Pictorial Review of Fibrotic Interstitial Lung Disease on High-Resolution CT Scan and Updated Classification

TOPIC IMPORTANCE

Given the recently expanded approval of antifibrotics for various fibrotic interstitial lung diseases (ILDs), early and correct recognition of these diseases is imperative for physicians. Because high-resolution chest CT scan forms the backbone of diagnosis for ILD, this review will discuss evidence-based imaging findings of key fibrotic ILDs and an approach for differentiating these diseases.

REVIEW FINDINGS

(1) Imaging findings of nonspecific interstitial pneumonia may evolve over time and become indistinguishable from usual interstitial pneumonia. Therefore, if remote imaging can be reviewed, this would increase the likelihood of an accurate imaging diagnosis, particularly if findings appear to represent a usual interstitial pneumonia pattern on the recent examination. (2) Given the difficulty and lack of objectivity in classifying patients with hypersensitivity pneumonitis into acute, subacute, and chronic categories and that prognosis depends primarily on presence or absence of fibrosis, the new set of guidelines released in 2020 categorizes patients with hypersensitivity pneumonitis as either nonfibrotic (purely inflammatory) or fibrotic (either purely fibrotic or mixed fibrotic/inflammatory) based on imaging and/or histologic findings, and the prior temporal terms are no longer used. (3) Interstitial lung abnormalities are incidental CT scan findings that may suggest early ILD in patients without clinical suspicion for ILD. Patients with high-risk features should undergo clinical evaluation for ILD and be actively monitored for disease progression.

SUMMARY

Fibrotic ILD on high-resolution chest CT scan is a complex topic, but with use of an evidence-based analysis and algorithm as provided in this article, the probability of a correct imaging diagnosis increases.

Integration and Application of Radiologic Patterns From Clinical Practice Guidelines on Idiopathic Pulmonary Fibrosis and Fibrotic Hypersensitivity Pneumonitis

BACKGROUND

Clinical practice guidelines separately describe radiologic patterns of usual interstitial pneumonia (UIP) and fibrotic hypersensitivity pneumonitis (fHP), without direction on whether or how to apply these approaches concurrently within a single patient.

RESEARCH QUESTION

How can we integrate guideline-defined radiologic patterns to diagnose interstitial lung disease (ILD) and what are the pitfalls associated with described patterns that require reassessment in future guidelines?

STUDY DESIGN AND METHODS

Patients from the Canadian Registry for Pulmonary Fibrosis underwent detailed reevaluation in standardized multidisciplinary discussion. CT scan features were quantified by chest radiologists masked to clinical data, and guideline-defined patterns were assigned. Clinical data then were provided to the radiologist and an ILD clinician, who jointly determined the leading diagnosis.

RESULTS

Clinical-radiologic diagnosis in 1,593 patients was idiopathic pulmonary fibrosis (IPF) in 26%, fHP in 12%, connective tissue disease-associated ILD (CTD-ILD) in 34%, idiopathic pneumonia with autoimmune features in 12%, and unclassifiable ILD in 10%. Typical and probable UIP patterns corresponded to a diagnosis of IPF in 66% and 57% of patients, respectively. Typical fHP pattern corresponded to an fHP clinical diagnosis in 65% of patients, whereas compatible fHP was nonspecific and associated with CTD-ILD or IPAF in 48% of patients. No pattern ruled out CTD-ILD. Gas trapping affecting > 5% of lung parenchyma on expiratory imaging was an important feature broadly separating compatible and typical fHP from other patterns (sensitivity, 0.77; specificity, 0.91).

INTERPRETATION

An integrated approach to guideline-defined UIP and fHP patterns is feasible and supports > 5% gas trapping as an important branch point. Typical or probable UIP and typical fHP patterns have moderate predictive values for a corresponding diagnosis of IPF and fHP, although occasionally confounded by CTD-ILD; compatible fHP is nonspecific.

Recurrent episodes of febrile dyspnoea: hypersensitivity pneumonitis caused by a household ultrasonic humidifier

Hypersensitivity pneumonitis is an immune-mediated interstitial lung disease that presents with respiratory symptoms, with or without systemic symptoms, following exposure to an identified or unidentified external factor. It can be caused by extrinsic factors including household items such as ultrasonic humidifiers.We present an intriguing case of a previously healthy 50-year-old man who displayed recurrent episodes of progressive dyspnoea and fever after repeated exposure to his household ultrasonic humidifier. He was treated with corticosteroids, followed by the removal of the humidifier, resulting in total recovery and absence of recurrence of further episodes.The clinical presentation of hypersensitivity pneumonitis can be dramatic, and the differential diagnosis is broad. The correct diagnosis is achieved by combining clinical, radiological and histopathological patterns. The key to finding the aetiology lies in a thorough history, with an important role for household investigations to identify the external factor.

ATS/JRS/ALAT Hypersensitivity Pneumonitis Guidelines for Diagnosis of humidifier lung and summer-type hypersensitivity pneumonitis

BACKGROUND

The ATS/JRS/ALAT Guidelines for the Diagnosis of Hypersensitivity Pneumonitis (GL for HP) were published in 2020. Humidifier lung and summer-type HP are forms of HP, but it is unclear whether they can be diagnosed using GL for HP. This study examined the level of confidence where humidifier lung and summer-type HP can be diagnosed with GL for HP.

METHODS

Data from 23 patients with humidifier lung and 20 patients with summer-type HP (mean age, 67.3 and 57.4 years, respectively) diagnosed between October 2012 and January 2022 were retrospectively reviewed. We evaluated high resolution computed tomography (HRCT) patterns, bronchoalveolar lavage fluid (BALF) findings, exposures, and histopathological findings to determine the level of confidence where a diagnosis of HP could be made using the GL for HP.

RESULTS

HRCT pattern was classified as typical HP in 5 (22%) and compatible with HP in 18 (78%) patients with humidifier lung and considered as typical HP in 17 (85%) and compatible with HP in 3 (15%) patients with summer-type. The confidence level for diagnosis of HP was definite in 2 (8.7%), moderate in 14 (60.9%), and low in 7 (30.4%) patients with humidifier lung. It was definite in 12 (60%), high in 3 (15%), and moderate in 5 (25%) patients with summer-type HP.

CONCLUSIONS

GL for HP showed utility in diagnosing humidifier lung in many patients with a moderate to low confidence. However, there was a definite to high confidence for patients with summer-type HP.

Acute Exacerbation and Proposed Criteria for Progressive Pulmonary Fibrosis in Patients with Fibrotic Hypersensitivity Pneumonitis and Idiopathic Pulmonary Fibrosis

BACKGROUND

Acute exacerbation (AE) occasionally develops in the course of fibrotic hypersensitivity pneumonitis (HP).

OBJECTIVE

The aim of the study was to compare AE of fibrotic HP with that of idiopathic pulmonary fibrosis (IPF).

METHODS

Consecutive patients with pathologically confirmed fibrotic HP and IPF diagnosed based on a multidisciplinary discussion were included in the analysis. AE in patients with fibrotic HP and IPF was evaluated retrospectively.

RESULTS

This study included 309 and 160 patients with fibrotic HP and IPF, respectively. Their 50% survival times were 96.1 and 78.0 months, respectively (hazard ratio [HR]: 0.54 [95% confidence interval, CI: 0.36-0.77], log-rank test; p < 0.001). Notably, the cumulative AE rates of fibrotic HP were 3% at 1 year and 10% at 3 years. Moreover, the corresponding rates of IPF were 8% at 1 year and 20% at 3 years (HR: 0.66 [95% CI: 0.45-0.93], log-rank test; p = 0.034). The 90-day survival rates from the AE onset of fibrotic HP and IPF were 75% and 64%, respectively (HR: 0.51 [95% CI: 0.31-0.83], log-rank test; p = 0.006). The respiratory function test on the physiological criteria of progressive pulmonary fibrosis (PPF) was a predictor of AE in fibrotic HP. However, the high-resolution CT (HRCT) changes in the criteria of PPF were not. Nevertheless, both the physiological and radiological criteria of PPF were a predictor of AE of IPF.

CONCLUSION

AE of fibrotic HP has a lesser prognostic effect than that of IPF. HRCT criteria for PPF were not a risk factor for AE in patients with fibrotic HP.

An unexpected and unusual cause of pulmonary hypertension in a patient with hypersensitivity pneumonitis: a partial anomalous pulmonary venous connection causing pulmonary artery hypertension

Partial anomalous pulmonary venous connection (PAPVC) occurs when any pulmonary vein, but not all, drains directly into the right atrium or its venous tributaries. PAPVC can very rarely present as an individual cause of pulmonary artery hypertension. Here we are presenting the case of a 41-year-old farmer with a history of exertional dyspnea for the past 3 years, which increased over 6 months. Chest high-resolution computed tomography was suggestive of non-fibrotic hypersensitivity pneumonitis. Hence, the patient was started on systemic steroids, with which the patient's oxygen saturation improved. On 2D echocardiography, the right ventricle systolic pressure was 48 + right atrial pressure. Right heart catheterization showed a mean pulmonary artery pressure of 73 mmHg and pulmonary vascular resistance of 8.7. On further evaluation, a computed tomography pulmonary angiogram was done, which surprisingly revealed the left superior pulmonary vein draining into the left brachiocephalic vein.

Fibrotic Hypersensitivity Pneumonitis Diagnosed by a Re-evaluation with Bronchoalveolar Lavage at Disease Deterioration

A 79-year-old man was admitted with worsening cough, dyspnea, and increased ground-glass opacity on chest computed tomography (CT). He had been diagnosed with idiopathic pulmonary fibrosis given the absence of an identifiable cause of interstitial pneumonia, chest CT findings, and absence of lymphocytosis in bronchoalveolar lavage (BAL) fluid. Meticulous history taking revealed extensive exposure to inciting antigens contained in chicken fertilizer before symptom worsening. A re-evaluation with BAL showed lymphocytosis, and clinical improvement with antigen avoidance confirmed the diagnosis of fibrotic hypersensitivity pneumonitis (fHP). A re-evaluation with BAL at disease deterioration after possible exposure to inciting antigen can facilitate a correct fHP diagnosis.

Inhalational lung diseases

The term inhalational lung disease comprises a group of entities that develop secondary to the active aspiration of particles. Most are occupational lung diseases. Inhalational lung diseases are classified as occupational diseases (pneumoconiosis, chemical pneumonitis), hypersensitivity pneumonitis, and electronic-cigarette-associated lung diseases. The radiologic findings often consist of nonspecific interstitial patterns that can be difficult to interpret. Therefore, radiologists' experience and multidisciplinary teamwork are key to ensure correct evaluation. The role of the radiologist is fundamental in preventive measures as well as in diagnosis and management, having an important impact on patients' overall health. It is crucial to take into account patients' possible exposure to particles both at work and at home.

Hypersensitivity Pneumonitis Caused by Exposure to a Gray Parrot (Psittacus erithacus)

A 73-year-old woman complaining of cough and dyspnea was admitted to our hospital. High-resolution computed tomography chest revealed patchy ground-glass attenuation in the upper lung field. The patient suffered an asthma attack and was diagnosed with allergic pneumonitis; prednisolone was administered for treatment. Bird-related hypersensitivity pneumonitis was suspected, as she had a gray parrot (Psittacus erithacus) and a budgerigar (Melopsittacus undulatus) at home. An immunoblotting analysis with the patient's serum demonstrated IgG-binding fractions to the gray parrot's feathers only; no binding was noted with the budgerigar antigens. The patient was conclusively diagnosed with hypersensitivity pneumonitis related to exposure to a gray parrot.

[Comparative pathomorphological characteristics of idiopathic pulmonary fibrosis and fibrotic hypersensitivity pneumonitis]

The paper presents an X-ray morphological differential diagnosis of idiopathic pulmonary fibrosis (IPF) and fibrotic hypersensitivity pneumonitis (FHP). It describes the etiology, pathogenesis, radiological signs, and pathoanatomy of IPF and FHP. For differential diagnosis, radiological and morphological signs were studied in 105 patients with IPF and in 111 patients with FHP. The mean ages of patients with IPF or FHP were 65.0±8.9 and 48.9±12.3 years, respectively. The history of IPF to the moment of its diagnosis ranged from 1 to 18 months, while that of FHP was 35 to 79 days. The authors describe the additional morphological signs of FHP: delicate collagen fibrosis; smooth muscle metaplasia in the interalveolar septa and fibrotic areas; fibroblastic foci mainly in the walls of bronchioles; plasma cell infiltration of interalveolar septa with a touch of neutrophils and eosinophils. A table has been compiled for differential diagnosis according to the morphological signs of IPF and FHP.

Texture-based classification of lung disease patterns in chronic hypersensitivity pneumonitis and comparison to clinical outcomes

Computer-aided detection algorithms applied to CT lung imaging have the potential to objectively quantify pulmonary pathology. We aim to develop an automatic classification method based on textural features able to classify healthy and pathological patterns on CT lung images and to quantify the extent of each disease pattern in a group of patients with chronic hypersensitivity pneumonitis (cHP), in comparison to pulmonary function tests (PFTs).27 cHP patients were scanned via high resolution CT (HRCT) at full-inspiration. Regions of interest (ROIs) were extracted and labeled as normal (NOR), ground glass opacity (GGO), reticulation (RET), consolidation (C), honeycombing (HB) and air trapping (AT). For each ROI, statistical, morphological and fractal parameters were computed. For automatic classification, we compared two classification methods (Bayesian and Support Vector Machine) and three ROI sizes. The classifier was therefore applied to the overall CT images and the extent of each class was calculated and compared to PFTs. Better classification accuracy was found for the Bayesian classifier and the 16x16 ROI size: 92.1±2.7%. The extent of GGO, HB and NOR significantly correlated with forced vital capacity (FVC) and the extent of NOR with carbon monoxide diffusing capacity (DLCO).Clinical Relevance- Texture analysis can differentiate and objectively quantify pathological classes in the lung parenchyma and may represent a quantitative diagnostic tool in cHP.

Hypersensitivity pneumonitis in a slaughterhouse worker: A case report

This case report describes a 60-year-old male, who presented to the Respiratory Outpatient Unit due to dyspnea on exertion and persistent dry cough, worsened during the preceding 6 months. He was nonsmoker with an otherwise unremarkable medical history and had been working in a sheep/goat slaughterhouse for the last 25 years. He recalled a number of episodes of flu-like symptoms in the past that subsided without any specific treatment. Given the compatible occupational history, the radiologic pattern in chest High-Resolution Computed Tomography and the Bronchoalveolar Lavage subpopulation analysis, hypersensitivity pneumonitis was diagnosed, and the patient was advised to leave temporarily his current occupational activity. Four weeks later, clinical and functional improvement was observed. A permanent job change was subsequently suggested, and sustained improvement was confirmed during his follow-up at 3 months.

Bronchoalveolar lavage and serum KL-6 concentrations in chronic hypersensitivity pneumonitis: correlations with radiological and immunological features

Chronic hypersensitivity pneumonitis (cHP) is a fibrotic interstitial lung disease (ILD) resulting from inhalation of different organic substances and chemical compounds determining an inflammatory and immunological response in sensitized individuals. KL-6, a human mucin protein expressed by type 2 pneumocytes, has been proposed as a prognostic biomarker of cHP. Assessment of usefulness KL-6 in ILD has been investigated primarily in Asiatic population. The aim of this study was to evaluate clinical utility of KL-6 in serum and bronchoalveolar lavage (BAL). In this study, we retrospectively analysed clinical, radiological and immunological data of a cohort of 42 patients affected by cHP: KL-6 concentrations were collected from serum and BAL. KL-6 clinical value was assessed through the analysis of association between KL-6 concentrations and clinical, functional, immunological and radiological features. KL-6 serum concentration results increased in 28/34 patients (82%). A positive direct correlation was observed between KL-6 concentrations in BAL and serum (r = 0.62, p < 0.05). In our study population we found that patients with extensive presence of ground glass opacities and centrilobular nodules at high-resolution computed tomography (HRCT) showed the highest concentrations of KL-6 in BAL and a predominantly CD3+ CD8+ BAL lymphocytosis. BAL lymphocytosis and KL-6 concentrations showed a direct correlation. BAL KL-6, a result of alveolar damage, caused in cHP by CD3+ CD8+ mediated flogosis and suggested by radiological evidence of ground-glass opacities and centrilobular nodules, can be considered a useful biomarker to assess, along with BAL cellular analysis and HRCT findings, disease activity.

Histology is critical but not always for the diagnosis of chronic hypersensitivity pneumonitis

BACKGROUND

The diagnosis of chronic hypersensitivity pneumonitis (CHP) is often based on the pathology, but evidence is scarce that a pathological diagnosis of CHP may mislead the multidisciplinary diagnosis.

METHOD

We enrolled patients from the consultation case archive whose pathological findings were suggestive of CHP but had a multidisciplinary diagnosis of non-CHP. The histopathological slides were sent to another pathologist, and the ones confirmed with CHP were sent for an additional multidisciplinary discussion (MDD). We examined clinicopathological features of the cases confirmed to be non-CHP through MDD.

RESULTS

Among the 243 cases, five were diagnosed as non-CHP through an additional MDD. The most common causes of discrepancy were the presence of strong autoimmune features, a low lymphocyte level in the bronchoalveolar lavage fluid, and a lack of nodular shadow or mosaic attenuation on computed tomography.

CONCLUSIONS

Cases of suspected CHP on pathology may be determined to be non-CHP through MDD.

Analysis of bronchoalveolar lavage samples collected from 30 patients with drug-induced pneumonitis

BACKGROUND

Drug-induced pneumonitis is a disease encountered by pulmonologists in the clinical setting. The diagnosis generally considers the patient's clinical course and the results of peripheral blood tests, radiological examinations, and often bronchoscopic examinations. However, few studies have reported the association between radiological patterns such as ground-glass opacity (GGO) or consolidation, and bronchoalveolar lavage fluid (BALF) cell fractions. This study aimed to clarify this association.

METHODS

Patients with a Naranjo's score of probable or definite were enrolled, and all 30 patients were categorized under probable. Data such as patient background, blood examination results, radiological findings, and BALF cell fractions were retrospectively collected. The association between BALF cell fractions and other factors such as chest computed tomography (CT) findings was evaluated.

RESULTS

The most common radiological finding in patients with lymphocyte-dominant BALF was GGO, with only one patient exhibiting consolidation. However, patients with eosinophil-dominant BALF were more likely to have consolidation; only three cases showed crazy paving and one showed GGO. In addition, patients with a GGO-dominant pattern on CT had an increased lymphocyte fraction of 41.0%; those with a consolidation-dominant pattern showed a relatively high eosinophil fraction of 5.2%; and those with a crazy paving pattern showed elevated eosinophil and neutrophil fractions of 19.1% and 9.9%, respectively.

CONCLUSIONS

In this study, a remarkable difference in radiological findings was observed among different BALF patterns.

Characteristics and outcomes of patients hospitalized with interstitial lung diseases in Spain, 2014 to 2015

To assess characteristics and outcomes of patients hospitalized with interstitial lung diseases (ILD) and to analyze patient's comorbidities, procedures, and in-hospital outcomes.We identified patients hospitalized with idiopathic pulmonary fibrosis and others ILD such as hypersensitivity pneumonitis, cryptogenic organizing pneumonia, lymphangioleiomyomatosis, pulmonary Langerhans cell histiocytosis, and sarcoidosis in Spain during 2014 and 2015.We identified 14,565 discharges among patients admitted for ILD in Spain during the study period: idiopathic pulmonary fibrosis (IPF) in 42.32% (n = 6164), sarcoidosis in 37.65% (n = 5484), hypersensitivity pneumonitis in 10.55% (n = 1538), cryptogenic organizing pneumonia in 7.06% (n = 1028), pulmonary Langerhans cell histiocytosis in 1.48% (n = 215), and lymphangioleiomyomatosis in 0.94% (n = 136). The most common associated comorbidities according to those included in the Charlson Comorbidity Index (CCI) were COPD, diabetes, and congestive heart disease. The presence of pulmonary hypertension increased the probability of dying in patients with idiopathic pulmonary fibrosis (OR 1.36; 95%CI 1.06-1.73). Patients with cryptogenic organizing pneumonia had the longest length of hospital stay and the highest percentage of hospital readmissions (23.64%). The highest IHM corresponded to the idiopathic pulmonary fibrosis (14.94%). Computed tomography of the chest was the procedure more used during admissions for ILD.IPF was responsible for larger percentage of hospital admission among ILD in our study. In addition, the IHM were higher in IPF patients in comparison with those with other ILD. The most common associated comorbidity in ILD according to those included in the CCI was COPD. Computed tomography of the chest was the procedure more frequently used.

The natural history of progressive fibrosing interstitial lung diseases

A proportion of patients with certain types of interstitial lung disease (ILD), including chronic hypersensitivity pneumonitis and ILDs associated with autoimmune diseases, develop a progressive fibrosing phenotype that shows similarities in clinical course to idiopathic pulmonary fibrosis. Irrespective of the clinical diagnosis, these progressive fibrosing ILDs show commonalities in the underlying pathogenetic mechanisms that drive a self-sustaining process of pulmonary fibrosis. The natural history of progressive fibrosing ILDs is characterized by decline in lung function, worsening of symptoms and health-related quality of life, and early mortality. Greater impairment in forced vital capacity or diffusion capacity of the lungs for carbon monoxide, and a greater extent of fibrotic changes on a computed tomography scan, are predictors of mortality in patients with fibrosing ILDs. However, the course of these diseases is heterogenous and cannot accurately be predicted for an individual patient. Data from ongoing clinical trials and patient registries will provide a better understanding of the clinical course and impact of progressive fibrosing ILDs.

Marijuana medusa: The many pulmonary faces of marijuana inhalation in adolescent males

Marijuana use has risen dramatically over the past decade. Over this same time period, pediatric hospitals have seen an increase in presentation of adolescents with acute respiratory symptoms after recent marijuana inhalation. We report a case series of three adolescent males with significant findings of bilateral pulmonary nodules and ground glass opacities on chest imaging associated with recent marijuana inhalation. Lung biopsies in two of the three patients confirmed silica-induced pneumoconiosis. The third patient was diagnosed with acute hypersensitivity pneumonitis without lung biopsy. Improvement in clinical symptoms and lung function testing were noted in two of three patients after marijuana inhalation cessation. This case series highlights the variety of severe pulmonary presentations in adolescents following recent marijuana inhalation. Future studies are required to assess whether these presenting pulmonary complications are from direct marijuana exposure or indirect associations with marijuana inhalation injuries.

Radiation Pneumonitis with Eosinophilic Alveolitis in a Lung Cancer Patient

A 59-year-old woman suffering from dry cough and dyspnea was admitted to our hospital. She had undergone concurrent chemo-radiotherapy five months earlier. Chest computed tomography revealed bilateral ground-glass opacities extending outside the irradiated lung field. Her eosinophil numbers were increased in both the peripheral blood and the bronchoalveolar lavage fluid; therefore, she was diagnosed with radiation pneumonitis accompanied by eosinophilic alveolitis. Steroid therapy promptly improved the pneumonitis. Radiation pneumonitis accompanied by eosinophilic alveolitis extending outside the irradiated field is rare. Bronchoalveolar lavage is useful for a diagnosis, and steroid therapy is effective for treatment.

Functional associations of pleuroparenchymal fibroelastosis and emphysema with hypersensitivity pneumonitis

BACKGROUND

Pleuroparenchymal fibroelastosis (PPFE) has been described in hypersensitivity pneumonitis (HP) yet its functional implications are unclear. Combined pulmonary fibrosis and emphysema (CPFE) has occasionally been described in never-smokers with HP, but epidemiological data regarding its prevalence is sparse. CTs in a large HP cohort were therefore examined to identify the prevalence and effects of PPFE and emphysema.

Methods

233 HP patients had CT extents of interstitial lung disease (ILD) and emphysema quantified to the nearest 5%. Lobar percentage pleural involvement of PPFE was quantified on a 4-point categorical scale: 0 = absent, 1 = affecting <10%, 2 = affecting 10–33%, 3 = affecting >33%. Marked PPFE reflected a total lung score of ≥3/18. Results were evaluated against FVC, DLco and mortality.

RESULTS

Marked PPFE prevalence was 23% whilst 23% of never-smokers had emphysema. Following adjustment for patient age, gender, smoking status, and ILD and emphysema extents, marked PPFE independently linked to reduced baseline FVC (p = 0.0002) and DLco (p = 0.002) and when examined alongside the same covariates, independently linked to worsened survival (p = 0.01).

CPFE in HP demonstrated a characteristic functional profile of artificial lung volume preservation and disproportionate DLco reduction. CPFE did not demonstrate a worsened outcome when compared to HP patients without emphysema beyond that explained by CT extents of ILD and emphysema.

CONCLUSIONS

PPFE is not uncommon in HP, and is independently associated with impaired lung function and increased mortality. Emphysema was identified in 23% of HP never-smokers. CPFE appears not to link to a malignant microvascular phenotype as outcome is explained by ILD and emphysema extents.

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In patients with HP, marked PPFE had a prevalence of 23% in our study cohort.

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23% of never-smokers with HP demonstrated emphysema on CT imaging.

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Outcome in HP patients with CPFE is explained by CT extents of ILD and emphysema.

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PPFE is independently associated with a worsened outcome in HP.

[Hypersensitivity pneumonitis and idiopathic pulmonary fibrosis - case report]

Hypersensitivity pneumonitis (HP), called extrinsic allergic alveolitis, is a syndrome characterized by diffuse inflammation of lung parenchyma and airways in response to the inhalation of antigens to witch the patient has been previously sensitized. The clinical presentation of HP have been categorized as acute, subacute and chronic. The patient with chronic HP may lack a history of acute episodes and usually reports the insidious onset of cough, dyspnoea, fatigue, and weight los. Idiopathic pulmonary fibrosis (IPF) is a type of lung disease that results in scarring (fibrosis) of the lungs for an unknown reason. Symptoms of IPF are the same as in chronic hypersensitivity pneumonitis and differentiation may be difficult. We present a case of patient with chronic HP, in whom the course of the end stage of the disease mimic acute exacerbations idiopathic pulmonary fibrosis.

Spectrum of interstitial lung disease from a tertiary care hospital in Karachi

OBJECTIVE

To determine the clinical features and patterns of interstitial lung disease.

METHODS

This retrospective study was conducted at the Aga Khan University Hospital, Karachi, and comprised record of patients diagnosed with interstitial lung disease from January 2005 to December 2015. All patients aged 16 years and above diagnosed with interstitial lung disease on the basis of clinical features, radiological features on high-resolution computed tomography of the chest, and lung biopsies were included. SPSS 19 was used for data analysis.

RESULTS

Of the 537 patients, 324(60.3%) of the participants were females. The overall mean age was 60.5±14.9 years. The most common co-morbid condition was diabetes mellitus in 72(13.4%) patients, followed by hypertension in 48(8.9%) and ischaemic heart disease in 21(3.9%). The most common interstitial lung disease was idiopathic pulmonary fibrosis in 217(40.4%) patients, followed by non-specific interstitial pneumonia in 106(19.7%), sarcoidosis in 82(15.3%) and connective tissue disease-related interstitial lung disease in 56(10.4%) patients.

CONCLUSIONS

Idiopathic pulmonary fibrosis was found to be the most common interstitial lung disease subtype followed by non-specific interstitial pneumonia, sarcoidosis and connective tissue disease-related-interstitial lung disease.

High-resolution CT predictors of hypersensitivity pneumonitis

BACKGROUND

The purpose of this study was to evaluate the use of high-resolution chest computed tomography (HRCT) to distinguish hypersensitivity pneumonitis (HP) from other diffuse parenchymal lung diseases (DPLDs).

METHODS

We examined 130 consecutive patients admitted to our hospital with DPLDs proved by HRCT. Patients underwent clinical and paraclinical examinations. Two readers interpreted 111 HRCT scans using predefined criteria.

RESULTS

The findings in patients with HP were compared to those with other DPLDs (non-HP) by univariate and multivariate analyses. Five independent radiological predictors were identified and were given a weight according to their regression coefficient: ground-glass attenuation nodules (4 points), homogeneous ground-glass opacity (3 points), patchy ground-glass opacity (2 points), absence of adenopathy (2 points), and absence of linear/reticular patterns (2 points). A total score (that we called "diagnostic index") of 5 offered the best trade-off between sensitivity and specificity. At this point of the ROC curve, the sensitivity, specificity, and likelihood ratio were 74%, 90% and 7.7, respectively. Given a pre-test probability of HP of 34% (i.e., 38 HP / 111 patients), the post-test probability was 79%.

CONCLUSION

Our results provide evidence that HRCT can accurately distinguish HP from other DPLDs.

[Quincke's edema and hypersensitivity pneumonitis induced by lenalidomide for multiple myeloma]

A 64-year-old man with recurrent multiple myeloma (BJP-κ type) was treated with 15 mg of lenalidomide (LEN) and dexamethasone. He developed Quincke's edema on his eyelid on day 4. Since the edema improved after withdrawal of LEN, the drug was subsequently re-administered at a decreased dose. However, the edema developed again on day 4. After withdrawal of LEN, the drug was administered again with gradually dose escalation, while confirming the absence of eyelid edema. Although edema did not develop, eosinophils and basophils were increased, and the CRP level was elevated. During the third course of LEN administration, his chest CT showed bilateral ground-glass opacity, and LEN-induced hypersensitivity pneumonitis was diagnosed. The pneumonitis resolved after LEN withdrawal and prednisolone administration. These observations suggested that Quincke's edema, eosinophilia and basophilia, CRP elevation, and hypersensitivity pneumonitis might occur due to the immunological effects of LEN, which is classified as an immunomodulatory drug.

[Prolonged disease in a farmer with simultaneous Q fever pneumonia and subacute hypersensitivity pneumonitis]

This case report describes the first incident of a patient with simultaneous occurrence of Q fever pneumonia and subacute hypersensitivity pneumonitis (HP). The 52-year-old patient was from his occupation as a farmer exposed to agents causing both diseases. Except for a weight loss in subacute/chronic incidents of HP the symptoms of Q fever and HP are similar. However, differences in CT findings and histopathology make it possible to differentiate between the two diseases. This report highlights the importance of a thorough occupational history.

[Severe interstitial lung disease due to treatment with infliximab and azathioprine]

A 41-year-old man developed severe interstitial lung disease (ILD) after treatment with infliximab (IFX) and azathioprine (AZA). A relapse of ulcerative colitis was treated with corticosteroids (CS) and IFX as rescue therapy. Following remission AZA was given as prophylaxis. AZA was initiated the same day as the third infusion of IFX (week 6). Within a few days he developed signs of lung involvement progressing into severe ILD. A high resolution computed tomography showed subacute hypersensitive pneumonitis. He was treated with oxygen and high dose CS. After three months his state of health had returned to normal.

[Hypersensitivity pneumonitis related to Penicillium chrysogenum and mesophilic Streptomyces: the usefulness of the Medical Indoor Environment Councelor (MIEC)]

Hypersensitivity pneumonitis (HP) occurred after organic antigens inhalation at home is rare and the diagnosis is very often difficult. We report the case of a 55-year male patient with allergic asthma since childhood, well controlled with inhaled corticosteroids, twice hospitalized for respiratory distresses. The patient presented fever (39°C), dry cough, rapidly progressive dyspnea, chest pain and crackles. Blood gas analysis found a hypoxemia of 52 mmHg, and CT-scan showed ground glass images in the upper lobes. Respiratory function tests showed severe obstructive syndrome and a decrease of diffusion test. HP was suspected because the symptoms were triggered by domestic environmental. The Medical Indoor Environment Councelor (MIEC) visited the patient's house and camper and performed air and dust samples. Moldy walnuts were found in the camper. The identification of microorganisms present in the air and on the surfaces in the camper was used for serum precipitins research by double diffusion (DD) and electrosyneresis (E) methods. From the 14 antigens tested, serological tests were considered significant for mesophilic Streptomyces (five arcs DD, six arcs E) and Penicillium chrysogenum (one arc DD, four arcs E). After removal from the camper of the objects suspected to be contaminated, the patient's symptoms regressed. This is a typical case of domestic HP to mesophilic Streptomyces and P. chrysogenum. The MIEC's intervention was useful in both diagnosis and treatment.

High-resolution computed tomography findings for patients with drug-induced pulmonary toxicity, with special reference to hypersensitivity pneumonitis-like patterns in gemcitabine-induced cases

BACKGROUND

Gemcitabine (GEM) is widely used as a chemotherapeutic agent. However, pulmonary toxicity has been rarely observed with GEM use. This article aims to determine the incidence and causes of drug-induced pulmonary toxicity, and to classify the high-resolution computed tomography (HRCT) findings for antitumor therapy-associated pulmonary toxicity based on characteristic patterns and pathological considerations, with a special focus on GEM-associated pulmonary toxicity (GAPT).

METHODS

Medical records of all patients with drug-induced pulmonary toxicity seen at Kyorin University hospital between April 2006 and December 2011 were retrospectively reviewed. The study examined correlations between HRCT and the assessed pathological or clinical findings, with a specific focus on antitumor drugs.

RESULTS

We identified 66 patients with drug-induced pulmonary toxicity. Among the antitumor drugs, GEM was the primary offending agent (n = 8) for pulmonary toxicity followed by docetaxel and gefitinib. HRCT patterns for the eight GAPT patients included the non-specific interstitial pneumonia (NSIP; n = 5) and the hypersensitivity pneumonitis (HP)-like pattern (n = 3). In contrast, four patients in the study were found to have the HP-like pattern, with three cases associated with GEM and one case associated with imatinib mesylate. The transbronchial lung biopsy or video-assisted thoracic surgery specimens for these patients showed granuloma or organizing tissue with a random distribution that was independent of the respiratory bronchiole. These results appeared to correspond to the HRCT-determined centrilobular nodules.

CONCLUSION

GEM was the leading cause of drug-induced pulmonary toxicity in the patients examined in this study. This toxicity appears as NSIP or an HP-like pattern during HRCT examinations. This HP-like pattern may be useful for diagnosing GEM-induced pulmonary toxicity, as well as demonstrating granuloma or organizing tissue during lung pathology examinations.

[Pathologic diagnosis and clinical analysis of chronic extrinsic allergic alveolitis]

OBJECTIVE

To study the clinicopathologic features and diagnostic approach of chronic extrinsic allergic alveolitis (EAA).

METHODS

Seven cases of chronic EAA diagnosed by open lung biopsy or lung transplant were enrolled into the study. The clinical and pathologic features were analyzed and the literature was reviewed.

RESULTS

There were altogether 4 men and 3 women. The age of the patients ranged from 30 to 65 years (mean = 48 years). All cases represented chronic form and five cases diagnosed by open lung biopsy also showed features of recent aggravation, leading to hospitalization. Four cases had known history of exposure to inciting gases, pollens and pets, and only 2 cases were positive for allergens. High-resolution CT scan showed ground-glass attenuation and reticular pattern that often had a patchy distribution and central predominance. Bronchoalveolar lavage analysis showed marked lymphocytosis, with CD4(+)/CD8(+) ratio less than 1. Lung function test demonstrated a restrictive ventilatory defect, with decreased compliance, reduced diffusion capacity and high airway obstruction. Five cases had open lung biopsy performed and two cases had undergone lung transplantation. Pathologic examination showed bronchiolocentric cellular interstitial pneumonia, interstitial fibrosis, non-caseating epithelioid granulomas, epithelioid histiocytic infiltrate in the respiratory bronchioles and intraluminal budding fibrosis. The five cases with open lung biopsy performed also showed neutrophilic infiltrate in the alveoli. The two lung transplant cases were complicated by severe fibrotic changes.

CONCLUSIONS

Chronic EAA demonstrates characteristic pathologic features. Definitive diagnosis requires correlation with clinical and radiologic findings due to possible morphologic mimicry of other diffuse parenchymal lung diseases.

[A case of acute hypersensitivity pneumonia in a worker at a feather duvet factory]

A 44-year-old woman was admitted to our hospital because of a 15-month history of exertional dyspnea, nonproductive cough and fever. Thoracic high-resolution computed tomography (HRCT) showed centrilobular ground-glass opacities distributed in bilateral lung fields. She had worked at a down quilt factory and had been exposed to a large amount of feathers for 5 years. A peripheral lymphocyte proliferation test by positive was positive for pigeon serum. We diagnosed bird-related hypersensitivity pneumonia. After quitting her job, improvement of her clinical symptoms and chest imaging findings were observed and she has been free of relapse.

[Diffuse pulmonary infiltrates--challenging diagnosis]

The diagnostics of diffuse pulmonary infiltrates is based on high-resolution computed tomography of the lungs. In typical cases, this technique can usually be applied to diagnose IPF, sarcoidosis and allergic alveolitis quite reliably. Radiological findings in several interstitial pulmonary diseases are, however, overlapping and the diseases may involve atypical manifestations. Analysis of tomographic images requires an experienced radiologist.

Chemical pneumonitis and acute lung injury caused by inhalation of nickel fumes

A 50-year-old man with a 30-year occupational history of welding presented with low-grade fever, fatigue and persistent dry cough. Computed tomography (CT) of the chest revealed interlobular septal thickening and bilateral non-segmental patchy ground-glass opacities except in the sub-pleural zone. He revealed that he had inhaled nickel fumes 3 days previously at work. These findings suggested a diagnosis of pneumonitis induced by inhalation of nickel fumes. Fewer reports describe pneumonitis associated with the inhalation of nickel compared with zinc fumes. Although nickel compounds are particularly pernicious among the transition metals and more toxic than zinc compounds, nickel fume inhalation rarely induces lethal acute respiratory distress syndrome. Our patient was successfully treated with corticosteroid.

[Valuation of diagnostic methods of pneumonia alveolitis]

The aim of this study was to identify effectiveness of modern complex of roentgenological, endoscopic, functional, citomorphologic and immunological methods in diagnosis of alveolitis. Between May-June 2002 and July-August 2003 the single-stage diagnosis was conducted among 1192 workers (400 - Siasan broiler, 391 - Baku flour mill and 401 - tobacco from Gabala zone). The patients with the diagnosis of various forms alveolitis were examined. 89 patients with symptoms of tympanal, acrocyanosis, tachycardia, tarnished glass effect, vascular lungs deformation were selected. Cough, short breath, crackling, infiltrative and cystous changes in lungs, acceleration of erythrocyte sedimentation rate (ESR) up to 27-36 mm/hour on average, decrease of total lung capacity, lymphocyte reaction, opacity, symptom of honeycomb lung and alteration in mucous of lung were considered as auxiliary factors. The investigation proofed that computed tomography was an effective technique for the diagnosis of alveolitis; the diagnostic reliability of computed tomography for the evaluation of various forms of alveolitis was 100%.

[Chest high resolution CT features of extrinsic allergic alveolitis and its diagnostic value]

OBJECTIVE

To summarize the chest high-resolution CT (HRCT) features of the patients with extrinsic allergic alveolitis (EAA).

METHODS

We analyzed the images of chest HRCT of 34 patients diagnosed as EAA at our hospital from February 2001 to August 2009.

RESULTS

All patients had a history of environmental exposure. The duration of intermittent or continuous antigen exposure was from 3 months to 13 years. Two patients showed acute clinical manifestations. There were 22 sub-acute and 10 chronic cases. Acute EAA was characterized by ground-glass opacities, air trapping and/or mosaic sign on HRCT. The HRCT features of subacute EAA included patchy ground-glass opacities with mosaic sign (n = 11, 50.0%) and diffusely distributed centrilobular nodules (n = 7, 31.8%) with mosaic sign (n = 4, 18.2%). All patients with chronic EAA had reticular and honeycombing lesions on HRCT. There were 3 cases with ground-glass opacities, 3 with mosaic sign, and 3 with centrilobular nodules.

CONCLUSION

The typical findings of chest HRCT are helpful for making a diagnosis and differential diagnosis of EAA.

A case of hard metal lung disease resembling a hypersensitive pneumonia in radiological images

A 42-year-old man was admitted to our hospital because of exertional dyspnea. He had worked as a metal grinder for 3 years, but had quit his job 1 month before admission. Chest radiography and high-resolution computed tomography showed diffuse ground-glass opacities like hypersensitivity pneumonitis shadows. The results of high-energy dispersion X-ray microanalysis indicated that the patient had hard metal pneumoconiosis associated with tungsten. Since the histological changes distributed terminal to respiratory bronchiole and surrounding alveoli, and macrophages engulfed black granules within the alveoli, in absence of giant cells, we considered this case to be a type of hypersensitivity pneumonitis of hard metal lung.

[Three cases of isocyanate-induced hypersensitivity pneumonitis with different HRCT findings]

We reported 3 cases of hypersensitivity pneumonitis who had been exposed to polyurethane material containing diphenylmethane diisocyanate (MDI) for 1-12 weeks. They had cough, fever and dyspnea before admission. All 3 cases were diagnosed immunologically using anti-MDI antibodies. Chest HRCT findings of the 3 cases were different. Case 1 showed an organizing pneumonia (OP) pattern : patchy peripheral consolidation with air bronchogram and ground-glass opacities (GGO), and case 2 showed a nonspecific interstitial pneumonia (NSIP) pattern : consolidation and reticular shadows in both lower lobes. In addition, case 3 showed a hypersensitivity pneumonitis (HP) pattern : centrilobular GGO and diffuse granular shadows. All cases were successfully treated by corticosteroids alone. This suggests that different amounts of inhaled antigen can cause different HRCT findings.

[Comparative study of different diagnostic methods in pulmonary alveolitis]

To evaluate and analyze, clinical and roentgenological manifestations of extrinsic allergic alveolitis (EAA) and idiopathic fibrosing alveolitis (IFA) 89 patients underwent bronchoscopy survey and functional test of lungs. Average age of patients was 38,3+/-5,8. Among examined 89 patients 31 (34,8%) patients were poultry farmers, 30 (33,7%) - millers, and 28 (31,5%) - tobacco-growers. EAA was found among 22 poultry farmers, 19 tobacco-growers, and 19 millers. IFA was found among 11 millers, 9 tobacco-growers and 9 poultry farmers. Acute respiratory disease (ARD) was found among 58 patients; 38 patients suffer from lung diseases. Control group consisted of 20 healthy people. Along with general blood analysis, all patients underwent - roentgenological analysis of thorax in two shifts. Recent studies show that CT lung screening is more sensitive than standard lung screening methods in detecting lung disease. Comparative analysis allowed concluding that Real-Time CT method is the most effective. CT lung screening is more sensitive than standard lung screening methods in detecting lung diseases.

[Two cases of summer-type hypersensitivity peumonitis with remarkable changes in the bronchioles]

A 56-year-old man and a 53-year-old woman with cough, sputum and dyspnea were admitted in the summer. High-resolution computed tomographic findings of the chest showed centrilobular branching opacities like diffuse panbronchiolitis with ground glass opacities. Both cases showed hypoxia, a high titer of serum anti-Tricosporon antibody and exacerbation in their own homes. Video-assisted thoracoscopic lung biopsy revealed granuloma in the bronchioles area. We diagnosed summer type hypersensitivity pneumonitis and this condition improved in response to antigen isolation and steroids. Remarkable changes in the bronchioles were characteristic in the two cases.