The Correlation Between Serum Matrix Metalloproteinase-9 And Cerebral Microbleeds In Patients With Cerebral Small Vessel Disease

BackgroudThe imaging signs of cerebral small vessel disease(CSVD)mainly include white matter hyperintensities,lacunae of presumed vascular origin and cerebral microbleeds(CMBs).CMBs appear as small,round or ovoid foci of homogeneous signal intensity on susceptibilityweighted imaging(SWI).CMBs mainly reflect the severity of underlying small vessel disease.Matrix metalloproteinase-9(MMP-9)is a mostly extracellularly operating proteases,which can be obviously activated after various physiological stimuli and pathological damages and lead to blood–brain barrier(BBB)damage.Previous studies have found that elevated serum MMP-9 level is a risk factor for patients with CSVD,but the correlation between MMP-9 and CMBs and the underlying mechanism are still unclear.ObjectiveTo investigate the correlation between serum MMP-9 level and the number and location of CMBs in patients with CSVD.MethodsA total of 120 CSVD patients admitted to the Department of Neurology of the First Affiliated Hospital of the Xinxiang Medical University from January 2019 to January2021 were enrolled.Among them,78 patients with CMBs served as CMBs group and 42 patients without CMBs served as no-CMBs group.The clinical data and biochemical indicators of the two groups were collected.Serum MMP-9 levels were measured by enzyme linked immunosorbent assay,and according to susceptibility-weighted imaging(SWI),the number of CMBs was divided into three levels: 1(n=1-2),2(n=3-10)and 3(n>10).According to the microbleed anatomical rating scale(MARS),CMBs were divided into lobar,deep or infratentorial and mixed groups.The relationship between serum MMP-9 level and the number and location of CMBs in patients with CSVD was analyzed.Results1.There was significant difference in hypertension,white matter hyperintensities,homocysteine(Hcy)level and MMP-9 level between the two groups(P<0.05).2.Multivariate logistic analysis showed that hypertension(OR=2.402,95%CI=1.045-5.520,P=0.039),high level of Hcy(OR=1.056,95%CI=1.013-1.101,P=0.011)and MMP-9(OR=2.541,95%CI=1.325-6.248,P=0.007)were an influencing factors of CMBs.3.After grading the number of CMBs in patients with CMBs,the results showed that the higher the levels of Hcy and MMP-9,the greater the number of CMBs,and the difference was statistically significant(P<0.05),and the levels of Hcy(r=0.243,P=0.032)and MMP-9(r = 0.362,P =0.001)were positively correlated with the number of CMBs.4.The results of grouping CMBs patients into groups of CMBs showed that the difference in serum MMP-9 levels was statistically significant(P<0.05),and serum MMP-9 levels were an influencing factor for cerebral lobe CMBs(OR=1.107,95%CI=1.011-1.220,P =0.013).Conclusion1.The increase of serum MMP-9 level may be an influencing factor of CMBs in patients with CSVD,and the increase of serum MMP-9 level may be an influencing factor of cerebral lobe CMBs.2.Serum MMP-9 level is positively correlated with the number of CMBs,that is,the higher the serum MMP-9 level,the greater the number of CMBs.