B cell hyperresponsiveness in Sjögren's syndrome.
We examined the production of and responsiveness to B cell growth factor (BCGF) by using proliferation assays in patients with Sjögren's syndrome (SS). We also studied the ability of SS B cells to respond to B cell stimulatory factors (BSF) by measuring the amount of IgG produced in vitro. SS patients showed normal production of and responsiveness to BCGF. They were also demonstrated to show a normal response to Staphylococcus aureus Cowan I (SAC). In addition, cell surface antigens of B cells in the peripheral blood of SS patients were not altered compared with normal controls. However, SS B cells produced a significant amount of IgG in vitro in response to BSF stimulation with or without anti-IgM antibody. Furthermore, there was a positive correlation between the hyperresponsiveness of B cells to BSF in vitro and serum IgG level in SS. We, therefore, suggest that the enhanced response of B cells to BSF might contribute to polyclonal B cell activation in SS.
Yamoaka
K
K
First Department of Medicine, Tokyo Medical and Dental University, Japan.
Miyasaka
N
N
Sato
K
K
Okuda
M
M
Nishioka
K
K
D000328:Adult; D001402:B-Lymphocytes / Q000276:immunology*; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000096:biosynthesis; D066298:In Vitro Techniques; D007376:Interleukin-2 / Q000494:pharmacology; D015847:Interleukin-4 / Q000096:biosynthesis / Q000494:pharmacology; D015850:Interleukin-6 / Q000494:pharmacology; D008213:Lymphocyte Activation; D008875:Middle Aged; D012859:Sjogren's Syndrome / Q000276:immunology*
D007074:Immunoglobulin G; D007376:Interleukin-2; D015850:Interleukin-6; D015847:Interleukin-4