The association of infection and coronary artery disease: an update

Cardiovascular biomarkers: increasing impact of laboratory medicine in cardiology practice

The practice of cardiology is in continual evolution, in parallel with the progress achieved by medical research in understanding the pathophysiology of cardiovascular disease and in developing new therapeutic procedures. Consequently, manufacturers of cardiac biomarkers are pressed with new demands to improve the performance of the existing and the development of novel ones. Several highly sensitive and/or specific assays for myocardial ischemic damage and myocardial function detection have already become commercially available. Moreover, an increasing number of novel risk factors have been added to the classical risk factors of cardiovascular disease. Finally, the recent surge of genetic analysis procedures will likely soon provide the clinical cardiologist with a number of laboratory tests for defining the molecular diagnosis, assessing new risk factors, and better targeting the pharmaceutical approaches in patients with cardiovascular disease. In this review, we first present the general characteristics of a biomarker followed by the analytical and clinical performance of assay methods.

Effect of Helicobacter pylori infection and eradication therapy on interleukin-6 levels in patients with Familial Mediterranean Fever

It is being questioned if Helicobacter pylori infection, which causes a chronic inflammatory response, can increase the frequency and severity of attacks in patients with Familial Mediterranean Fever (FMF) and if the impact of inflammatory response can be diminished by eradication of the infection. To evaluate if there is difference in interleukin (IL)-6 levels of H. pylori-positive and -negative patients both before and during FMF attacks; if there is a change in IL-6 levels following successful eradication treatment; and if MEFV gene mutations have an effect on IL-6 levels. IL-6 levels were evaluated in 47 FMF patients before and during FMF attacks. Genetic testing to determine M694V, M694I, E148Q, V726V, M680I mutations was also performed in all patients. IL-6 levels were also determined after successful eradication of the infection in H. pylori-positive patients. IL-6 levels were compared in H. pylori-positive and -negative patients, and before and after eradication treatment in patients who cleared the infection. Number of patients in tested mutation groups was not enough to compare IL-6 levels in these groups. Thirty-four patients (73.9%) were H. pylori-positive. Before FMF attack there was no statistically significant difference in IL-6 levels of H. pylori-positive and -negative groups. IL-6 levels were significantly higher in both groups during the attacks than before the attacks (p < 0.05). There was a statistically significant decline in IL-6 levels both before and during FMF attacks, following eradication therapy in patients who cleared the infection (p < 0.05). In patients with homozygous M694V mutation, IL-6 levels before and during the FMF attacks were not significantly different in H. pylori-positive and -negative groups, despite a much lower level found in H. pylori-negative group (p > 0.05). Comparisons were not performed in other mutation groups because of small number of patients in each group. C-reactive protein (CRP) and fibrinogen levels were not significantly different between the groups (p > 0.05). We believe that the observation of IL-6 levels are lower both before and during FMF attacks both in H. pylori-negative patients and in patients who cleared the infection after eradication therapy is very important in the determination of the role of eradication of H. pylori on decreasing the frequency and severity of FMF attacks. As for today, the correlation between H. pylori infection and FMF seems unlikely; however, studies evaluating the interaction of cytokines in both diseases and their relations and roles will be needed to reach better conclusions.

Co-existence of Helicobacter pylori infection in patients with Familial Mediterranean Fever (FMF) and the effect of Helicobacter pylori on the frequency and severity of FMF attacks

BACKGROUND

The inflammatory reactions both in Familial Mediterranean Fever and in Helicobacter pylori infection have similarities. Whether there is interactions in case of co-existence of both diseases has not been evaluated. AIM.: To evaluate, if there is a significant relation between H. pylori infection and Familial Mediterranean Fever; if H. pylori has an effect on the frequency and severity of Familial Mediterranean Fever attacks; and if eradication treatment has any affects.

METHODS

Thirty-two Familial Mediterranean Fever patients were tested for H. pylori infection. Acute phase responses were evaluated and attack frequency and severity were determined in both H. pylori-positive and H. pylori-negative groups. Same determinations were done after the eradication treatment in H. pylori-positive patients. Levels of acute phase determinants as well as frequency and severity of attacks were compared in H. pylori-positive and -negative groups.

RESULTS

C-reactive protein, erythrocyte sedimentation rate, white blood count and fibrinogen levels were significantly (p<0.01) higher during the attacks than before the attacks in all patients. However, there was no difference between the groups. H. pylori-positive patients have a higher frequency and a longer duration of attacks when compared to H. pylori-negative patients before treatment (p<0.05). The frequency was also significantly lower and duration was shorter in patients whose infections were eradicated (p<0.05).

CONCLUSION

H. pylori infection was not significantly frequent in our group of Familial Mediterranean Fever patients. H. pylori can decrease both the frequency and the duration of the attacks. Studies that will evaluate the relationship of H. pylori and MEFV gene along with the roles of yet unknown cytokines, which can presumably play a role in the pathogenesis of both diseases, are needed to reach better conclusions.

Helicobacter pylori infection negatively influences pregnancy outcome in a mouse model

BACKGROUND

Helicobacter pylori infects the human stomach, causing gastritis, peptic ulcer, and gastric cancer. H. pylori infection has also been related to extra-gastric disorders. We investigated whether H. pylori infection can influence pregnancy in a murine model.

METHODS

Female CD1 mice were infected with the H. pylori SPM326 strain before mating, and then assessed throughout pregnancy for embryo/fetus characteristics and histopathological changes of the endometrium.

RESULTS

Infected mice showed higher numbers of resorption and lower fetal weights than noninfected controls. These pathological phenomena were accompanied by macrophage activation, and increases both of CD4+ and CD8+ lymphocytes and of interferon-gamma and major histocompatibility complex class II expression at the endometrial level, as evaluated by immunohistochemistry.

DISCUSSION

During pregnancy, preferential induction of Th2-type cytokines downregulates Th1-type responses, allowing fetal survival. Our results suggest that H. pylori infection can induce activation of resident uterine immune cells and/or recruitment of cells at the endometrial level. It can be hypothesized that the local Th1-type response induced by H. pylori infection could alter the systemic Th1/Th2-type cytokine balance at sites under particular physiopathological conditions of active tissue and/or vascular formation, such as pregnancy.

CONCLUSIONS

This is the first evidence in an animal model of the possible influence of H. pylori infection on pregnancy. Further work is required on its mechanism and its relevance for humans.

The increasing impact of laboratory medicine on clinical cardiology

The practice of cardiology continues to evolve along with a better understanding of the pathophysiology of cardiovascular disease and the development of new therapeutic procedures. Consequently, new demands are being made on the in vitro diagnostics industry to improve the performance of existing cardiac markers and to develop novel markers for new cardiac disease indications. Indeed, in the last 20 years there has been a progressive increase in new laboratory tests for markers of cardiac diseases. Several highly sensitive and/or specific assays for the detection of myocardial ischemic damage as well as some immunoassays for cardiac natriuretic hormones, now considered a reliable marker of myocardial function, have become commercially available. In parallel, a growing number of some novel risk factors, which can be assessed and monitored by laboratory methods, have been added to the classical risk factors for cardiovascular disease. Finally, the recent explosion of genetic analysis may soon place at the clinical cardiologist's disposal many laboratory tests for defining the diagnosis at the molecular level, assessing new risk factors, and better targeting the pharmaceutical approaches in patients with cardiovascular disease. In the present article, after a brief description of the analytical tests included in these four groups, each group's impact on clinical cardiology is discussed in detail.

Atherosclerotic plaque formation and risk factors

Atherosclerosis (AT) is a progressive disease characterized by the accumulation of lipids, fibrous materials, and mineral in the arteries. Although many generalized or systemic risk factors predispose to its development, AT affect various regions of the circulation preferentially and yields distinct clinical manifestations depending on the particular circulatory bed affected. The progression of AT is currently believed to involve the interaction of endothelium, monocytes, and leukocytes, as well as the influences of cytokines, oxidized lipoproteins, hypertension, tobacco use, dyslipidemia, homocystinemia, and genetic determinants.

Apoptosis in atherosclerosis: pathological and pharmacological implications

Normal embryonic development, tissue differentiation and repair in the eukaryote requires a tightly regulated apoptosis, or programmed cell death. Apoptosis also plays an essential role in different pathological processes including atherosclerosis, in which it affects all cell types in the atherosclerotic lesion, including endothelial cells, vascular smooth muscle cells, and macrophages. During atherosclerosis progression, pro- and anti-apoptotic signals abound in the evolving lesion. Apoptosis limits the number of a particular cell type that accumulates in the lesion and slows down the overall progression of the lesion. On the other hand, it contributes to the production of unstable plaques. Many pharmacological agents used to treat cardiovascular and lipid disorders have pro- or/and anti-apoptotic effects. Pharmaceuticals that modulate apoptosis in specific types of cell can potentially serve as anti-atherogenic agents. However, to develop agents for clinical use requires a thorough knowledge of the pathophysiology of apoptosis in atheromatous lesions, a highly cell-specific process. Here we review our current understanding of the process to provide a background for future pharmacological research in the area.