[Apolipoprotein(a) and cortical cerebral infarction]

To elucidate the correlation of apolipoprotein(a)[apo(a)] with cerebral infarction at the level of molecule and protein.

The serum Lp(a) level, by means of ELISA, the polymorphism of apo(a) protein, by SDS-PAGE/Western blotting combined with silver staining assays, and the sequence polymorphism in 5' control region, the first exon and intron of apo(a) gene, by PCR-SSCP/AFLP assays, were detected in 85 healthy controls and 42 cases of cortical cerebral infarction.

The serum Lp(a) level was remarkadly higher in the patients (153 +/- 3 mg/L) than that in the controls(56 +/- 4 mg/L) (t = 4.15, P < 0.001), even in the subjects with the same apo(a) phenotype. The allele frequency of low molecular weight phenotype containing B, S1 and S2 isoforms was also significantly higher in the patients than that in the controls (0.5238 vs. 0.2941). There were 2 sites of sequence variance in the 5' control region of apo(a) gene in the studied population, which were of significant difference between the patients and controls, and were related to the variation of serum Lp(a) level.

On the basis of proving further the risk of high serum Lp(a) level for AS event, we found that the low molecular weight phenotype of apo(a) is closely associated with cerebral infarction. The variation of serum Lp(a) level is also related to the sequence of apo(a) gene, indicating that both the size and sequence of apo(a) are associated with the susceptibility to cerebral infarction due to its impact on serum Lp(a) level.