Abstracts of the 3rd Joint Meeting of Pathology and Laboratory Medicine

Background: Degenerative forms of mitral valve diseases (MVDs) are complex pathologies. Thus, it is difficult to make generalizations about MVD pathways or genetic risk factors. However, a key role of metalloproteinases (MMPs) in their pathophysiology is emerging. Thus, we performed a study to assess eventual associations of some functional SNPs in MMP-2 and MMP-9 genes with MVD risk, symptom severity and short- and long-term (4.8 years) complications. Methods: For this purpose, 90 patients and two control groups were genotyped for MMP-2 and MMP-9 gene SNPs, and systemic levels of proatrial natriuretic peptide (ANP), and two enzymes were quantified and correlated to the MMP-2 and MMP-9 SNPs. In addition, associations between these SNPs and symptom severity and short- and long-term complications were evaluated. Results: Interestingly, rs3918242 MMP-9 and rs2285053 MMP-2 SNPs were significantly represented in cases compared to two control groups, and were associated with a higher MVD risk. Cases stratified for New York Heart Association (NYHA) symptoms, and particularly NYHA III+IV, with rs3918242 CT+TT MMP-9 and rs2285053CT+TT genotypes also showed higher severity related to significant higher systemic levels of MMP enzymes and pro-ANP at enrollment and 4.8-year follow-up times. In addition, cases with these genotypes, and particularly NYHAIII+IV, had a very significant percentage of complications, particularly at the 4.8-year follow-up. Surprisingly, 20% of patient controls developed MVD at 4.8- year follow-up and were carriers of these genotypes. Conclusions: The associations observed seem to suggest that the two SNPs might represent useful biomarkers and targets for preventing and monitoring MVDs, leading to a more appropriate management and outcome