Impact of partial pressure of arterial oxygen and radiologic findings on postoperative acute exacerbation of idiopathic interstitial pneumonia in patients with lung cancer.

PURPOSE: To establish accurate diagnostic criteria and predictors of treatment response for postoperative acute exacerbation (AE) in patients with lung cancer and idiopathic interstitial pneumonia (IIP). METHODS: Among 93 patients with IIP who underwent surgery for lung cancer, suspected postoperative AE developed in 20 (21.5%). Patients were divided into a progressive AE group, comprising patients with bilateral alveolar opacities and decreasing PaO2 ≥ 10 mmHg (n = 5); an incipient AE group, comprising patients with unilateral alveolar opacities and decreasing PaO2 ≥ 10 mmHg (n = 10); and an indeterminate AE group, comprising patients with alveolar opacities but decreasing PaO2 < 10 mmHg (n = 5). RESULTS: The progressive AE group had significantly higher 90-day mortality (80%) than the incipient AE group (10%, P = 0.017) or the indeterminate AE group (0%, P = 0.048). Bilateral opacities may indicate advanced AE and poor prognosis, whereas unilateral opacities may indicate an early stage of AE and a good prognosis. PaO2 < 10 mmHg may indicate conditions other than AE. CONCLUSIONS: In patients with lung cancer and IIP, decreasing PaO2 and HRCT findings may allow for the initiation of rapid and accurate treatment strategies for postoperative AE.

Outcomes of lung cancer surgery for patients with interstitial pneumonia and coronary disease.

PURPOSE: To evaluate the surgical outcomes of lung cancer patients with idiopathic interstitial pneumonia (IIP) and/or coronary artery disease (CAD). METHODS: The subjects of this retrospective study were 2830 patients who underwent surgical resection for lung cancer between 2009 and 2018. Seventy-one patients (2.6%) had both IIP and CAD (FC group). The remaining patients were divided into those with IIP only (group F), those with CAD only (group C), and those without IIP or CAD (group N). We compared mortality and overall survival (OS) among the groups. RESULTS: The 90-day mortality and OS were poorer in group FC than in groups C and N, but equivalent to those in group F. Multivariate analyses revealed that IIP (odds ratio [OR] 3.163; p = 0.001) and emphysema (2.588; p = 0.009) were predictors of 90-day mortality. IIP (OR 2.991, p < 0.001), diabetes (OR 1.241, p = 0.043), and a history of other cancers (OR 1.347, p = 0.011) were all predictors of OS. CONCLUSIONS: Short-term and long-term mortality after lung cancer surgery were not dependent on coexistent CAD but were related to IIP. Thus, computed tomography (CT) should be done preoperatively to check for IIP, which is a risk factor for surgical mortality.

Idiopathic Interstitial Pneumonias and COVID-19 Pneumonia: Review of the Main Radiological Features and Differential Diagnosis.

COVID-19 pneumonia represents a challenging health emergency, due to the disproportion between the high transmissibility, morbidity, and mortality of the virus and healthcare systems possibilities. Literature has mainly focused on COVID-19 pneumonia clinical-radiological diagnosis and therapy, and on the most common differential diagnoses, while few papers investigated rare COVID-19 pneumonia differential diagnoses or the overlapping of COVID-19 pneumonia on pre-existing lung pathologies. This article presents the main radiological characteristics of COVID-19 pneumonia and Idiopathic Interstitial Pneumonias (IIPs) to identify key radiological features for a differential diagnosis among IIPs, and between IIPs and COVID-19 pneumonia. COVID-19 pneumonia differential diagnosis with IIPs is challenging, since these entities may share common radiological findings as ground glass opacities, crazy paving patterns, and consolidations. Multidisciplinary discussion is crucial to reach a final and correct diagnosis. Radiologists have a pivotal role in identifying COVID-19 pneumonia patterns, reporting possible overlapping with long-lasting lung diseases, and suggesting potential differential diagnoses. An optimal evaluation of HRTC may help in containing the disease, in promoting better treatment for patients, and in providing an efficient allocation of human and economic resources.

Central paradiaphragmatic middle lobe involvement in nonspecific interstitial pneumonia.

OBJECTIVES: Nonspecific interstitial pneumonia (NSIP) lacks specific diagnostic guidelines or criteria for imaging diagnosis, and the need for more reliable computed tomography (CT) characterization remains. We hypothesized that central paradiaphragmatic middle lobe (ML) involvement is present in most patients with NSIP. The purpose of this study was to evaluate the prevalence of ML involvement and thus to assess its potential as a unique feature of NSIP. METHODS: We conducted a retrospective CT-imaging review of 40 patients with biopsy-proven (7/40, 18%) or clinically established (33/40, 82%) NSIP. Three subspecialty-trained thoracic radiologists reviewed CTs for ML involvement both independently and in consensus, and additional CT findings previously described in NSIP independently. RESULTS: ML involvement was present in most cases (70%, 28/40, independent review, 78%, 31/40, consensus reading), with substantial agreement among all three readers (κ = 0.65). Fibrosis was present in almost all cases (93%, 37/40). Subpleural sparing occurred in one-third of patients (30%, 12/40). Homogeneity (48%, 19/40), central bronchiectasis (45%, 18/40), and peripheral bronchiectasis (53%, 21/40) were present in about half of patients. Apart from substantial inter-reader agreement on fibrosis (κ = 0.65), the above-mentioned imaging characteristics had fair to slight universal agreement (κ = 0.07-0.30). CONCLUSIONS: Central paradiaphragmatic ML ground glass attenuation superimposed on reticulation and traction bronchiectasis occurs in most patients with NSIP, with high interobserver agreement. KEY POINTS: • Central paradiaphragmatic middle lobe ground glass attenuation superimposed on reticulation and traction bronchiectasis is common in nonspecific interstitial pneumonia (NSIP). • This finding occurs more frequently than subpleural sparing and has a better interobserver agreement.

Correlation between preoperative 18F-FDG PET/CT findings and postoperative short-term prognosis in lung cancer patients with idiopathic interstitial pneumonia after lung resection.

BACKGROUND: The present study aimed to investigate the correlation between preoperative 2-deoxy-2-[18F]fluoro-d-glucose (18F-FDG) PET/CT findings and short-term survival in lung cancer patients with idiopathic interstitial pneumonia (IIP). METHODS: We retrospectively reviewed the data of 425 patients who underwent lung resection for non-small cell lung cancer without preoperative radiation therapy between November 2012 and October 2017. The maximum SUV (SUVmax) in the IIP area except the lung cancer site was measured in each patient. RESULTS: Thirty-one of the 425 patients (7.3%) showed findings of IIP in chest CT. Five of the 31 patients (16.1%) developed acute exacerbation (AE) after lung resection (AE+ group). Twenty-six of the 31 patients (83.9%) did not develop AE (AE- group). In the AE+ group, 18F-FDG SUVmax in the IIP area was significantly higher (1.9 ± 0.6 vs. 2.7 ± 0.7, p = 0.02) compared with that in the AE- group. The receiver operating characteristic analysis identified an SUVmax threshold score of 2.55 (p = 0.02) for AE. There was no 90-day mortality in the patients with SUVmax < 2.55 (n = 25). On the other hand, the 90-day mortality rate in patients with SUVmax ≥ 2.55 (n = 6) was 33.3% (2 patients). CONCLUSIONS: 18F-FDG PET/CT may predict AE after lung resection and could be related to short-term survival in lung cancer patients with IIP. Further investigations are needed to improve the prognosis in patients with high SUVmax in the IIP area.

Computed tomography findings of current nonspecific interstitial pneumonia based on the 2013 updated classification of idiopathic interstitial pneumonias: What is a characteristic of previously diagnosed nonspecific interstitial pneumonia excluded from the updated classification.

PURPOSE: To evaluate computed tomography (CT) findings of nonspecific interstitial pneumonia (NSIP) based on the current classification of idiopathic interstitial pneumonias (IIPs) and elucidate a characteristic of previously diagnosed NSIP excluded from the current classification. MATERIALS AND METHODS: The study included 74 patients with biopsy-proven NSIP (idiopathic NSIP [I-NSIP], 39 patients; NSIP associated with connective tissue disease [CTD-NSIP], 35 patients). Among patients who were compatible with the current classification of IIPs, 29 and 21 were categorized as having current I-NSIP and current CTD-NSIP, respectively. The remaining 24 patients were categorized as having previous I-NSIP or previous CTD-NSIP due to the primary pathologic diagnosis of cellular NSIP or associated findings of acute inflammatory changes. CT findings were evaluated and compared among the four groups. RESULTS: Current I-NSIP was indicated by ground-glass attenuation and reticulation with traction bronchiectasis/bronchiolectasis in predominantly peribronchovascular areas of the lower lung zone. The previous I-NSIP group tended to show broader airspace consolidation than the current I-NSIP group (p = 0.068). The previous CTD-NSIP group showed significantly broader airspace consolidation than the current I-NSIP group (p = 0.035). CONCLUSION: Broad airspace consolidation is a characteristic of previously diagnosed CTD-NSIP excluded from the current classification of IIPs.

The pathogenesis and pathology of idiopathic pleuroparenchymal fibroelastosis.

Idiopathic pleuroparenchymal fibroelastosis (IPPFE) is a rare subtype of idiopathic interstitial pneumonias that consists of elastofibrosis involving the lung parenchyma and pleural collagenous fibrosis predominantly located in the upper lobes. IPPFE has various distinct clinical and physiological characteristics, including platythorax and a marked decrease of forced vital capacity with an increased residual volume on a respiratory function test. The concept of IPPFE is now widely recognized and some diagnostic criteria have been proposed. In addition, the accumulation of cases has revealed the pathological features of IPPFE. However, little is known about the pathogenesis or the process of disease formation in IPPFE. This review article will provide a summary of the pathological features and previously reported hypotheses on disease formation in IPPFE, to discuss the potential etiologies and pathogenesis of IPPFE.

Clinical, radiological, and pathological evaluation of "NSIP with OP overlap" pattern compared with NSIP in patients with idiopathic interstitial pneumonias.

BACKGROUND: Nonspecific interstitial pneumonia (NSIP) and organizing pneumonia (OP) are major subtypes of idiopathic interstitial pneumonias (IIPs) and closely related to connective tissue diseases (CTDs). "NSIP with OP overlap" is a controversial finding that has recently appeared in the criteria of interstitial pneumonia with autoimmune features (IPAF). However, details of this controversial entity are not well known. OBJECTIVE: To determine the frequency of "NSIP with OP overlap" pattern in IIPs and to identify differences from idiopathic NSIP (iNSIP). METHODS: In 524 patients with interstitial pneumonia from 39 institutes who underwent surgical lung biopsy, 444 were diagnosed as IIPs by a multidisciplinary discussion meeting via a cloud-based integrated database. Among these patients, 44 (9.9%) who had iNSIP and 21 (4.7%) with histopathologically-defined "NSIP with OP overlap" pattern (a pathological NSIP and OP pattern, but without a UIP pattern) were retrospectively studied. RESULTS: Patients with "NSIP with OP overlap" pattern showed a significantly greater extent of consolidation (p < 0.001), more subpleural ground glass attenuation (p = 0.036), and more peripheral + bronchovascular distribution (p = 0.009) on high-resolution computed tomography than those with iNSIP. The incidences of newly-developed CTDs during follow-up was similar between the groups and polymyositis/dermatomyositis was the most frequent CTD in both groups. Nearly half of the patients fulfilled IPAF criteria, but no significant difference was found between iNSIP and "NSIP with OP overlap" pattern (47.7% vs. 42.9, p = 0.712). The incidence of acute exacerbation and the survival rates were similar between the groups. CONCLUSIONS: The incidence of "NSIP with OP overlap" pattern is 4.7% in IIPs. The frequency of newly-developed CTDs during follow-up, mainly polymyositis/dermatomyositis, the frequency of acute exacerbation, and the survival rate in "NSIP with OP overlap" pattern are similar to those of iNSIP.

Disease course and prognosis of pleuroparenchymal fibroelastosis compared with idiopathic pulmonary fibrosis.

BACKGROUND: Idiopathic pleuroparenchymal fibroelastosis (iPPFE) is a rare interstitial lung disease characterized by unique radiological and pathological findings. However, pathological evaluations are available only in a limited number of patients. Therefore, several clinical diagnostic criteria have been proposed. Nevertheless, the applicability of these criteria has not yet been validated. Moreover, the clinical course of iPPFE and its prognosis have not yet been completely elucidated. METHODS: The present study assessed previously proposed clinical diagnostic criteria by comparing the clinical features between pathologically diagnosed iPPFE (p-iPPFE) and clinically diagnosed iPPFE (c-iPPFE). Subsequently, the clinical features of iPPFE were characterized and compared with those of idiopathic pulmonary fibrosis (IPF, n = 323). RESULTS: Clinical characteristics of c-iPPFE (n = 27) and p-iPPFE (n = 35) were similar. No significant difference was observed in terms of prognosis between c-iPPFE and p-iPPFE. The number of patients with iPPFE (both c-iPPFE and p-iPPFE) who developed lung cancer was significantly lower than that of patients with IPF. However, acute exacerbation (AE) showed similar incidence in patients with iPPFE and IPF. Survival of patients with iPPFE was significantly worse than that of patients with IPF (5-year survival rate: 38.5% vs. 63.5%, p < 0.0001), and the most common cause of death was chronic respiratory failure (73.8%), followed by AE (14.3%). Male gender was the only poor prognostic factor of iPPFE. CONCLUSION: The present study demonstrated efficiency of clinical diagnosis and also revealed clinically important characteristics of iPPFE that should be considered for management of iPPFE.

The significance of multidisciplinary classifications based on transbronchial pathology in possible idiopathic interstitial pneumonias.

Surgical lung biopsy is regarded as the golden standard for the diagnosis of idiopathic interstitial pneumonias (IIPs). Here, we attempted to show the diagnostic accuracy of multidisciplinary classifications based on transbronchial pathology including transbronchial lung cryobiopsy (TBLC) , bronchoalveolar lavage fluid (BALF) and endobronchial ultrasound-guided transbronchial needle aspiration biopsy (EBUS-TBNA).Patients with suspected interstitial lung diseases admitted from June 1, 2016 to December 31, 2018 were involved. Patients with known causes of interstitial lung diseases and typical idiopathic pulmonary fibrosis diagnosed through clinical, radiological information were excluded. Patients with atypical idiopathic pulmonary fibrosis and possible IIPs accepted transbronchial pathological evaluation. Initial multidisciplinary diagnosis (MDD) classifications were made depending on clinical, radiological and transbronchial pathological information by a multidisciplinary team (MDT). The final MDD classifications were confirmed by subsequent therapeutic effects. All patients were followed up for at least 6 months.A total of 70 patients were finally involved. The samples of lung parenchyma extracted through TBLC were enough for confirmation of pathological diagnoses in 68.6% (48/70) cases. Samples of 6 cases were extracted by EBUS-TBNA. Bacteriological diagnoses were positive in 1 case by BALF. Pathological diagnoses of 77.1% (54/70) cases were achieved through TBLC, EBUS-TBNA and BALF. During the follow up study, the pulmonary lesions of 60% patients were improved, 11.43% were relapsed when glucocorticoid was reduced to small dose or withdrawal, 14.29% were leveled off and 8.57% were progressed. The diagnoses of 4 patients with progressed clinical feature were revised. As a result, 94.3% initial MDD classifications based on transbronchial pathology were consistent with the final MDD, and the difference of diagnostic yield wasn't significant between initial and final MDD (Z = -1.414, P = .157).Classifications of IIPs based on transbronchial pathology were useful and quite agreed with final MDD.

Delayed contrast dynamics as marker of regional impairment in pulmonary fibrosis using 5D MRI - a pilot study.

OBJECTIVE: To analyse delayed contrast dynamics of fibrotic lesions in interstitial lung disease (ILD) using five dimensional (5D) MRI and to correlate contrast dynamics with disease severity. METHODS: 20 patients (mean age: 71 years; M:F, 13:7), with chronic fibrosing ILD: n = 12 idiopathic pulmonary fibrosis (IPF) and n = 8 non-IPF, underwent thin-section multislice CT as part of the standard diagnostic workup and additionally MRI of the lung. 2 min after contrast injection, a radial gradient echo sequence with golden-angle spacing was acquired during 5 min of free-breathing, followed by 5D image reconstruction. Disease was categorized as severe or non-severe according to CT morphological regional severity. For each patient, 10 lesions were analysed. RESULTS: IPF lesions showed later peak enhancement compared to non-IPF (severe: p = 0.01, non-severe: p = 0.003). Severe lesions showed later peak enhancement compared to non-severe lesions, in non-IPF (p = 0.04), but not in IPF (p = 0.35). There was a tendency towards higher accumulation and washout rates in IPF compared to non-IPF in non-severe disease. Severe lesions had lower washout rate than non-severe ones in both IPF (p = 0.003) and non-IPF (p = 0.005). Continuous contrast agent accumulation, without washout, was found only in IPF lesions. CONCLUSIONS: Contrast agent dynamics are influenced by type and severity of pulmonary fibrosis, which might enable a more thorough characterisation of disease burden. The regional impairment is of particular interest in the context of antifibrotic treatments and was characterised using a non-invasive, non-irradiating, free-breathing method. ADVANCES IN KNOWLEDGE: Delayed contrast enhancement patterns allow the assessment of regional lung impairment which could represent different disease stages or phenotypes in ILD.

Cicatricial organizing pneumonia: a clinicopathologic and radiologic study on a cohort diagnosed by surgical lung biopsy at a single institution.

Cicatricial organizing pneumonia (CiOP) refers to intraluminal collagen deposition in a background of otherwise classic appearing organizing pneumonia (OP), sometimes with formation of peculiar fibrous nodules or densely fibrotic linear bands. Dendriform ossification has been also described in CiOP cases. This study is to evaluate the clinicopathologic and radiologic characteristics of CiOP identified in a cohort of OP cases diagnosed by surgical lung biopsy at a single institution. Electronic search was performed to find surgical lung biopsy cases with OP as the main histopathologic diagnosis during a 9-year period (2005-2013). The presence of mature collagen deposition in intraluminal plugs of OP (Masson bodies), linear fibrous bands, and ossification in association with OP was evaluated. Pertinent clinical information was obtained from medical records, and available chest computed tomography (CT) scans were reviewed by a chest radiologist. A total of 56 cases met the study criteria. Thirty-two of 56 cases (57.1%) showed at least 10% of cicatricial element within Masson bodies, 9 of which revealed cicatricial elements comprising 50% or higher proportion of OP. All 9 cases with CiOP as the major component (≥50%) revealed some areas of linear fibrous bands. Five of these 9 cases had intraluminal ossification, with features suggestive of dendriform ossification. Twenty of 32 cases with the cicatricial component had postoperative follow-up CT scans ranging from 0.4 to 171 months (median = 44) after the biopsy; 18 of these 20 cases showed stable finding or resolution of radiologic densities. Six of 9 patients with CiOP with major cicatricial change (≥50%) were alive and well at the time of clinical follow-up (median = 47 months; range = 12-125). In summary, minor cicatricial changes involving Masson bodies were seen in more than half of our OP cases, and patients with CiOP seem to follow an indolent and favorable course on radiologic and clinical follow-up, even in those with major cicatricial changes (≥50%) that were often accompanied by linear fibrous bands and/or intraluminal ossification.

Impact of radiological honeycombing in rheumatoid arthritis-associated interstitial lung disease.

BACKGROUND: Interstitial lung disease (ILD) is the most common and important pulmonary manifestation of rheumatoid arthritis (RA). A radiological honeycomb pattern has been described in diverse forms of ILD that can impact survival. However, the clinical course and sequential radiological changes in the formation of the honeycomb pattern in patients with RA-ILD is not fully understood. METHODS: We evaluated the sequential changes in computed tomography findings in 40 patients with chronic forms of RA-ILD without the honeycomb pattern at initial diagnosis. We classified the patients into the Non-honeycomb group and Honeycomb group, and then analyzed the characteristics and prognosis of the two groups. The term "honeycomb formation" indicated a positive finding of honeycombing on any available follow-up CT. RESULTS: Our RA-ILD cohort included patients with probable usual interstitial pneumonia (UIP) (35%), nonspecific interstitial pneumonia (NSIP) (20%), and mixed NSIP/UIP (45%). Among all RA-ILD patients, 16 (40%) showed honeycomb formation on follow-up CT (median time between initial and last follow-up CT was 4.7 years). Patient characteristics and prognosis were not significantly different between the Non-honeycomb and Honeycomb groups. However, Kaplan-Meier survival curve for the time from the date of honeycomb formation to death showed a poor median survival time of 3.2 years. CONCLUSIONS: A certain number of patients with RA-ILD developed a honeycomb pattern during long-term follow-up, regardless of whether they had UIP or NSIP. Prognosis in the patients with characteristics of both progressive ILD and honeycomb formation could be poor. Although radiological findings over the disease course and clinical disease behavior in RA-ILD are heterogenous, clinicians should be alert to the possibility of progressive disease and poor prognosis in patients with RA-ILD who form a honeycomb pattern during follow-up observation.

Probable usual interstitial pneumonia pattern on chest CT: is it sufficient for a diagnosis of idiopathic pulmonary fibrosis?

Recent studies have suggested that in patients with an idiopathic interstitial pneumonia (IIP), a probable usual interstitial pneumonia (UIP) pattern on chest computed tomography (CT) is sufficient to diagnose idiopathic pulmonary fibrosis (IPF) without histopathology.We retrospectively compared the prognosis and time to first acute exacerbation (AE) in IIP patients with a UIP and a probable UIP pattern on initial chest CT.One hundred and sixty IIP patients with a UIP pattern and 242 with a probable UIP pattern were identified. Probable UIP pattern was independently associated with longer survival time (adjusted hazard ratio 0.713, 95% CI 0.536-0.950; p=0.021) and time to first AE (adjusted hazard ratio 0.580, 95% CI 0.389-0.866; p=0.008). In subjects with a probable UIP pattern who underwent surgical lung biopsy, the probability of a histopathological UIP pattern was 83%. After multidisciplinary discussion and the inclusion of longitudinal behaviour, a diagnosis of IPF was made in 66% of cases. In IPF patients, survival time and time to first AE were not associated with CT pattern. Among subjects with a probable UIP pattern, compared to non-IPF patients, survival time and time to first AE were shorter in IPF patients.In conclusion, IIP patients with a probable UIP pattern on initial chest CT had a better prognosis and longer time to first AE than those with a UIP pattern. However, when baseline data and longitudinal behaviour provided a final diagnosis of IPF, CT pattern was not associated with these outcomes. This suggests diagnostic heterogeneity among patients with a probable UIP pattern.

Anaplastic lymphoma kinase inhibitor related pneumonitis in patients with non-small cell lung cancer: Clinical and radiologic characteristics and risk factors.

Anaplastic lymphoma kinase (ALK) inhibitor-related pneumonitis (ALK-IIP) is relatively rare but sometimes fatal, so the timely diagnosis of ALK-IIP is important for enabling prompt management. However, the detailed radiologic characteristics and clinical course of ALK-IIP are still unclear. This study was performed to investigate the clinical and radiologic characteristics and risk factors of ALK-IIP in patients with non-small cell lung cancer (NSCLC).A total of 250 NSCLC patients who had been treated with ALK inhibitors were retrospectively enrolled. Chest computed tomography (CT) was classified into 4 CT patterns using the 2013 guideline for idiopathic interstitial pneumonia: cryptogenic organizing pneumonia (COP), hypersensitivity pneumonitis (HP), acute interstitial pneumonia (AIP), and nonspecific interstitial pneumonia. Clinical characteristics including toxicity grading and treatment course were analyzed in regarding to CT patterns. Clinical characteristics were compared between patients with ALK-IIP and without ALK-IIP.ALK-IIP was identified in 11 patients (4.4%). The most common CT pattern was the COP pattern (n = 7, 63.6%) and followed by HP and AIP patterns (both, n = 2, 18.2%). ALK-IIP showed pneumonitis toxicity grade ranged from 1 to 4, and AIP pattern had the highest toxicity grade, followed by HP and COP patterns (median grade: 3.5, 2.5, 1). All of the patients with the COP pattern were successfully treated, while half of patients with the AIP pattern died during treatment. The smoking history and extrathoracic metastasis were more frequent in patients with ALK-IIP (P < .005). The smoking history was associated with a higher incidence of ALK-IIP (odds ratio: 3.586, 95% confidence interval: 1.058-13.432, P = .049).ALK-IIP showed a spectrum of chest CT patterns, which reflected the toxicity grades. The COP pattern was the most common CT pattern of ALK-IIP, and patients with ALK-IIP of the COP pattern were successfully treated. ALK inhibitors should be used with caution in NSCLC patients with smoking history.

MUC5B variant is associated with visually and quantitatively detected preclinical pulmonary fibrosis.

BACKGROUND: Relatives of patients with familial interstitial pneumonia (FIP) are at increased risk for pulmonary fibrosis. We assessed the prevalence and risk factors for preclinical pulmonary fibrosis (PrePF) in first-degree relatives of patients with FIP and determined the utility of deep learning in detecting PrePF on CT. METHODS: First-degree relatives of patients with FIP over 40 years of age who believed themselves to be unaffected by pulmonary fibrosis underwent CT scans of the chest. Images were visually reviewed, and a deep learning algorithm was used to quantify lung fibrosis. Genotyping for common idiopathic pulmonary fibrosis risk variants in MUC5B and TERT was performed. FINDINGS: In 494 relatives of patients with FIP from 263 families of patients with FIP, the prevalence of PrePF on visual CT evaluation was 15.6% (95% CI 12.6 to 19.0). Compared with visual CT evaluation, deep learning quantitative CT analysis had 84% sensitivity (95% CI 0.72 to 0.89) and 86% sensitivity (95% CI 0.83 to 0.89) for discriminating subjects with visual PrePF diagnosis. Subjects with PrePF were older (65.9, SD 10.1 years) than subjects without fibrosis (55.8 SD 8.7 years), more likely to be male (49% vs 37%), more likely to have smoked (44% vs 27%) and more likely to have the MUC5B promoter variant rs35705950 (minor allele frequency 0.29 vs 0.21). MUC5B variant carriers had higher quantitative CT fibrosis scores (mean difference of 0.36%), a difference that remains significant when controlling for age and sex. INTERPRETATION: PrePF is common in relatives of patients with FIP. Its prevalence increases with age and the presence of a common MUC5B promoter variant. Quantitative CT analysis can detect these imaging abnormalities.

The similarities and differences between pleuroparenchymal fibroelastosis and idiopathic pulmonary fibrosis.

The idiopathic form of pleuroparenchymal fibroelastosis (PPFE) is categorized as a rare idiopathic interstitial pneumonia in the current classification. The majority of PPFE cases are idiopathic, but many predisposing factors or comorbidities have been reported. Although histological PPFE is predominantly located in the upper lobes, which are less often affected by fibrosis in patients with idiopathic pulmonary fibrosis (IPF), the clinical course of PPFE is seemingly similar to that of IPF. However, upper lobe fibroelastosis has various clinical and physiological characteristics that differ from those of IPF, including a flattened thoracic cage and a marked decrease in the forced vital capacity (FVC) but with a preserved residual volume. Compared with IPF, the decrease in the walking distance is mild despite the markedly decreased FVC in PPFE, and chest radiograph more frequently shows the elevation of bilateral hilar opacities with or without tracheal deviation. The prognosis may be related to the development of fibrosing interstitial pneumonia in the lower lobes with elevated levels of serum Krebs von den Lungen-6; however, there is marked variation in the pathogenesis and clinical features in PPFE. A proposal of the diagnostic criteria for idiopathic PPFE with and without surgical lung biopsy, which has recently been published, may be useful.

Comparison of anti-aminoacyl-tRNA synthetase antibody-related and idiopathic non-specific interstitial pneumonia.

BACKGROUND AND PURPOSE: Patients with anti-aminoacyl-tRNA synthetase (ARS) antibodies frequently experience complications of interstitial pneumonia (ARS-IP), and the computed tomography (CT) of ARS-IP frequently shows nonspecific interstitial pneumonia (NSIP) pattern. The CT pattern of ARS-IP might be different from that of idiopathic IP. However, the clinical differences in patients with ARS-IP and idiopathic IP showing the similar CT patterns have not yet been well studied. The objective of this study was to evaluate the clinical differences between patients with ARS-NSIP and idiopathic NSIP (I-NSIP). METHODS: Two groups of 34 patients each, with ARS-NSIP and I-NSIP, who visited Hiroshima University Hospital between January 2005 and December 2017, were enrolled. Clinical features and outcomes were retrospectively compared between the two groups. RESULTS: The ARS-NSIP group included more female patients and significantly younger patients than the I-NSIP group. The percentage of lymphocytes in bronchoalveolar lavage fluid (BALF) was significantly higher, and the CD4/CD8 ratio in BALF was significantly lower in the ARS-NSIP group compared with the I-NSIP group. The proportion of patients with traction bronchiectasis detected by CT was significantly higher in I-NSIP compared with ARS-NSIP. The number of patients who received corticosteroid and/or immunosuppressant therapy was significantly larger in the ARS-NSIP group than in the I-NSIP group. In addition, the patients in the I-NSIP group who underwent the immunosuppressive therapy demonstrated shorter survival than those who underwent no treatment; this tendency was not observed in the ARS-NSIP group. The 10-year survival rate of patients in the ARS-NSIP group was significantly higher than that of patients in the I-NSIP group (91.8% vs. 43.0%; log-rank, p = 0.012). The multivariate survival analysis revealed that positive anti-ARS antibody was an independent favorable prognostic factor in the patients with NSIP (OR, [95% CI]:0.12 [0.02-0.55], p = 0.013). CONCLUSIONS: Patients with ARS-NSIP had a significantly better prognosis than those with I-NSIP; this may be associated with the sensitivity to immunosuppressive therapies, and the different findings of BALF and HRCT between the two groups.