Serum amyloid P component: a new biomarker for low sperm concentration?

Abstract

Serum amyloid P component (SAP) is present in seminal plasma, on spermatozoa, and in different tissues of the male reproductive tract, but its function is not known. The aims of this study were to determine if the concentration of SAP in seminal plasma is associated with commonly assessed semen parameters and to investigate if SAP could be a new, indirect biomarker for these parameters. In a cross-sectional study of 203 young volunteers, the concentration of SAP in seminal plasma was measured with a in-house developed enzyme-linked immunosorbent assay. Scatter plots, Pearson's correlation coefficients ( r ), and linear regression models were produced, and SAP showed a statistically significant correlation with sperm concentration ( r = 0.75), sperm number ( r = 0.68), semen volume ( r = −0.19), progressive sperm motility ( r = 0.24), and sperm immotility ( r = −0.20). When the study group was dichotomized, SAP could be used to discriminate samples with a sperm concentration < or ≥5 × 10 6 ml −1 , 15 × 10 6 ml −1 , or 40 × 10 6 ml −1 , and in receiver operating characteristic curves, the corresponding areas under the curves were 0.97, 0.93, and 0.82, respectively, with P < 0.001 for all three cutoff values studied. The concentration of SAP in seminal plasma showed a strong, positive correlation with the concentration of spermatozoa in semen. SAP may be used as a new indirect potential biomarker for sperm concentration in fresh and in frozen, stored samples. In addition, it is envisaged that the assay could be developed into a home fertility test to differentiate between a low and a normal sperm concentration.

Semen Proteomics of COVID-19 Convalescent Men Reveals Disruption of Key Biological Pathways Relevant to Male Reproductive Function

“…Substantial evidence indicates the role of amyloid fibers in various reproductive processes, including gametogenesis, sperm maturation, and fertilization . A recent study by Sonesson et al confirmed the presence of serum amyloid p component and its correlation with sperm concentration . Downregulation of serum amyloid p component (SAMP) in recovered patients indicates the disruption of amyloid fiber formation and crucial reproductive processes due to SARS-CoV-2 infection.…”

“…56 confirmed the presence of serum amyloid p component and its correlation with sperm concentration. 57 Downregulation of serum amyloid p component (SAMP) in recovered patients indicates the disruption of amyloid fiber formation and crucial reproductive processes due to SARS-CoV-2 infection. Besides, pathways such as glycosylation, regulated exocytosis, vesiclemediated transport, and membrane protein proteolysis, which are essential biological processes for fertilization, are also dysregulated in COVID-19-recovered patients.…”

Non-Invasive Diagnostics of Male Spermatogenesis from Seminal Plasma: Seminal Proteins

“…SAP is also a protein of seminal plasma located on sperm flagellum and the tissues of testes and epididymides. Its concentration in seminal plasma correlates with spermiogram parameters [44].…”

Proteomic Landscape of Human Sperm in Patients with Different Spermatogenic Impairments

“…These findings are in agreement with previous studies reporting a correlation between APCS and sperm motility and count in seminal plasma. Previous studies also suggested that APCS may be used as a biomarker for low sperm concentrations [ 44 ]. APCS is localized on the surface of mature sperm specifically in the tail of spermatozoa and plays a physiological role in reproduction, more precisely in tail-associated functions such as sperm motility [ 45 ].…”