[1934] Lymphocyte Subset Reference Ranges for Evaluation of Immune Reconstitution after Allogeneic Stem Cell Transplantation.
Bernard C Schur, Alexandra M Harrington, Steven H Kroft, Horatiu Olteanu. Medical College of Wisconsin, Milwaukee; Dynacare Laboratories, Milwaukee
Background: Allogeneic stem cell transplantation (SCT) has become a common procedure for treating hematologic malignancies. Unfortunately, cure is often hampered by relapse of underlying disease, graft-versus-host disease, or severe opportunistic infections, which account for the majority of deaths after SCT. Therefore, it is important to evaluate the reconstitution of different immune cell subsets after SCT. Since there is only limited literature data on suitable reference ranges, we conducted a large study to establish comprehensive reference ranges for peripheral blood (PB) lymphocyte subsets useful in monitoring immune reconstitution after SCT.
Design: PB specimens from 76 healthy volunteers were run on an Advia 2120 hematology analyzer to determine white blood cell and absolute lymphocyte counts. Flow cytometry was performed on a FACSCanto II instrument, with the following antibodies: CD45RA/CD8/CD3/CD4/CD45, CD3/CD16+56/CD20/CD45, and HLA-DR/CD25/CD3/CD45. Boolean gates and quadrant markers were employed to record the following lymphocyte subsets: CD3+CD4+, CD3+CD8+, total CD3+, CD4/CD8 ratio, CD4+CD45RA+, total CD45RA+, CD(16+56)+CD3-, total CD19, total CD20, CD3+CD25+, CD3+HLA-DR+, CD25+HLA-DR+, total CD25+ and total HLA-DR. Statistical analysis was performed with EP Evaluator (Data Innovations, South Burlington, VT).
Results: There were 23 men and 53 women (mean age=37 years). The median white blood cell and absolute lymphocyte counts were: 6550/ul and 2065/ul. Study ranges for CD3+CD4+, CD3+CD8+, total CD3+, CD4/CD8 ratio, CD(16+56)+CD3-, total CD19, and total CD20 agreed with published data. Mean and standard deviation (SD) were calculated for the remaining subsets and ± 2SD ranges are shown in Table 1.
| Subset | Mean | Mean±2SD |
| %CD4+CD45RA+ | 22.3 | 9-36 |
| absolute CD4+CD45RA+/μL | 456.4 | 145-768 |
| total %CD45RA+ | 62.0 | 43-81 |
| total absolute CD45RA+/μL | 1268.7 | 691-1846 |
| %CD3+CD25+ | 28.5 | 13-44 |
| absolute CD3+CD25+/μL | 576.7 | 217-936 |
| %CD3+HLA-DR+ | 8.7 | 1-16 |
| absolute CD3+HLA-DR+/μL | 176.4 | 13-340 |
| %CD25+HLA-DR+ | 3.0 | 1-5 |
| absolute CD25+HLA-DR+/μL | 60.4 | 14-107 |
| total %CD25+ | 33.8 | 17-50 |
| total absolute CD25+/μL | 687.6 | 276-1099 |
| total %HLA-DR+ | 22.8 | 11-34 |
| total absolute HLA-DR+/μL | 460.9 | 198-724 |