Pulmonary eosinophilia with and without allergic bronchopulmonary aspergillosis

Pulmonary eosinophilia may indicate onset stage of allergic bronchopulmonary aspergillosis

BACKGROUND

Allergic bronchopulmonary aspergillosis (ABPA) and chronic eosinophilic pneumonia (CEP) both display peripheral eosinophilia as well as pulmonary infiltration, together described as pulmonary eosinophilia, and differentiation is sometimes problematic. This study therefore examined the distinctions between ABPA with and without CEP-like shadows.

METHODS

This retrospective cohort study from a single center included 25 outpatients (median age, 65 years) with ABPA diagnosed between April 2015 and March 2019, using criteria proposed by the International Society of Human and Animal Mycology (ISHAM), which focuses on positive specific IgE for Aspergillus fumigatus. Patients were assigned to either the eosinophilic pneumonia (EP) group or Non-EP group, defined according to findings on high-resolution computed tomography (HRCT). The EP group included patients with HRCT findings compatible with CEP; i.e., the presence of peripheral consolidation (p-consolidation) or ground-glass opacities (GGO), with no evidence of high-attenuation mucus. The Non-EP group comprised the remaining patients, who showed classical findings of ABPA such as mucoid impaction. Differences between the groups were analyzed.

RESULTS

Baseline characteristics, frequency of a history of CEP (EP, 50% vs. Non-EP, 26%) and tentative diagnosis of CEP before diagnosis of ABPA (67% vs. 16%) did not differ significantly between groups. Although elevated absolute eosinophil count and Aspergillus-specific immunoglobulin E titers did not differ significantly between groups, the Non-EP group showed a strong positive correlation between these values (R  = 0.7878, p  = 0.0003). The Non-EP group displayed significantly higher levels of the fungal marker beta-D glucan (median, 11.7 pg/ml; interquartile range, 6.7-18.4 pg/ml) than the EP group (median, 6.6 pg/ml; interquartile range, 5.2-9.3 pg/ml). Both groups exhibited frequent recurrence of shadows on X-rays but no cases in the EP group had progressed to the Non-EP group at the time of relapse.

CONCLUSIONS

The ABPA subgroup with imaging findings resembling CEP experienced frequent recurrences, as in typical ABPA. In pulmonary eosinophilia, even if there are no shadows indicating apparent mucous change, the Aspergillus-specific immunoglobulin E level is important in obtaining an accurate diagnosis and in the selection of appropriate therapies for this type of ABPA.

Chronic Eosinophilic Pneumonia with Subpleural Curvilinear Shadow

We report a rare case of chronic eosinophilic pneumonia with subpleural curvilinear shadow. CT scan showed a patchy consolidation in the bilateral upper lungs. In addition, subpleural curvilinear shadow was found in the bilateral upper lungs. A bronchoalveolar lavage obtained from the right middle lobe showed 25 % eosinophils. Although very rare, we should therefore keep in mind that patients, who have patchy consolidation with areas of subpleural curvilinear shadow in the bilateral upper lungs, may have chronic eosinophilic pneumonia.

Evolution of the Immune Response to Chronic Airway Colonization with Aspergillus fumigatus Hyphae

Airway colonization by the mold Aspergillus fumigatus is common in patients with underlying lung disease and is associated with chronic airway inflammation. Studies probing the inflammatory response to colonization with A. fumigatus hyphae have been hampered by the lack of a model of chronic colonization in immunocompetent mice. By infecting mice intratracheally with conidia embedded in agar beads (Af beads), we have established an in vivo model to study the natural history of airway colonization with live A. fumigatus hyphae. Histopathological examination and galactomannan assay of lung homogenates demonstrated that hyphae exited beads and persisted in the lungs of mice up to 28 days postinfection without invasive disease. Fungal lesions within the airways were surrounded by a robust neutrophilic inflammatory reaction and peribronchial infiltration of lymphocytes. Whole-lung cytokine analysis from Af bead-infected mice revealed an increase in proinflammatory cytokines and chemokines early in infection. Evidence of a Th2 type response was observed only early in the course of colonization, including increased levels of interleukin-4 (IL-4), elevated IgE levels in serum, and a mild increase in airway responsiveness. Pulmonary T cell subset analysis during infection mirrored these results with an initial transient increase in IL-4-producing CD4(+) T cells, followed by a rise in IL-17 and Foxp3(+) cells by day 14. These results provide the first report of the evolution of the immune response to A. fumigatus hyphal colonization.

Eosinophilic pneumonias

This review starts with discussions of several infectious causes of eosinophilic pneumonia, which are almost exclusively parasitic in nature. Pulmonary infections due specifically to Ascaris, hookworms, Strongyloides, Paragonimus, filariasis, and Toxocara are considered in detail. The discussion then moves to noninfectious causes of eosinophilic pulmonary infiltration, including allergic sensitization to Aspergillus, acute and chronic eosinophilic pneumonias, Churg-Strauss syndrome, hypereosinophilic syndromes, and pulmonary eosinophilia due to exposure to specific medications or toxins.

Blood eosinophilia: a new paradigm in disease classification, diagnosis, and treatment

Acquired blood eosinophilia is considered either a primary or a secondary phenomenon. Causes of secondary (ie, reactive) eosinophilia include tissue-invasive parasitosis, allergic or inflammatory conditions, and malignancies in which eosinophils are not considered part of the neoplastic process. Primary eosinophilia is classified operationally into 2 categories: clonal and idiopathic. Clonal eosinophilia stipulates the presence of either cytogenetic evidence or bone marrow histological evidence of an otherwise classified hematologic malignancy such as acute leukemia or a chronic myeloid disorder. Idiopathic eosinophilia is a diagnosis of exclusion (ie, not secondary or clonal). Hypereosinophilic syndrome is a subcategory of idiopathic eosinophilia; diagnosis requires documentation of both sustained eosinophilia (absolute eosinophil count > or = 1500 cells/microL for at least 6 months) and target organ damage (eg, involvement of the heart, lung, skin, or nerve tissue). Genetic mutations involving the platelet-derived growth factor receptor genes (PDGFR-alpha and PDGFR-beta) have been pathogenetically linked to clonal eosinophilia, and their presence predicts treatment response to imatinib. Accordingly, cytogenetic and/or molecular investigations for the presence of an imatinib-sensitive molecular target should accompany current evaluation for primary eosinophilia. In the absence of such a drug target, specific treatment is dictated by the underlying hematologic malignancy in cases of clonal eosinophilia; however, the initial treatment of choice for symptomatic patients with hypereosinophilic syndrome is prednisone and/or interferon alfa.

Blood eosinophilia: a new paradigm in disease classification, diagnosis, and treatment

Acquired blood eosinophilia is considered either a primary or a secondary phenomenon. Causes of secondary (ie, reactive) eosinophilia include tissue-invasive parasitosis, allergic or inflammatory conditions, and malignancies in which eosinophils are not considered part of the neoplastic process. Primary eosinophilia is classified operationally into 2 categories: clonal and idiopathic. Clonal eosinophilia stipulates the presence of either cytogenetic evidence or bone marrow histological evidence of an otherwise classified hematologic malignancy such as acute leukemia or a chronic myeloid disorder. Idiopathic eosinophilia is a diagnosis of exclusion (ie, not secondary or clonal). Hypereosinophilic syndrome is a subcategory of idiopathic eosinophilia; diagnosis requires documentation of both sustained eosinophilia (absolute eosinophil count > or = 1500 cells/microL for at least 6 months) and target organ damage (eg, involvement of the heart, lung, skin, or nerve tissue). Genetic mutations involving the platelet-derived growth factor receptor genes (PDGFR-alpha and PDGFR-beta) have been pathogenetically linked to clonal eosinophilia, and their presence predicts treatment response to imatinib. Accordingly, cytogenetic and/or molecular investigations for the presence of an imatinib-sensitive molecular target should accompany current evaluation for primary eosinophilia. In the absence of such a drug target, specific treatment is dictated by the underlying hematologic malignancy in cases of clonal eosinophilia; however, the initial treatment of choice for symptomatic patients with hypereosinophilic syndrome is prednisone and/or interferon alfa.

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: disease pattern in central Arabia

Despite a high prevalence of asthma in Saudi Arabia, allergic bronchopulmonary aspergillosis (ABPA) has not been reported. We reviewed the medical records in a large university hospital in Saudi Arabia where thousands of asthmatics are being followed up. Over a 9-year period starting January 1986, the diagnosis of ABPA was made in 10 patients only. Delay in diagnosis was common and in some patients the disease was confused with fungal pneumonia, tuberculosis or tumours. Aspergillus fumigatus was isolated from one patient only and different Aspergillus species were cultured from respiratory secretions of the others. Corticosteroids were uniformly effective in all patients with active disease. Low humidity may account for this apparent rarity of ABPA, although it is possible that some cases are overlooked. Further work is needed on the prevalent fungi in the Arabian environment and their potential health effects and particularly on the prevalence of allergic bronchopulmonary fungal disease.

Pulmonary eosinophilia

The pulmonary eosinophilias are a diverse group of disorders characterised by pulmonary infiltrates, rich in eosinophils usually associated with a peripheral blood eosinophilia. Known causes of pulmonary eosinophilia include fungi--in particular Aspergillus fumigatus, parasites, toxins and drugs. Pulmonary eosinophilias of unknown cause include Löffler's syndrome, acute and chronic eosinophilic pneumonia, the hypereosinophilic syndrome, bronchocentric granulomatosis and pulmonary eosinophilia associated with vasculitis. The chest radiographic appearances of pulmonary eosinophilia are often characteristic and HRCT in selected cases can give important additional information.

Pulmonary eosinophilia with systemic features: therapy and prognosis

Of 65 patients presenting with pulmonary eosinophilia to one Respiratory Unit during a 20-year period, 12 (18%) had systemic features associated with their pulmonary disease. Eleven had fever, three night sweats, three arthralgia, three vasculitic rashes and two weight loss. Anaemia, myalgia, peripheral neuropathy, mononeuritis, pericardial effusion and photosensitivity rash were each recorded in single patients. None had evidence of hypersensitivity to drugs, helminthes or other allergens. Ten of the 12 patients could be classified as cryptogenic pulmonary eosinophilia and two as Churg Strauss syndrome. Ten were female. The maximum recorded eosinophil counts were higher in the 12 patients with systemic features compared with the remaining 53 patients [mean (SD) 5613 (3883) vs. 2359 (3046) x 10(6) 1(-1), P < 0.02], whereas both asthma and recurrent episodes of eosinophilia were significantly less common. Steroid therapy achieved a good clinical response and radiological clearing in the majority of patients. All 12 patients were treated with prolonged duration oral prednisolone [mean (SEM) dose 8.5 (3.8) mg day-1 duration 5.5 (1.3) years]. The two patients with Churg Strauss syndrome required azathioprine in addition to long-term prednisolone. There were no deaths and currently four patients are off all steroids and six receive less than 5 mg day-1. During a median follow-up period of 11 years, there was no significant decline in FEV1 or VC, measured as percent predicted values. Persistent radiographic abnormalities consistent with fibrosis or bronchiectasis were not seen.(ABSTRACT TRUNCATED AT 250 WORDS)

Precipitins and specific IgG antibody to Aspergillus fumigatus in a chest unit population

BACKGROUND

The enzyme linked immunosorbent assay (ELISA) for detecting IgG antibodies to Aspergillus fumigatus is more sensitive than the measurement of Aspergillus precipitins. The relation of the results from both techniques to the clinical pattern of disease in a large unselected group of patients from a large referral centre is unknown.

METHODS

The clinical relation of precipitins to Aspergillus fumigatus to clinical disease was determined retrospectively in 98 patients attending a primary referral centre. Precipitin results were compared with the specific IgG antibody to A fumigatus in 88 of the sera. Precipitins were determined by the agar gel double diffusion test and specific IgG antibody to A fumigatus by a quantitative ELISA.

RESULTS

Precipitins were detected in the unconcentrated serum of 51 patients. Thirty nine of these had a mycetoma or allergic bronchopulmonary aspergillosis, 34 having specific IgG antibody to A fumigatus more than the control range. Forty seven patients had precipitins only after threefold concentration of serum or to only one of the four A fumigatus antigen extracts. Most of these had specific IgG in or near the control range. Thirty of these had A fumigatus skin test negative asthma or bronchiectasis, in which aspergillus was probably not pathogenic. There was a close relation between the level of antibody detected by the ELISA and the number of precipitin lines.

CONCLUSIONS

This study reaffirmed the supportive role of aspergillus precipitins in the diagnosis of pulmonary aspergillosis. No additional benefit in the routine use of the ELISA was seen. It also showed that care should be taken in interpreting positive precipitin results from concentrated serum and that using several rather than one A fumigatus antigen extract is helpful for identifying allergic aspergillosis.

Corticosteroid treatment and prognosis in pulmonary eosinophilia

The acute and long term responses to corticosteroid treatment in 65 patients with pulmonary eosinophilia have been reviewed. Of the 247 episodes of pulmonary eosinophilia that were documented during a median follow up period of 14 years, 186 were treated with prednisolone. Complete clearing of chest radiographic infiltrates occurred in 65% of the 247 episodes, partial clearing in 25%, and no response in 9%. Blood eosinophil counts were monitored during 194 episodes and returned to normal in 72%, decreased in 19%, and remained raised in 9%. Complete radiological clearing and a reduction in blood eosinophil counts were more common in episodes treated with prednisolone. Long term prednisolone was given to 28 of the 33 patients with allergic bronchopulmonary aspergillosis (mean 7.4 mg/day for 11 years) and to 29 of the 32 "non-aspergillosis" patients (mean 8.1 mg/day for 4.6 years). Initial pulmonary function, measured between episodes, was worse in patients with allergic aspergillosis than in those without (mean % predicted: FEV1 57% v 83%, vital capacity (VC) 76% v 88%). During a mean follow up period of 12 years neither group displayed further decline in FEV1 or VC.