Panel Developed for Immunophenotyping Lymphocytes

A lymphoproliferative disorder screening tube (LPD-ST) has been developed with the aim to provide comprehensive immunophenotyping of lymphocyte subsets with minimal need for additional testing.

Lymphoproliferative disorders are a set of disorders characterized by the abnormal proliferation of lymphocytes into a monoclonal lymphocytosis. The two major types of lymphocytes are B cells and T cells, which are derived from pluripotent hematopoietic stem cells in the bone marrow. Individuals who have some sort of dysfunction with their immune system are susceptible to develop a lymphoproliferative disorder.

Scientists at the LifeLabs and their colleagues analyzed a total of 60 peripheral blood (PB), bone marrow (BM), fine needle aspirates (FNA), body fluids (BF), and lymph node biopsies using the newly developed LPD-ST, the University Health Network 10-color LPD panel (two tubes/20 antibodies) and the OneFlow Lymphoid Screening Tube (LST) eight color/12 antibodies. The LPD-ST panel was then implemented in clinical practice using dried monoclonal antibody reagents on 649 patient samples in Sweden.

The LPD-ST consists of CD4/kappa FITC, CD8/lambda PE, CD3/CD14ECD, CD38PC5.5, CD20/CD56PC7, CD10APC, CD19APC-A700, CD5APC-A750, CD57/CD23PB and CD45KO. The Navios flow cytometer instrument scatter settings were optimized using a lysed whole blood sample. OneFlow LST acquisition was performed using a Becton Dickinson (BD) 3-laser, 10-color FACSCanto flow cytometer and BD FACSDiva Software (BD). BD FACSDiva CS&T IVD beads were used to define the baseline of the cytometer and to run a daily performance check of the cytometer.

The scientists reported that in 204 of 649 samples (31%), a monotypic B-cell population was found. Of these cases, a final diagnosis could be rendered in 106 cases (52%), and in the remainder, additional B-cell immunophenotyping was performed. In 20 (3%) samples, an aberrant T-cell population was confirmed by additional testing. Of 425 samples diagnosed as normal/reactive lymphoid tissue, 50 (12%) required additional immunophenotyping, mostly due to an abnormal CD4/CD8 ratio.

The authors concluded that implementation of the developed LPD-ST makes it possible to render a final flow cytometry report in 74% of the samples submitted for LPD immunophenotyping. The tube minimizes the need for additional reflex testing, improves the turn-around time, and reduces the cost of LPD immunophenotyping. It is also suitable for investigating paucicellular samples such as cerebrospinal fluid and FNA. The study was published on April 27, 2017, in the International Journal of Laboratory Hematology.