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Updated: Jun 15, 2026

Flow Cytometry Analysis of Immune Cell Subsets within the Murine Spleen, Bone Marrow, Lymph Nodes and Synovial Tissue in an Osteoarthritis Model
Published on: April 24, 2020
Alterations on peripheral blood B-cell subpopulations in very early arthritis patients
Rita A Moura1, Pamela Weinmann, Patrícia A Pereira
1Rheumatology Research Unit, Instituto de Medicina Molecular, Edifício Egas Moniz, Faculdade de Medicina da Universidade de Lisboa, Av. Professor Egas Moniz, 1649-028 Lisboa, Portugal.
Objective:
To characterize circulating B-cell subpopulations of arthritis patients with <6 weeks of disease duration.
Methods:
Peripheral blood samples were collected from very early untreated polyarthritis patients, with <6 weeks of disease duration, for flow cytometric evaluation of B-cell subpopulations. Samples from patients who were later diagnosed as RA [very early RA (VERA)] were also collected 4-6 weeks after starting a low dose of prednisone (5-10 mg) and 4 months after reaching the minimum effective dose of MTX. A matched healthy group was used as a control.
Results:
VERA patients have a lower percentage of total peripheral blood memory B cells (CD19(+)CD27(+)) and a significant decrease in the frequency of circulating pre-switch memory B cells (CD19(+)IgD(+)CD27(+)) as compared with controls. Therapy with corticosteroids or MTX was unable to restore the normal frequencies of these B-cell subpopulations. A significant decrease in peripheral pre-switch memory B cells is equally observed in other early arthritis patients. Furthermore, no significant differences are found in the frequencies of CD4(+) and CD8(+) T cells in all patient groups.
Conclusions:
In very early polyarthritis patients, there is a reduction in circulating pre-switch memory B cells. The reasons that may account for this effect are still unknown. Short-term corticosteroids and MTX do not seem to have a direct effect on circulating B-cell subpopulations in VERA patients.

