Mechanisms of pulmonary disease in F344 rats after workplace-relevant inhalation exposure to cross-linked water-soluble acrylic acid polymers.

BACKGROUND: Recently in Japan, six workers at a chemical plant that manufactures resins developed interstitial lung diseases after being involved in loading and packing cross-linked water-soluble acrylic acid polymers (CWAAPs). The present study focused on assessing lung damage in rats caused by workplace-relevant inhalation exposure to CWAAP and investigated the molecular and cellular mechanisms involved in lung lesion development. METHODS: Using a whole-body inhalation exposure system, male F344 rats were exposed once to 40 or 100 mg/m3 of CWAAP-A for 4 h or to 15 or 40 mg/m3 of CWAAP-A for 4 h per day once per week for 2 months (9 exposures). In a separate set of experiments, male F344 rats were administered 1 mg/kg CWAAP-A or CWAAP-B by intratracheal instillation once every 2 weeks for 2 months (5 doses). Lung tissues, mediastinal lymph nodes, and bronchoalveolar lavage fluid were collected and subjected to biological and histopathological analyses. RESULTS: A single 4-h exposure to CWAAP-A caused alveolar injury, and repeated exposures resulted in regenerative changes in the alveolar epithelium with activation of TGFß signaling. During the recovery period after the last exposure, some alveolar lesions were partially healed, but other lesions developed into alveolitis with fibrous thickening of the alveolar septum. Rats administered CWAAP-A by intratracheal instillation developed qualitatively similar pulmonary pathology as rats exposed to CWAAP-A by inhalation. At 2 weeks after intratracheal instillation, rats administered CWAAP-B appeared to have a slightly higher degree of lung lesions compared to rats administered CWAAP-A, however, there was no difference in pulmonary lesions in the CWAAP-A and CWAAP-B exposed rats examined 18 weeks after administration of these materials. CONCLUSIONS: The present study reports our findings on the cellular and molecular mechanisms of pulmonary disease in rats after workplace-relevant inhalation exposure to CWAAP-A. This study also demonstrates that the lung pathogenesis of rats exposed to CWAAP-A by systemic inhalation was qualitatively similar to that of rats administered CWAAP-A by intratracheal instillation.

Dose-response relationship of pulmonary disorders by inhalation exposure to cross-linked water-soluble acrylic acid polymers in F344 rats.

BACKGROUND: In Japan, six workers handling cross-linked water-soluble acrylic acid polymer (CWAAP) at a chemical plant suffered from lung diseases, including fibrosis, interstitial pneumonia, emphysema, and pneumothorax. We recently demonstrated that inhalation of CWAAP-A, one type of CWAAP, causes pulmonary disorders in rats. It is important to investigate dose-response relationships and recoverability from exposure to CWAAPs for establishing occupational health guidelines, such as setting threshold limit value for CWAAPs in the workplace. METHODS: Male and female F344 rats were exposed to 0.3, 1, 3, or 10 mg/m3 CWAAP-A for 6 h/day, 5 days/week for 13 weeks using a whole-body inhalation exposure system. At 1 h, 4 weeks, and 13 weeks after the last exposure the rats were euthanized and blood, bronchoalveolar lavage fluid, and all tissues including lungs and mediastinal lymph nodes were collected and subjected to biological and histopathological analyses. In a second experiment, male rats were pre-treated with clodronate liposome or polymorphonuclear leukocyte-neutralizing antibody to deplete macrophages or neutrophils, respectively, and exposed to CWAAP-A for 6 h/day for 2 days. RESULTS: CWAAP-A exposure damaged only the alveoli. The lowest observed adverse effect concentration (LOAEC) was 1 mg/m3 and the no observed adverse effect concentration (NOAEC) was 0.3 mg/m3. Rats of both sexes were able to recover from the tissue damage caused by 13 weeks exposure to 1 mg/m3 CWAAP-A. In contrast, tissue damage caused by exposure to 3 and 10 mg/m3 was irreversible due to the development of interstitial lung lesions. There was a gender difference in the recovery from CWAAP-A induced pulmonary disorders, with females recovering less than males. Finally, acute lung effects caused by CWAAP-A were significantly reduced by depletion of alveolar macrophages. CONCLUSIONS: Pulmonary damage caused by inhalation exposure to CWAAP-A was dose-dependent, specific to the lung and lymph nodes, and acute lung damage was ameliorated by depleting macrophages in the lungs. CWAAP-A had both a LOAEC and a NOAEC, and tissue damage caused by exposure to 1 mg/m3 CWAAP-A was reversible: recovery in female rats was less than for males. These findings indicate that concentration limits for CWAAPs in the workplace can be determined.

A case report of pulmonary Botrytis sp. infection in an apparently healthy individual.

BACKGROUND: Botrytis species are well known fungal pathogens of various plants but have not been reported as human pathogens, except as allergenic precipitants of asthma and hypersensitivity pneumonitis. CASE PRESENTATION: The asymptomatic patient was referred because of a nodule revealed by chest X-ray. Computed tomography (CT) showed a cavitary nodule in the right upper lobe of the lung. He underwent wedge resection of the nodule, which revealed necrotizing granulomas and a fungus ball containing Y-shaped filamentous fungi, which was confirmed histopathologically. Culture of the specimen yielded white to grayish cotton-like colonies with black sclerotia. We performed multilocus gene sequence analyses including three single-copy nuclear DNA genes encoding glyceraldehyde-3-phosphate dehydrogenase, heat-shock protein 60, and DNA-dependent RNA polymerase subunit II. The analyses revealed that the isolate was most similar to Botrytis elliptica. To date, the pulmonary Botrytis sp. infection has not recurred after lung resection and the patient did not require any additional medication. CONCLUSIONS: We report the first case of an immunocompetent patient with pulmonary Botrytis sp. infection, which has not recurred after lung resection without any additional medication. Precise evaluation is necessary for the diagnosis of pulmonary Botrytis infection because it is indistinguishable from other filamentous fungi both radiologically and by histopathology. The etiology and pathophysiology of pulmonary Botrytis infection remains unclear. Further accumulation and analysis of Botrytis cases is warranted.

Grade 4 asbestosis does not extend directly from the respiratory bronchiole to the peripheral lung.

AIMS: To confirm whether or not grade 4 asbestosis progresses from the respiratory bronchiole to the peripheral lung. METHODS AND RESULTS: We examined retrospectively the autopsy or lobectomy specimens from 31 cases (29 males; mean age 64 years) satisfying the pathological criteria of grade 4 asbestosis. Asbestos bodies (ABs) were quantified in samples of dissolved lung and in tissue preparations on glass slides. Respiratory bronchiolar lesions were graded as 0, 1 and ≥2. Grade 4 asbestosis was subdivided into an atelectatic induration (AI) and usual interstitial pneumonia pattern (UIP pattern). Five, 10, and 16 cases had grades 0, 1 or ≥2 lesions, respectively, with mean respective numbers of ABs in dissolved lung of 117 000/g dry lung, 468 000/g and 968 000/g; and in specimens on glass slides of seven ABs/cm2 of tissue slice, 34 ABs /cm2 and 195 ABs /cm2 . The differences were significant. Fifteen and 16 cases showed AI and UIP patterns, respectively, with mean respective numbers of ABs in dissolved lung of 1 006 000/g dry lung and 354 000/g, and 186 and 56 ABs/cm2 on glass slides. The differences were significant. AI patterns originated in subpleural lobules or subpleural zonal areas and UIP patterns originated in subpleural, peripheral lobules. CONCLUSIONS: Grade 4 asbestosis does not start in the respiratory bronchiole. The presence of a grade 1 lesion is not required for the diagnosis of grade 4 asbestosis.

Pemetrexed-related interstitial lung disease reported from post marketing surveillance (malignant pleural mesothelioma/non-small cell lung cancer).

BACKGROUND: Interstitial lung disease (ILD) is important drug related toxicity because it commonly forced to discontinue the treatment. METHODS: To characterize the prevalence and patterns of pemetrexed induced ILD, an independent ILD advisory board composed of external experts performed reassessment of ILD in two post marketing surveillance (PMS) studies for malignant pleural mesothelioma (MPM) and non-small cell lung cancer (NSCLC). RESULTS: ILD incidences were originally 1.6% and 2.6% in 903 MPM and 683 NSCLC patients in safety analyses, respectively. Based on the reassessment by the board, the incidence was 1.1% MPM and 1.8% NSCLC. Common possible risk factors of ILD in MPM and NSCLC patients were male gender, 60 years or older age, and pre-existing ILD. Asbestosis in MPM, and smoking history in NSCLC are also considered as risk, respectively. In terms of computed tomography (CT) pattern, 7 of 10 cases in MPM patients had acute interstitial pneumonia pattern, which four were fatal. Eight of the 12 NSCLC patients had diffuse grand glass opacity, which all had recovered. Onset of ILD in MPM varied between the first and the fifth courses of pemetrexed treatment, and the latest onset was 48 days after the last administration. For NSCLC, it was between the second and the ninth course, 7 and 56 days after the last administration. CONCLUSIONS: The risk of pemetrexed-related ILD is similar level as other anti-cancer drugs under clinical settings. Careful observations continuously during and at least for 2 months after the last administration of pemetrexed are advised.

Hypereosinophilic syndrome as a cause of fatal thrombosis: two case reports with histological study.

Herein we present two cases of hypereosinophilic syndrome with a unique clinical presentation. One patient showed severe systemic thrombosis with splenic rupture and the other patient showed finger gangrene with various systemic symptoms. Both patients were examined histologically, and several characteristics were noted. First, fresh or organized thrombosis with marked eosinophilic infiltration was observed in the cavity and walls of the thrombosed vessels. Second, many eosinophils showed degranulation and were positive for eosinophilic cationic protein on immunohistological examination. Third, the structures of thrombosed vessels were well preserved, which is not observed in systemic vasculitis. These patients exhibited no neoplastic features and were treated with prednisolone with excellent therapeutic results.

Two recurrent types of IGH::5' BCL2 breakpoints representing cytogenetic ins(14;18)(q32;q21q21) and t(14;18)(q32;q21), mediated by the VDJ and class switch recombination processes, respectively.

We describe two types of IGH::BCL2 breakpoints involving the 5' region of BCL2 (5' BCL2). One was ins(14;18)(q32;q21q21) observed in 2 follicular lymphoma (FL) cases, in which IGH was cleaved at 3' of IGHD and 5' of IGHJ and BCL2 was cleaved at 5' BCL2 and downstream regions, and a 281- or 201-kilobase pair fragment containing the BCL2 protein-coding sequences was invertedly inserted into IGH. In another type observed in 2 FL and 2 chronic lymphocytic leukemia (CLL) cases, breakage and reunion occurred within the switch region associated with IGHM (Sµ) and 5' BCL2, creating IGH Sµ::5' BCL2 fusion sequences on der(18)t(14;18)(q32;q21). The former is considered to be mediated by VDJ-recombination, while the latter by the class switch recombination process. There were no particular features in FL or CLL cases with IGH::5' BCL2 breakpoints compared with those with t(14;18)(q32;q21)/IGH::BCL2 involving the 3' breakpoint cluster regions.

Histopathological significance of connective tissue disease-associated interstitial lung disease in transbronchial lung cryobiopsy specimens.

Differentiating between idiopathic interstitial pneumonia (IIP) and secondary interstitial pneumonia, particularly connective tissue disease-associated interstitial lung disease (CTD-ILD), can be challenging histopathologically, and there may be discrepancies among pathologists. While surgical lung biopsy has traditionally been considered the gold standard for diagnosing interstitial pneumonia, the usefulness of transbronchial lung cryobiopsy (TBLC) has been reported. If TBLC could effectively distinguish between primary and secondary diseases, it would provide a less invasive option for patients. The aim of this study was to identify specific pathologic findings in TBLC specimens that could assist in distinguishing CTD-ILD from IIP. A total of 93 underwent TBLC at Tenri Hospital between 2018 and 2022. We retrospectively reviewed cases of CTD-ILD exhibiting a nonspecific interstitial pneumonia (NSIP) pattern (CTD-NSIP) and cases of NSIP with an unknown etiology (NSIP-UE), as determined through multidisciplinary discussion. Nineteen patients with CTD-NSIP and 26 patients with NSIP-UE were included in the study for clinicopathological analysis. The CTD-NSIP group had a significantly higher proportion of female patients compared to the NSIP-UE group (79% vs. 31%; p = 0.002). The presence of both fresh and old intraluminal fibrosis within the same TBLC specimen was significantly more frequent in CTD-NSIP group than in the NSIP-UE group (p = 0.023). The presence of an NSIP pattern with co-existing fresh and old intraluminal fibrosis in TBLC specimens raised suspicion for CTD-ILD.

Respiratory disease in workers handling cross-linked water-soluble acrylic acid polymer.

Eight workers involved in packing cross-linked water-soluble acrylic acid polymer, an organic substance, developed pulmonary fibrosis, and the upper lobe was the most affected. The dust concentration in the polymer packing workstation was measured. Chest computed tomography (CT) was obtained for 82 individuals, including the 8 workers mentioned above. Three workers were histopathologically examined. In six of these eight workers, central pulmonary fibrosis and secondary bulla formation caused pneumothorax. Histopathologically, multiple centrilobular fibrotic foci were observed. Chest CT revealed centrilobular nodular opacity and interlobular septal thickening, suggesting early lesions in the workers because the dust concentration was remarkably high. Although the pathogenesis of the disease is unclear, we reported the occurrence of pulmonary fibrosis caused by the exposure to cross-linked water-soluble acrylic acid polymers in humans as it has not been reported earlier.

Molecular cloning of two novel mucin-like genes in the disease-susceptibility locus for diffuse panbronchiolitis.

Diffuse panbronchiolitis (DPB) is a rare complex genetic disease affecting East Asians and is strongly associated with the class I human leukocyte antigens (HLA)-B54 in Japanese and HLA-A11 in Koreans. We recently showed that an HLA-associated major susceptibility gene for DPB is probably located within the 200 kb in the class I region 300 kb telomeric of the HLA-B locus on the chromosome 6p21.3. We cloned two novel mucin-like genes designated panbronchiolitis related mucin-like 1 and 2 (PBMUCL1 and PBMUCL2) in the candidate region, which form a mucin-like gene cluster together with two adjacent genes, MUC21 and DPCR1. PBMUCL1 gene expression was remarkably upregulated by polyinosine-polycytidylic acid [poly(I:C)] stimulation in normal human bronchial epithelial cells redifferentiated at the air-liquid interface. We found genetic polymorphisms in PBMUCL1 gene which were associated with DPB: the A-allele of the PBMUCL1 intron 2 single nucleotide polymorphism (SNP) was positively associated and variable numbers of tandem repeats (VNTR) polymorphism in exon 3 (1,890-base pair deletion) was negatively associated. Despite a strong association with HLA-B in the Japanese, the mucin-like gene PBMUCL1 is also one of the candidate genes of DPB susceptibility.

Erdheim-Chester disease presenting with pneumothorax.

Erdheim-Chester disease (ECD) is a rare non-Langerhans cell histiocytosis most commonly characterized by symmetrical skeletal involvement and may present with pulmonary involvement leading to chronically progressive pulmonary symptoms. Characteristics on chest radiography include non-specific findings of diffuse interstitial and pleural thickening, micronodules, ground-glass opacities and parenchymal condensation as a result of infiltration by lipid-laden histiocytes. We present the case of a 50-year-old man with ECD presenting with acute pulmonary symptoms due to rupture of a large cystic lesion with resultant pneumothorax. He was brought by ambulance to our hospital, complaining of acute anterior chest pain and severe dyspnea. Chest radiography showed right-sided pneumothorax with a collapsed lung, a large, left-sided cystic lesion in the upper lung field and accentuated interstitial markings. Bullectomy and surgical biopsy were performed, demonstrating histologically histiocytic infiltrates that were strongly positive for CD68, but negative for S-100 protein and CD1a. Subsequent systemic examinations indicated widespread symmetrical skeletal involvement, leading to a definitive diagnosis of ECD.

Molecular profile of apomucin and p53 protein as predictors of malignancy in intraductal papillary mucinous neoplasms of the pancreas.

BACKGROUND/AIMS: Invasive intraductal papillary mucinous neoplasms (IPMNs) of the pancreas show poor prognosis similar to ductal adenocarcinomas. The aim of this study was to evaluate the molecular indicators of invasion and risk factors of recurrence of IPMNs. METHODOLOGY: For 46 curative resections of IPMNs, we analyzed the expression of apomucin antigens (MUC1, MUC2 and MUC5AC), p53 and Ki67 using resected specimens. RESULTS: All 46 IPMNs were classified into 4 groups; MUC1+/p53+, MUC1+/p53-, MUC2+ and MUC1-/MUC2-. The incidence of MUC1 expression increased according to the grade of dysplasia and all of 5 invasive carcinomas expressed MUC1. None of the invasive carcinoma, but almost half of IPMNs of non-invasive carcinoma and sever dysplasia expressed MUC2. Additionally, p53 expression was limited to invasive IPMNs and a non-invasive IPMN which recurred after the operation. The Ki67 labeling index was increased according to the grade of dysplasia and was highest in the MUC1+/p53+ group. In the MUC2+ cases, Ki67 labeling index was significantly higher than that in the MUC1-/MUC2- cases. MUC5AC was expressed in all IPMNs. CONCLUSIONS: The expression of MUC1, MUC2 and p53 might be indicators of malignancy and the expressions of MUC1 and p53 were the predictors of tumor invasion and recurrence.

[A case of respiratory bronchiolitis-associated interstitial lung disease].

A 37-year-old man was referred to our hospital with a cough. His blood test result and chest radiography findings were normal. High resolution chest computed tomography (HRCT) showed diffuse ground glass attenuation (GGA) with centrilobular distribution in the bilateral upper lung fields. As diagnosis could not be made using transbronchial lung biopsy and bronchoalveolar lavage, video-assisted lung biopsy was performed. The histological findings were a thickening of the alveolar walls with infiltration of lymphocyte-dominant inflammatory cells, and exudation of pigmented macrophages in the air spaces of the respiratory bronchioles and alveolis. We diagnosed his illness as respiratory bronchiolitis-associated interstitial lung disease. Six months after stopping smoking, his symptoms, and the GGA on chest HRCT improved.

[A case of lymphomatoid granulomatosis which initially demonstrated a diffuse ground glass appearance].

Lymphomatoid granulomatosis is defined as an Epstein-Barr virus-associated B-cell lymphoma which possibly progresses to malignant lymphoma. The pulmonary lesions associated with this disease typically reveal multiple poorly defined nodules. A 71-year-old man with acute respiratory failure consulted a local doctor. A chest CT scan demonstrated a bilateral lower ground glass appearance. The shadow improved after pulse steroid therapy but it showed multiple nodules after the corticosteroid treatment was tapered. We finally diagnosed lymphomatoid granulomatosis (grade 2) based on the findings of a thoracoscopic lung biopsy. Pathologically, an angiocentric proliferation of large atypical lymphoid cells were observed which were positive for EBER (EBV-encoded small RNA). We herein report the details of this case because of its rare radiographic findings.

Combination of multicolor flow cytometry for circulating lymphoma cells and tests for the RHOAG17V and IDH2R172 hot-spot mutations in plasma cell-free DNA as liquid biopsy for the diagnosis of angioimmunoblastic T-cell lymphoma.

We applied two-step multicolor flow cytometry (FCM) for circulating lymphoma cells in the blood of 20 patients with angioimmunoblastic T-cell lymphoma (AITL) and confirmed neoplastic T-cells in all. Eleven exhibited dim expression of CD3 and 7 lost its expression. The proportion of CD10+ lymphoma cells ranged widely from 0 to 100%, with a median of 15.7%. Ten patients demonstrated expansion of a single T-cell receptor ß-chain repertoire. Lymphoma cells comprised 0.01 to 18.22% (median, 0.26%) of white cells and the absolute numbers ranged from 0.5 to 1491.6 cells (median, 29.3 cells) per microliter of blood. We next found that 14 (70%) and 3 (15%) patients carried RHOAG17V and IDH2R172 mutations, respectively, in cell-free DNA (cfDNA) in the plasma. The combination of multicolor FCM of the blood, and tests for RHOAG17V and IDH2R172 hot-spot mutations in plasma cfDNA provides a blood-based 'liquid biopsy' for the diagnosis of AITL.

[Hypersensitivity pneumonitis caused by isocyanate exposure during recreational painting].

A 36-year-old man began painting his car as a hobby every weekend in early February 2007 using a paint containing isocyanate. In March, 2007, he developed a dry cough, dyspnea and fever of 40 degrees C. These symptoms appeared repeatedly several hours after engaging in painting activity. His chest X-ray film showed diffuse small granular and reticular shadows in bilateral lung fields. His computed tomogram showed ground glass images in bilateral lung fields. Pulmonary function tests showed significantly decreased DLco. Histological findings of transbronchial lung biopsy revealed cellular interstitial pneumonia. These symptoms improved after cessation of painting and administration of prednisolone. Based on these results, we diagnosed this patient's illness as hypersensitivity pneumonitis due to isocyanate exposure.

[Long-term follow up study of four cases of pulmonary Langerhans' cell histiocytosis].

We reported the clinical features of 4 cases with pulmonary Langerhans' cell histiocytosis. All of them were men who had a history of smoking. They ranged in age from 23 to 46 years. Cases 1 and 3 did not stop smoking, while Cases 2 and 4 did stop smoking. All of the chest CTs revealed small nodules and cysts, and during the follow-up period of 8 to 13 years, the numbers of nodules decreased and the walls of the cysts became thin in all of the cases. Their pulmonary function tests revealed restrictive impairment in 3 cases and reduced diffusion capacity in 2 cases, but none showed obstructive impairment. FEV1% and DL(CO) deteriorated during the follow-up period. Case 1 died of respiratory failure after 8 years. Cases 2 and 4 were both alive with home oxygen therapy after 11 and 12 years, respectively. Case 3 was alive but complained of dyspnea on exertion after 13 years. In conclusion, all of the 4 cases showed deterioration of pulmonary function, and one of them died due to respiratory failure. The prognosis of patients with pulmonary Langerhans' cell histiocytosis appears to be poor.

Preoperative evaluation of malignancy in intraductal papillary mucinous neoplasms of the pancreas, especially in relation to dysplastic epithelial changes.

BACKGROUND/AIMS: Intraductal papillary mucinous neoplasms have a better prognosis than ductal adenocarcinomas of the pancreas. The aim of this study was to evaluate the malignant potential of IPMNs by their preoperative images. METHODOLOGY: Forty-three intraductal papillary mucinous neoplasms were divided into 3 duct ectatic types using preoperative images (the main duct type, the branch duct type, and the mixed type), and into 2 groups using resected specimens (the malignant group including severe dysplasia based on the WHO classification and the benign group). The diameters of the tumor, main pancreatic duct and mural nodule were measured on the images. RESULTS: Two thirds of main duct type cases were in the malignant group. For the branch duct and mixed types, the diameters of the tumor and detectable mural nodules were larger in the malignant group than in the benign group. A tumor diameter larger than 3.5cm and a mural nodule diameter larger than 6mm were risk factors for malignancy (p < 0.05). CONCLUSIONS: The main duct type, a tumor larger than 3.5cm of the branch duct or mixed type, and a mural nodule larger than 6mm were all indicators of malignancy risk.