes

CD3 is the pan-T-cell marker, so this quantity is the near-sum of the two major T subsets measured on the same panel. Will be confused with the CD4+ and CD8+ percentages and with the absolute CD4+ count; treating all of them as independent evidence triple-counts a single measurement from a single blood draw. Percentage and absolute count are not interchangeable -- a stable count inside a falling total lymphocyte pool reads as a rising percentage.