CD14 promoter polymorphism (- 159C-->t) is not associated with myocardial infarction or coronary artery disease in patients with assumed high genetic risk.

OBJECTIVE: Inflammation plays a major role in the pathogenesis of coronary artery disease (CAD) and myocardial infarction (MI). CD14 is the receptor for bacterial lipopolysaccharide in monocytes and mediates the production of proinflammatory cytokines. The promoter of the CD14 gene has a polymorphic site in position - 159 (C-->T) and T-homozygotes have been shown to express higher amounts of CD14 by some investigators. We and others have found an association of the T-allele with past MI in former studies, but reports in the literature are contradictory. METHODS AND RESULTS: We investigated a study group with an assumed high genetic risk by selecting 200 patients suffering from angiographically verified CAD or MI who were younger than 50 years or who had only one or no risk factor (hypertension, smoking, elevated body mass index, impaired glucose tolerance or elevated cholesterol levels). We used 252 healthy subjects as controls. Additionally, the levels of soluble (s) CD14 in plasma and amount of membranous (m) CD14 on the surface of monocytes were determined in different genotypes. We found no association of either genotype with CAD, extent of CAD, or a history of MI. No significant correlation was found after adjustment for vascular risk factors. In addition, no significant differences in the density of monocyte mCD14 or in plasma levels of sCD14 were detectable among the various genotypes. CONCLUSIONS: The assumed weak association of the TT-genotype of the CD14 promoter polymorphism with MI could not be not established in a well-defined group of young patients with a high genetic risk. The association of the polymorphism with expression of sCD14 or mCD14 was not confirmed.

Localization of the Br polymorphism on a 144 bp exon of the GPIa gene and its application in platelet DNA typing.

Alloimmunization against the human platelet alloantigen system Br (HPA-5) is the second most common cause of neonatal alloimmune thrombocytopenia (NAIT) in Caucasian populations. We have recently shown that a single base polymorphism at position 1648 on platelet mRNA coding for GPIa results in an aminoacid substitution at position 505 on the mature GPIa which is associated with the two serological defined Br phenotypes. Since DNA-typing of platelet alloantigens offers possibilities for useful clinical applications, we designed genomic DNA-based restriction fragment length polymorphism (RFLP) typing for Br alloantigens. To establish this technique we analyzed the genomic organization of GPIa adjacent to the polymorphic base. Using the polymerase chain reaction (PCR) of blood cell DNA we have identified two introns (approximately 1.7 and 1.9 kb) flanking a 144 bp coding sequence of the GPIa gene encompassing the polymorphic base 1648. Based on the intron sequence, a PCR primer was constructed to amplify a 274 bp fragment which was used for allele-specific RFLP to determine the Br genotypes. The results of RFLP analysis using MnlI endonuclease obtained from 15 donors (2 Bra/a, 2 Bra/b and 11 Brb/b) correlate perfectly with serological typing by monoclonal antibody-specific immobilization of platelet antigens (MAIPA) assay.

[Comparison of serologic typing and DNA typing of platelet alloantigens]. / Vergleich zwischen serologischer Typisierung und DNA-Typisierung von Plättchenalloantigenen.

Platelet alloantigens of the Zw, Ko, Bak und Br systems were determined by restriction fragment length polymorphism (RFLP) analysis of appropriate PCR products in 98 unselected patients. Results were compared with serological typing by monoclonal antibody immobilization of platelet antigens (MAIPA) and platelet agglutination.

Genomic RFLP typing of human platelet alloantigens Zw(PlA), Ko, Bak and Br (HPA-1, 2, 3, 5).

The diallelic human platelet alloantigen systems 1-5 have been found to result from single base pair substitutions in the encoding genes of platelet membrane glycoproteins IIIa, Ib, IIb and Ia. This is the basis of DNA methods for determination of platelet alloantigens. In this study, 98 blood donors were typed in the HPA-1, 2, 3 systems and, for the first time, in the HPA-5 system. Serologically obtained data (MAIPA and platelet agglutination) were compared with results from analysis of restriction fragment length polymorphisms (RFLP). Discordances were found in the HPA-2 and 3 systems and can be ascribed to false typing results in both the serological and genomic methods. In the HPA-1, 2 and 5 systems, all samples were typed correctly with RFLP analysis. Serologically, two donors were falsely typed positive with anti-HPA-2b in platelet agglutination and one donor with anti-HPA-3a in MAIPA assay. In the HPA-3 system, another four donors were misinterpreted to be HPA-3a negative in RFLP analysis. Possible technical problems in PCR-RFLP-typing are discussed and another strategy of HPA-1 typing using the restriction enzyme Scr FI is evaluated.

New polymorphism on platelet glycoprotein IIIa gene recognized by endonuclease Msp I: implications for PlA typing by allele-specific restriction analysis.

BACKGROUND: Five human platelet alloantigen systems have been shown to result from single base pair substitutions in encoding regions of platelet glycoprotein genes IIIa, Ib, IIb, and Ia. For each of the diallelic systems, at least one restriction enzyme is known to cut only one of the two haplotypes. In the PlA system, restriction endonucleases Nci I and Msp I both recognize the PlA2 allele. STUDY DESIGN AND METHODS: A causal observation of an unexpected Msp I restriction pattern of a PlA2/PlA2 individual was made. Samples from 261 blood donors were then typed for antigens of the PlA system by restriction fragment length polymorphism analysis using the Nci I and Msp I restriction enzymes. RESULTS: Applying both enzymes, concordant restriction patterns were found in 258 of 261 blood donors. Three donors had a base pair mutation on the PlA2 allele, which creates an additional restriction site for Msp I 20 base pairs downstream from the PlA polymorphic site. Nucleotide sequence analysis revealed a CT217-->CG217G base exchange resulting in a Leu40-->Arg40 polymorphism of glycoprotein IIIa. CONCLUSION: Presuming that the mutation is not a singular phenomenon and also occurs with the PlA1 haplotype, it could lead to false interpretations of restriction analysis with Msp I. To exclude that possibility, Nci I is preferred for restriction fragment length polymorphism typing in the PlA system.

A new promoter polymorphism in the gene of lipopolysaccharide receptor CD14 is associated with expired myocardial infarction in patients with low atherosclerotic risk profile.

Recent findings suggest that inflammation plays a role in atherosclerosis and its acute complications. Cellular response in infections with Gram-negative bacteria is mediated by bacterial lipopolysaccharide (LPS), which activates monocytes to expression of cytokines, growth factors, and procoagulatory factors via LPS receptor CD14. Endothelial cells and smooth muscle cells are stimulated by a complex of LPS and soluble CD14. In this study, LPS receptor CD14 was analyzed to find genetic variants and check them for an association with coronary artery disease or myocardial infarction (MI). When screening the CD14 gene by single-strand conformation polymorphism analysis, a promoter polymorphism was detected and confirmed as a T-to-C exchange at position -159. We determined the genotypes of 2228 men who had undergone coronary angiography for diagnostic purposes. Within the total study group there was no significant association of either genotype with MI or coronary artery disease. However, in a subgroup with low coronary risk (normotensive nonsmokers), a relative risk for MI in probands homozygous for the T allele could be evaluated (OR, 1.6; 95% CI, 1.0 to 2.4; P<0.05). The association was even stronger in low-risk patients older than 62 years (OR, 3.8; 95% CI, 1.6 to 9.0; P<0.01). In conclusion, we describe a new CD14 promoter polymorphism that is associated with MI, especially in older patients with a low atherosclerotic risk profile.