Serum levels of soluble CD21 in patients with systemic sclerosis.
Systemic sclerosis (SSc) is a systemic disorder that typically results in fibrosis of the skin and multiple internal organ systems. Although the precise mechanism is unknown, overproduction of extracellular matrix proteins, including collagens and fibronectins, and aberrant immune activation might be involved in the pathogenesis. The soluble cluster of differentiation 21 (sCD21) represents the extracellular portion of the CD21 glycoprotein that is released by shedding from the cell surfaces into plasma. sCD21 binds complement fragments and activates monocytes through binding to membrane CD23. The present study was undertaken to investigate the serum levels of sCD21 in patients with SSc. Serum sCD21 levels were reduced with age both in patients with SSc and normal controls. Serum sCD21 levels in patients with SSc were significantly decreased compared to those in control subjects. When we divided patients with SSc into limited cutaneous SSc (lcSSc) and diffuse cutaneous SSc (dcSSc), patients with lcSSc had lower levels of serum sCD21 than those with dcSSc. Moreover, the prevalence of pulmonary fibrosis in the patients with dcSSc inversely correlated with serum sCD21 levels. Our finding may support the notion that B-cell activation is involved in the mechanism for pulmonary fibrosis and skin sclerosis.
Department of Dermatology, Faculty of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
Manabu
M
Tomita
Takafumi
T
Kadono
Norihito
N
Yazawa
Tomohiko
T
Kawashima
Zenshiro
Z
Tamaki
Ryuichi
R
Ashida
Hanako
H
Ohmatsu
Yoshihide
Y
Asano
Makoto
M
Sugaya
Masahide
M
Kubo
Hironobu
H
Ihn
Kunihiko
K
Tamaki
Shinichi
S
Sato
D000328:Adult; D000368:Aged; D015536:Down-Regulation / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011658:Pulmonary Fibrosis / Q000097:blood / Q000453:epidemiology / Q000276:immunology; D017464:Receptors, Complement 3d / Q000097:blood*; D012595:Scleroderma, Systemic / Q000097:blood* / Q000453:epidemiology* / Q000276:immunology; D012867:Skin / Q000276:immunology / Q000473:pathology; D012995:Solubility
D017464:Receptors, Complement 3d