Clonal Analysis of Regulatory T Cell Defect in Patients with Autoimmune Polyendocrine Syndrome Type 1 Suggests Intrathymic Impairment.

Mutations in the autoimmune regulator gene disrupt thymic T cell development and negative selection, leading to the recessively inherited polyendocrine autoimmune disease autoimmune polyendocrine syndrome type 1 (APS-1). The patients also have a functional defect in the FOXP3+ regulatory T cell population, but its origin is unclear. Here, we have used T cell receptor sequencing to analyse the clonal relationship of major CD4+ T cell subsets in three patients and three healthy controls. The naive regulatory T cells showed little overlap with helper T cell subsets, supporting divergence in the thymus. The activated/memory regulatory T cell subset displayed more sharing with helper T cells, but was mainly recruited from the naive regulatory T cell population. These clonal patterns were very similar in both patients and controls. However, naive regulatory T cells isolated from the patients had a significantly longer T cell receptor complementarity-determining region 3 than any other population, suggesting failure of thymic selection. These data indicate that the peripheral differentiation of regulatory T cells in APS-1 patients is not different from that in healthy controls. Rather, the patients' naive regulatory T cells may have an intrinsic defect imprinted already in the thymus.

Molecular characterisation of Mycobacterium bovis isolates from cattle carcases at a city slaughterhouse in Uganda.

During a period of eight months, the carcases of 16,800 slaughter cattle were inspected at a city abattoir in Uganda. Eighty-seven of them had tuberculosis-like lesions and tissue samples were cultured. Only 17 cultures yielded acid-fast bacilli; 11 of them were confirmed as Mycobacterium bovis and six as non-tuberculous mycobacteria (NTM). GenoType Mycobacterium assays on the six NTM identified two as Mycobacterium fortuitum and one as Mycobacterium intracellulare, but three were unidentified. Characterisation of the M bovis isolates by spoligotyping and IS6110 restriction fragment length polymorphism (RFLP) revealed that five of the six spoligotype patterns observed in the 11 strains had not been previously reported, and seven of the nine isolates typed by RFLP had multicopy number IS6110 patterns. Six of the 11 infected carcases had multiple sites of infection, but none was condemned as unfit for human consumption.

Vitamin C for preventing and treating tetanus.

BACKGROUND: Tetanus is a severe infection that can be prevented by vaccination. In developing countries vaccination coverage is not always high and in developed countries cases may still occur, particularly in elderly people owing to their reduced immunoprotection. It has been estimated that there are about one million cases of tetanus per year globally. In animal studies, vitamin C protected against various infections. In a study with rats, vitamin C protected against tetanus toxin. OBJECTIVES: To assess the prophylactic and therapeutic effect of vitamin C in tetanus. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2007, issue 4), MEDLINE (1950 to January 2008), EMBASE (1980 to 2008 Week 03), the Cochrane Wounds Group Specialised Register (January 2008), the Cochrane Infectious Diseases Group Specialised Register (June 2007), and the reference lists of relevant reviews and monographs. SELECTION CRITERIA: We included controlled trials of vitamin C as a prevention or treatment for tetanus, whether or not placebo controlled, in any language, published or unpublished. Two authors independently made inclusion decisions. DATA COLLECTION AND ANALYSIS: Both review authors independently extracted data from trial reports. MAIN RESULTS: One single trial was eligible for inclusion. This non randomised, controlled, unblinded treatment trial involved 117 tetanus patients and was undertaken in Bangladesh. Vitamin C at a dosage of 1 g/day was administered intravenously alongside conventional treatment. At recruitment, the participants were stratified into two age groups and the results were reported by age. In the children aged 1 to 12 years (n = 62), vitamin C treatment was associated with a 100% reduction in tetanus mortality (95% confidence interval from -100% to -94%). In people aged 13 to 30 years (n = 55), vitamin C treatment was associated with a 45% reduction in tetanus mortality (95% confidence interval from -69% to -5%). AUTHORS' CONCLUSIONS: A single, non randomised, poorly reported trial of vitamin C as a treatment for tetanus suggests a considerable reduction in mortality. However, concerns about trial quality mean that this result must be interpreted with caution and vitamin C cannot be recommended as a treatment for tetanus on the basis of this evidence. New trials should be carried out to examine the effect of vitamin C on tetanus treatment.

Mycobacterium tuberculosis Uganda genotype is the predominant cause of TB in Kampala, Uganda.

SETTING: Rubaga Division, Kampala, Uganda. OBJECTIVE: To use polymerase chain reaction (PCR) based regions of difference (RD) analysis to study the species diversity of Mycobacterium tuberculosis complex isolates from a community-based sample of tuberculosis (TB) patients from Rubaga and to perform long sequence polymorphism (LSP) analysis to further characterise the M. tuberculosis Uganda genotype, a group of strains previously recognised by their characteristic spoligotype patterns. DESIGN: For the present study, 344 consecutive TB patients attending clinics in Rubaga Division were enrolled. Sample processing and culture were performed at the National Tuberculosis and Reference Laboratory and molecular assays at Makerere Medical School. Species identification was achieved by determining the RDs, while spoligotyping and LSP analysis were performed to characterise the M. tuberculosis Uganda genotype. RESULTS: Of the 344 isolates, 343 (99.7%) were M. tuberculosis sensu stricto, while one was classical M. bovis. The Uganda genotype strains characteristically lacked RD724, a locus that defines one of the major sub-lineages of M. tuberculosis, which suggested that this geographically constrained lineage is specifically adapted to a central African human host population. CONCLUSION: M. tuberculosis is the most prevalent species of the M. tuberculosis complex in Kampala, and the Uganda genotype is the predominant strain.

Characterization of the brewery spoilage bacterium Obesumbacterium proteus by automated ribotyping and development of PCR methods for its biotype 1.

AIMS: To study the ability of automated ribotyping to characterize Obesumbacterium proteus and Hafnia alvei, to design primers and to evaluate standard end-point and real-time PCR for the detection of O. proteus biotype 1 in beer and in brewers's yeast-containing samples. METHODS AND RESULTS: Automated ribotyping was carried out using the standard method with EcoRI and PvuII. The digestions with both enzymes clearly differentiated O. proteus biotypes 1 and 2 and H. alvei. PCR primers were designed according to the 16S rRNA gene sequence of the O. proteus type strain. Two primer sets (Obs137-Obs558 and Obs137-Obs617) detected O. proteus biotype 1 and H. alvei but not O. proteus biotype 2 or other tested beer spoilage bacteria (40 species) in the end-point and real-time PCR, indicating their high specificity. The detection limit for O. proteus was 160-1600 CFU 100 ml(-1) beer in the end-point PCR reactions and < or =160 CFU 100 ml(-1) beer in the real-time PCR reactions. More cells (from 16 to 3200) were needed for detection in the presence of brewer's yeast cells. CONCLUSIONS: Automated ribotyping is a useful tool to characterize and identify O. proteus and H. alvei isolates. The designed primers are suitable for the rapid detection of O. proteus biotype 1 and H. alvei in brewery samples by PCR. SIGNIFICANCE AND IMPACT OF THE STUDY: Automated ribotyping and PCR could improve microbiological quality control in breweries by facilitating the detection, identification and tracing of spoilage bacteria.

Outbreak of Mycobacterium tuberculosis infection among captive Asian elephants in a Swedish zoo.

Between 2001 and 2003, there was an outbreak of tuberculosis in a Swedish zoo which involved elephants, giraffes, rhinoceroses and buffaloes. Cultures of trunk lavages were used to detect infected elephants, tuberculin testing was used in the giraffes and buffaloes, and tracheal lavage and tuberculin testing were used in the rhinoceroses. The bacteria isolated were investigated by spoligotyping and restriction fragment length polymorphism. Five elephants and one giraffe were found to have been infected by four different strains of Mycobacterium tuberculosis.

Promoter polymorphism of IL-10 and severity of multiple sclerosis.

Functional polymorphisms of the genes for interleukin-10 (IL-10; promoter position -1082), chemokine receptor-5 (CCR5 32 bp deletion), tumor necrous factor-alpha (TNFalpha promoter position -308) and cytotoxic T-lymphocyte antigen-4 (CTLA-4 exon 1 position 49) were investigated for possible influence on susceptibility and outcome of multiple sclerosis (MS). The polymorphisms were typed by polymerase chain reaction based methods or by direct sequencing in MS patients (n=93-116) and controls (n=109-400). The studied genes were not associated with MS susceptibility. Patients were classified as suffering from a mild/moderate [Expanded Disability Status Scale (EDSS) 0-5.5] or severe (EDSS 6-8.0) form of MS. The AG genotype of IL-10 proved to be protective against severe MS in all patients (OR=0.32, P=0.010), the effect being increased over the years (10 years; OR=0.33, P=0.043, 15 years; OR=0.21, P=0.025 or 20 years; OR=0.14, P=0.026). Our results suggest that differential production of IL-10 might be a factor in the severity of MS.

The mtp40 gene is not present in Mycobacterium bovis.

The mtp40 gene was initially reported to be lacking in classical Mycobacterium bovis strains, while being specific to classical M. tuberculosis strains. Later two clinical isolates reported to be M. bovis were shown to possess the mtp40 gene (A. Weil, B.B. Plikaytis, W.R. Butler, C.L. Woodley and T.M. Shinnik, J Clin Microbiol 1996; 34: 2309-2311). The two strains were, however, not fully characterized biochemically or genotypically. By PCR amplification of whole cell lysates and subsequent spoligotyping, which classifies isolates within the M. tuberculosis complex, the two strains were found to possess the spacers 40-43 which typically are lacking in classicalM. bovis, but had a spoligotyping pattern compatible with M. africanum. We conclude that the two strains, previously designated M. bovis, should be designated M. africanum. This reinvestigation has implications for the phylogenetic classification of M. bovis.

In vitro activity of thiacetazone on mycobacterial species belonging to the Mycobacterium tuberculosis complex.

Thiacetazone, despite frequent side-effects, may still be considered for the treatment of new tuberculosis cases when there is a shortage of drugs and for the management of multidrug-resistant tuberculosis. Fifty-four strains of M. tuberculosis complex were characterised based on the minimum inhibitory concentration (MIC) of thiacetazone and the growth pattern in the presence of different concentrations of the drug. The results showed that the MIC of thiacetazone to type II M. africanum strains was significantly higher than for other strains in the study (P < 0.01). Thiacetazone showed a paradoxical effect on 63% of strains where lower concentrations exhibited a better inhibiting activity than higher concentrations.

Methylenetetrahydrofolate reductase gene polymorphism, hyperhomocysteinemia and occlusive retinal vascular disease in type 2 diabetic and non-diabetic subjects.

BACKGROUND: Methylenetetrahydrofolate reductase (MTHFR) gene polymorphism may cause hyperhomocysteinemia, which affects the vascular endothelium and may induce occlusive vascular disease (OVD). Hypertension thickens small-sized arterial walls and attenuates intramural blood flow. Such OVD can be studied in retinal angiograms as a decrease in the arterio-venous ratio (AVR). Diabetes, by altering microvascular structure and function, in many ways modifies this AVR. OBJECTIVE: To assess whether MTHFR gene polymorphism (C677T) by causing hyperhomocysteinemia affects the retinal AVR in type 2 diabetic and non-diabetic subjects. METHODS: Eighty-four recently diagnosed (< 1 year) type 2 diabetic and 115 non-diabetic subjects were included in the study. Retinal fluoresceine angiograms were recorded and the mean AVR was calculated by measuring transverse vessel diameters at 6 locations. The mean AVR was used as a marker of OVD. The MTHFR VV, VA and AA genotypes were determined by PCR and plasma homocysteine by high-pressure liquid chromatography. RESULTS: In the diabetic subjects with the VV, VA and AA genotypes, the plasma homocysteine levels were 16.5 +/- 7, 12.5 +/- 4.6 and 11.3 +/- 4.9 microM, respectively (p = 0.008, ANCOVA). The corresponding values in controls were 14.6 +/- 3.8, 13.7 +/- 5.7 and 11.6 +/- 4.4 (p = 0.08). Correspondingly, in the diabetic subjects, the AVR values were 0.71 +/- 0.07, 0.75 +/- 0.07 and 0.73 +/- 0.1 (p = NS, ANOVA) and in the control subjects they were 0.8 +/- 0.14, 0.81 +/- 0.12 and 0.76 +/- 0.09 (p = NS, ANOVA). Multiple linear regression analysis (best model chi2 = 18.2, R2 = 0.10, p < 0.001) showed that AVR was related to diastolic blood pressure (t = -3.7, p < 0.001) and GFR (t = -2.2, p = 0.03). There was no relation between the AVR and plasma homocysteine levels. CONCLUSION: In the present study of recently diagnosed type 2 diabetic and non-diabetic subjects, MTHFR gene polymorphism (C677T mutation) slightly affected the plasma homocysteine level but did not alter the arterio-venous ratio.

Oestrogen receptor gene variation is a determinant of coronary reactivity in healthy young men.

BACKGROUND: Oxidised low-density lipoprotein (ox-LDL) is a determinant of impaired coronary function and oestrogens inhibit its formation probably throughout genetically-variable oestrogen receptor 1 (ESR1) in artery wall. We hypothesized that the ESR1 polymorphism might influence coronary function and reactivity as measured by positron emission tomography (PET), which allows the detection of coronary dysfunction before appearance of angiographic lesions. MATERIALS AND METHODS: Fifty-one healthy young men (aged 35 +/- 4 years), with normal or slightly-elevated serum cholesterol, underwent PET with intravenous adenosine. ESR1 PvuII genotypes P/P, P/p, and p/p in addition to the plasma autoantibody titre against ox-LDL, a marker of in vivo oxidation, were determined. RESULTS: The ESR1 genotype persisted as the only significant predictor of adenosine stimulated coronary flow (P = 0.035) after adjustment for other coronary risk factors. Subjects with P/P genotype had 33.4 and 41.8% lower adenosine-stimulated flow values than subjects with P/p and p/p genotypes (P = 0.030). Furthermore, plasma levels of ox-LDL titre were on average 59 and 77% higher in subjects with P/P genotype than in subjects with P/p or p/p genotypes (P = 0.049). CONCLUSIONS: These tentative findings from our pilot study provide evidence that genetic variation in ESR1 may modify coronary reactivity and LDL oxidation and reflect differences in the early pathogenesis of coronary dysfunction in these healthy young men.

Methylenetetrahydrofolate reductase gene C677T mutation is related to the defects in the internal elastic lamina of the artery wall.

BACKGROUND: The C677T mutation of the methylenetetrahydrofolate reductase (MTHFR) gene leads to C/C, C/T and T/T genotypes, which affect the plasma homocysteine concentration in humans. In mini-pigs, high serum homocysteine levels are associated with defects in the internal elastic lamina (IEL) of the artery wall, which are apparently related to the migration of smooth muscle cells into the intima during atherogenesis. We studied the association between the MTHFR genotypes and the number of gaps in the IEL in the wall of the five major abdominal arteries. MATERIALS AND METHODS: The autopsy study included 123 subjects (90 males and 33 females) aged 18-93. For the light microscopy, a 0.5 cm circular segment of the coeliac, the superior mesenteric, the inferior mesenteric and the renal arteries were cut and embedded in paraffin blocks. The circumference of the IEL, the thickness of the intima and the number of the gaps per millimetre in the IEL were measured by MOP 3 image analysis. RESULTS: The T-allele carriers (C/T and T/T) of the MTHFR gene had significantly less gaps in the IEL than the subjects with the C/C genotype in the superior mesenteric and in the left renal arteries (2.02 +/- 2.25 vs. 2.53 +/- 1.89, P < 0.04 and 0.56 +/- 1.09 vs. 1.82 +/- 2.66, P < 0.02, respectively). The trend was similar for the coeliac and the right renal arteries. CONCLUSIONS: Our result suggests that MTHFR polymorphism may be involved in the fragmentation of the IEL.

Relationship between high-density lipoprotein paraoxonase gene M/L55 polymorphism and carotid atherosclerosis differs in smoking and nonsmoking men.

The enzyme paraoxonase (PON) can eliminate lipid peroxides and is believed to protect against low-density lipoprotein oxidation. A common polymorphism in the PON gene (PON1) causes an amino acid substitution of methionine (M) for leucine (L) at position 55 in the protein, which changes the activity of PON and can affect the risk of atherosclerosis. Because smoking is associated with increased lipid peroxidation, we studied the relationship between PON M/L55 polymorphism and the carotid artery intima-media thickness (IMT) in smokers or previous smokers (n = 112) and nonsmokers (n = 87). IMT was measured at 3 standardized segments by B-mode ultrasonography, and the overall mean IMT value of 199 randomly selected men (mean age 54.2 +/- 3.0 years) was calculated. Subjects with IMT > 1.7 mm in at least 1 standard site were considered to have carotid artery atherosclerotic disease (CAAD). For analysis, L55 homozygotes were compared with the M55 allele carriers. Nonsmoking L55 homozygotes had an 8.9% (95% confidence interval [CI], 1.6 to 16.8) higher overall mean IMT than M55 allele carriers. In smokers, however, the M55 allele carriers tended to have higher overall mean IMT values than L55 homozygotes. There was also a statistically significant interaction between M/L55 genotype and smoking status on CAAD (P =.009) by logistic regression analysis. Among nonsmokers, the L55 homozygotes had an odds ratio of 4.22 (95% CI, 1.06 to 16.8) for CAAD compared with nonsmoking M55 allele carriers. Contrary to nonsmokers, the smoking M55 allele carriers had an odds ratio of 2.22 (95% CI, 0.82 to 6.01) for CAAD when the L55/L55 genotype of smokers was a reference group. These data suggest that in nonsmoking men, a PON L55/L55 genotype may represent a genetic risk factor for CAAD. The reverse effect in smokers implies that the ability of PON to protect against CAAD is influenced by cigarette smoking. The efficiency of this inhibition probably depends on the PON M/L55 genotype.

Coronary artery complicated lesion area is related to functional polymorphism of matrix metalloproteinase 9 gene: an autopsy study.

Matrix metalloproteinase 9 (MMP9) is expressed in human atherosclerotic plaques, and the protein is localized in human coronary atherosclerotic lesions. The MMP9 gene has a C-to-T promoter polymorphism at position -1562, which affects transcription and leads to promoter low-activity (C/C) and high-activity (C/T, T/T) genotypes. To determine whether these genotypes exert an influence on the atherosclerotic lesion area, we investigated their association with different types of coronary lesions in an autopsy cohort of 276 men aged 33 to 69 years. Areas of the coronary wall covered with fatty streaks and fibrotic, calcified, and complicated lesions were measured, and the percentage of coronary narrowing was determined. MMP9 genotypes were determined by polymerase chain reaction and restriction enzyme digestion. In men aged >/=53 years, the mean area of complicated lesions in 3 coronaries was significantly associated with the MMP9 genotype (P=0.008). Subjects with high promoter activity genotypes had, on average, larger complicated lesion areas than did those with the low-activity genotype. The MMP9 genotype persisted as an independent predictor of complicated lesion area after adjustment for age, body mass index, hypertension, diabetes, and smoking (P=0.012). These data provide evidence that the proposed effect of MMP9 in the process of atherosclerotic lesion development may be modified by the MMP9 genotype.

Spread of drug-resistant pulmonary tuberculosis in Estonia.

Restriction fragment length polymorphism (RFLP) analysis of 209 Mycobacterium tuberculosis clinical isolates obtained from newly detected pulmonary tuberculosis patients (151 male and 58 female; mean age, 41 years) in Estonia during 1994 showed that 61 isolates (29%) belonged to a genetically closely related group of isolates, family A, with a predominant IS6110 banding pattern. These strains shared the majority of their IS6110 DNA-containing restriction fragments, representing a predominant banding pattern (similarity, >65%). This family A comprised 12 clusters of identical isolates, and the largest cluster comprised 10 strains. The majority (87.5%) of all multidrug-resistant (MDR) isolates, 67.2% of all isolates with any drug resistance, but only 12% of the fully susceptible isolates of M. tuberculosis belonged to family A. These strains were confirmed by spoligotyping as members of the Beijing genotype family. The spread of Beijing genotype MDR M. tuberculosis strains was also frequently seen in 1997 to 1999. The members of this homogenous group of drug-resistant M. tuberculosis strains have contributed substantially to the continual emergence of drug-resistant tuberculosis all over Estonia.

Reference intervals for the markers of proteinuria with a standardised bed-rest collection of urine.

Reference intervals for markers of proteinuria or glomerular charge selectivity were measured in 61 healthy female and 61 healthy male individuals. Timed bed-rest and daytime collections were used to assess significance of preanalytical variability of results. Bed-rest collections are advisable for research on renal damage, whereas in routine care, robust protein/creatinine ratios work as practical estimates of protein excretion rates, the correlations to excretion rates improving with increasing proteinuria. For glomerular charge selectivity, pancreatic/salivary isoamylase clearance ratio showed lower within-subject biological variation than IgG/IgG4 clearance ratio, allowing more accurate classification into normal and reduced charge selectivity. With our method, the lower 2.5% reference intervals for isoamylase clearance ratio were 1.1 in men and 1.9 in women.

High mortality and severe immunosuppression in hospitalized patients with pulmonary tuberculosis and HIV-2 infection in Guinea-Bissau.

The aim of this study was to prospectively compare the clinical outcomes in HIV-2-infected and HIV-negative patients with culture-confirmed pulmonary tuberculosis, evaluate immunological changes and investigate risk factors for decreased survival in HIV-2-positive subjects. From 1994 to 1997, 127 consecutive patients with pulmonary tuberculosis were included at the Raoul Follereau Hospital in Bissau, the capital of Guinea-Bissau. All subjects were initially hospitalized, and then followed to the end of the 8-month treatment period. CD4 T-lymphocyte counts were determined by flow cytometry before, during and at the end of the treatment period. The prevalences of HIV-1, HIV-2 and HIV-1/HIV-2 dual reactivity were 8.7%, 23.6% and 9.4%, respectively (95% confidence intervals 3.8-13.6, 16.2-31.0 and 4.4-14.5, respectively). The mortality rate during the study period was significantly higher in HIV-2-positive (p < 0.01) and HIV-1/HIV-2 dually reactive (p < 0.01) patients than in HIV-negative individuals (52.9, 83.3 and 8.7 per 100 person-years, respectively). In HIV-1-positive patients the mortality rate was 30.8/100 person-years (p = NS). Baseline total CD4 cell counts were 213, 104, 235 and 624 x 10(6)/l (% CD4 = 17, 15, 20 and 40) among HIV-1-, HIV-2- and HIV-1/HIV-2-positive and HIV-negative subjects, respectively. The median rates of change per year of total CD4 cell counts in HIV-2-positive and HIV-negative subjects were 66 and 340 x 10(6)/l, respectively (interquartile ranges -78-249 and 21-624). In conclusion, we found a significantly higher mortality rate in HIV-2-positive compared to HIV-negative individuals. Baseline CD4 cell counts were markedly suppressed and similar in all 3 HIV-positive groups, and in a multivariate logistic regression analysis a value of CD4 percentage of < 10 was shown to be an independent predictor of decreased survival in HIV-2-infected subjects.

Hepatic lipase gene variation is related to coronary reactivity in healthy young men.

BACKGROUND: Impaired coronary flow reserve (CFR) can be used to indicate vascular dysfunction before the appearance of angiographic lesions. The hepatic lipase (HL) gene has a functional promoter polymorphism at position C-480T, which affects transcription and leads to high activity (C/C) and low activity (C/T, T/T) genotypes. These genotypes modulate HL activity, but their role in coronary artery disease is controversial and the effect on coronary function has not been studied. We investigated whether HL genotypes are associated with coronary artery function in healthy young men. MATERIALS AND METHODS: We studied 49 healthy, mildly hypercholesterolemic men (aged 35 +/- 4 years). Myocardial blood flow was measured at rest and during adenosine induced hyperaemia with positron emission tomography using [15O] H2O. HL genotype was determined by PCR and Nla III enzyme digestion. RESULTS: Resting myocardial blood flow was not statistically different in subjects with high and low activity HL genotypes. However, CFR (the ratio of adenosine flow to resting flow) was 24% higher (4.62 +/- 1.52 vs. 3.73 +/- 1.08 mL g-1 min-1, P = 0.024) in men with the high activity genotype (n = 26) than in those with low activity (n = 23). In multivariate analysis, the HL genotype remained a significant predictor of CFR (P = 0.038) after adjusting for age, body mass index, serum lipids and smoking. CONCLUSIONS: The findings of our preliminary study suggest that the C-480T polymorphism of the HL gene may modify coronary reactivity and reflect differences in the early pathogenesis of coronary dysfunction in these healthy young men. If the association between HL polymorphism and impaired CFR is also present in subjects with other dyslipoproteinemias, the HL polymorphism could be a new risk factor for cardiovascular disease.

Serum homocysteine does not associate with uncomplicated coronary heart disease.

BACKGROUND: Elevated serum homocysteine concentrations have been related to coronary heart disease. However, the association has not indisputably been proven, and the mechanisms by which homocysteine may be atherogenic have only partially been elucidated. The objective of the present study was to investigate whether serum homocysteine is associated with angina pectoris and myocardial infarction. METHODS: We compared serum homocysteine concentrations in subjects with clinical evidence of angina pectoris or history of myocardial infarction to age-matched controls. The study included 248 males, who participated in a large cross-sectional risk factor survey carried out in five geographic areas in Finland. RESULTS: Serum homocysteine concentration was significantly higher in subjects with a history of myocardial infarction compared to controls (15.3 micromol L-1 and 13.9 micromol L-1 respectively, P = 0.037). In a logistic regression model including several cardiovascular risk factors, serum homocysteine was significantly associated with myocardial infarction (95% CI 1.0157-1.2990, P = 0.027). Serum homocysteine concentrations did not differ between subjects with angina pectoris and age-matched controls (13.9 micromol L-1 and 14.2 micromol L-1 respectively). CONCLUSIONS: Our results suggest that elevated serum homocysteine is associated with myocardial infarction but not with uncomplicated coronary heart disease.

Paraoxonase producing PON1 gene M/L55 polymorphism is related to autopsy-verified artery-wall atherosclerosis.

Paraoxonase (PON) is an antioxidative enzyme, which eliminates lipid peroxides. PON has two common polymorphisms (M/L55 and R/Q192) that influence PON concentration and activity. We studied whether the M/L55 or R/Q192 genotype relates with the severity of atherosclerosis of the abdominal aorta, and the mesenteric and common iliac arteries in 123 consecutive autopsy cases (90 males and 33 females, aged 18-93 years). The severity of atherosclerosis in the arteries was evaluated, and the percentage of stenosis was measured. The intimal thickness in the internal elastic lamina (IEL) of the coeliac (CA), superior mesenteric (SMA) and inferior mesenteric (IMA) arteries were measured by light-microscopy. The LL homozygous men had more atherosclerotic plaques and complicated lesions in the common iliac arteries (56.8%) than the M allele carriers (28.3%, P=0.007). In logistic regression analysis, age (P<0.001) and the PON M/L55 genotype (P=0.015) were associated significantly with the severity of atherosclerosis in the common iliac arteries independent of smoking status, R/Q192 genotype, hypertension, diabetes mellitus, BMI and sex. The mean intima of the IMA was significantly thicker (P=0.035) and the number of stenotic lesions in SMAs significantly higher (P=0.008) in the LL homozygous men than M allele carriers. In turn, the R/Q192 genotype was not statistically significantly associated with plaque type, intimal thickness in the IEL or with the number of stenotic lesions. This study demonstrates that PON L55 homozygosity is an independent risk factor for autopsy-verified atherosclerosis in Finns.