Journal of Molecular Biomarkers & Diagnosis

Measurement of Serum EGF Levels, a Methodological Approach: Learning What Means “Low-/High-Concentration of EGF In Serum”. Some Clinical Implications

Abstract

Gonzalez-Perez Idania, Cáceres Lavernia Haslen Hassiul, Carr Pérez Adriana and León Monzón Kalet

Background: Although the contribution of platelets to the measured serum EGF levels was reported by Oka since 1983, the majority of reports in healthy donors or patients do not control clotting times during the collection of the sera. This results in a variation of the notified values, additionally to the one already caused by the functional EGF SNP of the gene, that modulates the expression of the molecule. Both issues -platelets and SNP- make the conventional stratification by absolute serum EGF levels not suitable. Within this study we evaluated serum EGF levels in a panel of 105 healthy Cuban donors, balanced by gender and age (from 18-78 years). As a result, a new stratification methodology for the comparison between individuals was proposed.

Methods: The EGF was estimated in sera collected at two different clotting times: 1h and 4h. Comparisons between groups were carried out. The estimations, normalized through the calculation of ratios from the two measured levels (r=[EGF]1h/[EGF]4h), were used for the stratification.

Results: Differences were found by age (4h, donors younger and older than 45 years, p=0.0083) and gender (1h, p=0.0167), and between 1h and 4h levels (p<0.0001, n=105). While 38 out of 105 individuals ranked different in 1h and 4h conventional stratifications, the methodology using ratios yielded a unique score for each individual.

Conclusions: The proposed methodology of stratification by ratios, in contrast to the conventional approach, allows for a proper comparison between EGF levels and individuals. Thus, it should have an impact on diseases for which the association of EGF with the illness has been established, aiding to clarify the connection of the molecule with the disease. This work might be of value to clinicians, scientists, and the healthcare community in general, conducting research regarding the role of EGF as a biomarker.