Within- and between-subject biological variation estimates for the enumeration of lymphocyte deep immunophenotyping...

This study aimed to deliver biological variation (BV) estimates for 25 types of lymphocyte subpopulations subjected to deep immunophenotyping (memory T/B cells, regulatory T cells, etc.) and classical, intermediate, and nonclassical monocyte subsets based on the full spectrum flow cytometry (FS-FCM) and a Biological Variation Data Critical Appraisal Checklist (BIVAC) design.

Samples were collected biweekly from 60 healthy Chinese adults over 10 consecutive two-week periods. Each sample was measured in duplicate within a single run for lymphocyte deep immunophenotyping and monocyte subset determination using FS-FCM, including the percentage (%) and absolute count (cells/μL). After trend adjustment, a Bayesian model was applied to deliver the within-subject BV (CV_I) and between-subject BV (CV_G) estimates with 95 % credibility intervals.

Enumeration (% and cells/μL) for 25 types of lymphocyte deep immunophenotyping and three types of monocyte subset percentages showed considerable variability in terms of CV_I and CV_G. CV_I ranged from 4.23 to 47.47 %. Additionally, CV_G ranged between 10.32 and 101.30 %, except for CD4⁺ effector memory T cells re-expressing CD45RA. No significant differences were found between males and females for CV_I and CV_G estimates. Nevertheless, the CV_Gs of PD-1⁺ T cells (%) may be higher in females than males. Based on the desired analytical performance specification, the maximum allowable imprecision immune parameter was the CD8⁺PD-1⁺ T cell (cells/μL), with 23.7 %.

This is the first study delivering BV estimates for 25 types of lymphocyte subpopulations subjected to deep immunophenotyping, along with classical, intermediate, and nonclassical monocyte subsets, using FS-FCM and adhering to the BIVAC design.