Bronchoalveolar Lavage Aspirate Research Articles

ARDS AND NECROTIZING PNEUMONIA FROM BLASTOMYCES INFECTION

ARDS AND NECROTIZING PNEUMONIA FROM BLASTOMYCES INFECTION

Aspiration techniques for bronchoalveolar lavage in translational respiratory research: Paving the way to develop novel therapeutic moieties.

Bronchoalveolar lavage (BAL) is a simple, yet informative tool in understanding the immunopathology of various lung diseases via quantifying various inflammatory cells, cytokines and growth factors. At present, this traditional method is often blended with several robust and sophisticated molecular and biological techniques sustaining the significance and longevity of this technique. Crucially, the existence of slightly distinct approaches and variables employed at different laboratories around the globe in performing BAL aspiration indeed demands an utmost need to optimize and develop an effective, cost-effective and a reproducible technique. This mini review will be of importance to the biological translational scientist, particularly respiratory researchers in understanding the fundamentals and approaches to apply and consider with BAL aspiration techniques. This will ensure generating a meaningful and clinically relevant data which in turn accelerate the development of new and effective therapeutic moieties for major respiratory conditions.

Undiagnosed TB in adults dying at home from natural causes in a high TB burden setting: a post-mortem study.

A high proportion of deaths in Africa occur at home, where cause of death (CoD) is often unknown. We ascertained undiagnosed pulmonary tuberculosis (TB) by performing limited autopsies in adults dying at home in whom there was no apparent CoD. Mortuaries in Matlosana, South Africa, identified potentially eligible adults with no ante-mortem diagnosis and/or no recent hospital admission. A questionnaire was administered to family members. Bilateral lung core biopsies and modified bronchoalveolar lavage (BAL) were performed. The biopsies were examined histologically and submitted with BAL aspirates for mycobacterial culture (MGIT(TM)) and Xpert(®) MTB/RIF testing. Human immunodeficiency virus (HIV) testing was not performed. Of 162 families approached, 28 refused and 29 of the deceased were on or had recently stopped anti-tuberculosis treatment; 85 were included. All were Black and 53% were men. The median age was 57 years (interquartile range [IQR] 44-66) and median symptom duration (mainly cough) was 63 days (IQR 14-112). Laboratory evidence of TB was found in 27 (31.8%); 21 were Xpert-positive, 23 were MGIT-positive and 14 had histological evidence consistent with active TB. In this high HIV prevalence setting, a quarter of the home deaths had evidence of undiagnosed, likely infectious TB, suggesting that TB-related mortality is under-ascertained and under-reported, with serious implications for TB control in high TB burden settings.

Bronchopulmonary pharmacokinetic and pharmacodynamic profiles of levofloxacin 750 mg once daily in adults undergoing treatment for acute exacerbation of chronic bronchitis

While previous reports have described the bronchopulmonary profile of the fluoroquinolones in healthy volunteers, limited data are available in infected patients. The purpose of this study was to determine the intrapulmonary profile of high-dose (750 mg) levofloxacin in patients during an acute exacerbation of chronic bronchitis (AECB). Twenty-four patients experiencing clinical signs and symptoms of AECB were enrolled. Once enrolled, patients received levofloxacin 750 mg once daily × 5 days. Bronchoalveolar lavage aspirates and simultaneous plasma samples were obtained at 4 h, 12 h or 24 h after the third dose. Concentrations in biologic matrixes were determined with a validated HPLC method. Epithelial lining fluid (ELF) concentrations were calculated using the urea dilution method. Five patients did not complete the trial, 19 patients underwent bronchoscopy, 18 (52 ± 13 yrs) had sufficient samples for analysis and confirmed medication compliance. Mean plasma concentrations at 4, 12, and 24 h were 8.0 ± 2.5, 5.8 ± 1.2, and 2.2 ± 1.2 μg/mL. Mean ELF values at 4, 12, and 24 h were 7.5 ± 3.0, 8.3 ± 6.0, and 1.2 ± 0.9 μg/mL. Mean alveolar macrophage (AM) concentrations at 4, 12, and 24 h were 38.5 ± 43.7, 13.4 ± 14.4, and 9.0 ± 7.5 μg/mL. The penetration (ELF/plasma ratio) into the infection site was 113%. In these subjects with AECB, levofloxacin 750 mg once daily reached adequate exposures in the plasma, ELF, and AMs for the most commonly associated pathogens.

Ulcer over Chin in an Immunocompromised Individual

A 45-year-old human immunodeficiency virus (HIV)-positive male from northeastern India presented with fever and cough as well as a 3-month-old ulcer over the chin. On examination, there was a 5 × 5-cm superficial ulcer with a thick adherent crust over the chin (Figure 1). The individual had three papules with central umbilication over the neck and face. He had anemia (hemoglobin = 7.5 g) and a cluster of differentiation 4 (CD4) count of 89 cells/μL. His chest radiograph and computed tomography (CT) scan of the thorax showed right mid- and lower-zone consolidation. Histopathology of the umbilicated papule and the ulcer showed numerous yeast forms and a few sausage-shaped structures with central septation within the histiocytes (Figure 2). Fungal tissue cultures from skin lesions and bronchoalveolar lavage aspirates showed a greenish yellow, flat, velvety wrinkled colony with surrounding diffusible red pigment (Figure 3). This was diagnostic of Penicillium marneffei infection. Sputum smears and culture were negative for tuberculosis. Direct immunofluorescence detection for Pneumocystis carinii from sputum sample was negative. Figure 1. Superficial ulcer with adherent crusts over the chin. This figure appears in color at www.ajtmh.org. Figure 2. Yeast and sausage shaped structure with central septation, PASD 400×. This figure appears in color at www.ajtmh.org. Figure 3. Greenish yellow, flat, velvety colony with surrounding diffusible red pigmentation. This figure appears in color at www.ajtmh.org. Mucocutaneous lesions are seen in two-thirds of patients with Penicillium marneffei infection. These include generalized papular eruptions, central umbilicated papules resembling molluscum contagiosum, acne-like lesions, folliculitis, subcutaneous nodules, necrotic nodules, papules and nodules with ulceration, oropharyngeal papules, palatal perforation, and genital papules.1

Inflammatory mediators in bronchoalveolar lavage fluid and plasma in leukocytopenic patients with septic shock-induced acute respiratory distress syndrome.

The acute respiratory distress syndrome (ARDS) is a frequent complication of severe sepsis and a major cause of death in patients with hematologic malignancy during chemotherapy-induced leukocytopenia. Inflammatory mediators are important modulators of host response to injury and have been found to be increased in the bronchoalveolar lavage (BAL) fluid of nonleukocytopenic patients with ARDS. Since inflammatory cytokines in plasma of nonleukocytopenic patients seem to be efficient predictors of the course of ARDS, we examined this hypothesis in leukocytopenic patients with septic shock-induced ARDS. Prospective, observational study. Intensive care unit (ICU) of a university hospital. Nineteen patients with leukocytopenia (white blood cell count of <1/nL) following cytoreductive chemotherapy for malignant disorders and severe sepsis with shock-induced ARDS (Murray score of >2.5). BAL and plasma sampling and ICU management. The proinflammatory cytokines tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, and IL-8 were measured in the BAL aspirates and in plasma samples, both obtained within 18 hrs after onset of ARDS. Hemodynamic and oxygen metabolism data were measured immediately before plasma samples were taken and BAL was performed. Of the 19 patients studied, nine patients responded to ICU treatment (e.g., mechanical ventilation as indicated by PaO2/FIO2, FIO2, shunt volume, and course of pulmonary infiltrates), whereas ten patients did not respond. BAL cytokine concentrations were significantly increased in nonresponders in comparison with responding patients (TNF-alpha, p = .021; IL-6, p = .008; IL-8, p = .019). In contrast, we did not observe any differences between the groups in terms of plasma cytokine concentrations. Determination of cytokine concentrations in BAL samples may be useful for evaluation of severity and course of ARDS in leukocytopenic patients, whereas measurement of plasma cytokines is not helpful.

The Effects of IL-10 on Proinflammatory Cytokine Expression (IL-1β and IL-8) in Hyaline Membrane Disease (HMD)

Deficient expression of the counterregulatory cytokine IL-10 by lung inflammatory cells may facilitate chronic inflammation and the pathogenesis of hyaline membrane disease (HMD), in premature infants. To determine if pathways which regulate proinflammatory cytokines in response to human recombinant IL-10 (rIL-10) were functional in the lungs of these neonates, bronchoalveolar lavage (BAL)-derived lung inflammatory cells (predominantly macrophages and neutrophils) from infants with HMD were cultured in the presence of lipopolysaccharide (LPS) and increasing concentrations of (rIL-10). The expression of IL-1beta and IL-8 protein was assessed 24 h later. IL-10 protein was also measured from the BAL aspirates of these newborns at 4-day intervals over the first month of life. In cell culture IL-1beta expression was inhibited by rIL-10 in a dose-dependent fashion while IL-8 expression was inhibited by higher concentrations of rIL-10. IL-10 protein was undetectable from BAL fluid of the premature infants sampled over 28 days. The results demonstrate that lung inflammatory cells, which do not express IL-10 in vivo, are capable of responding to rIL-10 in cell culture with reduction of IL-1beta and IL-8 expression. These data support the rationale for the development of rIL-10 as a potential anti-inflammatory agent in the treatment of HMD.

Albumin is not suitable as a marker of bronchoalveolar lavage dilution in interstitial lung disease.

We have investigated the origin of raised bronchoalveolar lavage (BAL) albumin levels in interstitial lung diseases (ILDs), and the hypothesis that acute flux during BAL might contribute to the elevated levels of albumin in samples from ILD patients. Total albumin concentrations were measured in three separately aspirated 60 mL aliquots of BAL in 12 ILD patients and seven control subjects, and previous work indicating that BAL albumin levels may be raised in ILD was confirmed. In addition, the extent of acute flux from the circulation was investigated using 1.48 MBq of 125I-radiolabelled human serum albumin injected intravenously shortly before the procedure. It was found that acute albumin flux occurred in only a minority of the ILD patients (4 out of 12) and control subjects (3 out of 7). These results indicate that the elevated levels of plasma proteins, such as albumin, documented in BAL aspirates from ILD patients are not an artefact of the BAL procedure related to increased vascular permeability, and that this finding is more likely to be related to the effects of chronic inflammatory changes in the lung due to the underlying disease. The work confirms that albumin is unsuitable as a denominator for the normalization of bronchoalveolar lavage solute results, since levels can vary, both as a result of acute flux and, more frequently, because of disease activity.

Bronchoalveolar lavage in asthma research.

A great deal of information about the pathophysiology of asthma and its treatment have been obtained through the use of bronchoalveolar lavage (BAL), especially in combination with airway biopsies. The introduction of highly sophisticated methods for examining BAL aspirate, including fluorocein activated cell scanning (FACS) analysis and molecular biology techniques has emphasized the potential power of this method of airway investigation. For those contemplating the use of BAL in asthma research programmes, we hope that this review will provide a useful insight into the current state of knowledge about the technique and its application, and that it will provide a solid platform for study design.

The origin of water and urea sampled at bronchoalveolar lavage in asthmatic and control subjects.

Bronchoalveolar lavage (BAL) urea has been advocated as a denominator that might allow for the dilution of the pulmonary epithelial lining fluid sampled at BAL, and so provide a meaningful method of expressing BAL data. We investigated the origin of water and urea sampled at BAL in five asthmatic and five control subjects using radiolabeled urea injected intravenously 5 min before BAL. Labeled BAL urea was found to be fully equilibrated with that in the bloodstream. A strong relationship was found between influx of radiolabeled water and radiolabeled urea from blood to BAL fluid, suggesting that urea sampled at BAL may be derived predominantly from an acute movement from the bloodstream into the BAL aspirate. We conclude that urea is an inappropriate denominator for the expression of BAL results, and that the fluid and solute dynamics that occur during BAL are both complex and variable.

Persistent elastase/proteinase inhibitor imbalance during prolonged ventilation of infants with bronchopulmonary dysplasia: evidence for the role of nosocomial infections.

Acute imbalance between elastase and alpha-1-proteinase inhibitor (alpha 1Pi) may contribute to the development of bronchopulmonary dysplasia (BPD). The question of whether such an imbalance persists in BPD infants still requiring mechanical ventilation after 4 wk of life has not been previously addressed. We studied 14 infants still on mechanical ventilation at 4 wk of age: nine had BPD and five did not. Weekly (4 to 9 wk) serum and bronchoalveolar lavage (BAL) specimens were taken. alpha 1Pi and alpha-2-macroglobulin were measured in serum and BAL by immunoturbidimetric assay. BAL elastase activity was measured by cleavage of a synthetic substrate and expressed as ng of porcine pancreatic elastase equivalent. Infants with BPD had higher levels of serum alpha 1Pi and alpha-2-macroglobulin than those without BPD. In contrast, the corresponding BAL levels were either similar or even decreased (alpha 1Pi). Moreover, there was a 3-fold increase in elastase-1Pi imbalance expressed as the BAL ng of porcine pancreatic elastase equivalent/2 alpha 1Pi ratio. The role of nosocomial infections was evident in a subgroup of 11 infected BAL aspirates in BPD infants. In such cases we found a 3-fold increase in the BAL ng of porcine pancreatic elastase equivalent/alpha 1Pi ratio as compared to 35 noninfected BAL in BPD infants. These data suggest a persistent alveolitis with imbalance between elastase and proteinase inhibitors in prolonged severe BPD. Such an imbalance is, in part, explained by a local destruction and/or inactivation of alpha 1Pi. Our results also emphasize the increase in proteolysis with nosocomial pneumonia.