Light chain-restricted autoantibodies in chronic idiopathic thrombocytopenic purpura, but no evidence for circulating clone B-lymphocytes

Ann Hematol. 1996 Jan;72(1):29-34. doi: 10.1007/BF00663013.


In chronic idiopathic thrombocytopenic purpura (ITP) platelet destruction is caused by antibodies directed against platelet membrane glycoproteins (GP), and the predominant autoantigens are known to be GPIb/IX and GPIIb/IIIa. In a recent study we reported that these antibodies frequently had a restricted light chain phenotype, thereby supporting a clonal origin. Similar findings and the presence of clonal B-cell populations in immune thrombocytopenias have been reported by others. In the present study we further explored the hypothesis of clonal B-cell expansions in chronic ITP. Twenty patients with chronic ITP were investigated. Antibodies were detected with an ELISA (MAIPA) specific for GPIb/IX and GPIIb/IIIa; circulating clonal B lymphocytes were assessed by flow-cytometric (FACS) clonal-excess analysis and by analyzing Ig-gene rearrangements (CDR3) with the PCR technique. Nine patients displayed a GP-specific antibody restricted to either kappa or lambda phenotype. However, FACS analysis and Ig-gene rearrangement studies did not disclose any circulating clonal B-cell population. Considering the sensitivity of the FACs analysis and Ig-gene rearrangement for detection of clonal B-cell populations, the hypothesis of clonally derived autoantibodies in ITP is still valid. Most probably, the clonal B-cell expansion responsible for the production of autoantibodies in ITP, if present, is below the detection limit for the techniques employed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Autoantibodies / blood
  • Autoantibodies / immunology*
  • B-Lymphocytes / immunology*
  • Base Sequence
  • Chronic Disease
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Humans
  • Immunoglobulin Light Chains / immunology*
  • Lymphocyte Subsets
  • Male
  • Middle Aged
  • Molecular Sequence Data
  • Purpura, Thrombocytopenic, Idiopathic / blood
  • Purpura, Thrombocytopenic, Idiopathic / immunology*


  • Autoantibodies
  • Immunoglobulin Light Chains