Using Surface-Enhanced Laser Desorption / Ionization Time-of-Flight Mass Spectrometry (SELDI-TOF-MS), we aimed to detect differences in protein profile in serum samples of two lacunar stroke subtypes. SELDI-TOF-MS, followed by protein identification, was performed in samples of 8 first-ever lacunar stroke patients with MR imaging showing a single symptomatic lacunar lesion (type 1), and 8 with multiple additional "silent" lacunar lesions and extensive white matter lesions (type 2). A 16 kDa protein, identified as alpha-2-chain of haptoglobin (Hp), was found to be overrepresented in type 1 compared to type 2 (peak intensity 12.5 vs. 5.0; p=0.02). As a polymorphism with two alleles, Hp-1 and Hp 2, determines the presence of alpha-1 and/or alpha-2-chains in the Hp-molecule, Hp phenotypic analysis was performed. Hp 1 : Hp-2 allele frequency was 0.562 : 0.438 in type 1 and 0.812 : 0.188 in type 2 (population reference approximately 0.4 : 0.6). We conclude that the overrepresentation of the alpha-2-chain in lacunar stroke type 1 compared to type 2 relates to a higher Hp-2 allele frequency in the former. Yet, compared to population reference, the phenotype distribution in both patient groups deviates towards a high Hp-1 allele frequency. Our findings suggest a role for the Hp gene in the etiology of cerebral small vessel disease. Larger studies are now needed to explore this new candidate gene.
Staals, J., Bons, J., van Oostenbrugge, R. J., Knottnerus, I. L., van Dieijen-Visser, M. P., Bouwman, F. G., Mariman, E. C., Delanghe, J. R., Lodder, J., & Wodzig, W. K. (2008). A SELDI-TOF-MS Study in Lacunar Stroke with Subsequent Haptoglobin Phenotyping. Current Neurovascular Research, 5(2), 93-98. https://doi.org/10.2174/156720208784310187