One-step solid-phase extraction procedure for F(2)-isoprostanes.

brovascular occlusive disease, or from peripheral arterial occlusive disease. As shown in Table 1, there were distinctly higher homocysteine concentrations for seropositive subjects in subgroups of age, renal function, smoking status, and MTHFR gene mutations. These variables influencing serum homocysteine, as well as vitamin B 6 , vitamin B 12 , and folic acid, are moreover homogeneously (not significantly different) distributed between the C. pneumoniae-seropos-itive and-seronegative groups. Drugs possibly influencing serum homocysteine were either well balanced between the two groups or not prescribed (antagonists of folic acid, cyclosporine, anticonvulsants). Possible confounding effects of these variables and inflammatory markers were considered by multiple regression analysis. However, the difference in serum ho-mocysteine observed between the C. pneumoniae-seropos-itive and-seronegative groups remained significant (P Ͻ0.005). The regression analysis also revealed considerable effects on serum homocysteine by age (P ϭ 0.012), creatinine concentration (P Ͻ0.005), smoking (P ϭ 0.023), MTHFR gene mutations (P ϭ 0.082), and tumor necrosis factor-␣ (P ϭ 0.038). Vitamin B 6 , vitamin B 12 , folic acid, C-reactive protein, and interleukin 6 were only weakly associated with serum homocysteine (P Ͼ0.1) and, therefore , were excluded from analysis. Our results indicate that C. pneumoniae seropositivity is linked with hyperhomocysteinemia in male patients with established atherosclerosis. This correlation was statistically significant no matter whether IgG (as shown above) or IgA was used as the marker for seropositivity. Understanding the relationship between the two variables requires further investigations, which are likely to be facilitated by the recent sequencing of the C. pneumoniae genome (5). Hyperhomocysteinemia is a predictor of morbidity and mortality in patients with atherosclerosis. If the association of hyperhomocysteinemia and C. pneu-moniae seropositivity can be confirmed in further studies, C. pneumoniae seropositivity may be associated with impaired prognosis in these patients. Physiologic, pathologic, genetic, and nutritional factors may increase serum homocysteine (6). Some of these variables were used as exclusion criteria (diabetes melli-tus, malignant neoplasia, chronic inflammatory disorders, severe renal insufficiency). Other variables (age, renal function, smoking, MTHFR gene mutations, vitamins, concomitant medication) were found not to be responsible for the difference in homocysteine between C. pneumoniae-seropositive and-seronegative patients. This was concluded from multiple regression analysis and the observation that the possibly confounding variables were homogeneously distributed between the C. pneumoniae-seropositive and-seronegative groups. The validity of the study is further supported by the finding that distinctly higher homocysteine concentrations for seropositive subjects were measured not only in the whole study …