The measurement of DLNO and DLCO: A manufacturer's perspective

The simultaneous measurement of the lung transfer factor for carbon monoxide (DLCO) and nitric oxide (DLNO) is now available as a powerful method for studying the alveolar-capillary gas exchange. However, application of the DLNO-CO technique in daily settings is still limited by some technical drawbacks. This paper provides a manufacturer's overview of the measuring principles, technical challenges and current available solutions for implementing the DLNO-CO measurement in to a marketed device. This includes the recent developments in technology for NO sensors, latest findings on NO uptake and new statistical methods.

Partial versus maximal forced exhalations in COPD: enhanced signal detection for novel therapies

BACKGROUND

Evaluation of novel compounds for COPD often relies on FEV1 for signal detection. Partial forced exhalations from end-tidal inspiration (PEFV) might complement FEV1 in identifying such a signal. We examined the prevalence of bronchodilator response (BDR) using PEFV and FEV1 in patients with COPD.

METHODS

110 consecutive COPD patients were tested prospectively with PEFV and maximal expiratory flow before and after inhalation of a short-acting β2 agonist (salbutamol, 400 μg). Partial flow at 800 ml above residual volume was derived from the PEFV (PF800). Significant changes in PF800 and/or FEV1 were set at the upper 95% confidence interval after placebo (n = 28).

RESULTS

Four groups were identified by the presence (+) or absence (-) of a BDR: Group 1 [PF800 (-)FEV1(-)] when no change was observed (n = 31), Group 2 [PF800(+)FEV1(-)] when PF800 alone improved (n = 31), Group 3 [PF800(-)FEV1(+)] when FEV1 alone improved (n = 26), and Group 4 [PF800(+)FEV1(+)] when both variables improved (n = 18). There were 35 non-responders in any parameter, and 75/110 subjects who showed a response in at least one parameter. The changes in PF800 and FEV1 were not correlated suggesting these assess different airway generations.

CONCLUSIONS

The use of PF800 increased detection of a BDR in COPD compared to FEV1 alone and may reflect small airway responses. The PEFV maneuver is simple, repeatable and may avoid some of the theoretical disadvantages of FEV1. The role of PF800 for evaluating novel anti-inflammatory agents remains to be determined.

A comparative study of clarithromycin modified release and amoxicillin/clavulanic acid in the treatment of acute exacerbation of chronic bronchitis

This phase III, investigator-blind, randomized, parallel-group study compared the efficacy and tolerability of clarithromycin modified release (MR) with those of amoxicillin/clavulanic acid in 250 adult outpatients with acute exacerbationof chronic bronchitis (AECB). Patients received either clarithromycin MR 500 mg once daily or amoxicillin/clavulanic acid 500 mg/125 mg three times daily for 7 days. Primary endpoints were sponsor-defined clinical response and pathogen outcome at the end of treatment. Secondary endpoints were sponsor-defined clinical response and pathogen outcome at study end, investigator-defined clinical response at end of treatment and end of study, resolution or improvement of signs and symptoms, eradication of baseline pathogens, serologic outcome for atypical pathogens, and occurrence of reinfection and superinfection. Adverse events and compliance were also evaluated. Clinical and bacteriologic outcomes with both treatments for all endpoints were statistically equivalent, as were total adverse events, although the incidences of digestive disturbances (13% vs 4%) and discontinuations due to adverse events (8 vs 2 patients; P < or =.05) were significantly higher with amoxicillin/clavulanic acid. Ninety-five percent of patients receiving clarithromycin MR and 80% receiving amoxicillin/clavulanic acid were 100% compliant with medication (P < or =.05). Clarithromycin MR and amoxicillin/clavulanic acid are both well tolerated and effective as therapy for AECB; however, clarithromycin produced fewer side effects and discontinuations and higher compliance rates.

Phagocyte enzymes in bronchoalveolar lavage from patients with pulmonary sarcoidosis and collagen vascular disorders

The balance between proteases and antiproteases in the lower respiratory tract is believed to play a role in the outcome of interstitial lung diseases. In this cross-sectional study, we measure several phagocyte derived enzymes, namely plasminogen activator, neutrophil elastase and an ill-defined protease active on the trialanine chromophore substrate succinyl-alanine3-nitroanilide (SLAPN) in bronchoalveolar lavage (BAL) fluid from 42 patients with pulmonary sarcoidosis and from 43 patients with collagen vascular disease (CVD), 22 without lung disease (group I) and 21 associated with parenchymal lung disease (group II). The results show: a) that sarcoidosis is associated with increased plasminogen activator activity and with the presence of enzymatic activity against SLAPN corresponding at least in part to a metalloprotease; b) that CVD in the absence of radiographic lung disease is associated with an increase of plasminogen activator activity and increased levels of alpha 1-antiprotease-neutrophil elastase complexes; c) that the majority of untreated CVD (group II) patients have detectable levels of neutrophil elastase activity. These data show that patients with pulmonary sarcoidosis and CVD have different enzymatic profiles in their lower respiratory tract as assessed by BAL. Thus, sarcoidosis (mostly lymphocytic) is associated with enhanced macrophage-derived proteolytic activity in BAL, while CVD patients both with and without lung disease have increased neutrophil counts and neutrophil elastase complexed to alpha 1-protease inhibitor and presumably inactive in BAL. Finally, only BAL from untreated CVD patients with interstitial lung disease contain neutrophil elastase activity. This latter activity could contribute to the lung lesions frequently observed in these disorders.

Phagocyte enzymes in bronchoalveolar lavage from patients with pulmonary sarcoidosis and collagen vascular disorders

The balance between proteases and antiproteases in the lower respiratory tract is believed to play a role in the outcome of interstitial lung diseases. In this cross-sectional study, we measure several phagocyte derived enzymes, namely plasminogen activator, neutrophil elastase and an ill-defined protease active on the trialanine chromophore substrate succinyl-alanine3-nitroanilide (SLAPN) in bronchoalveolar lavage (BAL) fluid from 42 patients with pulmonary sarcoidosis and from 43 patients with collagen vascular disease (CVD), 22 without lung disease (group I) and 21 associated with parenchymal lung disease (group II). The results show: a) that sarcoidosis is associated with increased plasminogen activator activity and with the presence of enzymatic activity against SLAPN corresponding at least in part to a metalloprotease; b) that CVD in the absence of radiographic lung disease is associated with an increase of plasminogen activator activity and increased levels of alpha 1-antiprotease-neutrophil elastase complexes; c) that the majority of untreated CVD (group II) patients have detectable levels of neutrophil elastase activity. These data show that patients with pulmonary sarcoidosis and CVD have different enzymatic profiles in their lower respiratory tract as assessed by BAL. Thus, sarcoidosis (mostly lymphocytic) is associated with enhanced macrophage-derived proteolytic activity in BAL, while CVD patients both with and without lung disease have increased neutrophil counts and neutrophil elastase complexed to alpha 1-protease inhibitor and presumably inactive in BAL. Finally, only BAL from untreated CVD patients with interstitial lung disease contain neutrophil elastase activity. This latter activity could contribute to the lung lesions frequently observed in these disorders.

Relationship between inflammatory processes and gas exchanges in pulmonary sarcoidosis

In the present study, we investigated whether the analysis of cells and proteins collected by bronchoalveolar lavage (BAL) could accurately reflect the degree of functional impairment in pulmonary sarcoidosis. Eighteen patients with biopsy-proven sarcoidosis were prospectively evaluated. An inverse relationship was demonstrated between BAL coefficient of excretion relative to albumin (RCE) values of IgG and IgA and diffusion for carbon monoxide (Dco). A similar negative correlation existed with PaO2 at the end of a maximal exercise. Steroid therapy in five patients lowered concomitantly BAL RCE of IgA and IgG while Dco values increased. Immunoperoxidase studies in three lung biopsies revealed numerous Ig-containing cells within the lung parenchyma. We suggest that these BAL Ig values reflected the mononuclear cell infiltration of the bronchiolovascular sheaths and lung interstitium. This cellular infiltration likely induces a distortion of the capillary bed and may affect the gas exchanges in a reversible way.

Clinical and subclinical alveolitis in collagen vascular diseases: contribution of alpha 2-macroglobulin levels in BAL fluid

The probability that patients with collagen vascular diseases (CVD) will develop fibrosis is unpredictable. Since changes in bronchoalveolar lavage (BAL) cell data can be observed in CVD patients without evidence of lung involvement, we investigated whether the study of soluble components in BAL could help to distinguish CVD patients with lung involvement (n = 15) from those without pulmonary disease (n = 37). Our results demonstrate that the alveolitis observed in patients with overt lung involvement is associated with an increase of BAL alpha 2-macroglobulin (alpha 2-MA). In contrast, the BAL alpha 2-MA levels were found to be normal in CVD patients without evidence of pulmonary disease as well as in CVD patients with overt lung involvement treated with steroids. This was observed even in the presence of high neutrophil or lymphocyte counts in BAL. In conclusion, when neutrophils or lymphocytes accumulate in the lungs of CVD patients without evidence of lung damage, in the majority of patients this cell accumulation is not associated with an increase of BAL soluble components.

Clinical and subclinical alveolitis in collagen vascular diseases: contribution of alpha 2-macroglobulin levels in BAL fluid

The probability that patients with collagen vascular diseases (CVD) will develop fibrosis is unpredictable. Since changes in bronchoalveolar lavage (BAL) cell data can be observed in CVD patients without evidence of lung involvement, we investigated whether the study of soluble components in BAL could help to distinguish CVD patients with lung involvement (n = 15) from those without pulmonary disease (n = 37). Our results demonstrate that the alveolitis observed in patients with overt lung involvement is associated with an increase of BAL alpha 2-macroglobulin (alpha 2-MA). In contrast, the BAL alpha 2-MA levels were found to be normal in CVD patients without evidence of pulmonary disease as well as in CVD patients with overt lung involvement treated with steroids. This was observed even in the presence of high neutrophil or lymphocyte counts in BAL. In conclusion, when neutrophils or lymphocytes accumulate in the lungs of CVD patients without evidence of lung damage, in the majority of patients this cell accumulation is not associated with an increase of BAL soluble components.

Antiproteases are increased in bronchoalveolar lavage in interstitial lung disease

The present study evaluates different cellular and soluble components in the bronchoalveolar lavage (BAL) from patients with interstitial lung disease. We observed an increased T4/T8 lymphocyte ratio in BAL but not in blood from 24 patients with active pulmonary sarcoidosis compared to sixteen normal individuals and to eleven patients with inactive pulmonary sarcoidosis. Seven patients with hypersensitivity pneumonitis had a normal T4/T8 ratio. In the active sarcoidosis and hypersensitivity pneumonitis groups, alpha 1-Protease Inhibitor (alpha 1 PI) in BAL is significantly higher than in the normal group and a significant correlation between the two antiproteases (alpha 2-macroglobulin and alpha 1 PI) is observed. These data demonstrate that antiprotease levels (alpha 1 PI and alpha 2 M) are increased in the lower respiratory tract of patients with interstitial lung disease and that among cellular and soluble components of BAL, alpha 2 M represents a sensitive marker of the alveolitis.

Antiproteases are increased in bronchoalveolar lavage in interstitial lung disease

The present study evaluates different cellular and soluble components in the bronchoalveolar lavage (BAL) from patients with interstitial lung disease. We observed an increased T4/T8 lymphocyte ratio in BAL but not in blood from 24 patients with active pulmonary sarcoidosis compared to sixteen normal individuals and to eleven patients with inactive pulmonary sarcoidosis. Seven patients with hypersensitivity pneumonitis had a normal T4/T8 ratio. In the active sarcoidosis and hypersensitivity pneumonitis groups, alpha 1-Protease Inhibitor (alpha 1 PI) in BAL is significantly higher than in the normal group and a significant correlation between the two antiproteases (alpha 2-macroglobulin and alpha 1 PI) is observed. These data demonstrate that antiprotease levels (alpha 1 PI and alpha 2 M) are increased in the lower respiratory tract of patients with interstitial lung disease and that among cellular and soluble components of BAL, alpha 2 M represents a sensitive marker of the alveolitis.

[Blood platelets and asthma caused by aspirin]

Platelets isolated from patients with aspirin-induced asthma (ASA patients) react abnormally in vitro to aspirin and to non-steroid anti-inflammatory drugs (NSAID), by generating cytocidal molecules, that can kill parasitic larvae and to oxygen-dependent free radicles, which may be detected by chemiluminescence, although these drugs do not have a similar effect on platelets from normal donors or allergic asthmatics. The abnormality appears to be associated with the inhibiting properties of NSAID and aspirin on the cyclo-oxygenase pathway, that leads to a defect of the binding of prostaglandin endoperoxide PGH2 to its receptors on the platelet membrane. In addition, another metabolite from the lipoxygenase pathway which is at present poorly defined seems to participate in the anomaly. Sodium salicylate, a naturally produced catabolite of aspirin, that is well-tolerated by ASA patients, inhibits the abnormal response of the platelets and this opens new perspectives in the management of aspirin-sensitive intolerance.

Dissecting aneurysm of the ascending aorta with aorto-caval fistula. Fiberoptic oximetric findings and surgical management

A patient presented the rare complication of a dissecting aneurysm of the ascending aorta ruptured into the superior vena cava producing a left-right fistula. Continuous oximetric measurements by a fiberoptic pulmonary artery floated catheter was used to localize the site of the shunt. Emergency surgical repair was successfully performed.