A Low Serum CCL4/MIP-1ß Level May Predict a Severe Asthmatic Responsiveness to Mepolizumab.

Objective Mepolizumab, a humanized anti-interleukin-5 monoclonal antibody, is effective for treating eosinophilic severe asthma. However, there is a need for more biomarkers that can predict the patient response to mepolizumab before starting therapy. This study aimed to identify a new biomarker in the serum that is able to accurately predict the responsiveness to mepolizumab. Methods This study enrolled 11 patients who had all been diagnosed with severe eosinophilic asthma and were then administered mepolizumab every 4 weeks for at least 4 months. Blood samples were collected, and pulmonary function tests and questionnaires were administered at baseline and after 4, 8 and 16 weeks of treatment. The response to mepolizumab was then assessed based on the difference in the Asthma Quality of Life Questionnaire (AQLQ) score after 16 weeks of mepolizumab therapy compared with that at baseline. Patients with an increase in the AQLQ score of more than 0.5 were defined as responders. The cytokine levels in the blood were measured by LUMINEX 200 and ELISA. Results There were 6 responders and 5 non-responders. The responders showed a significantly lower serum level of chemokine (C-C motif) ligand 4/macrophage inflammatory protein-1ß (CCL4/MIP-1ß) at baseline compared to the non-responders. Receiver operating characteristic curves to distinguish responders from non-responders using the baseline serum CCL4/MIP-1ß level showed a good area under the curve of 0.9. The non-responders showed a significant increase in the level of CCL4/MIP-1ß after 4 weeks compared to the baseline. Conclusion A low baseline serum CCL4/MIP-1ß level may be useful for predicting a good mepolizumab response in severe eosinophilic asthma.

Baseline serum CXCL10 and IL-12 levels may predict severe asthmatics' responsiveness to omalizumab.

BACKGROUND: Omalizumab, a humanized anti-IgE monoclonal antibody, is the first molecularly targeted drug for severe asthmatics. However, responses to omalizumab vary widely among patients. OBJECTIVES: This study aimed to assess the potential of baseline serum cytokine levels as predictors of responsiveness to omalizumab. METHODS: Thirty-one patients with severe, persistent asthma were enrolled in this study and administered omalizumab for at least 1 year. Response to omalizumab was assessed based on the physician's global evaluation of treatment effectiveness (GETE) at 48 weeks of treatment. Blood samples were collected at baseline and 16 and 32 weeks after starting omalizumab and measured for 30 cytokines by Luminex 200 and ELISA. Exhaled nitric oxide (FeNO) levels, peripheral blood eosinophil counts, pre-bronchodilator pulmonary functions and Asthma Quality of Life Questionnaire scores were determined at baseline and 16, 32 and 48 weeks after starting omalizumab. The numbers of clinically significant asthma exacerbations in the previous year and during 48 weeks of treatment with omalizumab were assessed. RESULTS: GETE assessment showed 19 responders (61.3%) and 12 non-responders (38.7%). Responders showed significantly higher levels of CXCL10 and IL-12 at baseline compared to non-responders (CXCL10: responders, 1530.0 ± 315.2 pg/ml vs. non-responders, 1066.0 ± 396.8 pg/ml, P = 0.001; IL-12: responders, 60.2 ± 39.2 pg/ml vs. non-responders, 32.2 ± 26.3 pg/ml, P = 0.04). ROC curves to distinguish responders from non-responders using the baseline serum CXCL10 level showed a good AUC of 0.83. At 32 weeks of omalizumab therapy, serum CXCL10 tended to be increased (1350 ± 412.3 pg/ml at baseline vs. 1529 ± 637.6 pg/ml at 32 weeks, P = 0.16) and serum IL-12 tended to be decreased (49.4 ± 37.0 pg/ml at baseline vs. 43.9 ± 30.9 pg/ml at 32 weeks, P = 0.05). On the other hand, serum IL-5 and PDGF were significantly decreased (IL-5: 54.2 ± 13.8 pg/ml at baseline vs. 49.1 ± 12.5 pg/ml at 32 weeks, P = 0.008; PDGF: 4821 ± 2458 pg/ml at baseline vs. 4219 ± 1951 pg/ml at 32 weeks, P = 0.048). CONCLUSIONS: High baseline serum CXCL10 and IL-12 levels may be useful in predicting a good omalizumab response in severe asthmatics.

Low Variability in Peak Expiratory Flow Predicts Successful Inhaled Corticosteroid Step-Down in Adults with Asthma.

BACKGROUND: The prognosis for patients beyond 1 year after reduction of their inhaled corticosteroid (ICS) dose remains unknown. Predictive factors that can be evaluated before the initiation of asthma treatment or at ICS dose reduction are unknown. METHODS: We prospectively studied 223 patients in 6 hospitals in the National Hospital Organization of Japan during the 36 months after 50% reduction of their daily ICS dose. All patients recorded their morning and evening peak expiratory flows (PEFs) in their diaries. Lung function, bronchial hyperresponsiveness, fractional nitric oxide levels, number of eosinophils in sputum, and serum IgE levels were measured in most patients. Serum levels of IL-10, IL-33, and thymic stromal lymphopoietin before ICS dose reduction were measured in all patients. RESULTS: During the 36-month study period, asthma control was retained in 127 (59.6%) of the 213 enrolled patients who underwent ICS dose reduction. Multivariate logistic regression analysis revealed that, at the initiation of dose reduction, the factors most predictive of maintenance of asthma control after ICS dose reduction were a low serum IL-33 level (P < .01), low PEF variability over 1 week (P = .014), childhood onset of asthma (at age <10 years) (P = .03), and high serum IL-10 level (P = .035). CONCLUSIONS: We demonstrated that low PEF variability over 1 week, high serum IL-10 level, and low serum IL-33 concentration were useful factors for predicting that an adult's asthma will remain in control for months to years after a 50% reduction in the daily ICS dose.

Japanese guidelines for atopic dermatitis 2017.

Given the importance of appropriate diagnosis and appropriate assessment of cutaneous symptoms in treatment of atopic dermatitis, the basics of treatment in this guideline are composed of (1) investigation and countermeasures of causes and exacerbating factors, (2) correction of skin dysfunctions (skin care), and (3) pharmacotherapy, as three mainstays. These are based on the disease concept that atopic dermatitis is an inflammatory cutaneous disease with eczema by atopic diathesis, multi-factorial in onset and aggravation, and accompanied by skin dysfunctions. These three points are equally important and should be appropriately combined in accordance with the symptoms of each patient. In treatment, it is important to transmit the etiological, pathological, physiological, or therapeutic information to the patient to build a favorable partnership with the patient or his/her family so that they may fully understand the treatment. This guideline discusses chiefly the basic therapy in relation to the treatment of this disease. The goal of treatment is to enable patients to lead an uninterrupted social life and to control their cutaneous symptoms so that their quality of life (QOL) may meet a satisfactory level. The basics of treatment discussed in this guideline are based on the "Guidelines for the Treatment of Atopic Dermatitis 2008" prepared by the Health and Labour Sciences Research and the "Guidelines for the Management of Atopic Dermatitis 2015 (ADGL2015)" prepared by the Atopic Dermatitis Guidelines Advisory Committee, Japanese Society of Allergology in principle. The guidelines for the treatment of atopic dermatitis are summarized in the "Japanese Guideline for the Diagnosis and Treatment of Allergic Disease 2016" together with those for other allergic diseases.

Leptin enhances ICAM-1 expression, induces migration and cytokine synthesis, and prolongs survival of human airway epithelial cells.

There is rising interest in how obesity affects respiratory diseases, since epidemiological findings indicate a strong relationship between the two conditions. Leptin is a potent adipokine produced mainly by adipocytes. It regulates energy storage and expenditure and also induces inflammation. Previous studies have shown that leptin is able to activate inflammatory cells such as lymphocytes and granulocytes, but little is known about its effect on lung structural cells. The present study investigated the effects of leptin on human airway epithelial cells by using human primary airway epithelial cells and a human airway epithelial cell line, BEAS-2B. Flow cytometry showed enhanced ICAM-1 expression by both of those cells in response to leptin, and that effect was abrogated by dexamethasone or NF-κB inhibitor. Flow cytometry and quantitative PCR showed that airway epithelial cells expressed leptin receptor (Ob-R), whose expression level was downregulated by leptin itself. Multiplex cytokine analysis demonstrated enhanced production of CCL11, G-CSF, VEGF, and IL-6 by BEAS-2B cells stimulated with leptin. Furthermore, transfection of Ob-R small interference RNA decreased the effect of leptin on CCL11 production as assessed by quantitative PCR. Finally, leptin induced migration of primary airway epithelial cells toward leptin, suppressed BEAS-2B apoptosis induced with TNF-α and IFN-γ, and enhanced proliferation of primary airway epithelial cells. In summary, leptin was able to directly activate human airway epithelial cells by binding to Ob-R and by NF-κB activation, resulting in upregulation of ICAM-1 expression, induction of CCL11, VEGF, G-CSF, and IL-6 synthesis, induction of migration, inhibition of apoptosis, and enhancement of proliferation.

Japanese Guideline for Atopic Dermatitis 2014.

Given the importance of appropriate diagnosis and appropriate assessment of cutaneous symptoms in treatment of atopic dermatitis, the basics of treatment in this guideline are composed of (1) investigation and countermeasures of causes and exacerbating factors, (2) correction of skin dysfunctions (skin care), and (3) pharmacotherapy, as three mainstays. These are based on the disease concept that atopic dermatitis is a inflammatory cutaneous disease with eczema by atopic diathesis, multi-factorial in onset and aggravation, and accompanied by skin dysfunctions. These three points are equally important and should be appropriately combined in accordance with the symptoms of each patient. In treatment, it is important to transmit the etiological, pathological, physiological, or therapeutic information to the patient to build a favorable partnership with the patient or his/her family so that they may fully understand the treatment. This guideline discusses chiefly the basic therapy in relation to the treatment of this disease. The goal of treatment is to enable patients to lead an uninterrupted social life and to control their cutaneous symptoms so that their quality of life (QOL) may meet a satisfactory level. The basics of treatment discussed in this guideline are based on the "Guidelines for the Treatment of Atopic Dermatitis 2008" prepared by the Health and Labour Sciences Research and the "Guidelines for the Management of Atopic Dermatitis 2012 (ADGL2012)" prepared by the Atopic Dermatitis Guidelines Advisory Committee, Japanese Society of Allergology in principle. The guidelines for the treatment of atopic dermatitis are summarized in the "Japanese Guideline for the Diagnosis and Treatment of Allergic Disease 2013" together with those for other allergic diseases.

Japanese Guideline for Atopic Dermatitis 2014.

Given the importance of appropriate diagnosis and appropriate assessment of cutaneous symptoms in treatment of atopic dermatitis, the basics of treatment in this guideline are composed of (1) investigation and coun- termeasures of causes and exacerbating factors, (2) correction of skin dysfunctions (skin care), and (3) pharmacotherapy, as three mainstays. These are based on the disease concept that atopic dermatitis is a inflammatory cutaneous disease with eczema by atopic diathesis, multi-factorial in onset and aggravation, and accompanied by skin dysfunctions. These three points are equally important and should be appropriately combined in accordance with the symptoms of each patient. In treatment, it is important to transmit the etiological, pathological, physiological, or therapeutic information to the patient to build a favorable partnership with the patient or his/her family so that they may fully understand the treatment. This guideline discusses chiefly the basic therapy in relation to the treatment of this disease. The goal of treatment is to enable patients to lead an uninterrupted social life and to control their cutaneous symptoms so that their quality of life (QOL) may meet a satisfactory level. The basics of treatment discussed in this guideline are based on the "Guidelines for the Treatment of Atopic Dermatitis 2008" prepared by the Health and Labour Sciences Research and the "Guidelines for the Management of Atopic Dermatitis 2012 (ADGL2012)" prepared by the Atopic Dermatitis Guidelines Advisory Committee, Japanese Society of Allergology in principle. The guidelines for the treatment of atopic dermatitis are summarized in the "Japanese Guideline for the Diagnosis and Treatment of Allergic Disease 2013" together with those for other allergic diseases.

Doctor's delay in endobronchial tuberculosis.

OBJECTIVE: The aim of this study was to investigate the current status of doctor's delay in diagnosing endobronchial tuberculosis (EBTB) and to elucidate the risk factors contributing to the delay. METHODS: Retrospective clinicopathological analysis. PATIENTS: Sixty-two patients with EBTB were admitted at our hospital between 1999 and 2010. Their backgrounds, symptoms, diagnoses at initial consultation, delay in diagnosis, and clinical examination results were analyzed. RESULTS: Of the 62 patients, 59 had acid-fast, bacillipositive sputum smear test results at admission. Among the 40 patients with total diagnostic delay of more than 2 months, only 11 experienced long patient's delay exceeding 2 months. However, 22 patients experienced long doctor's delay of more than 2 months (28% vs. 55%, respectively, p < 0.05), suggesting that doctor's delay contributes more to total delay than patient's delay. Fever was less frequent in patients with long doctor's delays than in those without (0% vs. 18%, respectively), at the initial consultation. In addition, radiographs showed that patients with long doctor's delays more frequently presented with shadows in the lower lung field (50% vs. 23%, p < 0.05), and most of these patients had noncavitary shadows on admission. All 7 patients diagnosed with bronchial asthma at the initial consultation had long doctor's delays. CONCLUSION: These findings demonstrate that long doctor's delays in diagnosing EBTB remain an issue. The clinical features of EBTB with long doctor's delays were confirmed to be quite different from those of pulmonary tuberculosis.

Undiagnosed submucous cleft palate interfering with inhalation therapy and a solution.

Patients with velopharyngeal insufficiency who require inhalation therapy should be advised to hold their noses when inhaling medication to ensure that they receive the dosage prescribed.

A patient with relapsing polychondritis who had been diagnosed as intractable bronchial asthma.

A 62-year-old woman, diagnosed as bronchial asthma 3 years previously, was admitted due to acute severe dyspnea. Physical examination revealed saddle nose, flare/swelling of the ear auricles, and stridor. Computed tomography demonstrated thickening of tracheal/bronchial walls and stenosis of the lumen that deteriorated on expiration, suggesting tracheobronchomalacia. Auricle biopsy indicated cartilage destruction. Based on these findings, the patient was diagnosed as relapsing polychondritis. As demonstrated in this case, relapsing polychondritis involving airways might be misdiagnosed as bronchial asthma due to stridor and transient corticosteroid-related improvement. Early diagnosis is necessary to prevent irreversible airway stenosis and progression to tracheobronchomalacia.

Suppressive effects of a pyrazole derivative of curcumin on airway inflammation and remodeling.

To advance the control of airway epithelial cell function and asthma, we investigated the effects of a new curcumin derivative, CNB001, which possesses improved pharmacological properties. Normal human bronchial epithelial (NHBE) cells were stimulated with synthetic double-stranded RNA, Poly(I:C). CNB001 significantly suppressed IL-6, TNF-α, and GM-CSF production by NHBE cells, and did so more effectively than did curcumin or dexamethasone (DEX). CNB001 significantly inhibited the decrease of E-cadherin mRNA expression and increase of vimentin mRNA expression observed in NHBE cells induced by a combination of TGF-ß1 and TNF-α, which are markers of airway remodeling. In NHBE cells stimulated by TGF-ß1, CNB001 significantly downregulated the level of active serine peptidase inhibitor clade E member (SERPINE) 1, which is also reported to be related to airway remodeling. Whereas DEX alone significantly increased the active SERPINE1 level, the combination of DEX and CNB001 significantly suppressed active SERPINE1. In addition, CNB001 significantly suppressed neutrophil infiltration, IL-6, TNF-α, IL-13 and active SERPINE1 production in bronchoalveolar lavage fluid of the murine asthma model, which was not observed in the case of DEX. In conclusion, the curcumin derivative, CNB001, is a promising candidate to treat asthma associated with neutrophilic airway inflammation and remodeling.

[A case of tuberculous pleurisy developing contralateral effusion during anti-tuberculosis chemotherapy].

A 55-year-old woman was admitted to our hospital because of chest pain, fever, and right pleural effusion that was exudative and lymphocyte-dominant with a high level of adenosine deaminase (ADA). Since her blood QuantiFERON-TB 3G test (QFT) was positive, she was diagnosed with tuberculous pleurisy. After initiation of anti-tuberculosis chemotherapy with isoniazid, rifampicin, ethambutol, and pyrazinamide, her symptoms improved. Later, liquid culture of the pleural effusion turned positive for Mycobacterium tuberculosis. On the 18th day of treatment, her chest X-ray and computed tomography exhibited pleural effusion in a moderate amount in the left thorax, with subsiding pleural effusion in the right thorax. Thoracocentesis demonstrated that the left thorax effusion was also exudative and lymphocyte-dominant, with elevated QFT response and high ADA concentration, suggesting tuberculous pleurisy. Mycobacterium tuberculosis was detected in the culture of a left pleural biopsy specimen obtained by thoracoscopy. We assumed that the left pleural effusion was due to paradoxical worsening because (1) on admission no effusion or lung parenchymal lesion was detected in the left hemithorax, (2) on the 14th day of treatment she was afebrile without pleural effusion on both sides, and (3) the bacilli were sensitive to the drugs she had been taking regularly. We performed drainage of the left effusion and continued the same anti-tuberculosis drugs, which led to the elimination of all her symptoms and of the pleural effusion on both sides. In conclusion, paradoxical worsening should be included in the differential diagnosis when contralateral pleural effusion is detected during the treatment of tuberculosis.

Addition of leukotriene receptor antagonists to inhaled corticosteroids improved QOL of patients with bronchial asthma surveyed in suburban Tokyo, Japan.

BACKGROUND: Bronchial asthma is a chronic inflammatory disease that has a severe impact on health worldwide. METHODS: A survey of 10,771 patients with bronchial asthma in the Tama region, Tokyo was conducted for 5 years to examine treatment and quality of life (QOL). Subjects were patients aged ≥ 16 years and their physicians who replied to a questionnaire sent in November from 2002 to 2006. Symptoms of bronchial asthma, visits to an emergency room, use of drugs, and severity of asthma were investigated. RESULTS: Asthmatic symptoms improved over the 5 years, with a reduction in the number of emergency room visits. Since inhaled corticosteroids (ICS) were used by >80% of patients in 2002, we suspected that increased use of concomitant leukotriene receptor antagonists (LTRA) and long-acting ß(2) agonists (LABA) might have contributed to these findings. The effects of these drugs were compared between ICS + LTRA (n = 45) and ICS + LABA (n = 54) groups of patients. There was no significant difference in the ICS dose between these groups. In the ICS + LABA group, 18.5% and 22.2% of patients visited an emergency room before and after initiation of combination therapy, respectively, with no statistically significant difference. In contrast, the rate of emergency room visits in the ICS + LTRA group decreased from 24.4% to 6.6% after addition of LTRA. CONCLUSIONS: These results suggest that the frequency of visits to an emergency room was decreased by complementing the anti-inflammatory effect of ICS with further treatment of inflammation, particularly with LTRA.

A case of acute eosinophilic pneumonia following short-term passive smoking: an evidence of very high level of urinary cotinine.

Acute eosinophilic pneumonia (AEP) is characterized by febrile illness, diffuse pulmonary infiltrates with eosinophilia. The pathogenesis is not well understood. We report a case of 22-year-old men who never smoke presented with AEP 2 days after acute passive smoke exposure. He developed acute respiratory failure despite having no history of the disease. Computed tomography of the lung revealed diffuse bilateral pulmonary infiltrates. Lung biopsy specimens revealed marked eosinophil infiltration in the alveolar septa without signs of vasculitis. Two days prior to the disease, he was exposed to cigarette smoke for 2 hours in a closed area. In the absence of other causes, passive smoking may cause lung inflammatory responses. The level of urinary cotinine, which is a biomarker of smoke exposure, was considerably higher (0.198 µg/ml [201 ng/mg Creatinine]) than that in nonsmokers, but never detected following period. This case suggests that short-term passive smoking may cause AEP.

[Clinical investigation among elderly patients with tuberculosis].

OBJECTIVES: We discussed the factors which may confuse diagnosis and treatment of tuberculosis (TB) in elderly patients, in order to improve the situation. SUBJECTS AND METHODS: 414 patients who were hospitalized for active tuberculosis in Tokyo National Hospital were divided into three groups according to their ages (in years): less than 65, 65 to 74, and greater than 75. The three groups were compared in terms of performance status (PS), serum albumin level (whether over 3 g/dl or not), underlying diseases, symptoms at onset, sputum smear findings for acid-fast bacilli, presence or absence of cavitary lesion, regimen of treatment, adverse reaction to medications, and treatment outcome. RESULT: The older group had significantly poorer PS (3 or 4), lower albumin level, more complications, a larger proportion of non-respiratory to respiratory symptoms, less cavity formation, less likelihood of continuing to take drugs regularly and higher mortality. It is supposed that these characteristics are mostly due to the aging itself. CONCLUSION: Diagnosing and treating active tuberculosis among elderly people is difficult because of nonspecific and thus confusing findings due to other diseases or aging. Delay in diagnosis and start of treatment makes prognosis of their TB poorer. To improve this situation we should keep a high index to TB and make better use of novel diagnostic technologies. For satisfactory treatment that allows maintenance of a high level of activity of daily life, it is necessary to pay more attention to such aspects as nutrition and rehabilitation and to offer appropriate supports.

Down-regulation of secreted lymphocyte antigen-6/urokinase-type plasminogen activator receptor-related peptide-1 (SLURP-1), an endogenous allosteric alpha7 nicotinic acetylcholine receptor modulator, in murine and human asthmatic conditions.

Whereas acetylcholine (ACh) acts as a bronchoconstrictor and stimulator of mucus secretion from bronchial epithelium, it acts via alpha7 nicotinic Ach receptors (nAChRs) on macrophages in the airways to exert anti-inflammatory effects by reducing synthesis of pro-inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-alpha). Moreover, the effects of ACh are modified by secreted ly-6/urokinase-type plasminogen activator receptor-related peptide-1 (SLURP-1), a positive allosteric modulator of alpha7 nAChR signaling. Our aim was to explore the roles played by SLURP-1 in the pathophysiology of asthma by assessing SLURP-1 expression in the OVA-sensitized murine asthma model and in cultured human bronchial epithelial cells. Using real-time PCR we found that expression of SLURP-1 mRNA is down-regulated in the lungs of asthmatic model mice, as compared to healthy mice. In addition, immunohistochemical studies confirmed the diminished expression of SLURP-1 in the bronchioles of asthmatic mice, and showed it was due to extensive metaplasia of mucus-secreting cells and the concomitant loss of ciliated epithelial cells. Expression of SLURP-1 mRNA and protein was also significantly down-regulated in human epithelial cells stimulated with the pro-inflammatory cytokine interleukin-13 (IL-13), which is related to asthmatic condition. Thus SLURP-1 appears to be down-regulated in both an animal model of asthma and human epithelial cells treated with an inflammatory cytokine related to asthma. Those findings suggest that diminished expression of SLURP-1 in asthma attenuates its negative regulation of airway inflammation, and that perhaps changes in SLURP-1 expression could serve as a marker of airway damage in asthma.

Involvement of fibronectin and matrix metalloproteinases in airway smooth muscle cell migration for the process of airway remodeling.

BACKGROUND: Airway remodeling is a repair process occurring after airway injury; its primary histopathological features are subepithelial fibrosis and smooth muscle thickening of the bronchi. These histopathological changes are considered to occur due to bronchial smooth muscle cells (bSMC) that secrete extracellular matrix (ECM) proteins, which work as chemoattractants and influence cell migration. Therefore, we examined the interaction between bSMCs and ECM proteins in vitro for understanding the remodeling process in the bronchi. METHODS: bSMCs were cultured to collect a bSMC-conditioned medium. Using the bSMC-conditioned medium thus obtained, we performed a cell migration assay, characterized beta integrin expression, and identified ECM proteins and matrix metalloproteinases by western blotting and gelatin zymography, respectively. RESULTS: The response of bSMC migration to bSMC-conditioned medium increased with time in culture, and fibronectin (FIB) was detected as a chemoattractant for bSMCs in bSMC-conditioned medium by western blot analysis and a cell migration assay using anti-FIB antibodies. The involvement of beta1 integrin in the migration of bSMCs toward FIB contained in bSMC-conditioned medium was demonstrated by inhibition of cell migration using anti-beta1 integrin antibodies. Expression of beta1 integrin on bSMCs was confirmed by using a beta-integrin-mediated cell adhesion array. In addition, metalloproteinases detected in bSMC-conditioned medium by gelatin zymography were suggested to be matrix metalloproteinase-1 and 2 by western blotting and amino acid sequencing. CONCLUSIONS: Our results suggest that FIB and matrix metalloproteinases secreted from bSMCs might play major roles in bSMC migration in the process of airway remodeling.

[Pulmonary disorders in indium-processing workers].

The production of indium-tin oxide has increased during the past decade, owing to the increased manufacture of liquid-crystal panels, especially in Japan. We carried out a medical checkup including high resolution CT (HRCT), pulmonary function test, KL-6, SP-D and serum indium concentration, for 40 men (mean age 40.4 +/- 12.4 years old) working in an indium plant. Four workers who were all smokers had emphysematous changes on HRCT and one subject (non-smoker) had lung cancer. There were no findings of interstitial changes on HRCT. Serum KL-6 was significantly elevated (over 500U/ml) in 9 subjects (22.5%). Subjects with a high concentration of serum indium (3ng/ml<) had significantly longer exposure periods, higher KL-6 and SP-D levels compared with those with a low concentration (3ng/ml>). The serum indium concentration positively correlated with the KL-6 level. These results suggest that inhaled indium compounds can cause pulmonary disorders such as interstitial changes.