The CCL2-CCR2 axis determines whether glomerular endocapillary hypercellularity or wire-loop lesions develop through glomerular macrophage and neutrophil infiltration in lupus nephritis.

The CCL2-CCR2 axis is involved in lupus nephritis, however the precise roles in the mechanisms by which different pathological lesions develop after glomerular immune complex deposition remain elusive. Previously, we demonstrated that genetic CCR2 inhibition induced a histological switch from glomerular endocapillary hypercellularity to wire-loop lesions in murine lupus nephritis. This study aimed to clarify the CCL2-CCR2 axis-mediated cellular mechanism in the formation of these different pathological lesions. We injected MRL/lpr mouse-derived monoclonal IgG3 antibody-producing hybridomas, 2B11.3 or B1, into wild-type (WT) mice to selectively induce glomerular endocapillary hypercellularity or wire-loop lesions. The expression of chemokine and chemokine receptors was analyzed using RT-quantitative PCR and/or immunofluorescence. We found 2B11.3 caused glomerular endocapillary hypercellularity in WT mice with glomerular infiltration of larger numbers of CCR2-expressing macrophages and neutrophils phagocyting immune complex, whereas B1 induced wire-loop lesions. In glomerular endocapillary hypercellularity, CCL2 was identified as the ligand involved in the CCR2-positive cell infiltration; it was expressed by glomerular endothelial cells and macrophages. Notably, 2B11.3-induced glomerular endocapillary hypercellularity converted to wire-loop lesions with reduced glomerular macrophage and neutrophil infiltration in CCL2-deficient (Ccl2-/-) mice similarly observed in Ccr2-/- mice. Moreover, this histological conversion was also observed when both glomerular macrophage and neutrophil infiltration were inhibited in anti-Ly6G antibody-treated Ccr5-/- mice but not when only glomerular macrophage infiltration was inhibited in Ccr5-/- mice or when only glomerular neutrophil infiltration was inhibited in anti-Ly6G antibody-treated WT mice. In contrast, B1 injection caused wire-loop lesions in Ccl2-/- and Ccr2-/- mice, as observed in WT mice. Moreover, 2B11.3 induced CCL2 from glomerular endothelial cells to a larger extent than B1 when injected into Ccr2-/- mice. In conclusion, the CCL2-CCR2 axis determines whether glomerular endocapillary hypercellularity or wire-loop lesions develop by regulating glomerular infiltration of phagocytic cells: macrophages and neutrophils. © 2024 The Pathological Society of Great Britain and Ireland.

Clinical characteristics of pulmonary Mycobacterium avium complex disease in patients with interstitial lung disease.

OBJECTIVE: Mycobacterium avium complex pulmonary disease (MAC-PD) is occasionally complicated by interstitial lung disease (ILD) in clinical practice, but clinical studies are limited. This study aims to elucidate the clinical and imaging characteristics of MAC-PD in patients with ILD. METHODS: We retrospectively analyzed imaging and clinical data from medical records of 54 consecutive ILD patients diagnosed with MAC-PD from 2011 to 2021 at our institution. We compared the imaging and clinical data of these patients with 2218 ILD patients diagnosed at our institution. RESULTS: The mean age of the patients was 74 years, with 25 males and 29 females, and a mean body mass index (BMI) of 20.0 kg/m2. Compared to all ILD patients, ILD-associated MAC-PD had older ages, lower BMI. The most common underlying ILD diagnosis was unclassifiable interstitial pneumonia. MAC-PD imaging classification was nodular-bronchiectatic (NB) type in 17 patients, fibro-cavitary (FC) type in 15 patients, and unclassifiable (UC) type in 22 patients. Many UC types were difficult to diagnose due to the absence of clear findings indicative of MAC infection. Chronic pulmonary aspergillosis complication was 24.1 %. The mean survival of ILD-associated MAC-PD was 55.6 months, shorter than that of regular MAC-PD. The UC type had a shorter survival than the NB type, similar to the FC type. CONCLUSION: MAC-PD associated with ILD frequently complicates chronic pulmonary aspergillosis and has a poor prognosis. The most common imaging type, UC type, particularly has a shorter survival. Careful management is essential for MAC-PD associated with ILD.

Inhaled Molgramostim Therapy in Autoimmune Pulmonary Alveolar Proteinosis.

BACKGROUND: Autoimmune pulmonary alveolar proteinosis (aPAP) is a rare disease characterized by progressive surfactant accumulation and hypoxemia. It is caused by disruption of granulocyte-macrophage colony-stimulating factor (GM-CSF) signaling, which pulmonary alveolar macrophages require to clear surfactant. Recently, inhaled GM-CSF was shown to improve the partial pressure of arterial oxygen in patients with aPAP. METHODS: In a double-blind, placebo-controlled, three-group trial, we randomly assigned patients with aPAP to receive the recombinant GM-CSF molgramostim (300 µg once daily by inhalation), either continuously or intermittently (every other week), or matching placebo. The 24-week intervention period was followed by an open-label treatment-extension period. The primary end point was the change from baseline in the alveolar-arterial difference in oxygen concentration (A-aDo2) at week 24. RESULTS: In total, 138 patients underwent randomization; 46 were assigned to receive continuous molgramostim, 45 to receive intermittent molgramostim, and 47 to receive placebo. Invalid A-aDo2 data for 4 patients (1 in each molgramostim group and 2 in the placebo group) who received nasal oxygen therapy during arterial blood gas measurement were replaced by means of imputation. For the primary end point - the change from baseline in the A-aDo2 at week 24 - improvement was greater among patients receiving continuous molgramostim than among those receiving placebo (-12.8 mm Hg vs. -6.6 mm Hg; estimated treatment difference, -6.2 mm Hg; P = 0.03 by comparison of least-squares means). Patients receiving continuous molgramostim also had greater improvement than those receiving placebo for secondary end points, including the change from baseline in the St. George's Respiratory Questionnaire total score at week 24 (-12.4 points vs. -5.1 points; estimated treatment difference, -7.4 points; P = 0.01 by comparison of least-squares means). For multiple end points, improvement was greater with continuous molgramostim than with intermittent molgramostim. The percentages of patients with adverse events and serious adverse events were similar in the three groups, except for the percentage of patients with chest pain, which was higher in the continuous-molgramostim group. CONCLUSIONS: In patients with aPAP, daily administration of inhaled molgramostim resulted in greater improvements in pulmonary gas transfer and functional health status than placebo, with similar rates of adverse events. (Funded by Savara Pharmaceuticals; IMPALA ClinicalTrials.gov number, NCT02702180.).

Serum Immunoglobulin G Testing against Pigeon Egg in Stable Fibrotic Hypersensitivity Pneumonitis.

INTRODUCTION: The accuracy of serum immunoglobulin (Ig) G testing for diagnosis of stable bird-related fibrotic hypersensitivity pneumonitis (HP) is controversial. Furthermore, avian serum, extracts, or feathers were employed as antigens in bird-related HP; however, the usage of egg whites has not been reported. We investigated the utility of IgG testing against pigeon egg whites in patients with stable bird-related fibrotic HP. METHODS: Patients having a positive inhalation test for pigeon antigen and a histological investigation with diagnostic confidence of fibrotic HP greater than moderate confidence were included. The control group consisted of patients with interstitial lung diseases (ILDs) other than HP. To select patients in the stable phase, patients with fibrotic HP were excluded if they were clinically considered to be in the acute exacerbation or acute phase. The IgG testing against pigeon egg whites by enzyme-linked immunosorbent assay and the commercialized anti-pigeon IgG testing by fluorescence enzyme immunoassay were investigated. RESULTS: In this study, 37 patients with stable bird-related fibrotic HP and 32 patients with ILDs other than HP participated. Serum IgG testing for pigeon egg whites revealed that the control group's optical density was 0.147 and the group with bird-related fibrotic HP had a mean value of 0.207 (p = 0.011). IgG testing in bronchial alveolar lavage fluid was not significantly higher in the bird-related fibrotic HP group than in controls (p = 0.42). No significant difference in area under the curve between an IgG testing against pigeon egg whites and a commercialized anti-pigeon IgG testing was observed (p = 0.24). Test accuracy for stable bird-related fibrotic HP ranged from 62% to 76% sensitivity and 59-66% specificity. CONCLUSION: IgG testing to identify the inciting antigen in patients with stable bird-related fibrotic HP had relatively low accuracy.

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.

Incidence of acute exacerbation in patients with interstitial lung disease after COVID-19 vaccination.

Acute exacerbations due to COVID-19 vaccination in patients with interstitial lung disease (ILD) have been reported, but their incidence is unknown. We investigated the incidence of exacerbations of ILD and respiratory symptoms due to the mRNA COVID-19 vaccines. A questionnaire survey was conducted on adverse reactions to the mRNA COVID-19 vaccination in 545 patients with ILD attending our hospital and retrospectively examined whether the eligible patients actually developed acute exacerbations of ILD induced by the vaccine. Of the 545 patients, 17 (3.1%) patients were aware of the exacerbation of respiratory symptoms, and four (0.7%) patients developed an acute ILD exacerbation after vaccination. Of the four patients who experienced exacerbations, two had collagen vascular disease-associated ILD, one had nonspecific interstitial pneumonia, another had unclassifiable idiopathic pneumonia, and none had idiopathic pulmonary fibrosis. Four patients were treated using steroid pulse therapy with a steroid taper, and two of the four also received intravenous cyclophosphamide pulse therapy. Tacrolimus was started in one patient with myositis-associated interstitial lung disease. Eventually, all patients exhibited improvement with immunosuppressive treatment and were discharged. COVID-19 vaccination for patients with ILD should be noted for developing acute exacerbations of ILD with low incidence, although manageable with early diagnosis and treatment.

Clinical and imaging features of interstitial lung disease in cancer patients treated with trastuzumab deruxtecan.

BACKGROUND: Interstitial lung disease/pneumonitis (ILD/pneumonitis) has been identified as a drug-related adverse event of special interest of trastuzumab deruxtecan (T-DXd), but there were a few reports of T-DXd-related ILD/pneumonitis in clinical practice. METHODS: Between May 25, 2020 (the launch of T-DXd in Japan) and February 24, 2022, there were 287 physician-reported potential ILD/pneumonitis cases from the Japanese post-marketing all-case surveillance. By February 27, 2022, an independent adjudication committee assessed 138 cases and adjudicated 130 cases as T-DXd-related ILD/pneumonitis. The clinical features and imaging characteristics of these cases were evaluated. RESULTS: The majority of adjudicated T-DXd-related ILD/pneumonitis cases were grade 1 or 2 (100/130, 76.9%). The most common radiological pattern types observed were organizing pneumonia patterns (63.1%), hypersensitivity pneumonitis patterns (16.9%), and diffuse alveolar damage (DAD) patterns (14.6%). Eleven cases (8.5%) from 130 resulted in death; the majority of these (8/11, 72.7%) had DAD patterns. The overall proportion of recovery (including the outcomes of recovered, recovered with sequelae, and recovering) was 76.9%, and the median time to recovery was 83.5 days (interquartile range: 42.25-143.75 days). Most cases (59/71, 83.1%) that were treated with corticosteroids were considered responsive to treatment. CONCLUSIONS: This is the first report to evaluate T-DXd-related ILD/pneumonitis cases in clinical practice. Our findings are consistent with previous reports and suggest that patients with DAD patterns have poor outcomes. Evaluation of a larger real-world dataset may further identify predictors of clinical outcome.

Concordance between transbronchial lung cryobiopsy and surgical lung biopsy for interstitial lung disease in the same patients.

BACKGROUND: The diagnostic accuracy and safety of transbronchial lung cryobiopsy (TBLC) via a flexible bronchoscope under sedation compared with that of surgical lung biopsy (SLB) in the same patients is unknown. METHODS: Retrospectively the data of fifty-two patients with interstitial lung diseases (median age: 63.5 years; 21 auto-antibody positive) who underwent TBLC followed by SLB (median time from TBLC to SLB: 57 days) was collected. The samples from TBLC and SLB were randomly labelled to mask the relationship between the two samples. Diagnosis was made independently by pathologists, radiologists, and pulmonary physicians in a stepwise manner, and a final diagnosis was made at multidisciplinary discussion (MDD). In each diagnostic step the specific diagnosis, the diagnostic confidence level, idiopathic pulmonary fibrosis (IPF) diagnostic guideline criteria, and treatment strategy were recorded. RESULTS: Without clinical and radiological information, the agreement between the histological diagnoses by TBLC and SLB was 42.3% (kappa [κ] = 0.23, 95% confidence interval [CI]: 0.08-0.39). However, the agreement between the TBLC-MDD and SLB-MDD diagnoses and IPF/non-IPF diagnosis using the two biopsy methods was 65.4% (κ = 0.57, 95% CI: 0.42-0.73) and 90.4% (47/52), respectively. Out of 38 (73.1%) cases diagnosed with high or definite confidence at TBLC-MDD, 29 had concordant SLB-MDD diagnoses (agreement: 76.3%, κ = 0.71, 95% CI: 0.55-0.87), and the agreement for IPF/non-IPF diagnoses was 97.4% (37/38). By adding the pathological diagnosis, the inter-observer agreement of clinical diagnosis improved from κ = 0.22 to κ = 0.42 for TBLC and from κ = 0.27 to κ = 0.38 for SLB, and the prevalence of high or definite diagnostic confidence improved from 23.0% to 73.0% and from 17.3% to 73.0%, respectively. Of all 383 TBLC performed during the same period, pneumothorax occurred in 5.0% of cases, and no severe bleeding, acute exacerbation of interstitial lung disease, or fatal event was observed. CONCLUSIONS: TBLC via a flexible bronchoscope under deep sedation is safely performed, and the TBLC-MDD diagnosis with a high or definite confidence level is concordant with the SLB-MDD diagnosis in the same patients.

CCR2- and CCR5-mediated macrophage infiltration contributes to glomerular endocapillary hypercellularity in antibody-induced lupus nephritis.

OBJECTIVES: LN comprises various glomerular lesions, including endocapillary hypercellularity with macrophage infiltration. In this study, we aimed to clarify the involvement of macrophage-tropic chemokine receptors in the pathogenesis of these glomerular lesions. METHODS: MRL/lpr mouse-derived monoclonal IgG3 antibody-producing hybridomas, 2B11.3 and B1, were injected intraperitoneally into BALB/c mice [wild type (WT)] to induce endocapillary hypercellularity and wire-loop lesions, respectively. The expression of chemokine and chemokine receptors was analysed by quantitative real-time PCR and IF. The roles of chemokine receptors in these lesions were evaluated using chemokine receptor-deficient mice or a selective CCR5 antagonist, maraviroc. RESULTS: 2B11.3 caused glomerular endocapillary hypercellularity with a significant number of glomerular CD68-positive macrophages. Further, enhanced expression of CCL2, CCL3, CCR2, CCR5 and CX3CR1 was observed in the renal cortex, compared with B1 injection, which induced wire-loop lesions. In 2B11.3-induced glomerular lesions, CD68 -positive glomerular macrophages expressed CCL2, CCL3, CCR2, CCR5 and CX3CR1, while glomerular endothelial cells expressed CCL2, CCL3, CX3CL1 and CCR2. When 2B11.3 was injected, CCR2-/- and CCR5-/-, but not CX3CR1-/-, mice exhibited reduced endocapillary hypercellularity, attenuated glomerular macrophage infiltration and improved serum blood urea nitrogen levels. Only CCR2-/- mice developed wire-loop lesions. B1 injection caused wire-loop lesions in these chemokine receptor-deficient mice to a similar extent as WT. Maraviroc treatment reduced 2B11.3-induced endocapillary hypercellularity and improved serum blood urea nitrogen levels. CONCLUSION: CCR2 and CCR5 regulate glomerular macrophage infiltration and contribute to the development of glomerular endocapillary hypercellularity in LN. CCR5 inhibition can be a specific therapy for endocapillary hypercellularity without inducing wire-loop lesions.

Validation of inhalation challenge test and serum immunoglobulin G test for bird-related fibrotic hypersensitivity pneumonitis.

BACKGROUND: The inhalation challenge test is considered to be the item for diagnosis of hypersensitivity pneumonitis (HP) and identifying the causative antigen in patients with fibrotic HP. However, the inhalation challenge test is not widely used. OBJECTIVE: To evaluate the values of the inhalation challenge test by comparing with serum immunoglobulin (Ig)G test. METHODS: This was a single-center, retrospective study. The patients with fibrotic HP were diagnosed pathologically by surgical lung biopsy or transbronchial lung cryobiopsy and were assumed to have bird-related fibrotic HP if they had a history of obvious avian exposure. RESULTS: On the basis of pathologic findings and history of avian exposure, 43 of 86 patients were diagnosed with having bird-related fibrotic HP. In 43 patients with bird-related fibrotic HP, 15 (35%) were positive for anti-bird IgG antibody and 36 (84%) were positive for the inhalation challenge test; in addition, the specificity of the inhalation challenge test was 67%. Patients with both positive results from inhalation challenge test and anti-bird IgG antibodies had a 2.7% decline in annual forced vital capacity (FVC) before the inhalation (P = .02). In patients with positive result from inhalation challenge test and negative result from anti-bird IgG antibodies, the annual FVC decreased by 5.8% (P = .03). FVC was not consistent in patients with positive result from the anti-bird IgG antibodies. CONCLUSION: The inhalation challenge test for bird-related fibrotic HP was more sensitive than the anti-bird IgG antibodies. Furthermore, the inhalation challenge test could select patients with similar disease progression.

Prognostic impact of HNF4α expression in interstitial lung disease.

Pneumocyte injury is a crucial factor influencing the severity of interstitial lung disease (ILD). In this study, we investigated the potential of hepatocyte nuclear factor α (HNF4α) as an immunohistochemical marker to detect pneumocyte injury and as a prognostic marker. Surgical lung biopsy specimens were collected from 309 patients with different types of ILDs (61 idiopathic pulmonary fibrosis (IPF), 173 non-IPF, and 75 unclassifiable ILD). HNF4α expression were examined and the frequency of positive cells (per mm2 ) was calculated. HNF4α was strongly expressed in regenerating pneumocytes present on fibroblastic foci, Masson bodies/organizing alveoli. In the non-IPF and unclassifiable ILD groups, cases with high frequency expression showed significantly poorer outcome. Particularly, in the unclassifiable ILD group, the prognostic impact was more significant (death due to ILD, log-rank test, p < 0.0001), with a 10-year survival rate (hazard ratio 11.1, Wald test, p = 0.0003), as compared to the non-IPF group (log-rank test, p = 0.0269; hazard ratio 2.7, Wald test, p = 0.0334). Multivariable analysis focusing on the unclassifiable ILD group confirmed that the frequent HNF4α expression was an independent prognostic factor (hazard ratio 28.6; Wald test, p = 0.0033). Thus, HNF4α can be utilized as an immunohistochemical marker for pneumocyte injury and have prognostic impact particularly in unclassifiable ILD.

Outcome of COVID-19 in interstitial lung disease patients treated with anti-inflammatory drugs and antiviral drugs.

A recent study reported that patients with interstitial lung disease (ILD) are at increased risk of death from coronavirus disease 2019 (COVID-19). However, there are no studies on the outcome of COVID-19 patients with preexisting ILD treated with corticosteroids or antiviral drugs. We extracted 26 patients with preexisting ILD by medical records and HRCT pattern. Of 503 patients with COVID-19, we selected 52 patients as control matched for age and sex. Twenty out of the 26 ILD patients (76.9%) received corticosteroid therapy, and 23 patients (88.5%) also received antiviral treatment with remdesivir or favipiravir. Although no statistical difference was found, the proportion of severe patients in ILD group tended to be higher than in non-ILD group (23.1% vs. 42.3%; p = 0.114). Also, mortality rate in ILD group tended to be higher than in non-ILD patients (11.5% vs. 3.8%; p = 0.326). In univariate analysis to evaluate risk factors for severe condition, diagnosis of idiopathic pulmonary fibrosis, usual interstitial pneumonia pattern, and honeycomb lung were not risk factors of severe disease. Treatment with corticosteroids, antiviral drugs, and immunosuppressive agents may affect the outcome of COVID-19 patients with ILD.

The new useful high-resolution computed tomography finding for diagnosing fibrotic hypersensitivity pneumonitis: "hexagonal pattern": a single-center retrospective study.

BACKGROUND: Centrilobular nodules, ground-glass opacity (GGO), mosaic attenuation, air trapping, and three-density pattern were reported as high-resolution computed tomography (HRCT) findings characteristic of fibrotic hypersensitivity pneumonitis (HP). However, it is often difficult to differentiate fibrotic HP from idiopathic pulmonary fibrosis (IPF). In fibrotic HP, the HRCT sometimes shows tortoiseshell-like interlobular septal thickening that extends from the subpleural lesion to the inner layers. This finding is called "hexagonal pattern," and this study is focused on the possibility that such finding is useful for differentiating fibrotic HP from IPF. METHODS: This study included patients with multidisciplinary discussion (MDD) diagnosis of fibrotic HP or IPF undergoing surgical lung biopsy between January 2015 and December 2017 in Kanagawa Cardiovascular and Respiratory Center. Two radiologists have evaluated the HRCT findings without clinical and pathological information. RESULTS: A total of 23 patients were diagnosed with fibrotic HP by MDD and 48 with IPF. Extensive GGO, centrilobular nodules, and hexagonal pattern were more frequent findings in fibrotic HP than in IPF. No significant difference was observed between the two groups in the presence or absence of mosaic attenuation, air trapping, or three-density pattern. In the multivariate logistic regression, the presence of extensive GGO and hexagonal pattern was associated with increased odds ratio of fibrotic HP. The sensitivity and specificity of the diagnosis of fibrotic HP in the presence of the hexagonal pattern were 69.6% and 87.5%, respectively. CONCLUSION: Hexagonal pattern is a useful finding for differentiating fibrotic HP from IPF.

Usefulness and safety of transbronchial lung cryobiopsy for reassessment of treatment in the clinical course of diffuse parenchymal lung disease.

BACKGROUND: The usefulness and safety of transbronchial lung cryobiopsy (TBLC) for reassessment of diffuse parenchymal lung disease (DPLD) with progression is still unknown. Our purpose was to clarify the usefulness and safety of TBLC for reassessment of DPLD with progression. METHODS: This retrospective study included 31 patients with DPLD diagnosed by surgical lung biopsy who progressed in the clinical course and underwent TBLC for reassessment between January 2017 and September 2019 at Kanagawa Cardiovascular & Respiratory Center. Two pulmonologists independently selected the clinical diagnosis, treatment strategy, and confidence level of the treatment strategy based on clinical and radiological information with and without pathological information from TBLC. A consensus was reached among the pulmonologists regarding the clinical diagnosis, treatment strategy, and confidence level of the treatment strategy. Complications of TBLC were also examined. RESULTS: Seven (22.6%), 5 (16.1%), and 6 (19.4%) of clinical diagnosis was changed after TBLC for Pulmonologist A, for Pulmonologist B, and for consensus, respectively. The treatment strategy was changed in 7 (22.6%), 8 (25.9%), and 6 (19.4%) cases after TBLC for Pulmonologist A, for Pulmonologist B and for consensus, respectively. The definite or high confidence level of the consensus treatment strategy was 54.8% (17/31) without TBLC and 83.9% (26/31) with TBLC. There were 6 cases of moderate bleeding, but no other complications were noted. CONCLUSIONS: Pathological information from TBLC may contribute to decision-making in treatment strategies for the progression of DPLD, and it may be safely performed.

Crucial contribution of GPR56/ADGRG1, expressed by breast cancer cells, to bone metastasis formation.

From a mouse triple-negative breast cancer cell line, 4T1, we previously established 4T1.3 clone with a high capacity to metastasize to bone after its orthotopic injection into mammary fat pad of immunocompetent mice. Subsequent analysis demonstrated that the interaction between cancer cells and fibroblasts in a bone cavity was crucial for bone metastasis focus formation arising from orthotopic injection of 4T1.3 cells. Here, we demonstrated that a member of the adhesion G-protein-coupled receptor (ADGR) family, G-protein-coupled receptor 56 (GPR56)/adhesion G-protein-coupled receptor G1 (ADGRG1), was expressed selectively in 4T1.3 grown in a bone cavity but not under in vitro conditions. Moreover, fibroblasts present in bone metastasis sites expressed type III collagen, a ligand for GPR56/ADGRG1. Consistently, GPR56/ADGRG1 proteins were detected in tumor cells in bone metastasis foci of human breast cancer patients. Deletion of GPR56/ADGRG1 from 4T1.3 cells reduced markedly intraosseous tumor formation upon their intraosseous injection. Conversely, intraosseous injection of GPR56/ADGRG1-transduced 4T1, TS/A (mouse breast cancer cell line), or MDA-MB-231 (human breast cancer cell line) exhibited enhanced intraosseous tumor formation. Furthermore, we proved that the cleavage at the extracellular region was indispensable for GPR56/ADGRG1-induced increase in breast cancer cell growth upon its intraosseous injection. Finally, inducible suppression of Gpr56/Adgrg1 gene expression in 4T1.3 cells attenuated bone metastasis formation with few effects on primary tumor formation in the spontaneous breast cancer bone metastasis model. Altogether, GPR56/ADGRG1 can be a novel target molecule to develop a strategy to prevent and/or treat breast cancer metastasis to bone.

Treatment and relapse of interstitial lung disease in nivolumab-treated patients with non-small cell lung cancer.

Nivolumab, a human monoclonal antibody against programmed death-1, is approved for the treatment of non-small cell lung cancer (NSCLC). Although nivolumab is generally well tolerated, it can cause interstitial lung disease (ILD), a rare but potentially fatal immune-related adverse event. Currently, there are limited data available on the treatment of nivolumab-induced ILD and its outcome. This retrospective cohort study based on a post-marketing study described the treatment of nivolumab-induced ILD and its outcome in NSCLC patients in Japan through the assessment of clinical and chest imaging findings by an expert central review committee. Treatment details for patients who experienced a relapse of ILD were also analyzed. Of the 238 patients identified as having nivolumab-induced ILD, 37 patients died of ILD. Corticosteroids were used in 207 (87.0%) patients. Of those, 172 (83.1%) patients responded well and survived and 35 (16.9%) died (most died during corticosteroid treatment). A total of nine patients experienced a relapse; at the time of relapse, four patients were taking nivolumab. Of those who were receiving corticosteroids at the time of relapse, three of four patients were taking low doses or had nearly completed dose tapering. All patients (except one, whose treatment was unknown) received corticosteroids for the treatment of relapse, but one patient died. Patients with NSCLC who experience nivolumab-induced ILD are treated effectively with corticosteroids, and providing extra care when ceasing or reducing the corticosteroid dose may prevent relapse of ILD.

Radiographic features and poor prognostic factors of interstitial lung disease with nivolumab for non-small cell lung cancer.

Nivolumab can cause interstitial lung disease (ILD), which may be fatal; however, mortality risk factors have not been identified. This postmarketing study evaluated the poor prognostic factors of ILD in nivolumab-treated patients with non-small cell lung cancer (NSCLC) in Japan. Clinical and chest imaging findings for each ILD case were assessed by an expert central review committee, and prognosis was evaluated by radiographic findings, including the presence/absence of peritumoral ground-glass opacity (peritumoral-GGO). Poor prognostic factors were identified by univariate and multivariate Cox regression analysis. Of the 238 patients with nivolumab-induced ILD, 37 died. The main radiographic patterns of ILD were cryptogenic organizing pneumonia/chronic eosinophilic pneumonia-like (53.4%), faint infiltration pattern/acute hypersensitivity pneumonia-like (20.2%), diffuse alveolar damage (DAD)-like (10.9%), and nonspecific interstitial pneumonia-like (6.3%). The main poor prognostic factors identified were DAD-like pattern (highest hazard ratio: 10.72), ≤60 days from the start of nivolumab treatment to the onset of ILD, pleural effusion before treatment, lesion distribution contralateral or bilateral to the tumor, and abnormal change in C-reactive protein (CRP) levels. Of the 37 deaths due to ILD, 17 had DAD-like radiographic pattern, three had peritumoral-GGO, and five had a change in radiographic pattern from non-DAD at the onset to DAD-like. Patients with NSCLC who develop ILD during nivolumab treatment should be managed carefully if they have poor prognostic factors such as DAD-like radiographic pattern, onset of ILD ≤60 days from nivolumab initiation, pleural effusion before nivolumab treatment, lesion distribution contralateral or bilateral to the tumor, and abnormal changes in CRP levels.

Clinical characteristics of Japanese patients with moderate to severe COVID-19.

INTRODUCTION: Although several reports on the risk factors for severe disease of COVID-19 already exist, reports on effective early indicators are still limited, especially from Japan. This study was conducted to clarify the patient's characteristics whose disease progressed to severe status. METHODS: The medical records of all consecutive 300 Japanese patients hospitalized at our institution between February and November 2020 were retrospectively reviewed. The clinical characteristics were evaluated to compare between mild (no oxygen needed), moderate (oxygen needs of 1-4 L/min), and severe diseases (oxygen needs of 5 L/min or more). RESULTS: The median age was 68 years old, with 123 (41.0%) males and 177 (59.0%) females. Of these, 199 patients (66.3%), 55 patients (18.3%), 46 patients (15.3%) patients were in the mild disease, moderate disease, severe disease groups, respectively. Patients with severe disease were more likely to be older, have more comorbidities, and tended to have higher body mass index. In laboratory data, lymphocyte count, levels of C-reactive protein (CRP), LDH, and AST on admission were significantly associated with the severity. In multivariate analysis, age and CRP were the independent risk factors for severe disease (OR = 1.050, 1.130, respectively). The optimal cut-off value for age was 74 years old and that for CRP was 3.15 mg/dL. CONCLUSIONS: Age and CRP were independently associated with disease severity of COVID-19 in multivariate analysis. Additionally, the numbers of underlying disease, lymphocyte count, and inflammatory markers such as LDH and D-dimer may also be related to disease severity.

Screening and diagnosis of acute and chronic bird-related hypersensitivity pneumonitis by serum IgG and IgA antibodies to bird antigens with ImmunoCAP®.

BACKGROUND: Bird antigens are some of the most relevant antigens in hypersensitivity pneumonitis (HP). Possible sources of bird antigens are bird breeding, feather products and fertilizer with fowl droppings. For the screening and diagnosis of HP, the measurement of bird-specific antibodies should be standardized. The aim of this study was to clarify the utility of serum IgG (sIgG) and IgA (sIgA) antibodies to bird antigens in screening and diagnosing acute/chronic bird-related HP with ImmunoCAP® in multi-centre clinical research. METHODS: We executed a clinical performance test by conducting a multi-institutional study to measure the levels of sIgG/sIgA against pigeon, parrot and budgerigar antigens by the ImmunoCAP® system in 29 acute and 46 chronic bird-related HP patients. RESULTS: The levels of sIgG/sIgA against the bird antigens of the three species were significantly higher in subjects with acute bird-related HP and chronic bird-related HP with acute episodes (recurrent type) than in the control subjects. For sIgG, the optimal cutoff values by receiver operating characteristic (ROC) analysis were 24.6 mgA/L for pigeon, 14.0 mgA/L for parrot, and 8.7 mgA/L for budgerigar. By measuring multiple bird antigens and combining sIgG values of two species, the sensitivity and specificity for acute and recurrent-type chronic bird-related HP patients were 85-91% and 73-80%, respectively. For recurrent and insidious types of chronic bird-related HP, the sensitivity and specificity were 48-61% and 73-80%, respectively. CONCLUSIONS: Measurement of the levels of sIgG/sIgA against pigeon, budgerigar and parrot antigens by ImmunoCAP® was useful for screening and diagnosis in bird-related HP.

Inhalation challenge test using pigeon eggs for chronic hypersensitivity pneumonitis.

BACKGROUND: Chronic hypersensitivity pneumonitis (CHP) remains a diagnostic challenge. The process of collecting and extracting serum and droppings from causative animals for the inhalation challenge test is complicated and the risk of inducing disease progression exists. OBJECTIVE: To investigate the utility and safety of an inhalation challenge test using pigeon eggs. METHODS: Pigeon eggs were pasteurized and mixed with a saline solution to produce an inhalation fluid. An inhalation challenge test was conducted on 19 patients with bird-related CHP and 17 patients with interstitial lung disease other than bird-related CHP. To identify antigens in pigeon eggs, the antigen-antibody responses of the pigeon eggs and serum from patients were evaluated using Western blotting. RESULTS: The mean changes in C-reactive protein, alveolar-arterial oxygen difference, erythrocyte sedimentation rate, and lactate dehydrogenase significantly increased by 0.32 mg/dL (P = .014), 7.8 Torr (P = .002), 1.4 mm/h (P = .012), and 5.4 U/mL (P = .0019), respectively, in bird-related CHP group compared to the control 24 hours after the inhalation challenge test. Furthermore, within 24 hours of the inhalation test, the mean forced vital capacity decreased by 2.3% in the bird-related CHP group compared with a decline of 0.05% in the control group (P = .035). Serum collected from seven bird-related CHP patients who underwent the inhalation challenge test and reacted to antigens with molecular weights of 37-75 KDa, and these molecular weights were consistent with egg albumin and globulin. CONCLUSION: Since a mild response was observed after the inhalation challenge test using pigeon eggs, this test was an obvious candidate for diagnosing bird-related CHP.