Diffuse CNS involvement in systemic lupus erythematosus: intrathecal synthesis of the 4th component of complement

Neurology. 1990 Oct;40(10):1593-6. doi: 10.1212/wnl.40.10.1593.


In extracerebral systemic lupus erythematosus (SLE), the complement system plays a prominent pathogenic role, and decreased serum concentration of the 4th component (C4) is a reliable indicator of systemic disease activity. In diffuse CNS-SLE, however, the pathogenic role of complement is less clear. In 12 patients with active diffuse CNS-SLE presenting with delirium (4), organic personality syndrome (3), or generalized seizures (5), we determined the CSF indexes of the complement components C3, C4, and factor B, and of IgG, IgA, and IgM. There was a significant increase of the C4 index in these patients compared with controls and a significantly higher CSF C4 index in patients with an increased IgM index. We conclude that intrathecal C4 is being produced in diffuse CNS-SLE.

Publication types

  • Comparative Study

MeSH terms

  • Adolescent
  • Adult
  • Central Nervous System / metabolism*
  • Complement C3 / analysis
  • Complement C3 / cerebrospinal fluid
  • Complement C4 / analysis
  • Complement C4 / cerebrospinal fluid*
  • Complement Factor B / cerebrospinal fluid
  • Female
  • Humans
  • Immunoglobulins / cerebrospinal fluid
  • Lupus Erythematosus, Systemic / cerebrospinal fluid
  • Lupus Erythematosus, Systemic / metabolism*
  • Male
  • Middle Aged
  • Osmolar Concentration


  • Complement C3
  • Complement C4
  • Immunoglobulins
  • Complement Factor B