The impact of tacrolimus on the immunopathogenesis of staphylococcal enterotoxin-induced systemic inflammatory response syndrome and pneumonia

Staphylococcal superantigens (SAg) are a family of potent exotoxins produced by Staphylococcus aureus. They play an important role in the pathogenesis of staphylococcal shock and pneumonia by causing a robust activation of the immune system and eliciting a strong surge in systemic cytokine and chemokine levels. Given the biological functions of SAg, we evaluated the efficacy of tacrolimus, a potent immunosuppressive agent, in the prophylaxis and therapy of staphylococcal TSS and pneumonia using human leukocyte antigen (HLA)-DR3 transgenic mice. Tacrolimus significantly inhibited staphylococcal SAg induced T cell activation in vitro. In vivo, tacrolimus significantly suppressed the SAg-induced elevation in serum cytokine and chemokine levels when given prophylactically, when administered immediately or even 2 h following systemic SAg challenge. Paradoxically, neither the prophylactic nor post-exposure treatment with tacrolimus protected mice from lethal SAg-induced TSS. A closer examination revealed that tacrolimus failed to suppress SAg-induced T cell proliferation and systemic pathology, including gut dysfunction. Tacrolimus also failed to protect from lethal pneumonia induced by a SAg-producing S. aureus strain. Thus, our study showed that even though T cell activation by SAg plays a major role in the immunopathogenesis of TSS and pneumonia, tacrolimus alone has no beneficial effect.     

The antiinflammatory effects of adenosine receptor agonists on the carrageenan-induced pleural inflammatory response in rats

Adenosine and adenosine receptor agonists have a variety of inhibitory effects on the generation of inflammatory mediators by neutrophils and other cell types. In human neutrophils stimulated with the chemotactic peptide FMLP, adenosine agonists inhibit O2- generation and degranulation. Because these findings suggest that the agonists may have potential as antiinflammatory agents, several compounds were evaluated for effects on the exudative and cellular phases of carrageenan-induced pleural inflammation in rats. All of the agonists tested inhibited both parameters of the inflammatory response. Inhibition appeared to correlate better with binding to the A1 than to the A2 receptor and was reversible by a known adenosine receptor antagonist, 8-phenyltheophylline. In mechanistic studies, R-N-(1-methyl-2-phenylethyl)adenosine, a standard A1 selective agonist, reversed the drop in circulating neutrophil count that occurs after injection of carrageenan. These results suggest that the agonists may prevent cell emigration by inhibiting adhesion to the endothelium or diapedesis. In addition (R)-N-(1-methyl-2-phenylethyl)adenosine had weak inhibitory effects on superoxide production by FMLP-stimulated rat neutrophils. Control studies showed that the effects of the agonists were not the result of agonist-induced hypotension nor corticosterone production by the adrenal glands. These findings indicate that adenosine receptor agonists are effective new pharmacologic tools for the study of inflammatory processes.     

Circadian variation and age dependence of human atrial natriuretic peptide levels in hospitalized patients

Circadian variation of plasma levels of human atrial natriuretic peptide (hANP) was studied in 8 patients less than or equal to 65 a of age (mean +/- SD = 43.8 +/- 13 a; 5 females, 3 males) and in 15 patients greater than 65 years of age (mean +/- SD = 81.4 +/- 5.7 a; 9 females, 6 males). Intraindividual variation was up to 40% relative to the day's mean level in both groups. A significant elevation of hormone levels in the evening was observed in patients greater than 65 years of age (P less than 0.002), no circadian rhythm could be detected in patients less than or equal to 65 years of age. All patients except the two eldest had average plasma levels of hANP within our normal range of 3-75 ng/l (N = 106; mean +/- SD = 29.9 +/- 15.3), found in healthy persons up to 65 years of age. We propose, that in the elderly hANP levels rise during the day by edema because of latent renal and/or cardial insufficiency. At rest, in the evening and during the night edema is eliminated by the well known nycturia, which might well be facilitated or at least partially caused by elevated levels of hANP.     

Risk of pneumonia recurrence in patients previously hospitalized for pneumonia--a retrospective study (1998-2000)

Although elderly hospitalized patients, irrespective of the cause of hospitalization, are known to be at a high risk of subsequent development of pneumonia, some studies suggest the risk to be even higher in those hospitalized for pneumonia than in those hospitalized for other diseases. The aim of this retrospective study was to determine the association of hospitalization for pneumonia and some other diseases with subsequent pneumonia morbidity and mortality. The risk of recurrent pneumonia in patients hospitalized for pneumonia was investigated. Rehospitalization of pneumonia patients previously hospitalized for the same disease was followed-up and compared with rehospitalization of patients hospitalized for other diseases during the same study period. The study included patients aged overl8, initially hospitalized in 1998 for pneumonia (J12-J18), or for some particular gastrointestinal (K20-K31) and urogenital diseases (N10-N12, N30-N39). All rehospitalizations for pneumonia in nine Zagreb hospitals were followed-up during a 3-year study period (1998-2000). Out of 975 patients followed-up for rehospitalization, 227 (23.3%) had initially been hospitalized for pneumonia, and 748 (76.7%) for other diagnoses. During the 3-year period, 30 patients were rehospitalized for pneumonia, out of which number 22 had initially been hospitalized for pneumonia, yielding a statistically significant difference between the two study groups (chi2 = 34.780, p < 0.001). The mortality directly caused by pneumonia was also significantly higher in the group of patients with the initial diagnosis of pneumonia than in the group of patients with other diagnoses (chi2 = 15.82, p < 0.001).     

The effects of tachykinins on inflammatory and immune cells

The aim of this article is to provide an up-dated overview of the available information on the role played by tachykinins in recruiting/regulating the function of immune/inflammatory cells, an issue which has received considerable input from the recent availability of potent and selective antagonists for tachykinin receptors. It appears that NK₁ receptors play a role in mediating the extravascular migration of granulocytes into inflamed tissues in response to various inflammatory stimuli, although this effect may not be due to the expression of NK₁ receptors by granulocytes themselves. Several data also imply a role for NK₁ and NK₂ receptors in regulating immune function. No data are available to suggest the expression of NK₃ receptors by inflammatory/immune cells. Mast cell degranulation by substance P appears to be a non-receptor dependent response which may take place in vivo during intense stimulation. An emerging concept in the field relates to the ability of certain immune cell types to synthesize and possibly release tachykinins. Immune cells could represent an additional source of tachykinins in inflamed tissues, providing a non-neurogenic tachykininergic contribution to the local inflammatory process.     

Current management of patients hospitalized with community-acquired pneumonia across Europe: outcomes from REACH

Background

Data describing real-life management and treatment of community-acquired pneumonia (CAP) in Europe are limited. REACH (http://{"type":"clinical-trial","attrs":{"text":"NCT01293435","term_id":"NCT01293435"}}NCT01293435) was a retrospective, observational study collecting data on the management of EU patients hospitalized with CAP.The purpose of this study was to understand patient and disease characteristics in patients hospitalized with CAP and to review current clinical practices and outcomes.

Methods

Patients were aged ≥18 years, hospitalized with CAP between March 2010 and February 2011, and requiring in-hospital treatment with intravenous antibiotics. An electronic Case Report Form was used to collect patient, disease and treatment variables, including type of CAP, medical history, treatment setting, antibiotics administered and clinical outcomes.

Results

Patients (N = 2,039) were recruited from 128 centres in ten EU countries (Belgium, France, Germany, Greece, Italy, the Netherlands, Portugal, Spain, Turkey, UK). The majority of patients were aged ≥65 years (56.4%) and had CAP only (78.8%). Initial antibiotic treatment modification occurred in 28.9% of patients and was more likely in certain groups (patients with comorbidities; more severely ill patients; patients with healthcare-associated pneumonia, immunosuppression or recurrent episodes of CAP). Streamlining (de-escalation) of therapy occurred in 5.1% of patients. Mean length of hospital stay was 12.6 days and overall mortality was 7.2%.

Conclusion

These data provide a current overview of clinical practice in patients with CAP in EU hospitals, revealing high rates of initial antibiotic treatment modification. The findings may precipitate reassessment of optimal management regimens for hospitalized CAP patients.     

Lung inflammatory pattern and antibiotic treatment in pneumonia

Background

In community-acquired pneumonia host inflammatory response against the causative microorganism is necessary for infection resolution. However an excessive response can have deleterious effects. In addition to antimicrobial effects, macrolide antibiotics are known to possess immunomodulatory properties.We aimed to evaluate inflammatory cytokine profiles – both locally (bronchoalveolar lavage) and systemically (blood) – in community-acquired pneumonia admitted patients after at least 72 hours of antibiotic treatment (with and without macrolide containing regimens) and requiring bronchoscopic examination for inadequate response due to infection progression and/or lack of clinical stability.

Methods

A prospective study was performed on 52 admitted patients who developed an inadequate response after 72 hours of antibiotic treatment - non-responders community-acquired pneumonia - (blood and bronchoalveolar lavage), and two control groups: 1) community-acquired pneumonia control (blood) and 2) non-infection control (blood and bronchoalveolar lavage). Cytokine profiles (interleukin (IL)-6, IL-8, IL-10), tumour necrosis factor α and clinical outcomes were assessed.

Results

Non–responders patients treated with macrolide containing regimens showed significantly lower levels of IL-6 and TNF-α in bronchoalveolar lavage fluid and lower IL-8 and IL-10 in blood than those patients treated with non-macrolide regimens. Clinical outcomes showed that patients treated with macrolide regimens required fewer days to reach clinical stability (p < 0.01) and shorter hospitalization periods (p < 0.01).

Conclusions

After 72 hours of antibiotic effect, patients who received macrolide containing regimens exhibited lower inflammatory cytokine levels in pulmonary and systemic compartments along with faster stabilization of infectious parameters.     

Decreased inflammatory response in Toll-like receptor 2 knockout mice is associated with exacerbated Pneumocystis pneumonia

Pneumocystis pneumonia (PcP) is marked by substantial inflammatory damage to the lung. We have found that Toll-like receptor 2 (TLR2) mediates macrophage inflammatory responses to Pneumocystis and hypothesized that TLR2 deficiency would lead to less severe inflammation and milder lung injury during PcP. Histopathology examination showed that TLR2-/- mice with PcP indeed exhibited milder pulmonary inflammation. TLR2-/- mouse lungs contained less TNF-alpha and displayed lower levels of NF-kappaB activation during PcP. However, TLR2-/- mice with PcP displayed increased severity in symptoms and organism burden. The increased organism burden is likely due to defects in protective mechanisms in TLR2-/- mice. mRNA levels of the inducible nitric oxide synthase and NADPH oxidase p47phox, as well as nitric oxide levels in the lungs, were decreased in TLR2-/- PcP mice. Taken together, this study shows that TLR2-mediated inflammatory responses contribute to a certain degree to the clearance of Pneumocystis organism in mice.     

Efficacy of osteopathic manipulation as an adjunctive treatment for hospitalized patients with pneumonia: a randomized controlled trial

Background

The Multicenter Osteopathic Pneumonia Study in the Elderly (MOPSE) is a registered, double-blinded, randomized, controlled trial designed to assess the efficacy of osteopathic manipulative treatment (OMT) as an adjunctive treatment in elderly patients with pneumonia.

Methods

406 subjects aged ≥ 50 years hospitalized with pneumonia at 7 community hospitals were randomized using concealed allocation to conventional care only (CCO), light-touch treatment (LT), or OMT groups. All subjects received conventional treatment for pneumonia. OMT and LT groups received group-specific protocols for 15 minutes, twice daily until discharge, cessation of antibiotics, respiratory failure, death, or withdrawal from the study. The primary outcomes were hospital length of stay (LOS), time to clinical stability, and a symptomatic and functional recovery score.

Results

Intention-to-treat (ITT) analysis (n = 387) found no significant differences between groups. Per-protocol (PP) analysis (n = 318) found a significant difference between groups (P = 0.01) in LOS. Multiple comparisons indicated a reduction in median LOS (95% confidence interval) for the OMT group (3.5 [3.2-4.0] days) versus the CCO group (4.5 [3.9-4.9] days), but not versus the LT group (3.9 [3.5-4.8] days). Secondary outcomes of duration of intravenous antibiotics and treatment endpoint were also significantly different between groups (P = 0.05 and 0.006, respectively). Duration of intravenous antibiotics and death or respiratory failure were lower for the OMT group versus the CCO group, but not versus the LT group.

Conclusions

ITT analysis found no differences between groups. PP analysis found significant reductions in LOS, duration of intravenous antibiotics, and respiratory failure or death when OMT was compared to CCO. Given the prevalence of pneumonia, adjunctive OMT merits further study.     

Influence of age on brain edema formation, secondary brain damage and inflammatory response after brain trauma in mice

After traumatic brain injury (TBI) elderly patients suffer from higher mortality rate and worse functional outcome compared to young patients. However, experimental TBI research is primarily performed in young animals. Aim of the present study was to clarify whether age affects functional outcome, neuroinflammation and secondary brain damage after brain trauma in mice. Young (2 months) and old (21 months) male C57Bl6N mice were anesthetized and subjected to a controlled cortical impact injury (CCI) on the right parietal cortex. Animals of both ages were randomly assigned to 15 min, 24 h, and 72 h survival. At the end of the observation periods, contusion volume, brain water content, neurologic function, cerebral and systemic inflammation (CD3+ T cell migration, inflammatory cytokine expression in brain and lung, blood differential cell count) were determined. Old animals showed worse neurological function 72 h after CCI and a high mortality rate (19.2%) compared to young (0%). This did not correlate with histopathological damage, as contusion volumes were equal in both age groups. Although a more pronounced brain edema formation was detected in old mice 24 hours after TBI, lack of correlation between brain water content and neurological deficit indicated that brain edema formation is not solely responsible for age-dependent differences in neurological outcome. Brains of old naïve mice were about 8% smaller compared to young naïve brains, suggesting age-related brain atrophy with possible decline in plasticity. Onset of cerebral inflammation started earlier and primarily ipsilateral to damage in old mice, whereas in young mice inflammation was delayed and present in both hemispheres with a characteristic T cell migration pattern. Pulmonary interleukin 1β expression was up-regulated after cerebral injury only in young, not aged mice. The results therefore indicate that old animals are prone to functional deficits and strong ipsilateral cerebral inflammation without major differences in morphological brain damage compared to young.     

DNAemia detection by multiplex PCR and biomarkers for infection in systemic inflammatory response syndrome patients

Fast and reliable assays to precisely define the nature of the infectious agents causing sepsis are eagerly anticipated. New molecular biology techniques are now available to define the presence of bacterial or fungal DNA within the bloodstream of sepsis patients. We have used a new technique (VYOO?) that allows the enrichment of microbial DNA before a multiplex polymerase chain reaction (PCR) for pathogen detection provided by SIRS-Lab (Jena, Germany). We analyzed 72 sepsis patients and 14 non-infectious systemic inflammatory response syndrome (SIRS) patients. Among the sepsis patients, 20 had a positive blood culture and 35 had a positive microbiology in other biological samples. Of these, 51.4% were positive using the VYOO? test. Among the sepsis patients with a negative microbiology and the non-infectious SIRS, 29.4% and 14.2% were positive with the VYOO? test, respectively. The concordance in bacterial identification between microbiology and the VYOO? test was 46.2%. This study demonstrates that these new technologies offer great hopes, but improvements are still needed.