Mannose-binding lectin 2 (Mbl2) gene polymorphisms are related to protein plasma levels, but not to heart disease and infection by Chlamydia

The presence of the single nucleotide polymorphisms in exon 1 of the mannose-binding lectin 2 (MBL2) gene was evaluated in a sample of 159 patients undergoing coronary artery bypass surgery (71 patients undergoing valve replacement surgery and 300 control subjects) to investigate a possible association between polymorphisms and heart disease with Chlamydia infection. The identification of the alleles B and D was performed using real time polymerase chain reaction (PCR) and of the allele C was accomplished through PCR assays followed by digestion with the restriction enzyme. The comparative analysis of allelic and genotypic frequencies between the three groups did not reveal any significant difference, even when related to previous Chlamydia infection. Variations in the MBL plasma levels were influenced by the presence of polymorphisms, being significantly higher in the group of cardiac patients, but without representing a risk for the disease. The results showed that despite MBL2 gene polymorphisms being associated with the protein plasma levels, the polymorphisms were not enough to predict the development of heart disease, regardless of infection with both species of Chlamydia.

Chlamydia pneumoniae e aterosclerose: identificaçäo do DNA bacteriano na parede arterial / Chlamydia pneumoniae and atherosclerosis: identification of bacterial DNA in the arterial wall

OBJECTIVE : The intracellular Gram-negative bacterium Chlamydia pneumoniae has been associated with atherosclerosis. The presence of Chlamydia pneumoniae has been investigated in fragments of the arterial. METHODS: Arterial fragments obtained from vascular surgical procedures in 58 patients were analyzed. From these patients, 39 were males and the mean age was 65ñ6 years. The polymerase chain reaction was used to identify the bacterial DNA with a pair of primers that codify the major outer membrane protein (MOMP) of Chlamydia pneumoniae. The amplified product was visualized by electrophoresis in the 2 porcento agarose gel stained with ethidium bromide, and it was considered positive when migrating in the band of molecular weight of the positive controls. RESULTS: Seven (12 per cent) out of the 58 patients showed positive results for Chlamydia pneumoniae. CONCLUSION: DNA from Chlamydia pneumoniae was identified in the arterial wall of a substantial number of patients with atherosclerosis. This association, which has already been described in other countries, corroborates the evidence favoring a role played by Chlamydia pneumoniae in therogenesis.