Cytokine gene polymorphisms in idiopathic pulmonary fibrosis

Pro- and anti-fibrotic cytokine gene polymorphisms may affect expression of idiopathic pulmonary fibrosis (IPF). The aims of the present case-control study were to examine polymorphisms in the IL-6, transforming growth factor (TGF)-beta1, tumour necrosis factor (TNF)-alpha and interleukin-1 (IL-1)Ra genes in patients with IPF (n=22)-compared to healthy controls (n=140). Genotyping was performed on DNA extracted from peripheral blood lymphocytes, using polymerase chain reaction-restriction fragment length polymorphism with gene polymorphisms determined according to-published techniques. The following sites were examined: (i) IL-1Ra*1-5 (86 bp variable tandem repeat intron 2), (ii) IL-6 (-174G>C), (iii) TNF-alpha (-308G>A) and (iv) TGF-beta1 (Arg25Pro). The TNF-alpha (-308 A) allele was over-represented in the IPF (p(corr)=0.004) group compared to controls. Risk of IPF was significant for heterozygotes for: (i) the TNF-alpha (-308 A) allele (A/G) (odds ratio (OR) 2.9; 95% confidence interval (CI) 1.2-7.2; P=0.02), (ii) homozygotes (A/A) (OR 13.9; 95%CI 1.2-160; P=0.04) and (iii) carriage of the allele (A/A+A/G) (OR 4; 95%CI 1.6-10.2; P=0.003). The distribution of alleles and genotypes for IL-6, TGF-beta1 and IL-1Ra between the two groups was not significantly different. This is the third study to independently confirm that there is a significant association of the TNF-alpha (-308 A) allele with IPF. Further research is needed to assess the utility of cytokine gene polymorphisms as markers of disease-susceptibility.

Risks for ross river virus disease in tropical Australia

Background There are no analytical studies of individual risks for Ross River virus (RRV) disease. Therefore, we set out to determine individual risk and protective factors for RRV disease in a high incidence area and to assess the utility of the case-control design applied for this purpose to an arbovirus disease. Methods We used a prospective matched case-control study of new community cases of RRV disease in the local government areas of Cairns, Mareeba, Douglas, and Atherton, in tropical Queensland, from January I to May 31, 1998. Results Protective measures against mosquitoes reduced the risk for disease. Mosquito coils, repellents, and citronella candles each decreased risk by at least 2-fold, with a dose-response for the number of protective measures used. Light-coloured clothing decreased risk 3-fold. Camping increased the risk 8-fold. Conclusions These risks were substantial and statistically significant, and provide a basis for educational programs on individual protection against RRV disease in Australia. Our study demonstrates the utility of the case-control method for investigating arbovirus risks. Such a risk analysis has not been done before for RRV infection, and is infrequently reported for other arbovirus infections.

Poverty and the economic effects of TB in rural China

OBJECTIVE: To investigate the economic effects of illness on individual tuberculosis (TB) cases in rural China and to use a case-control study to show a strong TB-poverty link. SETTING: In 2002-2004 we studied 160 new smear-positive pulmonary tuberculosis (PTB) cases and 320 age- and sex-matched controls living in neighbouring houses in four rural counties of Henan Province. DESIGN: Cases and controls were interviewed 1-3 months after patients were diagnosed. We used matched multivariate logistic regression to compare cases with controls for poverty status using household income, household assets and relative wealth within the village. We conducted follow-up interviews of patients 10-12 months later to assess economic effects by collecting data on treatment costs, income losses, coping strategies and treatment completion. RESULTS: Poverty is strongly associated with TB incidence even after controlling for smoking and other risk factors. Excluding income losses, direct out-of-pocket treatment costs (medical and non-medical) accounted for 55.5 % of average annual household income, and most TB cases fell into heavy debt. The DOTS cure rate was 91 %. When DOTS was incomplete or not done, mortality was high. CONCLUSIONS: Poverty is both a cause and a devastating outcome of TB. Ongoing poverty reduction schemes in China must also include reducing TB.

Association between glutathione S-transferase M1 and T1 and the risk for coronary heart disease (CHD)

Deficiency of Glutathione S-transferases (GST) M1 and T1 are associated with chronic diseases (e.g. lung cancer, MS) and could be one factor for the risk for CHD.We conducted a pros-pective case-control study in 93 pts. with angiographically proven CHD and 161 controls matched for age ±2y and gender (resulting in n=91 pairs, of which 18 were female). Genes coding for functional GST M1 and T1 were analysed acoording to previously published methods. The association between GST M1, T1 was tested using Fisher's exact test; logistic regression analysis was performed to control for HDL-cholesterol, diabetes smoking, diabetes, hypertension. 41% of cases were smokers, 25% had diabetes and 68% hypertension, corresponding figures for controls were 31%, 13% and 33%. Mean HDL-cholesterol levels were comparable (pts: 46±14 mg/dl, controls: 43± 19 mg/dl). There was no overall significant correlation between functional GST T1 and M1 genotypes and CHD, however, there seems to be an association between GST M1, HDL-cholesterol and CHD. Larger studies are needed to verify these data.