A randomized trial of itraconazole in allergic bronchopulmonary aspergillosis

[Update in pneumology]

The end of the century has not brought any great modification in pneumology therapy. Prospective studies in asthma using combined therapeutic approaches, systemic or local steroid treatment in mild or moderate chronic obstructive pulmonary disease or itraconazole in allergic bronchopulmonary aspergillosis are summarized in this review. Innovation is coming from radiology, with confirmation of the interest of positive-emission tomography for the preoperative stage of lung cancer.

Rationale for combination antifungal therapy

The relentless increase of invasive fungal infections and poor outcomes associated with available antifungal agents prompted the search for better therapeutic strategies. Combining antifungal drugs was recommended as a means to enhance efficacy in a variety of invasive infections including cryptococcosis, candidiasis, and aspergillosis. With the exception of cryptococcal meningitis, data from controlled clinical trials supporting such combinations are sparse. Moreover, little consensus exists regarding which combinations are synergistic or antagonistic in vitro and in vivo. Based on available data, several principles underlie these combinations.

Need for alternative trial designs and evaluation strategies for therapeutic studies of invasive mycoses

Studies of invasive fungal infections have been and remain difficult to implement. Randomized clinical trials of fungal infections are especially slow and expensive to perform because it is difficult to identify eligible patients in a timely fashion, to prove the presence of the fungal infection in an unequivocal fashion, and to evaluate outcome in a convincing fashion. Because of these challenges, licensing decisions for antifungal agents have to date depended heavily on historical control comparisons and secondary advantages of the new agent. Although the availability of newer and potentially more effective agents makes these approaches less desirable, the fundamental difficulties of trials of invasive fungal infections have not changed. Therefore, there is a need for alternative trial designs and evaluation strategies for therapeutic studies of invasive mycoses, and this article summarizes the possible strategies in this area.

Fungal rhinosinusitis: diagnosis and therapy

Fungal rhinosinusitis presents in five clinicopathologic forms, each with distinct diagnostic criteria, treatment, and prognosis. The invasive forms are acute fulminant, chronic, and granulomatous ("indolent") invasive fungal sinusitis. The noninvasive forms are fungal ball ("sinus mycetoma") and allergic fungal sinusitis (AFS). AFS is the most common form of fungal rhinosinusitis. Patients with AFS are atopic to aeroallergens including the involved fungal organism, immunocompetent, have nasal polyps and chronic allergic rhinosinusitis, often produce nasal casts, and may occasionally present with proptosis from orbital extension of disease. Sinus CT shows sinus mucosal hypertrophy and often hyperattenuation of sinus contents. Diagnosis is made from surgical histopathology with or without an associated positive surgical sinus fungal culture. The histopathology shows extramucosal allergic mucin that stains positive for scattered fungal hyphae and eosinophilic-lymphocytic sinus mucosal inflammation. Bipolaris spicifera is the most common fungus cultured. The immunopathology of AFS has been shown to be analogous to allergic bronchopulmonary aspergillosis. Treatment requires surgery and aggressive postoperative medical management with close follow-up. Medical treatment includes allergy medications, allergen immunotherapy, and in many cases the addition of oral corticosteroids. Although medical management clearly improves patient outcomes, more studies are needed because AFS recurrence rates remain high.

Bronchiectasis

Bronchiectasis is a structural derangement of the bronchial wall that is characterized by airway dilatation and bronchial wall thickening. As a result of this abnormality, chronic inflammation and secondary microbial infections occur, which cause additional damage to the bronchi. Recent insights into the potential pathophysiological mechanisms of bronchiectasis, as well as improvements in computed tomography and the development of new pharmacological agents, might help to improve the clinical management of this chronic infective/inflammatory disorder.

Allergic bronchopulmonary aspergillosis: new concepts of pathogenesis and treatment

Allergic bronchopulmonary aspergillosis (ABPA) is a condition that results from a hypersensitivity reaction to the fungus Aspergillus fumigatus. The purpose of the present review is to examine the pathogenesis of this condition and the evidence for treatments available. Allergic bronchopulmonary aspergillosis is characterized by an intense airway inflammation with eosinophils and the formation of mucus plugs. Clinically, there are periods of exacerbation and remission that may lead to proximal bronchiectasis and fibrotic lung disease. New evidence confirms the role of intense airway inflammation with eosinophils, but also suggests a role for interleukin (IL)-8/neutrophil-mediated inflammation in this process, and the potential deficiency of anti-inflammatory cytokines such as reduced IL-10. Treatment for ABPA has so far focused on corticosteroids to suppress eosinophilic airway inflammation. An expanding knowledge of the pathology of ABPA also suggests other therapies may be of potential benefit, particularly the use of azole antifungal agents. Allergic bronchopulmonary aspergillosis is itself an important complication of asthma and cystic fibrosis. A greater understanding of the condition is required to improve management and well-designed clinical trials need to be carried out to critically assess new and current treatments. In addition, the information gained from the studies of its pathogenesis has the potential to benefit our understanding of the disease processes in asthma and bronchiectasis.

Report of successful prolonged antifungal therapy for refractory allergic fungal sinusitis

Allergic fungal sinusitis (AFS) is an increasingly recognized cause of refractory chronic sinusitis in the young immunocompetent host, analogous to allergic bronchopulmonary aspergillosis (ABPA), a related process in the lower respiratory tract. Most patients experience remittent disease despite corticosteroid therapy and aggressive sinus surgery. Because controlled trials have shown adjunctive antifungal therapy to be of benefit in treating ABPA, long-term oral itraconazole was used in a young man with remittent AFS, which was able to break the cycle of relapsing disease.

Practice guidelines for diseases caused by Aspergillus. Infectious Diseases Society of America

Aspergillosis comprises a variety of manifestations of infection. These guidelines are directed to 3 principal entities: invasive aspergillosis, involving several organ systems (particularly pulmonary disease); pulmonary aspergilloma; and allergic bronchopulmonary aspergillosis. The recommendations are distilled in this summary, but the reader is encouraged to review the more extensive discussions in subsequent sections, which show the strength of the recommendations and the quality of the evidence, and the original publications cited in detail. Invasive aspergillosis. Because it is highly lethal in the immunocompromised host, even in the face of therapy, work-up must be prompt and aggressive, and therapy may need to be initiated upon suspicion of the diagnosis, without definitive proof (BIII). Intravenous therapy should be used initially in rapidly progressing disease (BIII). The largest therapeutic experience is with amphotericin B deoxycholate, which should be given at maximum tolerated doses (e.g., 1-1.5 mg/kg/d) and should be continued, despite modest increases in serum creatinine levels (BIII). Lipid formulations of amphotericin are indicated for the patient who has impaired renal function or who develops nephrotoxicity while receiving deoxycholate amphotericin (AII). Oral itraconazole is an alternative for patients who can take oral medication, are likely to be adherent, can be demonstrated (by serum level monitoring) to absorb the drug, and lack the potential for interaction with other drugs (BII). Oral itraconazole is attractive for continuing therapy in the patient who responds to initial iv therapy (CIII). Therapy should be prolonged beyond resolution of disease and reversible underlying predispositions (BIII). Adjunctive therapy (particularly surgery and combination chemotherapy, also immunotherapy), may be useful in certain situations (CIII). Aspergilloma. The optimal treatment strategy for aspergilloma is unknown. Therapy is predominantly directed at preventing life-threatening hemoptysis. Surgical removal of aspergilloma is definitive treatment, but because of significant morbidity and mortality it should be reserved for high-risk patients such as those with episodes of life-threatening hemoptysis, and considered for patients with underlying sarcoidosis, immunocompromised patients, and those with increasing Aspergillus-specific IgG titers (CIII). Surgical candidates would need to have adequate pulmonary function to undergo the operation. Bronchial artery embolization rarely produces a permanent success, but may be useful as a temporizing procedure in patients with life-threatening hemoptysis. Endobronchial and intracavitary instillation of antifungals or oral itraconazole may be useful for this condition. Since the majority of aspergillomas do not cause life-threatening hemoptysis, the morbidity and cost of treatment must be weighed against the clinical benefit. Allergic bronchopulmonary aspergillosis (APBA). Although no well-designed studies have been carried out, the available data support the use of corticosteroids for acute exacerbations of ABPA (AII). Neither the optimal corticosteroid dose nor the duration of therapy has been standardized, but limited data suggest the starting dose should be approximately 0.5 mg/kg/d of prednisone. The decision to taper corticosteroids should be made on an individual basis, depending on the clinical course (BIII). 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 corticosteroids should be used (BII). Multiple asthmatic exacerbations in a patient with ABPA suggest that chronic corticosteroid therapy should be used (BIII). Itraconazole appears useful as a corticosteroid sparing agent (BII). (ABSTRACT TRUNCATED)

Treatment strategies for Aspergillus infections

Infections caused by Aspergillus species consist of many different disease presentations, ranging from relatively benign asthma in atopic disease to life-threatening systemic invasive infections. The spectrum of disease manifestations is determined by a combination of genetic predisposition, host immune system defects, and virulence of the Aspergillus species. For the purposes of this discussion, we will address three principal entities: invasive aspergillosis, both primary and disseminated, pulmonary aspergilloma, and allergic bronchopulmonary aspergillosis. Amphotericin B is the standard of treatment for severe Aspergillus infections, despite the fact that mortality in these patients remains high. Alternative therapies such as combination regimens and itraconazole also have efficacy against Aspergillus infections. We discuss the role of current therapies, the potential role of drugs in development, and the results of ongoing research with combination and immunotherapies. Copyright 2000 Harcourt Publishers Ltd.

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.