Value of the peripheral blood B-cells subsets in patients with ankylosing spondylitis.
BACKGROUND
The role of B-cell remains an enigma in the pathogenesis of ankylosing spondylitis (AS). This study aimed to investigate the distributions of B-cells and subsets in peripheral blood of AS patients and observe their changes in etanercept-treated AS patents.


METHODS
We detected the proportions of CD19(+) B-cell, naive B-cell (CD19(+)CD27-), memory B-cell (CD19(+)CD27dim) and plasmablast (CD19(+)CD27high) in peripheral blood of 66 patients with AS (39 at active stage, 27 at stable stage; 35 patients with peripheral joint involvement, 31 patients with axial involvement alone), 30 patients with rheumatoid arthritis (RA) and 30 healthy volunteers using flow cytometry. And then we observed the changes of the above indexes of 39 active AS patients treated with etanercept in a randomized, double-blind, placebo-controlled trial.


RESULTS
(1) Percentages of CD19(+) B-cells in active or peripheral joint involvement AS patients increased more obviously than those in stable or axial involvement alone AS patients (both P = 0.001), and percentage of CD19(+)CD27high B-cells in AS patients with peripheral joint involvement was significantly higher than that in cases with axial involvement alone or healthy volunteers (P = 0.005 and 0.006, respectively); (2) The percentage of CD19(+) B-cells in AS patients was positively correlated with Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) scores, Patient's Global Assessment (PGA) scores, total back pain scores and nocturnal back pain scores (r = 0.270, 0.255, 0.251 and 0.266, P = 0.029, 0.039, 0.042 and 0.031, respectively); (3) At week 6 and week 12, there were no statistical differences of the percentages of B-cells and subsets between etanercept group and placebo group of AS patients (P > 0.05); the percentage of CD19(+) B-cells in etanercept group was higher than that in healthy volunteers at week 12 (t = 3.320, P = 0.003).


CONCLUSIONS
Misbalance is present in B-cells and some subsets in peripheral blood of active AS patients with peripheral joint involved. B-cells might play an important role in the pathogenesis of AS patients. The high percentage of CD19(+) B-cells in active AS patients cannot be down-regulated after 12-week etanercept treatment.
Lin
Qu
Q
Department of Rheumatology, Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510630, China.
Gu
Jie-ruo
JR
Li
Tian-wang
TW
Zhang
Fu-cheng
FC
Lin
Zhi-ming
ZM
Liao
Ze-tao
ZT
Wei
Qiu-jing
QJ
Cao
Shuang-yan
SY
Li
Li
L
D000293:Adolescent; D000328:Adult; D018941:Antigens, CD19 / Q000276:immunology; D001402:B-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D000068800:Etanercept; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007074:Immunoglobulin G / Q000494:pharmacology / Q000627:therapeutic use; D007166:Immunosuppressive Agents / Q000494:pharmacology / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D018124:Receptors, Tumor Necrosis Factor / Q000627:therapeutic use; D013167:Spondylitis, Ankylosing / Q000188:drug therapy / Q000276:immunology*; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7 / Q000276:immunology; D055815:Young Adult
D018941:Antigens, CD19; D007074:Immunoglobulin G; D007166:Immunosuppressive Agents; D018124:Receptors, Tumor Necrosis Factor; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7; D000068800:Etanercept