Advertisement

The accumulative and maturative type of B-cell activation in synovitis: a new concept of B-cell activation in autoimmune diseases

  • VK Krenn
  • LM Morawietz
  • H-JK Kim
  • JM Möller
  • CB Berek
Meeting abstract
  • 851 Downloads

Keywords

Rheumatoid Arthritis Synovitis Maturative Type Germinal Centre Histological Pattern 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Introduction

B-cells and plasma cells in chronic synovitis of osteoarthritis (OA), reactive arthritis (ReA) and rheumatoid arthritis (RA) show two different histological patterns: lymphoplasmacellular pattern and germinal centre (GC) pattern. To clarify what immunological mechanisms stands beyond these histological patterns, IgVh gene analysis from the B and plasma cells present in those patterns was performed.

Methods

IgVh gene repertoires were determined from RNA (OA = 5, ReA = 2, RA = 5), prepared from tissue cryosections and from isolated B-cells and plasma cells (plc) by micromanipulation. The B-cell environment was analysed immunohistochemically by detecting plc (IgM, IgG, IgA), B-lymphocytes (CD20) and Ki-67 positive (proliferating) cells.

Results

In the lymphoplasmacellular pattern of OA (n = 5), somatically highly mutated IgVh genes (R/S: CDR=R/S = 5.3; Fr=R/S = 2.0) could be detected, but no clonal relation could be established amongst them. The plc of the GC pattern in ReA (n = 2) and RA (n = 5) revealed highly somatically mutated IgVh genes: R/S: CDr=R/S = 3.4; Fr=R/S = 1.7; and CD20+ B cells in germline configuration. A clonal relation between low mutated B cells and highly mutated plc could be established indicating a local clonal expansion. A proliferation of CD20+ B cells could only be observed in GC.

Conclusions

Therefore, two different patterns of B-cell activation may be defined: (1)The accumulative type: already activated B cells migrate into the synovial tissue and accumulate there without further IgVh diversification. (2)The maturative type of B-cell proliferation with IgVh diversification occurring in a GC like reaction. The two different patterns of B-cell activation may reflect that different antigens are involved in autoimmune and degenerative diseases. Since in organ specific autoimmune diseases (RA, Morbus Sjögren, Morbus Basedow) a local germinal centre reaction takes place, it is likely that the B cells are expanded by disease specific antigens. The experimental expression of IgVh genes isolated from these germinal centre B cells may therefore lead to the identification of pathogenic organ specific antigens.

Copyright information

© BioMed Central Ltd 2002

Authors and Affiliations

  • VK Krenn
    • 1
  • LM Morawietz
    • 1
  • H-JK Kim
    • 2
  • JM Möller
    • 1
  • CB Berek
    • 2
  1. 1.Universitàtsklinikum CharitéBerlinGermany
  2. 2.RheumaforschungszentrumBerlinGermany

Personalised recommendations