Exacerbation of Intimal Fibrosis and Endarteritis in a Kidney Transplant Recipient with Chronic Active Antibody-Mediated Rejection and COVID-19: A Case Report.

Kidney transplant recipients are immunocompromised hosts at risk for comorbidity and mortality due to infection. Currently, there are no established guidelines for the management of immunosuppressed transplant recipients with coronavirus disease 2019 (COVID-19). The impact of COVID-19 and its therapeutic management on chronic active antibody-mediated rejection (CAAMR) are still unclear. Here, we report a case of CAAMR exacerbation with endarteritis and intimal fibrosis after COVID-19. A 41-year-old female kidney transplant recipient with CAAMR was admitted to a local hospital with moderately severe COVID-19. Her doses of tacrolimus and mycophenolate mofetil were reduced, and she was administered methylprednisolone pulse and antiviral drugs. This resulted in a good clinical course and she was discharged in 15 days. During and after hospitalization, the immunosuppressants were gradually returned to the baseline levels. However, about 1.5 months after discharge, the serum creatinine level became elevated. An indication kidney biopsy showed CAAMR with intimal fibrosis and endarteritis in all interlobular arteries. An increase of immunosuppressant led to a decrease of the serum creatinine level. Factors contributing to CAAMR with intimal fibrosis and endarteritis may include (1) insufficient immunosuppression due to changes in the levels of immunosuppressive; (2) overlap with endothelial cell injury caused by COVID-19, and (3) an immune-activated state associated with COVID-19. COVID-19 is a life-threatening disease that can result in unexpected changes in immunological status. Possible allograft rejection should be carefully managed in such patients.

Quantitative Evaluation of Changes in Three-Dimensional CT Density Distributions in Pulmonary Alveolar Proteinosis after GM-CSF Inhalation.

BACKGROUND: A previous clinical trial for autoimmune pulmonary alveolar proteinosis (APAP) demonstrated that granulocyte-macrophage colony-stimulating factor (GM-CSF) inhalation reduced the mean density of the lung field on computed tomography (CT) across 18 axial slice planes at a two-dimensional level. In contrast, in this study, we challenged three-dimensional analysis for changes in CT density distribution using the same datasets. METHODS: As a sub-study of the trial, CT data of 31 and 27 patients who received GM-CSF and placebo, respectively, were analyzed. To overcome the difference between various shooting conditions, a newly developed automatic lung field segmentation algorithm was applied to CT data to extract the whole lung volume, and the accuracy of the segmentation was evaluated by five pulmonary physicians independently. For normalization, the percent pixel (PP) in a certain density range was calculated as a percentage of the total number of pixels from -1,000 to 0 HU. RESULTS: The automatically segmented images revealed that the lung field was accurately extracted except for 7 patients with minor deletion or addition. Using the change in PP from baseline to week 25 (ΔPP) as the vertical axis, we created a histogram with 143 HU bins set for each patient. The most significant difference in ΔPP between GM-CSF and placebo groups was observed in two ranges: from -1,000 to -857 and -143 to 0 HU. CONCLUSION: Whole lung extraction followed by density histogram analysis of ΔPP may be an appropriate evaluation method for assessing CT improvement in APAP.

Critical Current Density and Vortex Dynamics in Pristine and Irradiated KCa2Fe4As4F2.

We report the critical current density (Jc) and vortex pinning properties in single crystals of a novel iron-based superconductor (IBS) KCa2Fe4As4F2 with large Jc in the pristine state, before and after introduction of artificial defects by swift-particle irradiation. The effects of 2.6 GeV U and 3 MeV proton irradiations in KCa2Fe4As4F2 single crystals on transition temperature Tc and Jc, including its dose dependence, are systematically studied. Jc~8 MA/cm2 under a self-field at 2 K in the pristine crystal is strongly enhanced up to 19.4 and 17.5 MA/cm2 by irradiation of 2.6 GeV U-ions and 3 MeV protons, respectively. Suppression of Tc and dose dependence of Jc in KCa2Fe4As4F2 is different from that in a representative IBS of (Ba,K)Fe2As2, which can be explained by considering the presence of embedded defects in pristine KCa2Fe4As4F2. The vortex dynamics in the pristine and proton irradiated KCa2Fe4As4F2 single crystals are also investigated from the analyses of the field dependence of Jc and the normalized magnetic relaxation rate. In addition to the contribution of embedded defects, weak collective pinning is considered for comprehensive analyses. Vortex dynamics in KCa2Fe4As4F2 is similar to those in (Ba,K)Fe2As2 to some extent, and different from that in anisotropic Li0.8Fe0.2OHFeSe. Large anisotropy, due to the presence of insulating blocking layers in KCa2Fe4As4F2, which leads to much lower irreversibility field (Hirr) compared with 122-type IBSs, strongly affect the vortex dynamics.

Curved Perylene Diimides Fused with Seven-Membered Rings.

Curved perylene diimides fused with seven-membered rings have been synthesized using a regioselective bay-functionalization method and Pd-catalyzed intramolecular C-H/C-Br coupling reaction. X-Ray analysis and temperature-dependent NMR spectroscopy revealed the curved molecular structure with a certain degree of conformational flexibility. The curved and expanded π-conjugation altered the electronic properties while retaining the intrinsic properties of the parent perylene diimide. Despite the absence of solubilizing N-substituents, the curved perylene diimides showed sufficient solubility for application in solution-processed organic photovoltaic devices. The devices showed superior performance with a power conversion efficiency of up to 2.76% due to suppressed charge recombination. Our detailed investigations suggest that the introduction of a curved structure enables the removal of the bulky N-substituents, which is an effective way to achieve a thin-film morphology suitable for photoelectric conversion.

Moss PPR-SMR protein PpPPR_64 influences the expression of a psaA-psaB-rps14 gene cluster and processing of the 23S-4.5S rRNA precursor in chloroplasts.

KEY MESSAGE: Moss PPR-SMR protein PpPPR_64 is a pTAC2 homolog but is functionally distinct from pTAC2. PpPPR_64 is required for psaA gene expression and its function may have evolved in mosses. The pentatricopeptide repeat (PPR) proteins are key regulatory factors responsible for the control of plant organellar gene expression. A small subset of PPR proteins possess a C-terminal small MutS-related (SMR) domain and have diverse roles in plant organellar biogenesis. However, the function of PPR-SMR proteins is not fully understood. Here, we report the function of PPR-SMR protein PpPPR_64 in the moss Physcomitrium patens. Phylogenetic analysis indicated that PpPPR_64 belongs to the same clade as the Arabidopsis PPR-SMR protein pTAC2. PpPPR_64 knockout (KO) mutants grew autotrophically but with reduced protonemata growth and the poor formation of photosystems' antenna complexes. Quantitative reverse transcription-polymerase chain reaction and RNA gel blot hybridization analyses revealed a significant reduction in transcript levels of the psaA-psaB-rps14 gene cluster but no alteration to transcript levels of most photosynthesis- and non-photosynthesis-related genes. In addition, RNA processing of 23S-4.5S rRNA precursor was impaired in the PpPPR_64 KO mutants. This suggests that PpPPR_64 is specifically involved in the expression level of the psaA-psaB-rps14 gene and in processing of the 23S-4.5S rRNA precursor. Our results indicate that PpPPR_64 is functionally distinct from pTAC2 and is a novel PPR-SMR protein required for proper chloroplast biogenesis in P. patens.

Validation of a new serum granulocyte-macrophage colony-stimulating factor autoantibody testing kit.

Very recently, a modest but significant efficacy of granulocyte-macrophage colony-stimulating factor (GM-CSF) inhalation therapy for the treatment of mild to moderate autoimmune pulmonary alveolar proteinosis (aPAP) has been reported. As the ability to measure the level of GM-CSF autoantibody (GMAb) in the serum is required to decide the indication for this therapy, we developed a high-performance GMAb testing kit for clinical use. As the kit succeeded in reducing nonspecific IgG binding to the ELISA plate, the predictive performance shown in the training study to discriminate aPAP patients from healthy subjects was perfect, providing a cut-off value of 1.65 U·mL-1 in 78 patients with aPAP and 90 healthy subjects in an operator-blinded manner using logistic regression analysis. As in the validation study, serum samples from another 213 patients with aPAP were also blinded and evaluated in an operator-blinded manner against external 207 samples from patients with other types of PAP and patients exhibiting various ground-glass opacities on chest high-resolution computed tomography that require discrimination from PAP. The logistic regression analysis of these validation data sets revealed values of 97.6% and 100% for specificity and sensitivity, respectively. Thus, this new GMAb testing kit is reliable for the diagnosis of aPAP and differential diagnosis of other lung diseases.

Inhaled GM-CSF for Pulmonary Alveolar Proteinosis.

BACKGROUND: Pulmonary alveolar proteinosis is a disease characterized by abnormal accumulation of surfactant in the alveoli. Most cases are autoimmune and are associated with an autoantibody against granulocyte-macrophage colony-stimulating factor (GM-CSF) that prevents clearing of pulmonary surfactant by alveolar macrophages. An open-label, phase 2 study showed some therapeutic efficacy of inhaled recombinant human GM-CSF in patients with severe pulmonary alveolar proteinosis; however, the efficacy in patients with mild-to-moderate disease remains unclear. METHODS: We conducted a double-blind, placebo-controlled trial of daily inhaled recombinant human GM-CSF (sargramostim), at a dose of 125 µg twice daily for 7 days, every other week for 24 weeks, or placebo in 64 patients with autoimmune pulmonary alveolar proteinosis who had a partial pressure of arterial oxygen (Pao2) while breathing ambient air of less than 70 mm Hg (or <75 mm Hg in symptomatic patients). Patients with severe pulmonary alveolar proteinosis (Pao2 <50 mm Hg) were excluded to avoid possible exacerbation of the disease in patients who were assigned to receive placebo. The primary end point was the change in the alveolar-arterial oxygen gradient between baseline and week 25. RESULTS: The change in the mean (±SD) alveolar-arterial oxygen gradient was significantly better in the GM-CSF group (33 patients) than in the placebo group (30 patients) (mean change from baseline, -4.50±9.03 mm Hg vs. 0.17±10.50 mm Hg; P = 0.02). The change between baseline and week 25 in the density of the lung field on computed tomography was also better in the GM-CSF group (between-group difference, -36.08 Hounsfield units; 95% confidence interval, -61.58 to -6.99, calculated with the use of the Mann-Whitney U test and the Hodges-Lehmann estimate of confidence intervals for pseudo-medians). Serious adverse events developed in 6 patients in the GM-CSF group and in 3 patients in the placebo group. CONCLUSIONS: In this randomized, controlled trial, inhaled recombinant human GM-CSF was associated with a modest salutary effect on the laboratory outcome of arterial oxygen tension, and no clinical benefits were noted. (Funded by the Japan Agency for Medical Research and Development and the Ministry of Health, Labor, and Welfare of Japan; PAGE ClinicalTrials.gov number, NCT02835742; Japan Medical Association Center for Clinical Trials number, JMA-IIA00205.).

Bicytopenia in Primary Lung Melanoma Treated with Nivolumab.

A 73-year-old man who was a current smoker complained of weakness in his limbs and slow movement and was diagnosed with primary lung melanoma with brain metastases. Following stereotactic brain radiotherapy, nivolumab was administrated. After the first cycle of nivolumab, his blood neutrophil count and hemoglobin levels started to decline. Excluding other possible causes, nivolumab was considered the most probable cause of bicytopenia. Nivolumab was not restarted, and the bicytopenia gradually recovered with no corticosteroid administration for this event. While serious hematological adverse events regarding immune checkpoint inhibitors have been assumed to be rare, severe neutropenia and anemia should be considered in patients receiving immune checkpoint therapy.

Clinical significance of serum anti-GM-CSF autoantibody levels in autoimmune pulmonary alveolar proteinosis.

AIM: Precise clinical significance of antigranulocyte-macrophage colony stimulating factor (GM-CSF) autoantibody levels in autoimmune pulmonary alveolar proteinosis (aPAP) has not been well studied. METHODS: We obtained sera from 50 healthy controls, 46 aPAP patients, 50 with sarcoidosis, 52 with idiopathic interstitial pneumonia and 75 with pneumoconiosis. The clinical course of aPAP patients was assessed by scoring computed tomography images in 19 patients. RESULTS: The cut-off level of anti-GM-CSF IgG for discrimination between aPAP and other diffuse lung diseases was 2.8 µg/ml with 100% sensitivity and 98% specificity. Antibody levels at baseline were significantly lower in the improved group than in the unimproved group (p = 0.008). CONCLUSION: Our results indicate the existence of threshold levels of serum anti-GM-CSF IgG for the development and persistence of aPAP.

Interstitial Lung Disease after Pleurodesis for Malignant Pleural Effusion.

Objective Pleurodesis is an effective therapy for malignant pleural effusion (MPE). While interstitial lung disease (ILD) has been regarded as a serious complication of pleurodesis, its clinicopathological characteristics have not been fully understood. This study was conducted to elucidate the incidence of ILD and the risk factors for ILD in patients who underwent pleurodesis to control MPE. Methods The medical records of patients who underwent pleurodesis in Aichi Medical University between March 2008 and February 2013, the period before the approval of talc in Japan, were retrospectively analyzed. Results A total of 84 patients underwent pleurodesis, all using OK-432. ILD occurred in 13 patients (15.5%). The development of ILD after pleurodesis was significantly associated with old age (odds ratio [OR]: 4.82, 95% confidence interval [CI]: 1.22-19.08) and epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) treatment (OR: 5.97, CI: 1.7-20.9). A multivariate analysis revealed that >67 years of age (p=0.01) and EGFR-TKI treatment (p=0.02) were significantly associated with the development of pleurodesis-related ILD. Among the patients who received both pleurodesis and EGFR-TKIs (n=23), 8 patients developed ILD. All of these patients were receiving EGFR-TKI therapy at the time of pleurodesis or within 30 days after pleurodesis. In contrast, no cases of ILD were observed among the patients who stopped EGFR-TKIs before pleurodesis or started EGFR-TKIs at more than 30 days after pleurodesis. Conclusion ILD seemed to be a frequent complication of pleurodesis in patients using OK-432, especially elderly patients and those who underwent pleurodesis while receiving EGFR-TKI therapy or who started EGFR-TKI therapy within 30 days after pleurodesis.

The ATS/ERS/JRS/ALAT statement "IPF by HRCT" could predict acute exacerbation of interstitial lung disease in non-small cell lung cancer.

INTRODUCTION: Patients with non-small cell lung cancer (NSCLC) and interstitial lung disease (ILD) are at high risk of acute exacerbation of ILD (AE-ILD) when treated with systemic chemotherapy. Standard treatment for NSCLC complicated by ILD has not been established. PURPOSE AND METHODS: To examine whether the type of ILD categorized by the official ATS/ERS/JRS/ALAT statement as "idiopathic pulmonary fibrosis (IPF) by high-resolution computed tomography (HRCT)" could predict chemotherapy-induced AE-ILD in NSCLC patients with ILD, we retrospectively reviewed all patients with NSCLC complicated by ILD who had received chemotherapy at our institute from January 2007 until December 2013. Patients' characteristics, pathology and clinical staging of lung cancer, chemotherapy, type of ILD and AE-ILD during chemotherapy were evaluated. ILD was classified according to the statement as follows: usual interstitial pneumonia (UIP), possible UIP, and inconsistent with a UIP pattern. RESULTS: A total of 46 patients had pre-existing ILD and received chemotherapy. The mean age was 73 years (range 46-83 years). Fifteen (32.6%) of 46 patients with ILD developed chemotherapy-induced AE-ILD, which was seen more frequently in patients with ILD with a UIP pattern or possible UIP pattern than in patients with a pattern inconsistent with UIP (80% versus 9.7%, p<0.001). Multivariate analyses including age, sex, performance status and radiographic patterns of ILD showed that the presence of a UIP or possible UIP pattern was an independent risk factor for chemotherapy-induced AE-ILD. CONCLUSIONS: ILD with a UIP pattern or possible UIP pattern by the classification could be a risk factor for AE-ILD in NSCLC patients with ILD.

Therapeutic and preventive antiemetic effect of aprepitant in Japanese patients with thoracic malignancies who truly need it.

PURPOSE: Neurokinin-1 (NK-1) receptor antagonist is recommended for chemotherapy-induced nausea and vomiting (CINV) in highly emetogenic chemotherapy (HEC) and has recently been introduced to oncology practice in Japan. However, whether all patients undergoing HEC truly need NK-1 receptor antagonist remains unknown, and increasing medical costs due to uniform use of NK-1 receptor antagonist are a concern. This study was conducted to examine the prevalence of patients who needed aprepitant at the time of its introduction in Japan, and therapeutic and preventive effects of aprepitant on HEC or moderately emetogenic chemotherapy (MEC). PATIENTS AND METHODS: Eligible patients with thoracic malignancies who were to undergo HEC or MEC received 5-hydroxytryptamine receptor antagonists and dexamethasone to prevent CINV. Aprepitant was administered to treat CINV occurring in the first course, or to prevent CINV in the second course. Frequency of vomiting, degree of nausea, and quality of life with respect to CINV were assessed. RESULTS: In total, 96 patients were enrolled. Aprepitant was not administered in 57 and 88 % of patients who received HEC and MEC, respectively. In patients treated with aprepitant (n = 18), therapeutic use of aprepitant after occurrence of CINV (n = 9) decreased average scores in numerical rating scale for nausea from 7.44 to 5.44 (p = 0.10), and average frequency of vomiting per day from 2.11 to 0.11 (p = 0.03). Prophylactic use of aprepitant in the second course (n = 18) increased the proportion of patients with no significant nausea from 6 % (first course) to 50 % (second course; p = 0.007), and those with no vomiting from 33 to 89 % (p = 0.002). Aprepitant use also significantly improved quality of life with respect to CINV in the second course. CONCLUSION: More than half of patients receiving HEC and 88 % of patients receiving MEC did not use aprepitant. Aprepitant showed significant therapeutic and preventive effects on CINV in patients who truly needed it.

UGT1A1*28 is associated with greater decrease in serum K⁺ levels following oral intake of procaterol.

BACKGROUND AND OBJECTIVE: Procaterol is a potent ß2-agonist frequently used for the management of asthma and chronic obstructive pulmonary disease. The efficacy and adverse effects of ß2-agonists are heterogeneous in individual patients, which may be partly caused by genetic variations in metabolizing enzymes and receptor molecules. The present study was designed to analyze the relationship between gene polymorphisms and physiological effects of procaterol in healthy subjects. METHODS: Ninety-two non-smoking healthy volunteers were given 1 µg/kg body weight (max 50 µg) of procaterol as a dry syrup preparation, and the serum concentrations of procaterol, serum K(+), and the physical responses were monitored for 240 min. We genotyped ß2-adrenergic receptor (ADRB2) (Arg16Gly and Gln27Glu), cytochrome P450 3A4 (rs2246709, rs4646437), and uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) (rs4148323 [allele A, *6], rs12479045, rs4148328, rs4663971, rs12052787, rs4148329, A (TA)6/7 TAA [seven-repeat allele, *28]). Procaterol concentrations in serum were measured by liquid chromatography-tandem mass spectrometry. RESULTS: No gene polymorphisms affected serum procaterol concentrations. Meanwhile, overall serum K(+) level changes were significantly lower in carriers of UGT1A1*28 than in non-carriers after correcting for strong effects of serum procaterol concentrations and baseline K(+) levels. No other polymorphisms were associated with serum K(+) levels. None of polymorphisms of ADRB2 were associated with any physical responses. CONCLUSION: The present study indicates that significant hypokalemia may occur in carriers of UGT1A1*28 by systemic administration of procaterol and potentially by other ß2-agonists metabolized in the liver.

A case of sarcoidosis with eosinophilia in peripheral blood and bronchoalveolar lavage fluid.

A 70-year-old woman, who has had a diagnosis of sarcoidosis since she was 38 years old, showed newly appearing diffuse ground-glass opacities in the bilateral lung field, and bilateral enlargement of the hilar and mediastinal lymph nodes. Based on findings from bronchoalveolar lavage fluid (BALF) and pathology analysis, eosinophilic pneumonia accompanied by sarcoidosis was suspected. Both disease conditions (sarcoidosis and BALF eosinophilia) worsened and improved simultaneously, and she showed two similar episodes during the follow-up. This case prompted us to conduct a retrospective investigation of eosinophil percentage in peripheral blood and BALF in 178 patients (excluding our patient) who had received a diagnosis of sarcoidosis between 2000 and 2009 in our department. Among the 178 patients, the highest eosinophil percentage in BALF was 2.6%; in contrast, peripheral blood eosinophilia was very common. Thus we concluded that, for subjects with sarcoidosis, marked eosinophilia in BALF, as observed in the case of this 70-year-old woman, was exceptional.

Genetic variants in mannose receptor gene (MRC1) confer susceptibility to increased risk of sarcoidosis.

BACKGROUND: Mannose receptor (MR) is a member of the C-type lectin receptor family involved in pathogen molecular-pattern recognition and thought to be critical in shaping host immune response. The aim of this study was to investigate potential associations of genetic variants in the MRC1 gene with sarcoidosis. METHODS: Nine single nucleotide polymorphisms (SNPs), encompassing the MRC1 gene, were genotyped in a total of 605 Japanese consisting of 181 sarcoidosis patients and 424 healthy controls. RESULTS: Suggestive evidence of association between rs691005 SNP and risk of sarcoidosis was observed independent of sex and age in a recessive model (P = 0.001). CONCLUSIONS: These results suggest that MRC1 is an important candidate gene for sarcoidosis. This is the first study to imply that genetic variants in MRC1, a major member of the C-type lectin, contribute to the development of sarcoidosis.

The role of atopy in the clinical course of pulmonary sarcoidosis in the Japanese population.

Sarcoidosis is a multisystem disorder characterized by a T-helper 1 (Th1)-mediated immune response. Conversely, atopy is characterized by the presence of a specific immunoglobulin E (IgE) E response in association with a Th2-type immune response. Several epidemiological studies have shown that atopic status influences disease activity and clinical course for several Th1-mediated diseases. The aim of this study was to evaluate associations between atopic status and clinical findings of sarcoidosis. We further evaluated the impact of atopic status on the clinical course of pulmonary sarcoidosis. We defined atopy as a positive specific IgE response to at least one common inhaled allergen (multiple antigen simultaneous test scores, lumicount of >1.01). Subjects comprised 134 patients given a diagnosis of sarcoidosis between 2000 and 2006, divided into atopic and nonatopic groups. Several clinical findings were compared between the two groups. Furthermore, 100 subjects observed 2 years after diagnosis were divided into resolving and persistent clinical course groups according to chest radiography and associations with atopic status were evaluated. Atopy was more prevalent among men than women (p = 0.009) and subjects with atopy were younger (p = 0.002) and showed less frequent lung parenchymal lesions (stages II and III; p = 0.018) compared with subjects without atopy. The prevalence of atopy was higher in the resolving clinical course group than in the persistent clinical course group (p = 0.002) and this association was independent of sex, age, presence of lung parenchymal lesions, and presence of extrapulmonary lesions (p = 0.037). Classification of sarcoidosis based on atopic status might be useful for predicting the clinical course of pulmonary sarcoidosis.

[Evaluating total serum IgE levels and peripheral eosinophil count in asthma and rhinitis].

BACKGROUND: Total serum immunoglobulin (Ig)E levels and peripheral blood eosinophil counts are widely examined to evaluate patients with various allergic diseases. Asthma and allergic rhinitis often coexist. However, the significance of these indices for asthma and rhinitis under consideration of the status of co-existence has not been fully elucidated and was therefore examined in the present study. METHODS: Subjects comprised 347 adult residents in Kamishihoro town, Hokkaido. Relationships between two indices and asthma, rhinitis and their coexistence were analyzed. RESULTS: Serum IgE (sIgE) levels were significantly higher in asthma with (p<0.01) or without (p<0.01) rhinitis, regardless of atopic status, but not in rhinitis alone. Peripheral eosinophil counts were significantly higher only in asthma with rhinitis (p<0.005). CONCLUSION: Compared with rhinitis, non-antigen-specific IgE production may contribute more to elevated levels of sIgE in asthma. In addition, the significance of sIgE and peripheral eosinophil count as indices of evaluating asthma and rhinitis might differ.

[Flow-volume curve as an aid to diagnosis in double aortic arch masquerading as asthma in a young adult].

We describe a young adult with double aortic arch who for several years had experienced stridor during exercise. He had been given a diagnosis of exercise-induced asthma, also known as hyperventilation syndrome. Antiasthmatic drugs, including inhaled corticosteroids and a short-acting bronchodilator, in addition to antidepressants, did not improve his symptoms. He had a history of allergic rhinitis and a familial history of asthma, but no signs of asthma as assessed by expectorated sputum and airway responsiveness (Dmin). However, flow-volume curves demonstrated a pattern consistent with upper airway constriction. Computed tomography confirmed severe tracheal narrowing caused by a double aortic arch. Compressive tracheal narrowing was also evaluated by fiber-optic tracheobronchoscopy. A treadmill exercise study induced respiratory distress with audible stridor that resolved itself without intervention. He underwent surgical division of the left aortic arch, which relieved the stridor during exercise. The flow-volume curve improved but constriction was still indicated even at 1.5 years after surgery. Double aortic arch should be considered in the differential diagnosis of drug-resistant stridor. This case re-emphasizes the value of flow-volume curves for diagnosing upper-airway obstruction.

A functional polymorphism (-603A --> G) in the tissue factor gene promoter is associated with adult-onset asthma.

Tissue factor (TF) is important for initiation of coagulation and for the increased thrombin activity observed at sites of inflammation. Thrombin activity is induced by allergen challenge in asthmatic airways and is involved in the pathogenesis of asthma. A -603A --> G polymorphism (rs1361600) in the promoter region of the TF gene has been associated with serum TF levels and with the development of cardiovascular diseases. The aim of this study was to determine whether the functional -603A --> G polymorphism has genetic influences on the development of asthma. Case-control analysis was performed of the association between six common single-nucleotide polymorphisms (SNPs), including the -603A --> G polymorphism, at the TF gene, and the development of asthma, using two unrelated Japanese populations. In the primary population (n=826), the GG genotype at the -603A --> G polymorphism was associated with adult-onset asthma (onset at >or=21 years of age) (odds ratio (OR) 2.886, P=0.0231). A second population showed a similar tendency (n=1654, OR 1.602, P=0.064). Transcriptional activity of promoters with -603A --> G genotypes were examined using luciferase promoter assays. The -603G allele was associated with higher promoter activity (P<0.05). The association between the functional polymorphism (-603A --> G) in the TF gene promoter and adult-onset asthma indicates that TF is a candidate gene contributing to asthma susceptibility.

Genetic variants in the mannose receptor gene (MRC1) are associated with asthma in two independent populations.

Mannose receptor is a member of the C-type lectin receptor family involved in pathogen molecular pattern recognition and thought to be critical in shaping host immune responses and maintaining homeostasis. The aim of this study was to investigate potential associations of genetic variants in the MRC1 gene with asthma in two independent populations. Seven single-nucleotide polymorphisms (SNPs; rs2477637, rs2253120, rs2477631, rs2477664, rs692527, rs1926736, and rs691005) in the MRC1 gene locus were genotyped and evaluated regarding association with asthma in 870 unrelated Japanese subjects (446 asthmatics, 424 controls). The same markers were validated in 176 unrelated African-American subjects (86 asthmatics, 90 controls). Suggestive evidence of association between five SNPs (rs2477637, rs2253120, rs2477664, rs692527, and rs1926736) and asthma was observed in the analysis of the Japanese population independent of sex, age, smoking status, and atopic status. SNPs rs692527 and rs691005 showed significant association with asthma in the African-American population. Haplotypes containing two linked SNPs (rs692527 and rs1926736) were significantly associated with asthma in both Japanese and African-American populations. Our results suggest that sequence variations in the MRC1 gene are associated with the development of asthma in two independent and ethnically diverse populations.