Chronic aspergillus infections of the respiratory tract: diagnosis, management and antifungal resistance

Pentraxin 3 Gene Polymorphisms and Pulmonary Aspergillosis in Chronic Obstructive Pulmonary Disease Patients

Background

Pentraxin 3 (PTX3) plays an important role in resistance to Aspergillus infections. Previous studies have suggested that PTX3 polymorphisms influence the risk of invasive aspergillosis among transplantation recipients. This study investigated the association between PTX3 gene polymorphisms and pulmonary aspergillosis in a chronic obstructive pulmonary disease (COPD) population.

Methods

We included 173 consecutive inpatients with COPD. Thirty-six case patients were finally diagnosed with pulmonary aspergillosis. Among these, 25 case patients had invasive pulmonary aspergillosis (IPA), and 11 case patients had chronic pulmonary aspergillosis (CPA). Three single nucleotide polymorphisms (SNPs; rs2305619, rs3816527, and rs1840680) in the PTX3 gene were detected by polymerase chain reaction direct sequencing, and their associations with aspergillosis were evaluated. Plasma PTX3 levels were measured by enzyme-linked immunosorbent assay.

Results

Three SNPs were consistent with Hardy-Weinberg equilibrium. The recessive model for SNP rs1840680 suggests that the AA homozygote is associated with a higher risk for pulmonary aspergillosis (both IPA and CPA) in COPD patients. However, for genotypic and allele frequencies of rs2305619 and rs3816527, no association was observed. The distribution of haplotypes (rs2305619 and rs3816527) also showed no significant differences. Plasma PTX3 levels significantly increased in IPA patients. In the IPA group, the rs1840680 AA genotype subjects showed lower plasma PTX3 levels than those harboring AG and GG genotypes.

Conclusions

This study showed a significant association between PTX3 rs1840680 polymorphisms and the susceptibility of pulmonary aspergillosis in patients with COPD. Plasma PTX3 levels may be potentially used as indicators for the diagnosis of IPA in COPD patients.

Treatment of chronic pulmonary aspergillosis with voriconazole: review of a case series

PURPOSE

Chronic pulmonary aspergillosis (CPA) is a rare disease that primarily affects subjects with moderate immunodepression and/or structural alterations in the lung.

METHODS

Data for patients with probable CPA were collected over 24 months. Patients with probable CPA received oral voriconazole, and clinical, laboratory and radiological follow-up was performed at 3, 6 and 12 months.

RESULTS

21 patients (mean age 52.4 years) were evaluated. Factors predisposing to CPA were tuberculosis (n = 8), chronic obstructive pulmonary disease (n = 7), corticosteroids (n = 14), chemo- or radio-therapy (n = 6), tracheostomy or endotracheal prosthesis (n = 5), smoking (n = 4), asthma (n = 3), and chronic liver disease (n = 3). Sputum or bronchial aspirate cultures were positive for Aspergillus spp. in 14 cases (66.6 %). (1,3)-β-D-glucan on serum was positive in 16 cases (76.2 %). Excavated pulmonary thickening was evident in 14 patients (66.6 %) and in 9 of these cases (64.2 %) aspergilloma was present. [(18)F]2-fluoro-2-deoxy-D-glucose-PET-CT was positive in 13/15 patients, and simple aspergilloma was diagnosed after surgical excision in one of the negative cases. All patients were treated with oral voriconazole. Therapy was discontinued due to skin toxicity (n = 3), liver toxicity (n = 2) and severe mental disorder (n = 1). At 12 months' follow-up, nine patients (42.9 %) were considered cured or improved. Seven patients (33.3 %) died during follow-up, mainly due to underlying disease.

CONCLUSIONS

A reasonable proportion of patients achieved cure or improvement with voriconazole, but 28.5 % of treated patients had to discontinue therapy because of toxicity. The high mortality makes it difficult to fully assess the real efficacy of voriconazole and to establish the correct duration of therapy.

[Invasive pulmonary aspergillosis in patients with chronic obstructive pulmonary disease]

Invasive pulmonary aspergillosis (IPA) is a common infection in immunocompromised patients with hematological malignancies or allogenic stem cell transplantation, and is less frequent in the context of chronic obstructive pulmonary disease (COPD). Mucociliary activity impairment, immunosuppression due to the inhibition of alveolar macrophages and neutrophils by steroids, and receiving broad-spectrum antibiotics, play a role in the development of IPA in COPD patients. Colonized patients or those with IPA are older, with severe CODP stage (GOLD≥III), and have a higher number of comorbidities. The mortality rate is high due to the fact that having a definitive diagnosis of IPA in COPD patients is often difficult. The main clinical and radiological signs of IPA in these types of patients are non-specific, and tissue samples for definitive diagnosis are often difficult to obtain. The poor prognosis of IPA in COPD patients could perhaps be improved by faster diagnosis and prompt initiation of antifungal treatment. Some tools, such as scales and algorithms based on risk factors of IPA, may be useful for its early diagnosis in these patients.

Chronic pulmonary aspergillosis

Chronic pulmonary aspergillosis (CPA) is a group of consuming diseases usually presenting with prolonged and relapsing cough, dyspnoea and weight loss. Acute symptoms such as haemoptysis and bronchial or pulmonary haemorrhage may occasionally occur. CPA affects patients with underlying pulmonary conditions, for example, chronic obstructive pulmonary disease or mycobacteriosis or common immunosuppressive conditions such as diabetes. Precise epidemiology is unknown, and while prevalence is considered low the chronic and relapsing nature of the disease challenges the treating physician. Diagnostics largely rely on serologic Aspergillus precipitins and findings on thoracic computed tomography. The latter are manifold comprising cavity formation, pleural involvement and sometimes aspergilloma. Other markers for aspergillosis are less helpful, in part due to the non- or semi-invasive nature of these forms of Aspergillus infection. Various antifungals were shown to be effective in CPA treatment. Azoles are the most frequently applied antifungals in the outpatient setting, but are now compromised by findings of Aspergillus resistance. Long-term prognosis is not fully elucidated and may be driven by the underlying morbidities. Prospective registry-type studies may be suitable to systematically broaden our CPA knowledge base. This article gives an overview of the available literature and proposes a clinical working algorithm for CPA management.

Correlation between triazole treatment history and susceptibility in clinically isolated Aspergillus fumigatus

This is the first report of a detailed relationship between triazole treatment history and triazole MICs for 154 Aspergillus fumigatus clinical isolates. The duration of itraconazole dosage increased as the itraconazole MIC increased, and a positive correlation was observed (r = 0.5700, P < 0.0001). The number of itraconazole-naïve isolates dramatically decreased as the itraconazole MIC increased, particularly for MICs exceeding 2 μg/ml (0.5 μg/ml versus 2 μg/ml, P = 0.03). We also examined the relationship between cumulative itraconazole usage and the MICs of other azoles. A positive correlation existed between itraconazole dosage period and posaconazole MIC (r = 0.5237, P < 0.0001). The number of itraconazole-naïve isolates also decreased as the posaconazole MIC increased, particularly for MICs exceeding 0.5 μg/ml (0.25 μg/ml versus 0.5 μg/ml, P = 0.004). Conversely, the correlation coefficient obtained from the scattergram of itraconazole usage and voriconazole MICs was small (r = -0.2627, P = 0.001). Susceptibility to three triazole agents did not change as the duration of voriconazole exposure changed. In addition, we carried out detailed analysis, including microsatellite genotyping, for isolates obtained from patients infected with azole-resistant A. fumigatus. We confirmed the presence of acquired resistance to itraconazole and posaconazole due to a G54 substitution in the cyp51A gene for a patient with chronic pulmonary aspergillosis after oral itraconazole therapy. We should consider the possible appearance of azole-resistant A. fumigatus if itraconazole is used for extended periods.

Clinical characteristics and prognosis of chronic pulmonary aspergillosis

BACKGROUND

The details of the clinical characteristics of patients with chronic pulmonary aspergillosis (CPA) have not been fully understood.

METHOD

One hundred twenty-nine consecutive patients with isolation of Aspergillus species by culture from respiratory specimens who attended our hospital between October 2001 and September 2009 were enrolled. Patients diagnosed with chronic pulmonary aspergillosis (CPA) were retrospectively reviewed for clinical characteristics and prognosis, compared with patients with Aspergillus species colonization.

RESULTS

Forty-two (32.6%) were diagnosed with CPA, whereas 87 (67.4%) with colonization. Aspergillus fumigatus was significantly more frequently detected in the CPA group than in the colonization group. Regarding underlying diseases, CPA patients had a significantly higher prevalence of a history of pulmonary tuberculosis and diabetes mellitus than colonization patients. There were no significant differences between the CPA and colonization group in Aspergillus antigen titers. Positivity for Aspergillus precipitating antibody was 74.3% in CPA and 15.8% in colonization, respectively. Sensitivity and specificity of Aspergillus precipitating antibody for the determination of CPA was 74.4% and 84.1%, respectively.Patients with CPA had significantly shorter survival than patients with colonization (mortality rate 50.0% vs. 13.8%, observation periods: 28.7 ± 26.6 months) (p < 0.0001). Multivariable analysis revealed that BMI was an independent predictor of prognosis (Odds Ratio, 1.973; p = 0.0223).

CONCLUSIONS

CPA is a disease with a poor prognosis, which shows distinct clinical characteristics from colonization.

Antifungal susceptibilities of Aspergillus fumigatus clinical isolates obtained in Nagasaki, Japan

We investigated the triazole, amphotericin B, and micafungin susceptibilities of 196 A. fumigatus clinical isolates in Nagasaki, Japan. The percentages of non-wild-type (non-WT) isolates for which MICs of itraconazole, posaconazole, and voriconazole were above the ECV were 7.1%, 2.6%, and 4.1%, respectively. A G54 mutation in cyp51A was detected in 64.2% (9/14 isolates) and 100% (5/5 isolates) of non-WT isolates for itraconazole and posaconazole, respectively. Amphotericin B MICs of ≥2 μg/ml and micafungin minimum effective concentrations (MECs) of ≥16 μg/ml were recorded for two and one isolates, respectively.

Serum and bronchoalveolar lavage fluid galactomannan assays in patients with pulmonary aspergilloma

The sensitivities of the serum and bronchoalveolar lavage galactomannan (GM) assays in 48 patients with pulmonary aspergilloma were 38% (13 of 34; 95% confidence interval [CI], 22%-56%) and 92% (33 of 36; 95% CI, 78%-98%), respectively. The positivity of serum GM assays was significantly higher in patients with hemoptysis than in those without hemoptysis (52% vs 9%; P=.02).