C-reactive protein and procalcitonin as predictors of survival and septic shock in ventilator-associated pneumonia

We evaluated the performance of procalcitonin (PCT) and C-reactive protein (CRP) threshold values and kinetics as predictors of ventilator-associated pneumonia (VAP) survival and septic shock development. 45 adult patients with VAP were studied. Serum CRP and PCT levels and the Sequential Organ Failure Assessment (SOFA) score were measured on days 1, 4 and 7 (D1, D4, D7) of VAP and their variations between different days (kinetics) were calculated (DeltaPCT, DeltaCRP). A multivariate logistic regression model was constructed with either VAP 28-day survival or septic shock development as dependent variables, and PCT values, CRP values, kinetics, age, sex, SOFA and Acute Physiology and Chronic Health Evaluation (APACHE) II score as independent variables. No difference was found in CRP levels between survivors and nonsurvivors. Nonsurvivors had significantly higher PCT levels on D1 and D7. In the multivariate analysis, the only factors predicting VAP survival were DeltaPCT(7-1) (OR 7.23, 95% CI 0.008-0.468) and DeltaCRP(7-4) (OR 4.59, 95% CI 0.013-0.824). VAP patients who developed septic shock had significantly higher CRP levels on D1 and D7 and higher PCT levels on D1 and D4. The only factor predicting the development of septic shock was SOFA on D1 (OR 7.44, 95% CI 1.330-5.715). Neither PCT and CRP threshold values nor their kinetics can predict VAP survival or septic shock development.

Adenosine deaminase activity and its isoenzymes in the sputum of patients with pulmonary tuberculosis

BACKGROUND

Adenosine deaminase (ADA) has been widely used for the diagnosis of tuberculous pleural effusion. Two isoenzymes have been described, ADA(1) and ADA(2).

OBJECTIVE

To evaluate the diagnostic value of sputum ADA, ADA(1) and ADA(2) activity in pulmonary tuberculosis (TB).

DESIGN

We measured total ADA, ADA(1) and ADA(2) activity in the sputum of 27 patients with pulmonary TB (11 had a negative Ziehl-Neelsen stain for acid-fast bacilli [AFB]). Nineteen patients with lung cancer were used as controls.

RESULTS

Sputum total ADA activity was significantly higher in TB than in lung cancer patients (median 18 U/l [range 3-70] vs. 6 U/l [2-16]; P < 0.001). Sputum ADA(2) activity was significantly higher in TB compared to lung cancer patients (9 U/l [0-65] vs. 5 U/l [0-12]; P = 0.001). Sputum ADA(2) was significantly higher than ADA(1) in TB patients (P = 0.001). Sputum ADA and ADA(2) were higher in both AFB-positive and AFB-negative TB patients. Using a cut-off level of respectively 16 UI/l and 5UI/l for sputum total ADA and ADA(2), sensitivity and specificity were 55.6% and 100% for total ADA and 81.5% and 63.2% for ADA(2).

CONCLUSION

Sputum total ADA and ADA(2) levels are elevated in patients with pulmonary TB. As they are elevated even in AFB-negative patients, they may assist in the early diagnosis of pulmonary TB.

Carcinoembryonic antigen, neuron-specific enolase and cytokeratin fragment 19 (CYFRA 21-1) levels in induced sputum of lung cancer patients

OBJECTIVES

The diagnosis of lung cancer is usually based on the histological and cytological examination of material obtained by bronchoscopy. Tumour markers in serum are of little use as a diagnostic tool for lung cancer. We hypothesized that induced sputum could be a suitable material for measuring tumour markers and, accordingly, attempted to evaluate the diagnostic value of such measurements in lung cancer. Induced sputum is minimally invasive and readily obtainable.

MATERIAL AND METHODS

Fifty patients with lung cancer and 24 subjects with chronic obstructive pulmonary disease (COPD) were included in the study. CEA, NSE and CYFRA 21-1 levels in serum and induced sputum were measured by immunoradiometric assays.

RESULTS

Serum and sputum CEA, serum and sputum NSE and serum CYFRA 21-1 did not differ significantly between lung cancer and COPD patients. Sputum CYFRA 21-1 was 7 times greater in the lung cancer group than in the COPD group. This finding was true in both small cell (SCLC) and non-small cell (NSCLC) lung cancer. The sensitivity, specificity, positive and negative predictive values were 86, 75, 88 and 72%, respectively.

CONCLUSION

Of tumour markers in induced sputum, sputum CYFRA 21-1 offered the best predictive values, although not sufficiently satisfactory to suggest its routine use in lung cancer diagnosis.

Plasma leptin and insulin-like growth factor I levels during acute exacerbations of chronic obstructive pulmonary disease

BACKGROUND

Recent studies have provided evidence for a link between leptin and tumor necrosis factor-alpha (TNF-alpha). Insulin-like growth factor I (IGF-I) mediates the metabolic effects of growth hormone (GH). The GH axis is believed to be suppressed in chronic obstructive pulmonary disease (COPD). The aim of this study is to find out whether acute exacerbations of COPD are followed by changes in plasma leptin and insulin-like growth factor I (IGF-I) levels and furthermore, whether these changes are related to systemic inflammation.

METHODS

We measured serum leptin, IGF-I, TNF-alpha, interleukin 1 beta (IL-1 beta), interleukin 6 (IL-6) and interleukin 8 (IL-8) levels in 52 COPD patients with acute exacerbation on admission to hospital (Day 1) and two weeks later (Day 15). 25 healthy age-matched subjects served as controls. COPD patients were also divided into two subgroups (29 with chronic bronchitis and 23 with emphysema). Serum leptin and IGF-I were measured by radioimmunoassay and TNF-alpha, IL-1 beta, IL-6 and IL-8 were measured by ELISA.

RESULTS

Serum leptin levels were significantly higher and serum IGF-I levels significantly lower in COPD patients on Day 1 than in healthy controls (p < 0.001). A positive correlation was observed between leptin and TNF-alpha on Day 1 (r = 0.620, p < 0.001). Emphysematous patients had significantly lower IGF-I levels compared to those with chronic bronchitis both on Day 1 and Day 15 (p = 0.003 and p < 0.001 respectively).

CONCLUSION

Inappropriately increased circulating leptin levels along with decreased IGF-I levels occurred during acute exacerbations of COPD. Compared to chronic bronchitis, patients with emphysema had lower circulating IGF-I levels both at the onset of the exacerbation and two weeks later.

Tuberculous Effusion: ADA Activity Correlates with CD4+ Cell Numbers in the Fluid and the Pleura

BACKGROUND

Adenosine deaminase (ADA) is a commonly used marker in the diagnosis of tuberculous effusion and there is evidence that its production is linked to T cells and monocytes. Data on the correlation between ADA and T cells or macrophages in tuberculous effusions are conflicting. Furthermore, no studies have examined a possible correlation between pleural tissue infiltration and ADA.

OBJECTIVES

We undertook this study to examine cell subsets in the fluid and the pleura in tuberculous effusion and their correlation to ADA. The use of cell subsets as a marker in the differential diagnosis was also examined.

METHODS

Pleural fluid from 36 patients with tuberculous and 34 patients with malignant effusion as well as pleural tissue biopsies from 16 patients with tuberculous pleurisy were examined. The APAAP and the avidin-biotin complex immunocytochemical methods were used to examine CD4+ T cells and macrophages (CD68+), while ADA activity was measured by the Giusti colorimetric method.

RESULTS

Our results showed that, in pleural fluid, CD4+ cells and ADA were significantly higher in tuberculous compared to malignant effusion (p<0.001 for all measurements). In pleural tissue biopsies, macrophages were the predominant cells but CD4+ T cells were also abundant. A significant correlation was found between ADA and CD4+ numbers in pleural fluid and tissue (r=0.45, p<0.01; r=0.75, p<0.001, respectively). ADA had high sensitivity and specificity for differential diagnosis while cell subsets did not.

CONCLUSIONS

These results indicate that ADA activity correlates to CD4+ T cell infiltration in the pleura and the fluid. Moreover, ADA but no cell subsets may be used as markers of tuberculous effusion.

Incidence and risk factors for ventilator-associated pneumonia in 4 multidisciplinary intensive care units in Athens, Greece

INTRODUCTION

Ventilator-associated pneumonia (VAP) is the most common nosocomial infection among intensive care unit (ICU) patients.

OBJECTIVE

Prospectively identify the factors associated with development of VAP and examine the incidence of VAP.

SUBJECTS

Over a 6-month period we had 175 patients who required mechanical ventilation for longer than 24 hours.

RESULTS

VAP occurred in 56 patients (32%). Stepwise logistic regression analysis identified 5 factors independently associated with VAP (p < 0.05): bronchoscopy (adjusted odds ratio [AOR] = 2.95; 95% confidence interval [CI], 1.1-8.3; p = 0.036); tube thoracostomy (AOR = 2.78; 95% CI, 1.1-6.6; p = 0.023); tracheostomy (AOR = 3.56; 95% CI, 1.7-8.4; p = 0.002); Acute Physiology and Chronic Health Evaluation (APACHE II) score >/= 18 (AOR = 2.33; 95% CI, 1.1-5.1; p = 0.033); and enteral feeding (AOR = 2.89; 95% CI, 1.3-7.7; p = 0.026). The duration of mechanical ventilation was longer among patients who developed VAP (p < 0.001). VAP was not associated with the cause of ICU admission.

CONCLUSIONS

VAP is a common infection and certain interventions might affect the incidence of VAP. ICU clinicians should be aware of the risk factors for VAP, which could prove useful in identifying patients at high risk for VAP and modifying patient care to minimize the risk of VAP, such as avoiding unnecessary bronchoscopy or modulating enteral feeding.

Simultaneous analysis of T cell clonality and cytokine production in rheumatoid arthritis using three-colour flow cytometry

In this study we examined the cytokine production by T cells and TCRVbeta subsets in peripheral blood (PB) and synovial fluid (SF) from six RA patients and PB from 10 normal subjects, using three-colour flow cytometry. In two RA subjects we assessed T cell clonality by RT PCR using TCRBV family-specific primers and analysed the CDR3 (complementarity determining region 3) length by GeneScan analysis. A high percentage of IFN-gamma- and IL-2- producing cells was observed among the PB T cells in both the RA patients and normal controls and among the SF T cells in RA patients. In contrast, the percentage of T cells producing IL-4 and IL-5 was small among PB T cells in both RA patients and normal controls and among SF T cells in RA patients. There was no significant difference in the production of IFN-gamma, IL-2 and IL-5 between the two compartments (PB and SF); however, there were significantly more IL-4-producing cells in SF. Molecular analysis revealed clonal expansions of four TCRBV families in SF of two of the RA patients studied: TCRBV6.7, TCRBV13.1 and TCRBV22 in one and TCRBV6.7, TCRBV21.3 and TCRBV22 in the second. These expansions demonstrated cytokine expression profiles that differed from total CD3+ cells, implying that T cell subsets bearing various TCR-Vbeta families may have the potential to modulate the immune response in RA patients.

Plasma and urine elastase alpha-1-proteinase inhibitor levels in neonatal urinary tract infection

OBJECTIVE

To examine whether plasma or urine elastase alpha(1)-proteinase inhibitor (E-alpha(1)-PI) levels could be used as a diagnostic marker of urinary tract infection (UTI) in neonates.

SUBJECTS AND METHODS

Plasma and urine E-alpha(1)-PI levels were measured by immunoassay in 23 neonates with UTI at the time of admission and 72 h after the onset of treatment and in 10 'normal' neonates (i.e. with trivial problems). Additionally E-alpha(1)-PI plasma levels were measured in 15 neonates with septicemia.

RESULTS

E-alpha(1)-PI plasma levels did not differ between normal neonates and those with UTI. Urine E-alpha(1)-PI levels were significantly higher in neonates with UTI on admission compared to normal neonates. A significant decrease in urine E-alpha(1)-PI levels was noticed 72 h after the onset of treatment in all but 2 neonates in whom infection persisted. In this study, we have found that the urine E-alpha(1)-PI concentration at a cutoff level of 48 microg/l had a sensitivity of 83%, a specificity of 90%, a positive predictive value of 95% and a negative predictive value of 69% for the diagnosis of neonatal UTI.

CONCLUSION

Elevated levels of E-alpha(1)-PI in urine seem to be a useful tool for the diagnosis of UTI in neonates (even in those that have already been started on antibiotics) and possibly a valuable marker for early recognition of treatment failure.

TCR usage and cytokine expression in peripheral blood and BAL T cells

T cells are thought to play an important regulatory role in atopic asthma. We hypothesized that human blood and BAL T cell subsets bearing various TCR-Vbeta genes might show selective differences in their cytokine profile. Peripheral blood (PB) and bronchoalveolar lavage (BAL) T cells from seven atopic asthmatic and six non-atopic non-asthmatic subjects were stimulated with PMA and ionomycin in the presence of monensin and analysed for TCR-Vbeta expression and production of cytokines at the single cell level. The percentage of IFN-gamma- and IL-2-producing BAL T cells was elevated compared with PB T cells from both the asthmatic subjects and the non-atopic, non-asthmatic controls. A small percentage of PB and BAL T cells produced IL-4 and IL-5, in asthmatic and normal subjects. In peripheral blood, the percentage of T cells expressing each cytokine was similar in the various TCR-Vbeta subsets and in total CD3+ T cells in all normal and six of seven asthmatic subjects. However, there was a substantial degree of heterogeneity in the cytokine profile of BAL TCR-Vbeta subsets compared with the total CD3+ T cells. This was more obvious in the asthmatic subjects with a reduction in the percentage of IFN-gamma- and IL-2-expressing T cells (five of seven asthmatic subjects) and an increase in the percentage of IL-4- and IL-5-expressing T cells (two of seven asthmatic subjects). These data confirm previous findings of an elevated proportion of IFN-gamma- and IL-2-producing BAL T cells while only a small proportion of PB and BAL T cells produce IL-4 and IL-5. Moreover, subsets of BAL T cells, defined by their TCR-Vbeta usage, may differ in their cytokine profile compared with the total CD3+ T cells, implying that T cells expressing different Vbeta elements may play different roles in regulating the airway inflammation in asthma.

Modification of T-cell receptor Vbeta repertoire in response to allergen stimulation in peanut allergy

BACKGROUND

Peanut is one of the most common foods causing allergic reactions and is the most common cause of fatal and near-fatal food-related anaphylaxis. Little is known of the immunologic mechanisms that underlie peanut allergy.

OBJECTIVES

In this study we examined clonality of the T-cell response (TCR) to peanut in MHC class II identical, peanut allergy-discordant sibling pairs.

METHODS

Four sibling pairs were investigated. The TCR repertoire was analyzed before and after in vitro stimulation of PBMCs with crude peanut or PHA, as control for general/nonspecific reactivity. Eighteen TCR-Vbeta families were examined by flow cytometry. Where significant differences in incidence of particular TCR-Vbeta families were observed, PCR familyspecific cDNA amplification and gene scanning were performed.

RESULTS

After stimulation with peanut, no selective expansion of any TCR-Vbeta subpopulation was observed with flow cytometry, in either the peanut-allergic or nonallergic siblings, with the exception of 1 peanut-allergic subject who demonstrated a significant increase of TCR-Vbeta11(+) cells (0.3%-5.9% of the total CD3(+) cells). However, gene scanning revealed predominant single-size PCR products for TCRBV11 in all peanut-allergic subjects after peanut stimulation. TCRBV11 polyclo-nality was observed in allergic and nonallergic subjects before peanut stimulation and in nonallergic subjects after peanut stimulation. In comparison, all subjects, before and after stimulation with peanut, showed polyclonality for TCRBV2.

CONCLUSIONS

Our results argue for clonal or oligoclonal TCRs to crude peanut and indicate that changes in the TCRBV11 subpopulation are restricted to peanut-allergic subjects after stimulation with crude peanut allergen.

Intracellular cytokine staining for analysis by flow cytometry

To determine the function of a particular cell type, it is necessary either to have a large number of similar (ideally identical) cells or to use extremely sensitive methods to detect the activity of a single cell. Lymphocytes present special difficulties, because they have very precise antigen (Ag) recognition requirements, and, under physiological conditions, they will only be activated if they are exposed to their particular Ag. Polyclonal mitogens, such as phytohemagglutinin (PHA) or anti-CD3, will activate most T-cells, but may not elicit a truly physiological response in terms of cytokine production, and so on. Moreover, the biological readout (release of cytokines into culture supernatant) will represent the net balance of the integrated response of all the activated cells, minus any consumption of cytokines by the cultured cells.

Adenosine deaminase activity and lysozyme levels in bronchoalveolar lavage fluid in patients with pulmonary tuberculosis

SETTING

The estimations of adenosine deaminase (ADA) activity and lysozyme (LYS) levels in pleural fluid have been proved useful tools in the diagnosis of tuberculous pleural effusions. Little is known about their usefulness when estimated in bronchoalveolar lavage fluid (BALF).

OBJECTIVE

To evaluate whether both ADA activity and LYS levels in BALF could be employed in the diagnosis of pulmonary tuberculosis, and especially in active but acid fast bacilli (AFB) smear negative cases.

DESIGN

ADA activity and LYS levels were determined in BALF and serum obtained on the same day in 28 patients with tuberculosis, 21 with interstitial lung diseases, 14 with lung cancer and 13 with infectious diseases.

RESULTS

Patients with pulmonary tuberculosis had significantly higher ADA activity in BALF than patients with non-tuberculous lung diseases (P < 0.001). High BALF ADA activity in pulmonary tuberculosis patients suggests increased local production. In contrast, in this group of patients BALF LYS levels were not significantly higher than in the other groups of patients, but were in the group with interstitial lung diseases.

CONCLUSION

BALF ADA activity seems to be a useful tool in the differentiation of tuberculosis from other lung diseases. Its estimation can be restricted to the detection of cases with AFB negative smears.