Alterations on peripheral blood B-cell subpopulations in very early arthritis patients.
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.
Moura
Rita A
RA
Rheumatology Research Unit, Instituto de Medicina Molecular, Edifício Egas Moniz, Faculdade de Medicina da Universidade de Lisboa, Av. Professor Egas Moniz, 1649-028 Lisboa, Portugal.
Weinmann
Pamela
P
Pereira
Patrícia A
PA
Caetano-Lopes
Joana
J
Canhão
Helena
H
Sousa
Elsa
E
Mourão
Ana F
AF
Rodrigues
Ana M
AM
Queiroz
Mário V
MV
Souto-Carneiro
Maria M
MM
Graça
Luís
L
Fonseca
João E
JE
D000305:Adrenal Cortex Hormones / Q000627:therapeutic use*; D000328:Adult; D000368:Aged; D001168:Arthritis / Q000188:drug therapy / Q000276:immunology*; D016175:B-Lymphocyte Subsets / Q000276:immunology*; D001773:Blood Cells / Q000276:immunology; D016022:Case-Control Studies; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D018655:Lymphocyte Count; D008297:Male; D008727:Methotrexate / Q000627:therapeutic use*; D008875:Middle Aged; D013997:Time Factors; D055815:Young Adult
D000305:Adrenal Cortex Hormones; D008727:Methotrexate