Allergic bronchopulmonary aspergillosis in cystic fibrosis: reported prevalence, regional distribution, and patient characteristics. Scientific Advisory Group, Investigators, and Coordinators of the Epidemiologic Study of Cystic Fibrosis

Infection control in cystic fibrosis

Over the past 20 years there has been a greater interest in infection control in cystic fibrosis (CF) as patient-to-patient transmission of pathogens has been increasingly demonstrated in this unique patient population. The CF Foundation sponsored a consensus conference to craft recommendations for infection control practices for CF care providers. This review provides a summary of the literature addressing infection control in CF. Burkholderia cepacia complex, Pseudomonas aeruginosa, and Staphylococcus aureus have all been shown to spread between patients with CF. Standard precautions, transmission-based precautions including contact and droplet precautions, appropriate hand hygiene for health care workers, patients, and their families, and care of respiratory tract equipment to prevent the transmission of infectious agents serve as the foundations of infection control and prevent the acquisition of potential pathogens by patients with CF. The respiratory secretions of all CF patients potentially harbor clinically and epidemiologically important microorganisms, even if they have not yet been detected in cultures from the respiratory tract. CF patients should be educated to contain their secretions and maintain a distance of >3 ft from other CF patients to avoid the transmission of potential pathogens, even if culture results are unavailable or negative. To prevent the acquisition of pathogens from respiratory therapy equipment used in health care settings as well as in the home, such equipment should be cleaned and disinfected. It will be critical to measure the dissemination, implementation, and potential impact of these guidelines to monitor changes in practice and reduction in infections.

Increased expression of Interleukin-13 but not Interleukin-4 in cystic fibrosis patients

BACKGROUND

Many patients with cystic fibrosis (CF) suffer from allergic disease, which can complicate treatment of CF lung disease. Interleukin (IL)-4 and IL-13 have been shown to be important mediators in allergic disease.

OBJECTIVE

To investigate the role of IL-4 and IL-13 in allergic and non-allergic CF patients.

METHODS

Expression of IL-4 and IL-13 mRNA was investigated in peripheral blood mononuclear cells (PBM) of seven CF patients with allergy, of six patients without allergy and of nine healthy subjects as well as in BAL cells of four patients and of all controls. PBM from six patients were incubated with recombinant human IL-13 or human antiIL-13 antibody without and with LPS stimulation and TNFalpha levels were measured by ELISA.

RESULTS

IL-13 mRNA expression was increased in allergic and non-allergic patients compared to controls. No significant difference in IL-4 expression could be found between patients and controls. Addition of IL-13 decreased TNFalpha in PBM culture supernatants.

CONCLUSION

Our data suggest that IL-13 rather than IL-4 might play an important role in both allergic and non-allergic CF patients. IL-13 might also compromise host defence by decreasing TNFalpha production.

Infection control recommendations for patients with cystic fibrosis: microbiology, important pathogens, and infection control practices to prevent patient-to-patient transmission

Infection Control Recommendations for Patients With Cystic Fibrosis: Microbiology, Important Pathogens, and Infection Control Practices to Prevent Patient-to-Patient Transmissionupdates, expands, and replaces the consensus statement,Microbiology and Infectious Disease in Cystic Fibrosispublished in 1994. This consensus document presents background data and evidence-based recommendations for practices that are intended to decrease the risk of transmission of respiratory pathogens among CF patients from contaminated respiratory therapy equipment or the contaminated environment and thereby reduce the burden of respiratory illness. Included are recommendations applicable in the acute care hospital, ambulatory, home care, and selected non-healthcare settings. The target audience includes all healthcare workers who provide care to CF patients. Antimicrobial management is beyond the scope of this document.

Aspergillus infection in lung transplant recipients with cystic fibrosis: risk factors and outcomes comparison to other types of transplant recipients

STUDY OBJECTIVES

To characterize Aspergillus infections in lung transplant recipients with cystic fibrosis (CF).

DESIGN

A retrospective analysis of 32 consecutive lung transplant recipients with CF who underwent bilateral lung transplant at the University of Wisconsin from 1994 to 2000 to determine the incidence, risk factors, and consequences of Aspergillus infection. The findings were compared to 101 non-CF recipients of lung transplants (93) and heart-lung transplants (8) for other transplant indications.

SETTING

A university hospital.

PATIENTS OR PARTICIPANTS

Lung transplant recipients with CF or other indications for transplantation.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

Seventeen of 32 CF recipients (53%) had Aspergillus fumigatus isolated from their respiratory secretions prior to undergoing transplantation. Ten of these 17 (59%) recipients had A fumigatus persistently found in their respiratory secretions posttransplant vs 6 of 15 CF patients (40%) who had not been colonized pretransplant and 28 of 101 of the non-CF recipients (28%). Four of the preoperatively colonized CF recipients developed tracheobronchial aspergillosis (TBA) just distal to the bronchial anastomoses, and one recipient had dehiscence of the involved anastomosis. None of the CF recipients developed disseminated aspergillosis or pneumonia. Prophylactic antifungal therapy did not prevent TBA, and IV amphotericin B therapy was required to clear the infection in all four patients, with endobronchial debridement of necrotic tissue required in two of them. In contrast, 10 of the non-CF (10%) recipients developed Aspergillus infections posttransplant (TBA, 4 recipients; pneumonitis, 6 recipients), and only 3 patients had successful treatment and long-term survival (TBA, 2 patients; pneumonia, 1 patient). Donor lung ischemia time, cytomegalovirus infection or pneumonia, or pretransplant mechanical ventilation did not increase the risk of developing TBA in CF recipients.

CONCLUSIONS

The risk of TBA for patients receiving lung transplants for CF warrants early surveillance bronchoscopy to detect TBA, particularly in recipients with pretransplant colonization.

Allergic bronchopulmonary aspergillosis

Allergic bronchopulmonary aspergillosis (ABPA) complicates asthma and cystic fibrosis. The survival factors in Aspergillus fumigatus that support saprophytic growth in bronchial mucus are not understood. Prednisone remains the most definitive treatment but need not be administered indefinitely. MHC II -restricted CD4(+) T( H)2 clones have been derived from patients with ABPA. The total serum IgE concentration is elevated sharply but is "nonspecific. " IgE serum isotypic antibodies to A fumigatus are useful in diagnosis; this is in contrast to the situation for patients with asthma without ABPA. High-resolution computed tomography of the chest demonstrates multiple areas of bronchiectasis in most patients with ABPA and is a useful radiologic tool. Some asthma control patients might have a few bronchiectatic airways, but not to the extent seen in or of the same character as those in ABPA. This review discusses clinical, radiologic, investigational, pathogenetic, and treatment issues of ABPA.

Saprophytic fungal infections and complications involving the bronchial anastomosis following human lung transplantation

STUDY OBJECTIVE

To demonstrate an association between saprophytic fungal infections occurring at the bronchial anastomosis (BA) and the development of additional complications arising at this site.

DESIGN

Retrospective review.

SETTING

University lung transplant center.

MATERIALS AND METHODS

Review of all single-lung and double-lung transplant (LTX) recipients who underwent transplantation between June 1993 and December 2000. All recipients were subjected to surveillance bronchoscopy with biopsy at predetermined intervals and when clinically indicated. Bronchial wash fluid and biopsy material were examined using appropriate fungal stains and culture techniques. An infection was defined when fungal organisms were identified in tissue specimens.

RESULTS

Fifteen saprophytic fungal infections involving the BA were identified in 61 LTX recipients (24.6%) who survived a minimum of 75 days post-transplantation. Infections were attributed to Aspergillus sp (n = 9), Candida sp (n = 2), Torulopsis sp (n = 1), and mixed flora (ie, Penicillium + Candida, two patients; and Aspergillus + Candida, one patient). Saprophytic fungal infections occurred by a median of postoperative day 35 (range, 13 to 159 days). Airway complications involving the BA ultimately developed in 11 of 61 recipients (18%). These complications included symptomatic bronchial stenosis (nine patients), bronchomalacia (one patient), and fatal hemorrhage (one patient). Bronchial complications arose in 7 of 15 recipients (46.7%) with saprophytic fungal infections of the BA in contrast to 4 of 46 (8.7%) without infections (p = 0.003, Fisher exact test). Also demonstrated was a positive correlation between anastomotic infections and bronchial complications (Phi coefficient = 0.43; p = 0.001), while logistic regression analysis revealed that the absence of anastomotic infections predicted the absence of such complications (p = 0.002). The risk of developing an additional complication following an anastomotic infection in patients with infections was five times that of those recipients without an infection (relative risk, 5.36; 95% confidence interval [CI], 1.82 to 15.79). The odds in favor of a bronchial complication following an infection were eight times greater than in those recipients without infection (odds ratio, 8.31; 95% CI, 1.96 to 35.16).

CONCLUSIONS

Following LTX, saprophytic fungal infections of the BA are associated with serious airway complications.

Allergic bronchopulmonary aspergillosis: a review of a disease with a worldwide distribution

Allergic bronchopulmonary aspergillosis (ABPA), an immunologically mediated lung disease, occurs predominantly in patients with asthma. This chronic relapsing disorder ranges clinically from mild asthma to fatal destructive lung disease and is caused by hypersensitivity to colonized Aspergillus fumigatus (Af). The immunopathogenesis of the disease is yet to be understood clearly. Specific IgE-Af and IgG-Af, the serological markers, contribute to the diagnosis. Radiologically, ABPA is characterized by fleeting pulmonary infiltrates often confused with pulmonary tuberculosis. However, central bronchiectasis on computed tomography is considered to be the hallmark of the disease. Early diagnosis and therapy with prednisolone, the cornerstone of management, could alter the course of the disease and prevent the development of end-stage lung fibrosis.

Serologic IgE immune responses against Aspergillus fumigatus and Candida albicans in patients with cystic fibrosis

OBJECTIVES

The objectives of this study were to determine the prevalence of Aspergillus fumigatus and Candida albicans in the sputa of patients with cystic fibrosis (CF), to assess serologic IgE responses of these patients to the presence of fungi in the sputum, to evaluate what effect this may have on clinical status, and to determine how the above-mentioned factors relate to allergic bronchopulmonary aspergillosis (ABPA).

PATIENTS

Seventy-six CF patients (40 male and 36 female patients; age, 15.3 plus minus 8.7 years [mean plus minus SD]) were studied.

MEASUREMENTS AND RESULTS

A total of 1,239 sputum samples from 66 patients were cultured for fungi. A fumigatus was grown in 256 sputum specimens (20.7%), and C albicans was grown in 588 sputum samples (47.5%). Forty patients (60.6%) had at least one positive culture finding for A fumigatus, and 58 patients (87.9%) had at least one positive culture finding for C albicans. Forty-nine patients (64.5%) were sensitized to A fumigatus, and 20 patients (26.7%) were sensitized to C albicans. No correlation was found between the finding of A fumigatus in sputum and IgE to A fumigatus. Only patients who had at least one positive culture finding for C albicans had IgE to C albicans develop. Lung function values and chest radiograph scores were not significantly lower in patients sensitized to either A fumigatus or C albicans as compared to nonsensitized patients. Of the 20 patients sensitized to C albicans, 10 patients had confirmed ABPA and 10 patients had some immunologic characteristics of ABPA.

CONCLUSIONS

A high prevalence of colonization and sensitization to A fumigatus and C albicans in CF patients was observed. The sensitization to these fungi was not related to the clinical severity. IgE to C albicans may be an immunologic marker related to the development of ABPA in patients with CF.

Allergic bronchopulmonary aspergillosis: a rare cause of pleural effusion

Aspergillus fumigatus is one of the most ubiquitous of the airborne saprophytic fungi. Allergic bronchopulmonary aspergillosis (ABPA) is a syndrome seen in patients with asthma and cystic fibrosis, and is characterized by hypersensitivity to chronic colonization of the airways with A. fumigatus. We report the case of a patient with ABPA presenting with pleural effusion. A 27-year-old male was referred with recurrent right pleural effusion. Past medical history was remarkable for asthma, allergic sinusitis, and recurrent pleurisy. Investigations revealed peripheral eosinophilia with elevated serum immunoglobulin E and bilateral pleural effusions with bilateral upper lobe proximal bronchiectasis. Precipitating serum antibodies to A. fumigatus were positive and the A. fumigatus immediate skin test yielded a positive reaction. A diagnosis of ABPA associated with bilateral pleural effusions was made and the patient was commenced on prednisolone. At review, the patient's symptoms had considerably improved and his pleural effusions had resolved. ABPA may present with diverse atypical syndromes, including paratracheal and hilar adenopathy, obstructive lung collapse, pneumothorax and bronchopleural fistula, and allergic sinusitis. Allergic bronchopulmonary aspergillosis is a rare cause of pleural effusion and must be considered in the differential diagnosis of patients presenting with a pleural effusion, in particular those with a history of asthma.

Diagnosis and treatment of allergic bronchopulmonary aspergillosis

Allergic bronchopulmonary aspergillosis (ABPA) is an underdiagnosed pulmonary disorder in asthmatic patients and patients with cystic fibrosis. Its clinical and diagnostic manifestations arise from an allergic response to multiple antigens expressed by fungi, most commonly Aspergillus fumigatus, colonizing the bronchial mucus. The clinical course is one of recurrent exacerbations characterized by chest infiltrates evident on chest x-ray films and associated with cough, wheeze, and sputum production that usually respond to oral corticosteroid treatment. Specific immunologic and radiologic markers of disease include elevation of the total serum IgE levels, presence of aspergillus IgE antibodies, and the occurrence of central bronchiectasis. Long-term treatment with corticosteroids is often required for effective management. The adverse effects of chronic corticosteroid use have led to attempts at treatment with antifungal agents such as itraconazole. Itraconazole has been reported anecdotally to be effective, and evidence for its effectiveness in randomized trials is still accruing. Consideration should be given to its use as a corticosteroid-sparing agent or for treatment of patients in whom corticosteroid response is poor. The natural history and prognosis of ABPA are not well characterized but may be complicated by progression to bronchiectasis and pulmonary fibrosis. If ABPA is diagnosed and treated before the development of bronchiectasis and fibrosis, these complications may be prevented.

Current pharmacotherapy of allergic bronchopulmonary aspergillosis

Although no well-designed studies have been carried out, the available data support the use of corticosteroids for acute exacerbations of allergic bronchopulmonary aspergillosis (ABPA). Neither the optimal steroid dose nor the duration of therapy has been standardised but limited data suggest the starting dose should be prednisone (approximately 0.5 mg/kg/day). The decision to taper steroids should be made on an individual basis, depending on clinical course. The available data suggest that clinical symptoms alone are inadequate to make such decisions, since significant lung damage may occur in asymptomatic patients. Increasing serum IgE levels, new or worsening infiltrate on chest radiograph and worsening spirometry suggest that steroids should be used. Multiple asthmatic exacerbations in a patient with ABPA suggest that chronic steroid therapy should be used. Itraconazole appears useful as a steroid sparing agent.

Allergic bronchopulmonary mycosis in patients with asthma: period prevalence at a university hospital in Saudi Arabia

Allergic bronchopulmonary mycosis (ABPM) is a known complication of asthma and can result in progressive lung damage, respiratory failure and death. Asthma is a common disease in Saudi Arabia and until now the prevalence of ABPM has not been investigated. The aim of this study was to estimate the period prevalence of ABPM due to Aspergillus and Candida in patients with asthma. The setting was an outpatient pulmonary clinic at a university hospital in the central region of Saudi Arabia. Two hundred and sixty-four consecutive patients with asthma (150 or 57% females) were evaluated. All patients were screened for ABPM with skin prick test (SPT) using a panel of fungal antigens. Those with positive skin reactions had further clinical, immunological, respiratory and radiological assessment. ABPM was diagnosed by the presence of a minimum of five of the major criteria suggested by Rosenberg in 1977. Of the 264 patients, 62 (23%) had a positive SPT for at least one fungal allergen, of whom 44 (71%) were females (P=0.01). Seven patients (six females) were diagnosed with ABPM due to Aspergillus and (or) Candida species. Therefore, we estimate the period prevalence of ABPM to be 2.7% (95% confidence interval 1.3-5.4%). A. niger was the commonest fungal species isolated in our group. In conclusion, ABPM is not uncommon in Saudi Arabia and females seem to be more at risk. Because asthma is common, physicians need to have high index of suspicion for this disease and pursue the diagnosis with the appropriate tests.

Allergic bronchopulmonary aspergillosis in cystic fibrosis

The current standards of care for allergic bronchopulmonary aspergillosis in patients with cystic fibrosis are presented. Recent studies have increased understanding of the inflammatory process that occurs in cystic fibrosis patients with allergic bronchopulmonary aspergillosis. This has resulted in more precise diagnostic criteria that facilitate more timely diagnosis and treatment of ABPA in these patients. In addition to traditional treatment with systemic corticosteroids, promising results have been documented with antifungal therapy.

Genotype and phenotype in cystic fibrosis

Cystic fibrosis (CF) is caused by mutations in the CF transmembrane conductance regulator (CFTR) gene which encodes a protein expressed in the apical membrane of exocrine epithelial cells. CFTR functions principally as a cAMP-induced chloride channel and appears capable of regulating other ion channels. Besides the most common mutation, DeltaF508, accounting for about 70% of CF chromosomes worldwide, more than 850 mutant alleles have been reported to the CF Genetic Analysis Consortium. These mutations affect CFTR through a variety of molecular mechanisms which can produce little or no functional CFTR at the apical membrane. This genotypic variation provides a rationale for phenotypic effects of the specific mutations. The extent to which various CFTR alleles contribute to clinical variation in CF is evaluated by genotype-phenotype studies. These demonstrated that the degree of correlation between CFTR genotype and CF phenotype varies between its clinical components and is highest for the pancreatic status and lowest for pulmonary disease. The poor correlation between CFTR genotype and severity of lung disease strongly suggests an influence of environmental and secondary genetic factors (CF modifiers). Several candidate genes related to innate and adaptive immune response have been implicated as pulmonary CF modifiers. In addition, the presence of a genetic CF modifier for meconium ileus has been demonstrated on human chromosome 19q13.2. The phenotypic spectrum associated with mutations in the CFTR gene extends beyond the classically defined CF. Besides patients with atypical CF, there are large numbers of so-called monosymptomatic diseases such as various forms of obstructive azoospermia, idiopathic pancreatitis or disseminated bronchiectasis associated with CFTR mutations uncharacteristic for CF. The composition, frequency and type of CFTR mutations/variants parallel the spectrum of CFTR-associated phenotypes, from classic CF to mild monosymptomatic presentations. Expansion of the spectrum of disease associated with the CFTR mutant genes creates a need for revision of the diagnostic criteria for CF and a dilemma for setting nosologic boundaries between CF and other diseases with CFTR etiology.

Antifungal therapies for allergic bronchopulmonary aspergillosis in people with cystic fibrosis

BACKGROUND

Allergic Bronchopulmonary Aspergillosis (ABPA) is an allergic reaction to colonisation of the lungs with the fungus Aspergillus fumigatus and affects around 10% people with cystic fibrosis. ABPA is associated with an accelerated decline in lung function. Corticosteroids, in high doses, are the main treatment for ABPA although the long-term benefits are not clear and their many side effects are well documented. A group of compounds, the azoles, have activity against Aspergillus fumigatus and have been proposed as an alternative treatment for ABPA. Of this group, Itraconazole is the most active. A separate antifungal compound, Amphotericin B has been employed in aerosolised form to treat invasive infection with Aspergillus fumigatus, and may have potential for the treatment of ABPA. Antifungal therapy for ABPA in cystic fibrosis needs to be evaluated.

OBJECTIVES

The review tested the hypotheses that antifungal interventions for the treatment of ABPA in cystic fibrosis: 1. improve clinical status compared to placebo or standard therapy (no placebo); 2. do not have unacceptable adverse effects. If benefit was demonstrated, the optimal type, duration and dose of antifungal therapy was assessed.

SEARCH STRATEGY

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group specialist trials register which comprises references identified from comprehensive electronic database searches, handsearching relevant journals and handsearching abstract books of conference proceedings. In addition, pharmaceutical companies were approached.

SELECTION CRITERIA

Randomised controlled trials, published or unpublished, where antifungal treatments have been compared to either placebo or no treatment, or where different doses of the same treatment have been used in the treatment of ABPA in patients with cystic fibrosis.

DATA COLLECTION AND ANALYSIS

No completed randomised controlled trials were identified.

MAIN RESULTS

No completed randomised controlled trials were identified.

REVIEWER'S CONCLUSIONS

At present, there are no randomised controlled trials to evaluate the use of antifungal therapies for the treatment of ABPA in people with cystic fibrosis. Trials with clear outcome measures are needed to properly evaluate this potentially useful treatment for cystic fibrosis.