Abnormal B cell differentiation in primary Sjögren's syndrome results in a depressed percentage of circulating memory B cells and elevated levels of soluble CD27 that correlate with Serum IgG concentration.
The percentage of CD27(+) B cells in peripheral blood (PB) of patients with primary Sjögren's syndrome (pSS) is significantly decreased compared to normals. In contrast, serum levels of the soluble form of CD27 (sCD27) are significantly higher in pSS patients, with a strong positive correlation between sCD27 and serum IgG levels. In vitro experiments demonstrate that normal B cells cultured under conditions driving plasma cell differentiation result in the production of substantial amounts of sCD27. Analyses of V(H)-region genes from sorted CD27(+) and CD27(-) B cells from pSS patients confirm that the CD27(+) population corresponds to the somatically mutated memory compartment, as in healthy individuals. Together our data indicate that in pSS, there is an abnormal differentiation of B cells to plasma cells resulting in a depression of the circulating memory B-cell pool and the release of significant amounts of sCD27 and IgG.
Bohnhorst
Janne Ø
JØ
Institute of Immunology, Rikshospitalet University Hospital, University of Oslo, 0027 Oslo, Norway. janne.bohnhorst@labmed.uio.no
Bjørgan
Marie B
MB
Thoen
Jørn E
JE
Jonsson
Roland
R
Natvig
Jacob B
JB
Thompson
Keith M
KM
D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000276:immunology; D001402:B-Lymphocytes / Q000502:physiology*; D019013:CD40 Antigens / Q000502:physiology; D002454:Cell Differentiation; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood* / Q000145:classification; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D007075:Immunoglobulin M / Q000097:blood; D007135:Immunoglobulin Variable Region / Q000235:genetics; D007156:Immunologic Memory; D008297:Male; D008875:Middle Aged; D012859:Sjogren's Syndrome / Q000276:immunology*; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7 / Q000096:biosynthesis / Q000097:blood
D019013:CD40 Antigens; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007143:Immunoglobulin Heavy Chains; D007075:Immunoglobulin M; D007135:Immunoglobulin Variable Region; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7