Can procalcitonin measurement help in differentiating between bacterial infection and other kinds of inflammatory processes?

OBJECTIVE: To study the levels of procalcitonin (PCT) in various inflammatory states seen in an internal medicine department and to evaluate the possible discriminative role of PCT in differentiating bacterial infection from other inflammatory processes. METHODS: PCT, C reactive protein (CRP), and white blood cell count (WBC) were measured in patients admitted to the department for fever or biological inflammatory syndrome, or both. The serum of 173 consecutive patients was analysed according to the aetiological diagnosis. The patients were divided into two groups: group I (n=60) with documented bacterial or fungal infection; group II (n=113) with abacterial inflammatory disease. RESULTS: PCT levels were >0.5 ng/ml in 39/60 (65%) patients in group I. In group II, three patients with a viral infection had slightly increased PCT levels (0.7, 0.8, and 1.1 ng/ml) as did two others, one with crystal arthritis and the other with vasculitis (0.7 ng/ml in both cases). All other patients in group II had PCT levels <0.5 ng/ml. In this study a value of PCT >0.5 ng/ml was taken as the marker of bacterial infection (sensitivity 65%, specificity 96%). PCT values were more discriminative than WBC and CRP in distinguishing a bacterial infection from another inflammatory process. CONCLUSION: PCT levels only rose significantly during bacterial infections. In this study PCT levels >1.2 ng/ml were always evidence of bacterial infection and the cue for starting antibiotic treatment.     

Is there a real risk of bacterial infection in patients receiving targeted and biological therapies?

Over the past decades, the advent of targeted and biological therapies has revolutionized the management of cancer and autoimmune, hematological and inflammatory conditions. Although a large amount of information is now available on the risk of opportunistic infections associated with some of these agents, the evidence regarding the susceptibility to bacterial infections is more limited. Biological agents have been shown to entail a variable risk of bacterial infections in pivotal randomized clinical trials and post-marketing studies. Recommendations on risk minimization strategies and therapeutic interventions are therefore scarce and often based on expert opinion, with only a few clear statements for some particular agents (i.e. meningococcal vaccination for patients receiving eculizumab). In the present review the available information regarding the incidence of and risk factors for bacterial infection associated with the use of different groups of biological agents is summarized according to their mechanisms of action, and recommendations based on this evidence are provided. Additional information coming from clinical research and real-world studies is required to address unmet questions in this emerging field.     

Is an invasive interventional strategy of value in non-ST-elevation acute coronary syndromes?

Cost-effectiveness can be a helpful indicator of therapeutic value and is an important consideration when determining whether to use an invasive strategy in patients with non-ST-elevation (NSTE) acute coronary syndromes. In an economic analysis using results from RITA 3, Henriksson et al. found that an invasive strategy was not cost-effective in patients with low-risk disease, but was cost-effective for patients with high-risk disease and of equivocal cost-effectiveness in patients with intermediate-risk disease. This finding is consistent with those of other studies, especially FRISC II and TACTICS-TIMI 18, which found an invasive strategy to be cost-effective in patients with biomarker-positive NSTE myocardial infarction. An invasive strategy should, therefore, be considered for treatment of patients with high-risk NSTE myocardial infarction. Although available data are not based on the latest technology, another trial in this area would be difficult to conduct and of questionable ethics.     

Cytomegalovirus infection in acute myocardial infarction. Is there a causative relationship?

BACKGROUND: Cytomegalovirus (CMV) infection has been suggested to play an important role in the pathogenesis of atherosclerosis. Whether CMV may be involved in the development of acute myocardial infarction (MI) has not yet been established. AIM: To asses the prevalence of active or latent CMV infection in patients with angina or acute MI. METHODS: The study group consisted of 158 subjects divided into three groups: group I - 70 patients (49 males, mean age 57.1+/-10.4 years) with acute MI, group II - 40 patients (21 males, mean age 59.1+/-7.9 years) with stable angina, and group III - 48 healthy controls (18 males, mean age 54.9+/-12.1 years). Anti-CMV IgM and IgG antibody titre in blood serum was measured in all subjects. In those in whom anti-CMV antibodies were present, quantitative polimerase chain reaction (Q-PCR) was performed in order to detect DNA of CMV in peripheral blood mono-nuclear cells (PBMC) and in serum. RESULTS: Anti-CMV IgM antibodies were not detected in any of the subjects. A positive result of anti-CMV IgG test was present in 60 (85.7%) patients from group I, 34 (85%) patients from group II, and 15 (31.5%) control subjects. The mean IgG antibody concentration was 72.2+/-13.6 aU/ml, 74.23+/-12.8 aU/ml and 19.57+/-3.56 aU/ml, respectively (p<0.001). In patients from group I, a significantly higher prevalence of serum DNA CMV was noted than in the remaining groups. CONCLUSIONS: Patients with symptomatic coronary artery disease have a significantly higher anti-CMV antibody titre than healthy subjects. The active form of infection is significantly more prevalent in patients with acute MI than in patients with stable angina.     

Is C-reactive protein a marker of inflammation?

C-reactive protein (CRP) is the prototype of acute-phase protein which is secreted by the liver in response to a variety of inflammatory cytokines. Levels of CRP can increase up to 1000-fold very rapidly after the onset of inflammation and decrease just as rapidly with the resolution of aggression. CRP is a member of the ancient highly conserved pentraxin family of proteins and it is arranged in a cyclic homopentameric structure. The important role of CRP in innate immunity is largely due to its opsonizing abilities, its capability to activate human complement and to bind to immunoglobulin G receptors. CRP can bind phosphocholine largely present in bacterial membranes, cell membrane and lipoproteins, in addition CRP can recognize nuclear constituent in damaged cells. CRP can activate C3 convertase through the classical pathway but not C5 convertase resulting in generation of opsonic complement fragments. Interactions of CRP with Fc receptors lead to the generation of proinflammatory cytokines and reactive oxygen species by monocyte/macrophage while inhibit neutrophiles functions. Recently, CRP was demonstrated to play an active role in atherogenesis and it has been largely proven that a microinflammatory state as defined by a moderate increase in CRP (up to 3 mg/l), is associated with an increased risk for arterial disease. Moreover it has been postulated that CRP may be a useful tool for monitoring drug therapy.     

Is acute hepatitis B still a nosocomially-acquired infection in Poland? A case-controlled study of transmission routes in a hospital sample

The aim of this study was to evaluate the role of medically linked risk factors for acute HBV infection in the Podlasie region of North-Eastern Poland. The records of 107 adult patients and 214 age- and sex-matched controls hospitalized in the Department of Infectious Diseases, Bia?ystok, Podlasie Region during the period 1997-2000 with the diagnosis of acute hepatitis B were reviewed. On multivariate analysis, household contact with hepatitis B [odds ratio (OR) = 18.0, 95% confidence interval (CI) 2.0-165.5] and a history of injections (OR = 2.7, 95% CI 1.5-4.7) in the preceding 6 months were independently associated with acute HBV infection. In conclusion, our data indicate that despite a significant decline in the incidence of hepatitis B, injections are still involved in the spread of HBV in Poland.     

Is public transport a risk factor for acute respiratory infection?

Background  

The relationship between public transport use and acquisition of acute respiratory infection (ARI) is not well understood but potentially important during epidemics and pandemics.