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Use of sensitive, broad-spectrum molecular assays and human airway epithelium cultures for detection of respiratory pathogens.

Rapid and accurate detection and identification of viruses causing respiratory tract infections is important for patient care and disease control. Despite the fact that several assays are available, identification of an etiological agent is not possible in ∼30% of patients suffering from respiratory tract diseases. Therefore, the aim of the current study was to develop a diagnostic set for the detection of respiratory viruses with sensitivity as low as 1-10 copies per reaction.

Evaluation of the assay using a training clinical sample set showed that viral nucleic acids were identified in ∼76% of cases. To improve assay performance and facilitate the identification of novel species or emerging strains, cultures of fully differentiated human airway epithelium were used to pre-amplify infectious viruses. This additional step resulted in the detection of pathogens in all samples tested.

Based on these results it can be hypothesized that the lack of an etiological agent in some clinical samples, both reported previously and observed in the present study, may result not only from the presence of unknown viral species, but also from imperfections in the detection methods used.

Local pulmonary administration of factor VIIa (rFVIIa) in diffuse alveolar hemorrhage (DAH) - a review of a new treatment paradigm.

Diffuse alveolar hemorrhage (DAH) is a clinical syndrome with typical symptoms dyspnea and hemoptysis. DAH is a complication of specific diseases, in some cases with acute catastrophic hemoptysis, while other patients present low grade alveolar bleeding with a need of chronic transfusion as in pulmonary hemosiderosis.

METHODS: Current literature in the PubMed database and other sources was reviewed in order to evaluate the current treatment recommendations, efficacy of this treatment, and finally the risk of complications after off-label use of rFVIIa in respect to DAH.

OBJECTIVES: (i) To elucidate the clinical aspects of alveolar hemorrhage, (ii) to develop a simple diagnostic algorithm in order to separate DAH from other important pulmonary diseases with similar clinical picture and comparably high mortality. Such an algorithm has important therapeutic consequences because these diseases: acute lung injury (ALI), acute respiratory distress syndrome (ARDS) and bronchiolitis obliterans organizing pneumonia (BOOP) have different therapies, (iii) to evaluate and discuss whether local pulmonary administration may improve outcome and reduce mortality in DAH, and (iv) to suggest a treatment schedule.

RESULTS: Hitherto the diagnosis and treatment of DAH has been based on anecdotal reports. The treatment has relied on different unspecific treatment modalities based on a mixture of treatment of the underlying disease and treatment without evidence targeted to stop the alveolar bleeding. However, recently a number of publications have advocated the use of intrapulmonary rFVIIa. Even in severe bleeding DAH has been shown to respond promptly without thromboembolic complication when FVIIa was administered locally via the air side, because the FVIIa does not penetrate the alveolo-capillary membrane to the blood-side. The incidence of DAH (in the US and Europe is 100,000-150,000, and 50,000 patients annually are at risk of developing DAH following hematopoietic stem cell transplant (HSCT) and autoimmune diseases. Finally 50,000-100,000 patients may be falsely categorized as having acute respiratory distress syndrome/acute lung injury (ARDS/ALI) because DAH and ARDS cannot be separated clinically. A new treatment paradigm of DAH is proposed as no other intervention has been able to ensure pulmonary hemostasis in DAH. The diagnosis of DAH is simple, a series of broncho-alveolar washes which become increasingly bloody. This test should be performed in all patients with pulmonary opacities in order to separate ARDS/ALI from DAH. FVIIa administrated via pulmonary route is "drug of choice", because it stops bleeding in the life-threatening syndrome DAH. Hemostasis is obtained after only one to two small doses of FVIIa (50 μg/kg body weight per dose) and after hemostasis the oxygen transport quickly improves.

CONCLUSION: Intrapulmonary administration of rFVIIa is recommended as the treatment of choice for DAH and blast lung injury (BLI) because the treatment has been shown to be successful and uncomplicated in spite of the fact that only a small series of DAH has been documented.

Vasculitis of the upper airways.

Systemic vasculitides are rare and potentially life-threatening diseases. Granulomatosis with polyangiitis (GPA; formerly Wegener's granulomatosis) and Churg Strauss syndrome (possibly to be renamed eosinophilic granulomatosis with polyangiitis; EGPA) are the 2 chief systemic vasculitides which may involve the upper respiratory tract.

Chronic allergic rhinitis and nasal polyposis in EGPA, and recurrent sinusitis and/or otitis in both conditions, are not specific and can thus represent real diagnostic challenges if they are the first manifestations of the disease. Nasal septum perforation, saddle nose deformity and/or subglottic stenosis (SGS), although not totally specific, are more suggestive of GPA.

Because upper airway manifestations often tend to be refractory to systemic therapy and/or to linger, local treatment represents a major aspect of management of the condition, especially for patients with SGS.

MRI of the lung: state of the art.

Magnetic resonance imaging (MRI) of the lung is technically challenging due to the low proton density and fast signal decay of the lung parenchyma itself. Additional challenges consist of tissue loss, hyperinflation, and hypoxic hypoperfusion, e.g., in emphysema, a so-called "minus-pathology".

However, pathologic changes resulting in an increase of tissue ("pluspathology"), such as atelectases, nodules, infiltrates, mucus, or pleural effusion, are easily depicted with high diagnostic accuracy. Although MRI is inferior or at best equal to multidetector computed tomography (MDCT) for the detection of subtle morphological features, MRI now offers an increasing spectrum of functional imaging techniques such as perfusion assessment and measurement of ventilation and respiratory mechanics that are superior to what is possible with MDCT. Without putting patients at risk with ionizing radiation, repeated examinations allow for the evaluation of the course of lung disease and monitoring of the therapeutic response through quantitative imaging, providing a level of functional detail that cannot be obtained by any other single imaging modality. As such, MRI will likely be used for clinical applications beyond morphological imaging for many lung diseases.

In this article, we review the technical aspects and protocol suggestions for chest MRI and discuss the role of MRI in the evaluation of nodules and masses, airway disease, respiratory mechanics, ventilation, perfusion and hemodynamics, and pulmonary vasculature.

How do dyspnoea scales compare with measurement of functional capacity in patients with COPD and at risk of COPD?

In primary care, formal functional capacity testing is not always feasible. Guidelines for family practitioners suggest the use of dyspnoea scales to assess exercise tolerance in patients with chronic obstructive pulmonary disease (COPD).

AIMS: To examine whether the use of activity-based dyspnoea scales can substitute for actual functional capacity testing.

METHODS: 128 subjects (49% at risk of COPD, 24% GOLD stage I, 17% GOLD stage II, 9% GOLD stage III) performed an Incremental Shuttle Walk Test (ISWT) and completed the Medical Research Council dyspnoea scale (MRC), Baseline Dyspnoea Index (BDI), Oxygen Cost Diagram (OCD), Clinical COPD Questionnaire (CCQ), and St George's Respiratory Questionnaire (SGRQ).

RESULTS: Analysis of variance showed that the relationship between the ISWT and the MRC dyspnoea scale was statistically significant but moderate (p<0.001, R2=0.166). Correlations between the ISWT and the other dyspnoea scales were also moderate (correlation coefficients 0.34-0.42). Combining the dyspnoea scales in one analysis resulted in a proportion of explained variance of the ISWT of 21.4% (R2=0.214).

CONCLUSIONS: Dyspnoea scales cannot substitute for formal functional capacity testing. Authors of COPD guidelines should consider stating more specifically that the MRC and similar scales measure (self-reported) activity-related dyspnoea but cannot replace objectively measured functional capacity.

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