Beta-Microseminoprotein in Serum Correlates With the Levels in Seminal Plasma of Young, Healthy Males

Authors

  • Camilla Valtonen-André,

    1. Department of Laboratory Medicine, Division of Clinical Chemistry, Lund University, Malmö University Hospital, Malmö, Sweden
    Search for more papers by this author
  • Charlotta Sävblom,

    1. Department of Laboratory Medicine, Division of Clinical Chemistry, Lund University, Malmö University Hospital, Malmö, Sweden
    Search for more papers by this author
  • Per Fernlund,

    1. Department of Laboratory Medicine, Division of Clinical Chemistry, Lund University, Malmö University Hospital, Malmö, Sweden
    Search for more papers by this author
  • Hans Lilja,

    1. Department of Laboratory Medicine, Division of Clinical Chemistry, Lund University, Malmö University Hospital, Malmö, Sweden
    2. Department of Clinical Laboratories, Urology, and Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York
    Search for more papers by this author
  • Aleksander Giwercman,

    1. Department of Clinical Sciences, Fertility Center, Lund University, Malmö University Hospital, Malmö, Sweden.
    Search for more papers by this author
  • Åke Lundwall

    Corresponding author
    1. Department of Laboratory Medicine, Division of Clinical Chemistry, Lund University, Malmö University Hospital, Malmö, Sweden
    Search for more papers by this author

Wallenberglaboratory, 4th floor, University Hospital MAS, SE-205 02 Malmö, Sweden (e-mail: ake.lundwall@med.lu.se).

Abstract

ABSTRACT: Beta-microseminoprotein (MSP) is one of the most abundant proteins secreted by the prostate gland. Because MSP is also synthesized in nonreproductive organs, the establishment of a solid relationship between the levels of MSP in serum and semen is crucial for future studies connecting MSP with aging or diseases of the prostate gland. We developed a specific, competitive, europium-based immunoassay to measure MSP in serum and seminal plasma. We also produced recombinant MSP in insect cells using baculo virus and purified it to homogeneity by a novel approach with ethanol extraction and gel filtration. The median values of MSP in 205 young men were 12 μg/L (2.5–97.5 percentile, 4.9–26 μg/L) in serum and 0.53 g/L (2.5–97.5 percentile, 0.13–2.0 g/L) or 1.8 mg (2.5–97.5 percentile, 0.32–6.6 mg) in seminal plasma. MSP in serum showed significant correlation to MSP in seminal plasma (r = .50, P < .001). Significant correlations were also found in seminal plasma between MSP and prostate-specific antigen (PSA) (r = .65, P < .001) and between MSP and Zn2+ (r = .54, P < .001). The yield of recombinant MSP in culture medium was 35 mg/L or higher, and recovery following ethanol extraction was 80%–90%. MSP in serum reflects the prostate secretion of MSP, and correlations were also found in seminal plasma between MSP and PSA and Zn2+. This suggests that MSP in serum can be used as a marker of prostate secretion, despite the contribution from extra prostatic tissues.

Ancillary