title: Serum antibodies against prostasomal clusterin in prostate cancer patients.
abstract: OBJECTIVE
  Clusterin is a ubiquitous secretory sulphated glycoprotein present in prostasomes. It is an anti-apoptotic mediator in prostate cancer and is among the most frequently occurring prostasomal proteins immunogenic in prostate cancer patients. The aim of the present study was to investigate the occurrence of anti-clusterin antibodies in the serum of patients with prostate cancer and whether there is a relationship between anti-clusterin antibody titres and other clinico-pathological variables.
  
  
  METHODS
  Serum samples were collected from 391 consecutive patients with suspected prostate cancer (150 benign prostate and 241 prostate cancer). The patients' serum samples were used in an ELISA where microtitre wells were coated with purified clusterin from serum of a healthy volunteer. Flow cytometric studies of clusterin and prostasomes were performed.
  
  
  RESULTS
  Flow cytometric analyses revealed the presence of clusterin on the surface of seminal prostasomes. Anti-clusterin ELISA titres in sera of patients did not differ significantly from those of a control group. A significant "inverse" correlation existed between anti-clusterin ELISA titres and lymph node metastases (p = 0.047), but only 11 out of 161 patients had metastases. These titres correlated significantly with total prostate (p = 0.021) and transitional zone (p = 0.015) volumes of the patients.
  
  
  CONCLUSIONS
  The correlation between serum anti-clusterin antibody titres and other clinico-pathological variables was generally weak in prostate cancer patients, although clusterin has been assigned an important role in tumourigenesis and progression of prostate cancer. However, the anti-clusterin antibody titre appeared to be related to prostate volume, correlating to both transitional zone volume and total volume of the prostate.
authors.affiliation: Department of Medical Sciences, Clinical Chemistry, University Hospital, Uppsala, Sweden. gunnar.ronquist@akademiska.se
authors.forename: K G
authors.initials: KG
authors.lastname: Ronquist
authors.forename: L
authors.initials: L
authors.lastname: Carlsson
authors.forename: G
authors.initials: G
authors.lastname: Ronquist
authors.forename: A
authors.initials: A
authors.lastname: Semjonow
authors.forename: C
authors.initials: C
authors.lastname: Wülfing
authors.forename: A
authors.initials: A
authors.lastname: Larsson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000097:blood*; D015153:Blotting, Western; D051152:Clusterin / Q000097:blood* / Q000302:isolation & purification; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000097:blood* / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D051152:Clusterin