Prognostic potential of a PSA complex in sera of prostate cancer patients with α2-macroglobulin deficiency

✍ Scribed by Yuhsaku Kanoh; Tadashi Ohara; Shin Egawa; Shiro Baba; Tohru Akahoshi

• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: English
• Weight: 101 KB
• Volume: 22
• Category: Article
• ISSN: 0887-8013
• DOI: 10.1002/jcla.20260

✦ Synopsis

Abstract

We previously reported on a number of cases of metastatic prostate cancer (PCa) in which serum α2‐macroglobulin (α2M) levels were markedly decreased to less than 20 mg/dl (α2M deficiency). In order to elucidate the relative proportions of free and a prostate‐specific antigen (PSA) complex in PCa patients with α2M deficiency, we have assessed serum α2M and total PSA levels, and ratios of free PSA to total PSA (F/T ratios) at each stage of PCa. Moreover, the PSA reactivity profile was determined on fractionated serum specimens of PCa patients using high‐performance liquid chromatography (HPLC) using a TSKG‐3000 SWXL column. Measurement of α2M concentration was performed by laser‐nephelometry. PSA levels were determined by enzyme immunoassay, free PSA by radioimmunoassay. In those PCa patients with α2M deficiency, serum α2M and F/T ratios were lower, whereas PSA levels were higher when compared with those PCa patients without α2M deficiency (P<0.05). PSA elution profiles on HPLC columns revealed two major peaks. The proportion of PSA‐antichymotrypsin (PSA‐ACT) increased, whereas the proportion of free PSA decreased in PCa patients with α2M deficiency as compared with those PCa patients without α2M deficiency. F/T ratios were significantly lower in PCa patients with α2M deficiency than in those PCa patients without α2M deficiency. PSA‐ACT and F/T ratio may be useful for monitoring bone metastasis in PCa. J. Clin. Lab. Anal. 22:302–306, 2008. © 2008 Wiley‐Liss, Inc.