Bronchiolitis obliterans organizing pneumonia (BOOP) in lung transplant recipients

Post-CMV Organizing Pneumonia - An Unusual Presentation 10 years after Kidney Transplantation

A 45-year-old gentleman underwent kidney transplantation in March 2010. He remained apparently healthy for the next 10 years when he developed anorexia and weight loss. Diagnostic workup revealed cytomegalovirus (CMV) pneumonia. While viremia resolved within 3 weeks of initiation of valganciclovir, he developed progressive breathlessness and hypoxia on exertion. Imaging of thorax revealed central peri-bronchovascular consolidation and fine reticulations with peripheral sparing. Computed tomography (CT)-guided percutaneous lung biopsy revealed organizing intra-alveolar exudates, suggestive of organizing pneumonia, with no evidence of active infection on biopsy as well as bronchoalveolar lavage (BAL) cytology. This atypical pattern of central distribution of opacities is not typical of organizing pneumonia where peripheral subpleural distribution is more common. Patient responded dramatically following escalation of steroids, with complete resolution of infiltrates on follow-up imaging.

The pulmonary nodule following lung transplantation

The clinical scenario of a pulmonary nodule following lung transplantation is one with limited experience and no supporting guidelines for the approach to diagnosis and management. Given the broad differential diagnosis for pulmonary nodules in this setting, most of which are life-threatening without appropriate treatment, aggressive evaluation is required. Here we present a case of a 70-year-old female with the development of a large pulmonary nodule in the native lung four years following a single lung transplant. She underwent bronchoscopy with endobronchial ultrasound to achieve a tissue diagnosis which showed small cell lung carcinoma. The patient was started on chemotherapy and has shown clinical and radiographic improvement at most recent follow up seven months after the initial diagnosis. In this report we discuss the differential diagnosis and corresponding imaging findings for the pulmonary nodule following lung transplantation to aid in guiding clinicians navigate this challenging clinical situation.

Acute and Chronic Respiratory Failure in Cancer Patients

In 2016, there was an estimated 1.8 million new cases of cancer diagnosed in the United States. Remarkable advances have been made in cancer therapy and the 5-year survival has increased for most patients affected by malignancy. There are growing numbers of patients admitted to intensive care units (ICU) and up to 20% of all patients admitted to an ICU carry a diagnosis of malignancy. Respiratory failure remains the most common reason for ICU admission and remains the leading causes of death in oncology patients. There are many causes of respiratory failure in this population. Pneumonia is the most common cause of respiratory failure, yet there are many causes of respiratory insufficiency unique to the cancer patient. These causes are often a result of immunosuppression, chemotherapy, radiation treatment, or hematopoietic stem cell transplant (HCT). Treatment is focused on supportive care and specific therapy for the underlying cause of respiratory failure. Noninvasive modalities of respiratory support are available; however, careful patient selection is paramount as indiscriminate use of noninvasive positive pressure ventilation is associated with a higher mortality if mechanical ventilation is later required. Historically, respiratory failure in the cancer patient had a grim prognosis. Outcomes have improved over the past 20 years. Survivors are often left with significant disability.

Organizing pneumonia secondary to Pneumocystis jirovecii infection in a kidney transplant recipient: Case report and review of literature

Organizing pneumonia (OP), previously known as bronchiolitis obliterans OP, is a diffuse parenchymal lung disease affecting the distal bronchioles, alveolar ducts, and alveolar walls. Pulmonary infections, especially bacterial and viral diseases, are known to be associated with the secondary form of OP. OP secondary to fungal infections is less common. Here, we report a case of OP associated with pneumocystis pneumonia (PCP) in a kidney transplant recipient on tacrolimus-based triple immunosuppression. The index case had developed new lung consolidation toward the end of trimethoprim-sulfamethoxazole therapy for PCP. Spontaneous clinical and radiographic resolution was seen without any increment in the dose of corticosteroids. We review the literature and present a summary of all reported cases of OP associated with PCP to date.

Imaging of Lung Transplantation

Lung transplantation has become a viable treatment option for end-stage lung disease. Common indications for lung transplantation are chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis, cystic fibrosis, alpha-1 antitrypsin deficiency, and pulmonary arterial hypertension. Either single or bilateral lung transplantation can be performed, but bilateral lung recipients appear to have a better median survival than single lung recipients. Complications after lung transplantation are common and may have nonspecific clinical and radiologic manifestations. The time point at which these complications occur relative to the date of transplant is crucial in formulating a differential diagnosis and recognizing them accurately. Significant advances in imaging techniques and recognition of air trapping in exhalation images and other patterns /distribution of parenchymal abnormalities have led to routine use of HRCT for diagnostic evaluation in patients manifesting respiratory decline in the lung transplant recipient.

Impact of Allograft Injury Time of Onset on the Development of Chronic Lung Allograft Dysfunction After Lung Transplantation

The impact of allograft injury time of onset on the risk of chronic lung allograft dysfunction (CLAD) remains unknown. We hypothesized that episodes of late-onset (≥6 months) allograft injury would produce an augmented CXCR3/ligand immune response, leading to increased CLAD. In a retrospective single-center study, 1894 transbronchial biopsy samples from 441 lung transplant recipients were reviewed for the presence of acute rejection (AR), lymphocytic bronchiolitis (LB), diffuse alveolar damage (DAD), and organizing pneumonia (OP). The association between the time of onset of each injury pattern and CLAD was assessed by using multivariable Cox models with time-dependent covariates. Bronchoalveolar lavage (BAL) CXCR3 ligand concentrations were compared between early- and late-onset injury patterns using linear mixed-effects models. Late-onset DAD and OP were strongly associated with CLAD: adjusted hazard ratio 2.8 (95% confidence interval 1.5-5.3) and 2.0 (1.1-3.4), respectively. The early-onset form of these injury patterns did not increase CLAD risk. Late-onset LB and acute rejection (AR) predicted CLAD in univariable models but lost significance after multivariable adjustment for late DAD and OP. AR was the only early-onset injury pattern associated with CLAD development. Elevated BAL CXCR3 ligand concentrations during late-onset allograft injury parallel the increase in CLAD risk and support our hypothesis that late allograft injuries result in a more profound CXCR3/ligand immune response.

Progressive delayed respiratory complications of sulfur mustard poisoning in 43 Iranian veterans, three decades after exposure

The most common delayed complication of sulfur mustard (SM) poisoning has been observed in the respiratory tracts. It was thus aimed to investigate the delayed respiratory complications in SM-exposed patients around 25 years before the study. Forty-three veterans with more than 25% disability of due to SM poisoning were investigated. Clinical examinations as well as pulmonary function test (PFT) were performed. High-resolution computed tomography (HRCT) of the lungs was done as clinically indicated. Triad of chronic cough, dyspnea, and expectoration were the most common symptoms that were recorded in 88.2%, 88.2%, and 64.7% of the patients, respectively. PFT abnormalities were detected in 44.18% of the patients. Restrictive pattern was the most common (41.86%), while pure obstructive pattern did not detect at all. Mixed pattern was significantly correlated with higher disability percentages among the veterans ( p < 0.001). Significant reverse correlation between the disability percentages and forced expiratory volume in 1 s/forced vital capacity ratio was obtained ( p = 0.010, r = −0.389). Air trapping was the most common abnormality in HRCTs (50%). Bronchiectasis (25%), pulmonary fibrosis (25%), and ground-glass attenuation (16.66%) were other common HRCT findings. Comparing with the previous studies on these patients, more restrictive and mixed pattern were observed. Moreover, bronchiolitis, bronchiectasis, and lung fibrosis were the main pathological findings in these patients.

Lung injury pathways: Adenosine receptor 2B signaling limits development of ischemic bronchiolitis obliterans organizing pneumonia

Purpose/Aim of the Study: Adenosine signaling was studied in bronchiolitis obliterans organizing pneumonia (BOOP) resulting from unilateral lung ischemia.

MATERIALS AND METHODS

Ischemia was achieved by either left main pulmonary artery or complete hilar ligation. Sprague-Dawley (SD) rats, Dahl salt sensitive (SS) rats and SS mutant rat strains containing a mutation in the A2B adenosine receptor gene (Adora2b) were studied. Adenosine concentrations were measured in bronchoalveolar lavage (BAL) by HPLC. A2A (A2AAR) and A2B adenosine receptor (A2BAR) mRNA and protein were quantified.

RESULTS

Twenty-four hours after unilateral PA ligation, BAL adenosine concentrations from ischemic lungs were increased relative to contralateral lungs in SD rats. A2BAR mRNA and protein concentrations were increased after PA ligation while miR27a, a negatively regulating microRNA, was decreased in ischemic lungs. A2AAR mRNA and protein concentrations remained unchanged following ischemia. A2BAR protein was increased in PA ligated lungs of SS rats after 7 days, and 4 h after complete hilar ligation in SD rats. SS-Adora2b mutants showed a greater extent of BOOP relative to SS rats, and greater inflammatory changes.

CONCLUSION

Increased A2BAR and adenosine following unilateral lung ischemia as well as more BOOP in A2BAR mutant rats implicate a protective role for A2BAR signaling in countering ischemic lung injury.

Republished: Fibrosing organising pneumonia

Organising pneumonia (otherwise referred to as bronchiolitis obliterans organising pneumonia) is characterised histologically by plugs of granulation tissue, which are present predominantly within small airways, alveolar ducts and peri-bronchiolar alveoli. This pattern is not specific for any disorder or cause, but is one type of inflammatory response to pulmonary injury, which may be seen in a wide variety of clinical conditions. Typically, organising pneumonia responds very well to corticosteroid treatment; however, a small percentage of patients appear to develop progressive fibrosis.

Rattus model utilizing selective pulmonary ischemia induces bronchiolitis obliterans organizing pneumonia

Bronchiolitis obliterans organizing pneumonia (BOOP), a morbid condition when associated with lung transplant and chronic lung disease, is believed to be a complication of ischemia. Our goal was to develop a simple and reliable model of lung ischemia in the Sprague-Dawley rat that would produce BOOP. Unilateral ischemia without airway occlusion was produced by an occlusive slipknot placed around the left main pulmonary artery. Studies were performed 7 days later. Relative pulmonary and systemic flow to each lung was measured by injection of technetium Tc 99m macroaggregated albumin. Histological sections were examined for structure and necrosis and scored for BOOP. Apoptosis was detected by immunohistochemistry with an antibody against cleaved caspase 3. Pulmonary artery blood flow to left lungs was less than 0.1% of the cardiac output, and bronchial artery circulation was ∼2% of aortic artery flow. Histological sections from ischemic left lungs consistently showed Masson bodies, inflammation, and young fibroblasts filling the distal airways and alveoli, consistent with BOOP. In quantitative evaluation of BOOP using epithelial changes, inflammation and fibrosis were higher in ischemic left lungs than right or sham-operated left lungs. Apoptosis was increased in areas exhibiting histological BOOP, but there was no histological evidence of necrosis. Toll-like receptor 4 expression was increased in ischemic left lungs over right. An occlusive slipknot around the main left pulmonary artery in rats produces BOOP, providing direct evidence that ischemia without immunomodulation or coinfection is sufficient to initiate this injury. It also affords an excellent model to study signaling and genetic mechanisms underlying BOOP.

Respiratory Diseases

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Pulmonary arteriovenous fistulas have congenital and hereditary etiology, and patients are at risk for life-threatening rupture requiring surgery.

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Wegener's granulomatosis can affect any organ system, although renal and pulmonary involvement is most common; men ages 40 to 50 are at increased risk.

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Lymphomatoid granulomatosis affects cardiopulmonary, neurologic, and myeloproliferative systems; may result from opportunistic infection, and frequently progresses to lymphoma; men age 50 to 60 are at increased risk. Spontaneous remission occurs in some cases; mortality is 60% to 90% at 5 years.

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Churg-Strauss syndrome is usually associated with long-standing asthma, with men and women affected equally, and can affect any organ system; major cause of death is cardiac related.

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Primary pulmonary hypertension is a diagnosis of exclusion; women are affected twice as likely as men; right-to-left shunt may occur in 30%, secondary to patent foramen ovale; hypoxia with resultant heart failure is typical cause of death.

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Cystic fibrosis is an autosomal recessive disease, eventually fatal, with increased risk for airway obstruction, fluctuating pulmonary function, and chronic hypoxia; risk for spontaneous pneumothorax is 20%.

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Bronchiolitis obliterans organizing pneumonia is a pulmonary obstructive disease that may be reversible and usually resolves spontaneously.

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Idiopathic pulmonary hemosiderosis is associated with autoimmune disorders; patients have recurrent hemorrhage, pulmonary fibrosis, restrictive lung disease, and pulmonary hypertension, with some cases of spontaneous remission.

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Chronic eosinophilic pneumonia may be preceded by adult-onset asthma; women are at increased risk; prognosis is good.

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Goodpasture's syndrome is a genetic autoimmune disorder involving the pulmonary and renal systems.

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Pulmonary alveolar proteinosis, a lipoprotein-rich accumulation in alveoli, has three forms: congenital, decreased alveolar macrophage activity, and idiopathic; some cases of spontaneous remission occur.

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Sarcoidosis may affect any organ system; African American, northern European, and females are at greater risk; many patients are asymptomatic.

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Systemic lupus erythematosus may affect any organ system; women of childbearing age are at increased risk.

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Idiopathic pulmonary fibrosis is a rare interstitial lung disease, with smokers at increased risk for pulmonary malignancy; survival is usually 2 to 3 years from diagnosis; no effective treatment exists, with lung transplant the only therapeutic option.

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Acute respiratory distress syndrome (ARDS) is associated with underlying critical illness or injury, developing acutely in 1 to 2 days; mortality is 25% to 35%.

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Pulmonary histiocytosis X is an interstitial lung disease associated with cigarette smoking and an unpredictable course; some spontaneous remission occurs.

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Lymphangioleiomyomatosis involves progressive deterioration of lung function, associated with tuberous sclerosis and exacerbated by pregnancy, with women at increased risk; possible spontaneous pneumothorax and chylothorax; death usually results from respiratory failure.

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Ankylosing spondylitis is a genetic inflammatory process resulting in fusion of axial skeleton and spinal deformities, with men at increased risk; radiologic bamboo spine, sacral to cervical progression, and restrictive lung disease with high reliance on diaphragm; extraskeletal manifestations may occur.

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Kyphosis (exaggerated anterior flexion) and scoliosis (lateral rotational deformity) are spinal/rib cage deformities with idiopathic, congenital, or neuromuscular etiology; corrective surgery done if Cobb thoracic angle >50% lumbar angle >40%.

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Bleomycin is an antineoplastic antibiotic used in combination chemotherapy, with no myelosuppressive effect; toxicity can cause life-threatening pulmonary fibrosis.

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Influenza A is highly infectious, presenting with flulike symptoms and possible progression to ARDS; human-to-human exposure is through droplets or contaminated surfaces, with high risk for infants, children, pregnancy, chronically ill, or renal replacement therapy patients. No prophylactic treatment exists; treat patients with high index of suspicion without definitive testing; rRT-PCR and viral cultures are sensitive for pandemic H1N1 strain.

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Severe acute respiratory syndrome (SARS) is highly infectious, transmitted by coronavirus with human-to-human exposure via droplets or surfaces, and may progress to ARDS.

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Echinococcal disease of lung is from canine tapeworm, transmitted by eggs from feces; rupture of cyst may result in anaphylactic reaction or spread of disease to other organs; children are at increased risk. No transthoracic needle aspiration is done; surgery is only option.

Bronchiolitis obliterans organizing pneumonia: pathogenesis, clinical features, imaging and therapy review

Bronchiolitis obliterans organizing pneumonia (BOOP) was first described in the early 1980s as a clinicopathologic syndrome characterized symptomatically by subacute or chronic respiratory illness and histopathologically by the presence of granulation tissue in the bronchiolar lumen, alveolar ducts and some alveoli, associated with a variable degree of interstitial and airspace infiltration by mononuclear cells and foamy macrophages. Persons of all ages can be affected. Dry cough and shortness of breath of 2 weeks to 2 months in duration usually characterizes BOOP. Symptoms persist despite antibiotic therapy. On imaging, air space consolidation can be indistinguishable from chronic eosinophilic pneumonia (CEP), interstitial pneumonitis (acute, nonspecific and usual interstitial pneumonitis, neoplasm, inflammation and infection). The definitive diagnosis is achieved by tissue biopsy. Patients with BOOP respond favorably to treatment with steroids.

Lack of association between beta-herpesvirus infection and bronchiolitis obliterans syndrome in lung transplant recipients in the era of antiviral prophylaxis

BACKGROUND

Cytomegalovirus (CMV), human herpesvirus-6 and -7 (HHV-6 and -7) are beta-herpesviruses that commonly reactivate and have been proposed to trigger acute rejection and chronic allograft injury. We assessed the contribution of these viruses in the development of bronchiolitis obliterans syndrome (BOS) after lung transplantation.

METHODS

Quantitative real-time polymerase chain reaction of bronchoalveolar lavage samples were performed for CMV, HHV-6 and -7 in a prospective cohort of lung transplant recipients. A time-dependent Cox regression analysis was used to correlate the risk of BOS and acute rejection in patients with and without beta-herpesviruses infection.

RESULTS

Ninety-three patients were included in the study over a period of 3 years. A total of 581 samples from bronchoalveolar lavage were obtained. Sixty-one patients (65.6%) had at least one positive result for one of the beta-herpesviruses: 48 patients (51.6%) for CMV and 19 patients (20.4%) for both HHV-6 and -7. Median peak viral load was 3419 copies/mL for CMV, 258 copies/mL for HHV-6, and 665 copies/mL for HHV-7. Acute rejection (>or=grade 2) occurred in 46.2% and BOS (>or=stage 1) in 19.4% of the patients. In the Cox regression model the relative risk of acute rejection or BOS was not increased in patients with any beta-herpesviruses reactivation. Acute rejection was the only independently associated risk factor for BOS.

CONCLUSIONS

In lung transplant recipients receiving prolonged antiviral prophylaxis, reactivation of beta-herpesviruses within the allograft was common. However, despite high viral loads in many patients, virus replication was not associated with the development of rejection or BOS.

Interstitial inflammatory lesions of the pulmonary allograft: a retrospective analysis of 2697 transbronchial biopsies

BACKGROUND

Parenchymal and bronchial inflammatory and fibrotic lesions other than acute cellular rejection (ACR) and lymphocytic bronchiolitis are prevalent; however, the context in which they appear is unknown, and often no specific treatment is instigated.

OBJECTIVES

To describe the prevalence, incidence and possible associations between commonly identified inflammatory and fibrotic lesions in the pulmonary allograft.

METHODS

Retrospective chart review of all transbronchial biopsies performed within the first 2 years of 299 lung-transplanted patients in the period 1996 to 2006.

RESULTS

A total of 2697 biopsies were evaluated corresponding to a mean of 6+/-2 (median 8) completed schedules per patient. Diffuse alveolar damage (DAD) was the second most common histological finding within the first 2 weeks after transplantation. The peak prevalence of bronchiolitis obliterans organizing pneumonia (BOOP) and interstitial pneumonitis occurred at 4 to 6 weeks, and 6 to 12 weeks, respectively. There was a steady increase in the cumulative proportion of patients with fibrosis and bronchiolitis obliterans, at each successive scheduled surveillance time point beyond 3 months posttransplantation. The strongest histological correlations were between ACR and lymphocytic bronchiolitis (OR 5.1, P<0.0001) or interstitial fibrosis (OR 3.2, P<0.0001). Patients with interstitial pneumonitis and pulmonary hemosiderosis were also more likely to demonstrate the finding of interstitial fibrosis (OR 3.0 and 3.7, P<0.0001, respectively). Acute cellular rejection was not associated with DAD, and patients with lymphocytic bronchiolitis were not more likely to demonstrate features of organizing pneumonia (DAD or BOOP).

CONCLUSIONS

Histologic findings of ACR, lymphocytic bronchiolitis, BOOP, and interstitial pneumonitis were directly associated with the development of interstitial fibrosis and bronchiolitis obliterans.

Pediatric lung transplantation: perspectives for the pathologist

Lung transplantation offers life-saving and life-extending treatment for children and adolescents with congenital and acquired forms of pulmonary and pulmonary vascular disease, for whom medical therapy is ineffective or insufficient for sustained response. This review summarizes the pathology related to lung transplantation for the practicing pediatric pathologist and also highlights aspects of lung transplantation unique to the pediatric population. Clinical issues related to availability of organs, candidate eligibility, surgical technique, and postoperative monitoring are discussed. Pathologic evaluation of routine surveillance transbronchial biopsies requires attention to acute cellular rejection, opportunistic infection, and other forms of acute and resolving lung injury. These findings are correlated in some cases with endobronchial biopsies and bronchoalveolar lavage as adjunctive tools in surveillance. Open or thoracoscopic biopsies also have diagnostic utility in cases with acute or chronic graft deterioration of uncertain etiology. Future challenges in pediatric lung transplantation are similar to those in the adult population, with continued efforts focused on prolonging graft survival, prevention of bronchiolitis obliterans syndrome due to chronic cellular rejection, and evaluation of humoral rejection.

Postoperative complications of lung transplantation: radiologic findings along a time continuum

In the past decade, lung transplantation has become established as an accepted therapy for end-stage pulmonary disease. Complications of lung transplantation that may occur in the immediate or longer postoperative term include mechanical problems due to a size mismatch between the donor lung and the recipient thoracic cage; malposition of monitoring tubes and lines; injuries from ischemia and reperfusion; acute pleural events; hyperacute, acute, and chronic rejection; pulmonary infections; bronchial anastomotic complications; pulmonary thromboembolism; upper-lobe fibrosis; primary disease recurrence; posttransplantation lymphoproliferative disorder; and native lung complications such as hyperinflation, malignancy, and infection. Radiologic imaging--particularly chest radiography, computed tomography (CT), and high-resolution CT--is critical for the early detection, evaluation, and diagnosis of complications after lung transplantation. To enable the selection of an effective and relevant course of therapy and, ultimately, to decrease morbidity and mortality among lung transplant recipients, radiologists at all levels of experience must be able to recognize and understand the imaging manifestations of posttransplantation complications.

Outcome of lung transplanted patients with primary graft dysfunction

OBJECTIVE

Primary graft dysfunction (PGD) causes significant mortality and morbidity after lung transplantation. The objectives of the study were to describe the clinical and histological sequelae of PGD.

METHODS

Histology of all patients receiving single-lung transplantation 1999-2004 (n=181) was reviewed. PGD was defined as diffuse radiological infiltration of the lung allograft occurring within the first 72h postoperatively.

RESULTS

One patient died intra-operatively. PGD was recorded in 63% (n=113) of 180 consecutive transplant recipients. Patients with PGD had a worse 90-day postoperative mortality (14% versus 3%, p=0.03) and 3-year survival (55% versus 77%, p=0.003). Freedom from bronchiolitis obliterans syndrome was similar in both groups. The maximal FEV(1) was significantly lower in patients with PGD, median 54% (quartiles 48-61%) predicted; compared to patients without PGD, median 59% (quartiles 54-69%) predicted (p=0.003). There was a significant linear trend in the decline of maximal FEV(1) with the presence and increasing severity of radiographic infiltrate (p=0.004). During follow-up, patients with PGD were more likely to demonstrate diffuse alveolar damage or bronchiolitis obliterans organizing pneumonia (p=0.009 and p=0.01, respectively). Histological findings of diffuse alveolar damage correlated closely with extent of radiological infiltration (p<0.0001).

CONCLUSIONS

Transplant recipient survival, lung function, and histological findings of diffuse alveolar damage appear to be closely correlated with the appearance and severity of PGD.

Mustard lung secrets: long term clinicopathological study following mustard gas exposure

Considering the undefinite nature of lung pathology in patients exposed to sulfur mustard (SM) many years after exposure, we conducted this study to document and quantify lung disease in this setting. In a cross sectional study, we selected 23 patients exposed to SM gas approximately 14 years ago during the Iran-Iraq war (1980-1988). We studied their clinical history, physical examination, pulmonary function test (PFT), high-resolution computed tomography scan (HRCT) of the chest, bronchoscopy, and bronchoalveolar lavage (BAL) sampling, and transbronchial lung biopsies. Other potential causes of lung disease, including smoking of cigarettes, were excluded. All 23 patients were symptomatic with cough, dyspnea, and/or felt tight in the chest. All of them had significant air trapping in HRCT and a marked increase of residual volume in PFT. The most common inflammatory cell in BAL fluid was neutrophil (88%). Of the 23 cases, there was sufficient tissue for detailed evaluation in 22. Histologically, 11 cases showed airway epithelial injury, and nine of the 14 lung biopsies with alveoli had histopathological changes diagnosable as organizing pneumonia (OP) or bronchiolitis obliterans OP (BOOP). Two out of 14 cases showed changes suggestive of OP. Inhalation of SM can lead to persistant and clinically significant lung disease, including bronchial mucosal injury and OP, many years after exposure.

Infection in Pediatric Acute Respiratory Distress Syndrome

Pediatric acute respiratory distress syndrome (ARDS) is a severe lung injury caused by pneumonia, sepsis, and trauma. ARDS results from inflammation and pulmonary capillary leak causing major changes in lung architecture and function. It has a low incidence, but its severity and duration cause major morbidity, mortality, and use of resources. Any organism can cause ARDS. Susceptible populations develop the syndrome more often and have worse outcomes. Aggressive diagnosis and intensive treatment are essential to good outcomes in ARDS caused by infection. The prognosis for survival is good, but morbidity after the syndrome is a major burden.

Lung Transplantation Biopsy Specimens With Bronchiolitis Obliterans or Bronchiolitis Obliterans Organizing Pneumonia Due to Aspiration

Context.—Bronchiolitis obliterans (BO) is generally thought to be a marker of chronic airway rejection in patients who have undergone lung transplantation. Bronchoscopic biopsy specimens, by virtue of their small size, may sample only BO and not a lesion of bronchiolitis obliterans organizing pneumonia (BOOP). A role for ongoing chronic infection or aspiration has also been suggested, and the distinction of these etiologies may be difficult clinically and pathologically.

Objective.—To investigate the etiology of BO and BOOP in lung transplantation patients who had chronic aspiration.

Design.—This is a clinicopathologic study of 7 patients who had undergone lung transplantation in which biopsy findings suggested the possibility of chronic airway rejection but in which aspiration was subsequently proven as a cause of the bronchiolar disease.

Results.—All patients were men, who ranged in age from 19 to 57 years. A clinical diagnosis of aspiration was considered based on history, acid reflux testing, and radiographic findings in all 7 patients. Three patients had BO and 4 patients had BOOP. Histiocytic giant cells or foreign material was absent. The interval from transplantation to BO ascribed to aspiration ranged from 2.5 months to 7 years. The patients were treated aggressively with medication for gastroesophageal reflux disease. Their respiratory function and chest radiography results improved.

Conclusion.—Although BO may be a manifestation of rejection, it may also be a manifestation of aspiration. Because the latter is potentially correctable, aspiration should be considered etiologically in lung transplantation patients with either BO or BOOP. Reliable distinction between aspiration-related or rejection-related BO and BOOP cannot be made on morphologic grounds alone. Clinical and radiologic correlations are indicated to establish the distinction.

Bronchiolitis obliterans organizing pneumonia after orthotopic liver transplantation

Bronchiolitis obliterans organizing pneumonia (BOOP) has been described after bone marrow, lung, heart-lung, and renal transplantation, but rarely after orthotopic liver transplantation (OLT). We report a case of BOOP after OLT to emphasize BOOP as an under diagnosed and treatable cause of nonresolving pneumonia, which may not be preventable by maintenance low-dose prednisone. A 48-year-old man was hospitalized for dyspnea and cough one month after OLT. Among his medications were tacrolimus and prednisone. Physical examination was significant for lung crepitations and bilateral leg edema. Chest x-ray revealed bilateral infiltrates. Computed tomography (CT) of the chest demonstrated bilateral diffuse infiltrates with areas of sparing and nodularities. Bronchoscopy was normal and bronchoalveolar lavage was negative. Lung biopsy was performed and demonstrated serpiginous plugs of fibroblastic tissue filling the alveolar spaces, focal fibrosis of some alveolar septa, and reactive pneumocytic hyperplasia consistent with BOOP. Methylprednisolone was continued with clinical improvement and weaning from the ventilator, but subsequent sepsis and multisystem organ failure finally led to the patient's death.

A 59-year-old liver-transplanted woman with fever, dyspnea and pulmonary infiltrates

A 59-year-old woman was admitted to hospital 10 months after receiving a liver transplant (LT) for hepatitis C virus (HCV) cirrhosis because of fever, dyspnea and basal patchy peripheral infiltrates. Microscopic examinations and blood, sputum and BAL cultures were negative. Empirical anti-infective therapy was ineffective. Thoracoscopic lung biopsy was performed, and histology showed a pattern suggesting bronchiolitis obliterans organizing pneumonia (BOOP). Prednisone led to rapid clinical and radiologic improvement. BOOP has been anecdotally reported in LT cases, and this case was unrelated to any infectious agent. BOOP should be taken into account in the differential diagnosis of pneumonia in LT.

Acute allograft rejection after lung transplantation: diagnosis and therapy

Acute rejection remains a significant problem after lung transplantation. While it generally is a treatable condition, significant resources and therapies are directed toward its prevention and resolution. Its larger significance undoubtedly rests in its contribution to the pathogenesis of BOS. Significant questions regarding the origins of AR, the role of LBB, alternative histologic appearances of acute allograft injury, and optimal therapy remain. Controversy regarding the utility of surveillance bronchoscopy and preemptive treatment of occult AR persists because of lack of conclusive evidence. Future investigations might resolve these matters and provide more efficacious and less toxic therapies that will hopefully reduce the impact of chronic rejection and improve long-term outcomes.

Bronchiolitis obliterans organizing pneumonia in an orthotopic liver transplant patient

A 67-year-old woman was hospitalized for progressive dyspnea on exertion. She had undergone orthotopic liver transplantation (OLT) 15 months before admission. Posttransplant therapy consisted of tacrolimus, trimethoprim/sulfamethoxazole, and prednisone (the latter two were discontinued after 1 year). Physical examination revealed fine bibasilar crackles. High-resolution chest CT demonstrated bilateral, diffuse, interstitial infiltrates. Symptoms persisted on i.v. antibiotics and bronchoscopy was performed demonstrating patchy fibroplastic plugs within air spaces consistent with bronchiolitis obliterans organizing pneumonia (BOOP). Prednisone was initiated and the patient had an uneventful recovery. BOOP was initially described as an idiopathic disease process with clinical, radiographic, pathological, and prognostic features distinguishing it from bronchiolitis obliterans and idiopathic pulmonary fibrosis. BOOP has been recognized as a complication of lung and bone marrow transplantation, but the mechanism is unknown. We report a case of BOOP after OLT to highlight the risk in all transplant patients as well as the protective effect of posttransplant prednisone.

Pulmonary function tests in interstitial lung disease: what role do they have?

Pulmonary function tests have been widely accepted and utilized in the management of interstitial lung diseases. Although the tests performed have changed little over the past several decades, extensive literature has been published highlighting their clinical role in the diagnosis, staging, prognostication, and follow-up of patients with a wide variety of interstitial lung diseases.

Burkholderia cepacia complex: a contraindication to lung transplantation in cystic fibrosis?

Previous studies have indicated that pulmonary infection with Burkholderia cepacia is associated with poor clinical outcome after lung transplantation in cystic fibrosis (CF). Many treatment centers consider B. cepacia infection an absolute contraindication to lung transplantation. However, the B. cepacia complex actually consists of several closely related bacterial species. Although each of these has been isolated from CF sputum culture, certain species are much more frequently recovered than others, and it is not yet clear whether all species have the same potential for virulence in CF. Additional study is needed to better define the relative risks associated with each species of the B. cepacia complex.

Recurrent, self-limited, menstrual-associated bronchiolitis obliterans organizing pneumonia

A 39-year-old woman presented with recurrent acute illness, characterized by high-grade fever, pleuritic chest pain, and unilateral nodular infiltrate on chest radiograph. During the follow-up period, there were six similar episodes, each starting 2 to 3 days prior to her menstrual period and resolving within 5 to 10 days. Persistent symptoms in the seventh episode led us to perform an open lung biopsy; the specimen showed histologic changes compatible with the diagnosis of bronchiolitis obliterans organizing pneumonia (BOOP). To the best of our knowledge, this is the first report describing BOOP in association with a menstrual period. This exceptional case emphasizes the wide and unexpected spectrum of this disease.

Pulmonary aspergillosis in an unselected autopsy series

The present study was performed to analyze the relationship between underlying diseases and the morphologic form of aspergillosis. This retrospective analysis of 3284 autopsies yielded 18 cases of aspergillosis. The specific diagnosis of aspergillosis was rendered by a monoclonal antibody versus Aspergillus spp. Patients with hematological disorders, such as acute leukemia and aplastic anemia, made up about 35% of all patients dying of invasive aspergillosis. Diseases of the airways and the pulmonary parenchyma constituted the second most pathogenetic factor for the development of aspergillosis. The morphologic form of aspergillosis was closely related to the underlying diseases. Non- and semi-invasive forms of aspergillosis--saprophytic infection and chronic necrotizing aspergillosis--were observed only in patients with an isolated underlying pulmonary disease devoid of any other precipitating factor. In contrast, seven patients, five of whom suffered from hematological diseases, had no underlying lung disease and developed aspergillus pneumonia. The remaining 5 patients with aspergillus pneumonia showed a combination of underlying extrapulmonary disease and pulmonary alterations that preceded aspergillosis. The local distribution of fungal infection showed a characteristic distribution pattern with a predominance of the upper lung lobes. Hematogeneous spread beyond the lungs occurred exclusively in cases with aspergillus pneumonia. We conclude that the different forms of aspergillosis are closely related to the nature of the underlying disease.

Lung allograft dysfunction correlates with gamma-interferon gene expression in bronchoalveolar lavage

BACKGROUND

Preceding episodes of acute cellular rejection (ACR) may predispose lung allografts to the subsequent development of irreversible dysfunction or bronchiolitis obliterans syndrome (BOS). Other histologic patterns such as bronchiolitis obliterans with organizing pneumonia (BOOP), organizing pneumonia, lymphocytic bronchiolitis and diffuse alveolar damage (DAD) may also adversely affect allograft function. We have previously reported the predominant expression of Th1 cytokines (IL-2 and interferon gamma) in rejecting and Th2 (IL-10) in a tolerant model of rat lung transplantation. Here we correlate the "Th1/Th2 paradigm" in clinical lung transplantation with histologic findings and assess the effect on serial spirometric function.

METHODS

We examined the mRNA expression of IL-2, interferon gamma, IL-10 and ICAM-1 in 53 bronchoalveolar lavage (BAL) specimens from 23 lung transplant (LT) recipients utilizing qualitative "nested" reverse transcriptase polymerase chain reaction (RT-PCR). We also measured IgG1 and IgG2 levels in 44 BAL specimens by ELISA. The mRNA expression for cytokines, ICAM-1 and the IgG2/IgG1 ratios were correlated with the presence or absence of ACR and alternate "histologic patterns". Serial spirometry were analyzed for the 2-3 month interval before bronchoscopic (FOB) assessment to derive "baseline" forced expiratory volume-one second (FEV1) values. The change in FEV1 coincident with (deltaFEV1 pre) and for the 2-3 month interval subsequent to (deltaFEV1 post) FOB were expressed relative to "baseline" spirometric indexes.

RESULTS

Detection of mRNA for interferon gamma and ICAM-1 correlated significantly with ACR, whereas IL-2 and IL-10 expression did not correlate. IL-10 was virtually "ubiquitous" in most BAL samples irrespective of the presence or absence of ACR. The highest correlation was observed with interferon gamma for acute cellular rejection whereupon the sensitivity was 77.7%, specificity 87.7%, positive predictive value 73.6% and negative predictive value 88.2%, although for ICAM-1 these values were 75%, 65.7%, 50.0% and 85.0%, respectively. Nevertheless, 4 of 5 episodes of respiratory tract infection (bacterial, CMV, Aspergillus spp.) were similarly associated with cytokine mRNA. The ratios of IgG2 to IgG1, a reflection of Th1/Th2 influence, were not statistically different when analyzed for the presence or absence of ACR (0.91+/-0.53 vs. 1.02+/-0.70, respectively; p = NS). By analysis of FEV1 trends, expression of interferon gamma was associated with a greater and persistent decrement (deltaFEV1 pre: -0.265+/-0.78 liters, and post: -0.236+/-0.1161; mean +/- SE) than ACR in the absence of interferon gamma expression (+0.158 +/- +0.065 and +0.236+/-0.007 liters, respectively) (Student-Newman-Keuls, p<.05).

CONCLUSION

Our findings suggest that interferon gamma mRNA expression and ICAM-1 may be valuable in both the diagnosis and prognosis for lung allograft ACR. IL-10, a Th2 cytokine, was locally expressed both in the presence and absence of ACR. Expression of mRNA for interferon y in BAL and, to a lesser extent ICAM-1, were associated with increased lung allograft dysfunction. Whether BAL cytokine "immunosurveillance" would complement or possibly supplant a specific "histologic pattern" and thereby direct different therapies after lung transplantation, may be potentially rewarding areas of further investigation.

Flexible bronchoscopy in lung transplantation

Bronchoscopy plays an indispensable role in lung transplantation. It is an essential part of the evaluation of potential lung donors, and it is the pivotal procedure in the management of lung transplant recipients. Although advances in immunodiagnostic methods may ultimately lead to noninvasive tests to detect rejection, histology will be the standard for some time, and transbronchial biopsy will remain the procedure of choice. Furthermore, the usefulness of bronchoscopy in the diagnosis of pulmonary infection after lung transplantation is unlikely to be supplanted by any emerging technique.

Burkholderia cepacia. Management issues and new insights

Although Burkholderia cepacia colonizes a relatively small proportion of individuals with cystic fibrosis (CF), it is associated with significant morbidity and mortality, and has had a profound impact on infection control practices. This article reviews the current understanding of the epidemiology of B. cepacia infection, describes important recent developments in the microbiology and taxonomy of this species, and presents issues that remain obstacles to defining the optimal management of B. cepacia infection in CF.