Detection of prostate-specific antigen coupled to immunoglobulin M in prostate cancer patients.
BACKGROUND
Several reports indicate that the main biomarkers for liver and colorectal cancer circulating in the blood stream associate with immunoglobulin M (IgM) to form stable complexes that show increased diagnostic relevance compared to circulating free biomarkers.


METHODS
To further investigate the association between cancer biomarkers and IgM, we assessed the presence of prostate-specific antigen (PSA) as IgM complexes in sera of patients with prostate cancer (PC) or benign prostatic hyperplasia (BPH) in comparison with PSA measurements.


RESULTS
PSA-IgM levels were significantly elevated in 40% (20/50) and 12% (6/51) of PC and BPH patients, respectively, compared to 22% (11/50) and 29% (15/51) of PSA positive patients in the same groups. Detection of cancer markedly increased from 22 to 60% by co-determination of both markers (30/50 patients). Significantly elevated levels of PSA-IgM were found in 13 out of 30 patients affected by PC with a PSA value between 4 and 10 ng/mL and only in 4 out of 34 BPH patients in the same PSA range.


CONCLUSIONS
The results are the first evidence of the occurrence of PSA-IgM complexes in patients with prostate cancer. The gain achieved in cancer detection by using the combination of PSA and PSA-IgM suggests that PSA-IgM could be a complementary serological marker of prostate cancer.
Beneduce
Luca
L
XEPTAGEN S.p.A., Via delle Industrie 9, Marghera Venezia, Italy. beneduce@xeptagen.com
Prayer-Galetti
Tommaso
T
Giustinian
Andrea Marcello Grimani
AM
Gallotta
Andrea
A
Betto
Giovanni
G
Pagano
Francesco
F
Fassina
Giorgio
G
D000936:Antigen-Antibody Complex / Q000097:blood*; D019540:Area Under Curve; D014408:Biomarkers, Tumor / Q000097:blood*; D002850:Chromatography, Gel; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood* / Q000737:chemistry / Q000276:immunology; D008297:Male; D017430:Prostate-Specific Antigen / Q000097:blood* / Q000737:chemistry / Q000276:immunology; D011470:Prostatic Hyperplasia / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood*; D012372:ROC Curve; D012680:Sensitivity and Specificity
D000936:Antigen-Antibody Complex; D014408:Biomarkers, Tumor; D007075:Immunoglobulin M; D017430:Prostate-Specific Antigen