Studies have continued on the demonstration of the terminal complement complex C5b-9 in fluids and tissues of patients with a variety of diseases.  SC5b-9 was demonstrated in the serum of patients with Guillain Barre Syndrome (GBS) and chronic recurrent polyneuritis.  The serum levels of SC5b-9 peaked on the 3-5th day after admission and declined thereafter, paralleling the levels of anti peripheral nerve myelin in serum as well as the disease status of the patients.  C5b-9 was also detected by immuno histochemistry in the peripheral nerves from a patient with GBS.  SC5b-9 was detected in the CSF from patients with Sjogren's Syndrome or Systemic Lupus Erythematosis who manifested CNS involvement.  C5b-9 was not detected in patients without CNS involvement.  C5b-9 was detected in the synovial membrane from patients with rheumatoid arthritis.  Results from all of these studies suggest that generation of C5b-9 may contribute to the tissue damaging process in these diseases.