Roles of Inflammatory Biomarkers in Exhaled Breath Condensates in Respiratory Clinical Fields / 결핵및호흡기질환

Background@#Exhaled condensates contain inflammatory biomarkers; however, their roles in the clinical field have been under-investigated. @*Methods@#We prospectively enrolled subjects admitted to pulmonology clinics. We collected exhaled breath condensates (EBC) and analysed the levels of six and 12 biomarkers using conventional and multiplex enzyme-linked immunosorbent assay, respectively. @*Results@#Among the 123 subjects, healthy controls constituted the largest group (81 participants; 65.9%), followed by the preserved ratio impaired spirometry group (21 patients; 17.1%) and the chronic obstructive pulmonary disease (COPD) group (21 patients; 17.1%). In COPD patients, platelet derived growth factor-AA exhibited strong positive correlations with COPD assessment test (ρ=0.5926, p=0.0423) and COPD-specific version of St. George’s Respiratory Questionnaire (SGRQ-C) score (total, ρ=0.6725, p=0.0166; activity, ρ=0.7176, p=0.0086; and impacts, ρ=0.6151, p=0.0333). Granzyme B showed strong positive correlations with SGRQ-C score (symptoms, ρ=0.6078, p=0.0360; and impacts, ρ=0.6007, p=0.0389). Interleukin 6 exhibited a strong positive correlation with SGRQ-C score (activity, ρ=0.4671, p=0.0378). The absolute serum eosinophil and basophil counts showed positive correlations with pro-collagen I alpha 1 (ρ=0.6735, p=0.0164 and ρ=0.6295, p=0.0283, respectively). In healthy subjects, forced expiratory volume in 1 second (FEV1)/forced vital capacity demonstrated significant correlation with CC chemokine ligand 3 (CCL3)/macrophage inflammatory protein 1 alpha (ρ=0.3897 and p=0.0068). FEV1 exhibited significant correlation with CCL11/eotaxin (ρ=0.4445 and p=0.0017). @*Conclusion@#Inflammatory biomarkers in EBC might be useful to predict quality of life concerning respiratory symptoms and serologic markers. Further studies are needed.

Low Skeletal Muscle Mass and Clinical Outcomes in Chronic Obstructive Pulmonary Disease / 결핵및호흡기질환

Background@#In patients with chronic obstructive pulmonary disease (COPD), decreased muscle mass is a frequently encountered comorbidity in clinical practice. However, the evaluation of muscle mass in patients with COPD in real-world practice is rare. @*Methods@#We retrospectively reviewed the electronic medical records of all patients with COPD who underwent bioelectrical impedance analysis at least once between January 2011 and December 2021 in three hospitals. Then, we analyzed the performance rate of muscle mass measurement in the patients and the correlation between muscle mass, clinical parameters, and COPD prognosis. @*Results@#Among the 24,502 patients with COPD, only 270 (1.1%) underwent muscle mass measurements. The total skeletal muscle mass index was significantly correlated with albumin, alanine transaminase, and creatinine to cystatin C ratio in patients with COPD (r=0.1614, p=0.011; r=0.2112, p=0.001; and r=0.3671, p=0.001, respectively). Acute exacerbation of COPD (AE COPD) was significantly correlated with muscle mass, especially the truncal skeletal muscle mass index (TSMI) in males (r=–0.196, p=0.007). In the multivariate analysis, TSMI and cystatin C were significant risk factors for AE COPD (hazard ratio, 0.200 [95% confidence interval, CI, 0.048 to 0.838] and 4.990 [95% CI, 1.070 to 23.278], respectively). @*Conclusion@#Low muscle mass negatively affects the clinical outcomes in patients with COPD. Despite its clinical significance, muscle mass measurement is performed in a small proportion of patients with COPD. Therefore, protocols and guidelines for the screening of sarcopenia in patients with COPD should be established.

Effects of Asthma Medication Type on Asthma Exacerbation in a Real-World Setting

Purpose@#Currently, there are multiple options for the pharmacological treatment of asthma. This study aimed to compare the effects of different asthma medications on exacerbation in a real-world setting. @*Materials and Methods@#We retrospectively reviewed electronic medical records of asthma patients who visited the hospital from November 1, 2016 to October 31, 2019. The number of asthma exacerbations requiring administration of systemic steroids was the primary outcome. A time-varying Cox regression analysis was used to reflect the real-world setting: variable usage times, discontinuation, and switching of medication. @*Results@#Among 937 patients with asthma, 228 (24.3%) experienced asthma exacerbation during the study period. Asthma exacerbation was observed in patients using short-acting β 2-agonists (SABA) alone (50.4% vs. 28.6%, p<0.001) as well as in patients not using inhaled corticosteroids (ICS) (58.8% vs. 40.3%, p<0.001), long-acting β 2-agonists (LABA) (54.8% vs. 36.1%, p<0.001), and leukotriene receptor antagonists (71.5% vs. 50.8%, p<0.001). A time-varying Cox regression analysis of asthma exacerbations according to the duration of asthma medication showed that SABA alone increased the risk of asthma exacerbation [hazard ratio (HR), 1.834; 95% confidence interval (CI), 1.299–2.588; p=0.001], whereas ICS-LABA decreased the risk (HR, 0.733; 95% CI, 0.538–0.997; p=0.048). However, in the subgroup analysis according to medication type, specific ingredients showed no significant differences. @*Conclusion@#In the real world, asthma medications affect asthma exacerbation variably according to the medication type.

Positive Effects of the National Cigarette Price Increase Policy on Smoking Cessation in South Korea / 결핵및호흡기질환

BACKGROUND@#In January 2015, South Korea's government raised the cigarette tax, and the retail price of cigarettes abruptly increased by 80% compared to the previous year. This research aimed to determine the effect of this increase on smoking cessation among South Korean smokers.@*METHODS@#We analyzed data collected by the 2013–2015 South Korea National Health and Nutrition Examination Survey of 15,203 South Koreans over 19 years old using regression analysis. We examined the recent non-smoking period of nonsmoking people, prepared according to the survey, and analyzed the recent smoking cessation ratio.@*RESULTS@#Among smokers, from 2013 to 2014, the smoking cessation rate was 7.2%, and it increased to 9.9% in 2015 after the increase in the cigarette tax. In 2015, the recent smoking cessation rate was higher among people over the age of 60 (odds ratio [OR], 2.67) compared to those between the ages of 40 and 49. The recent smoking cessation rate was higher among people with below elementary education (OR, 2.28) and above university education (OR, 1.94) compared to high school, higher for those with apartments (OR, 1.74) compared to general type residences, and higher among those with a household income in the low-middle quartile (Q2) (OR, 2.32) compared to the highest quartile (Q4).@*CONCLUSION@#This innovative policy including increase in cigarette prices affected smoking cessation, and its impact varied by sub-group of smokers in South Korea.

Positive Effects of the National Cigarette Price Increase Policy on Smoking Cessation in South Korea / 결핵및호흡기질환

BACKGROUND@#In January 2015, South Korea's government raised the cigarette tax, and the retail price of cigarettes abruptly increased by 80% compared to the previous year. This research aimed to determine the effect of this increase on smoking cessation among South Korean smokers.@*METHODS@#We analyzed data collected by the 2013–2015 South Korea National Health and Nutrition Examination Survey of 15,203 South Koreans over 19 years old using regression analysis. We examined the recent non-smoking period of nonsmoking people, prepared according to the survey, and analyzed the recent smoking cessation ratio.@*RESULTS@#Among smokers, from 2013 to 2014, the smoking cessation rate was 7.2%, and it increased to 9.9% in 2015 after the increase in the cigarette tax. In 2015, the recent smoking cessation rate was higher among people over the age of 60 (odds ratio [OR], 2.67) compared to those between the ages of 40 and 49. The recent smoking cessation rate was higher among people with below elementary education (OR, 2.28) and above university education (OR, 1.94) compared to high school, higher for those with apartments (OR, 1.74) compared to general type residences, and higher among those with a household income in the low-middle quartile (Q2) (OR, 2.32) compared to the highest quartile (Q4).@*CONCLUSION@#This innovative policy including increase in cigarette prices affected smoking cessation, and its impact varied by sub-group of smokers in South Korea.

A case of glutathione-induced life-threatening asthma attack

Baek-ok injection (glutathione) has been widely used antioxidant therapy to whiten and has antiaging effects in Korea. Glutathione is an enzyme which synthesizes leukotriene, then it can induce asthma attack theoretically; however, there have been few case reports concerning this therapy. In this report, we described a 41-year-old woman who developed glutathione-induced life-threatening asthma attack. She has asthma history controlled by an intermittent salbutamol inhaler. She developed general weakness and dyspnea right after glutathione injection, and injection was discontinued. Dyspnea was progressively aggravated, and she lost consciousness with shock. Cardiopulmonary resuscitation was started, and she arrived at the Emergency Department with wheezing, hypoxia, severe respiratory acidosis, and nonmeasurable blood pressure. Intubation and mechanical ventilation were started with intramuscular epinephrine/intravenous methylprednisolone injection and repeated salbutamol/ipratropium/budesonide inhalation. After 5 hours, extubation and spontaneous breathing were successful without wheezing. Next day, pulmonary function test showed moderate an obstructive airway disease pattern, and she was discharged with inhaled fluticasone/salmeterol, oral methylprednisolone, and montelukast. We can exclude anaphylaxis, because serum tryptase obtained at the Emergency Department was 0.0 mg/dL and the absence of skin lesions and angioedema at arrival. Baek-ok injection (glutathione) should be carefully performed in asthma patients.

Positive Effects of the National Cigarette Price Increase Policy on Smoking Cessation in South Korea / 결핵

Asthma-COPD Overlap Shows Favorable Clinical Outcomes Compared to Pure COPD in a Korean COPD Cohort

PURPOSE: Comparisons of the characteristics of chronic obstructive pulmonary disease (COPD) and asthma-COPD overlap syndrome (ACOS) have been the focus of several studies since the diseases were defined by the Global Initiative for Asthma and Global Initiative for Chronic Obstructive Lung Disease guidelines. However, no consensus is available yet. In this study, we aimed to compare the characteristics of asthma-COPD overlap (ACO) and COPD. METHODS: We retrospectively reviewed 1,504 patients with COPD in a Korean COPD Subtype Study cohort. The occurrence of ACO was defined as a positive response to a bronchodilator (an increase in forced expiratory volume in 1 second [FEV1] of 12% and 200 mL). RESULTS: Among 1,504 patients with COPD, 223 (14.8%) were diagnosed with ACO. Men (95.5%) and current smokers (32.9%) were more prevalent in the ACO group compared with the pure COPD group (90.5% and 25.3%, respectively; P=0.015 and P=0.026, respectively). Patients with ACO had a better quality of life (St. George's Respiratory Questionnaire for COPD score=31.0±18.0 [mean±standard deviation]) than those with pure COPD (35.3±19.1) (P=0.002). Although the prevalence of acute exacerbation was not different between the 2 groups, patients with severe exacerbation required hospital admission significantly more frequently in the pure COPD group than in the ACO group. Patients with ACO showed a higher likelihood of FEV1 recovery than those with pure COPD (P<0.001). CONCLUSIONS: We suggest that ACO is characterized by less severe symptoms, and therefore it might lead to rare severe exacerbation and the possibility of lung function recovery.

Association of Specific Immunoglobulin E to Staphylococcal Enterotoxin with Airway Hyperresponsiveness in Asthma Patients / 결핵및호흡기질환

BACKGROUND: Specific immunoglobulin E (IgE) sensitization to staphylococcal enterotoxin (SE) has been recently considered to be related to allergic disease, including asthma. Despite studies on specific IgE (sIgE) to SE and its relationship to asthma diagnosis and severity, the association of sIgE to SE with airway hyperresponsiveness (AHR) remains unclear. METHODS: We enrolled 81 asthma patients admitted to the Severance Hospital in Korea from March 1, 2013, to February 28, 2015 and retrospectively reviewed the electronic medical records of the enrolled subjects. The serum levels of sIgE to SE (A/B) of all subjects was measured using the ImmunoCAP 250 (Phadia) system with SE-sIgE positive defined as >0.10 kU/mL. RESULTS: The SE-sIgE level was not significantly correlated with asthma severity (forced expiratory volume in 1 second [FEV₁], FEV₁/forced vital capacity, sputum eosinophils, and serum eosinophils), whereas the SE-sIgE level in patients with positive AHR (mean±standard error of the mean, 0.606±0.273 kU/mL) was significantly higher than that in patients with negative AHR (0.062±0.015 kU/mL, p=0.034). In regression analysis, SE sensitization (sIgE to SE ≥0.010 kU/mL) was a significant risk factor for AHR, after adjustment for age, sex, FEV₁, and sputum eosinophils (odds ratio, 7.090; 95% confidence interval, 1.180–42.600; p=0.032). Prevalence of SE sensitization was higher in patients with allergic rhinitis and non-atopic asthma patients, as compared to patients without allergic rhinitis and atopic asthma patients, respectively, but without statistical significance. CONCLUSION: SE sensitization is significantly associated with AHR.

Efficacy of Surgical Treatment for Brain Metastasis in Patients with Non-Small Cell Lung Cancer

PURPOSE: Patients with non-small cell lung cancer (NSCLC) and simultaneously having brain metastases at the initial diagnosis, presenting symptoms related brain metastasis, survived shorter duration and showed poor quality of life. We analyzed our experiences on surgical treatment of brain metastasis in patients with NSCLC. MATERIALS AND METHODS: We performed a single-center, retrospective review of 36 patients with NSCLC and synchronous brain metastases between April 2006 and December 2011. Patients were categorized according to the presence of neurological symptoms and having a brain surgery. As a result, 14 patients did not show neurological symptoms and 22 patients presented neurological symptoms. Symptomatic 22 patients were divided into two groups according to undergoing brain surgery (neurosurgery group; n=11, non-neurosurgery group; n=11). We analyzed overall surgery (OS), intracranial progression-free survival (PFS), and quality of life. RESULTS: Survival analysis showed there was no difference between patients with neurosurgery (OS, 12.1 months) and non-neurosurgery (OS, 10.2 months; p=0.550). Likewise for intracranial PFS, there was no significant difference between patients with neurosurgery (PFS, 6.3 months) and non-neurosurgery (PFS, 5.3 months; p=0.666). Reliable neurological one month follow up by the Medical Research Council neurological function evaluation scale were performed in symptomatic 22 patients. The scale improved in eight (73%) patients in the neurosurgery group, but only in three (27%) patients in the non-neurosurgery group (p=0.0495). CONCLUSION: Patients with NSCLC and synchronous brain metastases, presenting neurological symptoms showed no survival benefit from neurosurgical resection, although quality of life was improved due to early control of neurological symptoms.

A Rare Case of Primary Thymic Adenocarcinoma Mimicking Small Cell Lung Cancer / 결핵및호흡기질환

Primary thymic adenocarcinoma is a very rare malignancy of the anterior mediastinum with no standardized treatment. A 36-year-old male patient presented with hoarseness over the past 3 months. A chest computed tomography (CT) scan showed an infiltrative mass to the proximal vessels and aortic arch in left upper mediastinum (4.1x3.1x5.4 cm). Brain magnetic resonance imaging (MRI) showed focal lesions, suggesting metastasis in the left frontal lobe. A thoracoscopic biopsy of the mediastinal mass confirmed a primary thymic adenocarcinoma forming a glandular structure with atypia of tumor cells. The patient received four cycles of systemic chemotherapy, consisting of etoposide and cisplatin, with concurrent radiotherapy (6,000 cGy/30 fractions) to the mediastinal lesion and the metastatic brain lesion (4,200 cGy/12 fractions). A follow-up chest CT scan and brain MRI showed a decrease in the size of the left upper mediastinal mass and brain lesion. We report a rare case of the primary thymic adenocarcinoma with a literature review.

Lipiodol-induced pneumonitis following transarterial chemoembolization for ruptured hepatocellular carcinoma / 영남의대학술지

Transarterial chemoembolization (TACE) is a widely accepted nonsurgical modality used for the treatment of multinodular hepatocellular carcinoma (HCC). The careful selection of the candidate is important due to the risk of developing various side effects. Fever, nausea, abdominal pain, and liver enzyme elevation are commonly known side effects of TACE. Hepatic failure, ischemic cholecystitis, and cerebral embolism are also reported, although their incidence might be low. Pulmonary complication after TACE is rare, and the reported cases of lipiodol pneumonitis are even rarer. A 53-year-old man was treated with TACE for ruptured HCC associated with hepatitis B virus infection. On day 19 after the procedure, the patient complained of dyspnea and dry cough. Chest computed tomography showed diffuse ground glass opacities in the wholelung fields, suggesting lipiodol-induced pneumonitis. After 2 weeks of conservative management, the clinical symptoms and radiologic abnormalities improved. Reported herein is the aforementioned case of lipiodol-induced pnemonitis after TACE, with literature review.

Late Respiratory Infection after Lung Transplantation / 결핵및호흡기질환

BACKGROUND: Aiming to improve outcome of lung transplantation (LTx) patients, we reviewed risk factors and treatment practices for the LTx recipients who experienced respiratory infection in the late post-LTx period (>1 month after LTx). METHODS: We analyzed the clinical data of 48 recipients and donors from 61 LTx, who experienced late respiratory infections. Late respiratory infections were classified according to the etiology, time of occurrence, and frequency of donor-to-host transmission or colonization of the recipient prior to transplantation. RESULTS: During the period of observation, 42 episodes of respiratory infections occurred. The organisms most frequently involved were gram (-) bacteria: Acinetobacter baumannii (n=13, 31.0%), Pseudomonas aeruginosa (n=7, 16.7%), and Klebsiella pneumoniae (n=4, 10.0%). Among the 42 episodes recorded, 14 occurred in the late post-LTx period. These were bacterial (n=6, 42.9%), fungal (n=2, 14.3%), viral (n=4, 28.5%), and mycobacterial (n=2, 14.3%) infections. Of 6 bacterial infections, 2 were from multidrug-resistant (MDR) A. baumannii and one from each of MDR P. aeruginosa, extended spectrum beta-lactamase (+) K. pneumoniae, methicillin-resistant Staphylococcus aureus and Streptococcus pneumoniae. Infection-related death occurred in 6 of the 14 episodes (43%). CONCLUSION: Although the frequency of respiratory infection decreased sharply in the late post-LTx period, respiratory infection was still a major cause of mortality. Gram (-) MDR bacteria were the agents most commonly identified in these infections.

A Cerebral Air Embolism after CT-Guided Percutaneous Transthoracic Fine-Needle Aspiration Biopsy of the Lung / 대한내과학회지

Low-dose thoracic computed tomography (CT) for the early diagnosis of lung cancer detects many solitary pulmonary nodules. Fine needle aspiration biopsy (FNAB) is the diagnostic method used most commonly in the diagnosis of solitary pulmonary nodules. Cerebral air embolism is a rare, fatal complication of FNAB. Hyperbaric oxygenation therapy within 6 hours of the event ensures a good prognosis with cerebral air embolisms. We present a case of cerebral air embolism that occurred during CT-guided lung FNAB biopsy that was treated with hyperbaric oxygenation within 6 hours. The patient recovered completely from the neurological deficit and had a favorable long-term outcome.

A Case of ANCA-Negative Generalized Wegener's Granulomatosis / 영남의대학술지

Wegener's granulomatosis is a very rare systemic vasculitis characterized by necrotizing granulomatosis. The detection of antineutrophil cytoplasm antibody (ANCA) is a valuable finding in diagnosing Wegener's granulomatosis because ANCA is positive in approximately 90 percent of patients with active, generalized Wegener's granulomatosis. But ANCA is not necessarily positive to make a diagnosis. A 59-year-old man was transferred to our hospital. He was diagnosed with lung abscess and treated with antibiotics at previous hospital. Initially, the ANCA was negative in immunofluorescence assay but we suspected Wegener's granulomatosis because of systemic inflammatory symptoms. Clinical symptoms deteriorated rapidly so we did bronchoscopic biopsy early. Wegener's granulomatosis was diagnosed according to pathologic finding that reported necrotizing granulomatous inflammation associated with vasculitis. Thus we treated with steroid then clinical symptoms and laboratory findings were improved.

Associations of Moderate to Severe Asthma with Obstructive Sleep Apnea

PURPOSE: This study aimed to evaluate the correlation between associating factors of moderate to severe asthma with obstructive sleep apnea (OSA). MATERIALS AND METHODS: One hundred and sixty-seven patients who visited the pulmonary and sleep clinic in Severance Hospital presenting with symptoms of sleep-disordered breathing were evaluated. All subjects were screened with ApneaLink. Thirty-two subjects with a high likelihood of having OSA were assessed with full polysomnography (PSG). RESULTS: The mean age was 58.8+/-12.0 years and 58.7% of subjects were male. The mean ApneaLink apnea-hypopnea index (AHI) was 12.7+/-13.0/hr. The mean ApneaLink AHI for the 32 selected high risk patients of OSA was 22.3+/-13.2/hr, which was lower than the sleep laboratory-based PSG AHI of 39.1+/-20.5/hr. When OSA was defined at an ApneaLink AHI > or =5/hr, the positive correlating factors for OSA were age, male gender, and moderate to severe asthma. CONCLUSION: Moderate to severe asthma showed strong correlation with OSA when defined at an ApneaLink AHI > or =5/hr.

Clinical Outcomes of Tigecycline in the Treatment of Multidrug-Resistant Acinetobacter baumannii Infection

PURPOSE: Acinetobacter baumannii (A. baumannii) has emerged as a major cause of nosocomial pneumonia and sepsis in seriously ill patients. Multidrug-resistant A. baumannii (MDRAB) is increasing in frequency, and the management of it's infections is consequently difficult. Therefore, tigecycline is considered to be the drug of choice for MDRAB treatment. The aim of our study was to evaluate the microbiological eradication and clinical effectiveness of tigecycline against MDRAB in seriously ill patients, including patients with ventilator-associated pneumonia (VAP). MATERIALS AND METHODS: We conducted a retrospective study including patients with A. baumannii infections who were treated with tigecycline between April 1, 2009 and March 31, 2010. We treated 27 patients with tigecycline for MDRAB infections. RESULTS: The mean age of patients was 66.2 years, and 20 (74.1%) patients were male. The median length of stay at hospital was 74.6 days. MDRAB was eradicated from the site of infection in 23 cases (85.2%), however, only 17 cases (63.0%) showed positive clinical responses. Overall, an in-hospital mortality rate of 51.9% was observed, and 4 cases of death were attributable to sepsis. The combination therapy showed better clinical and microbial success rates than the monotherapy without significant difference. CONCLUSION: We observed the relatively low clinical success rate although the microbial eradication rate was high, probably due to superinfections in VAP and bacteremia. We suggest that clinicians should limit tigecycline monotherapy for MDRAB infection in critically ill patients, until large controlled clinical trials should be conducted.

A Case of Multiple Tuberculosis Associated with Infliximab Therapy in Crohn's Disease / 대한내과학회지

Infliximab, a tumor necrosis factor-alpha (TNF-alpha) inhibitor, has been approved for the treatment of a variety of inflammatory illnesses, including Crohn's disease. However, infliximab can increase the risk of reactivation of latent tuberculosis (Tbc) infection by affecting host immune responses. Therefore, a screening test should be performed before the initiation of infliximab therapy, and patients with evidence of latent infection should be treated with prophylactic anti-Tbc therapy. Here, we report a case of multifocal disseminated tuberculosis after treatment with infliximab in a patient diagnosed with Crohn's disease who had no past history of Tbc and showed a negative screening test.

A Case of Cranial Nerve Palsy as a Paraneoplastic Syndrome in Non-Small Cell Lung Cancer / 결핵및호흡기질환

Paraneoplastic neurologic syndrome is a group of assorted disorders resulting from damage to the nervous system in cancer, remote from primary site, and not related to metastasis, infection, or metabolic disorder associated with cancer. Patient with small cell lung cancer sometimes shows various neurological syndromes, but patient with non-small cell lung cancer rarely shows neurologic syndromes and few antineuronal antibodies have been found. Here, we report a case of 53-year-old male patient who developed ptosis and extraocular muscular limitation of left eye due to third and forth cranial nerve palsy in non-small cell lung cancer without brain metastasis. These neurologic symptoms improved after lobectomy without any other treatment immunotherapy.

Clinical Features and Outcomes of Idiopathic Pulmonary Alveolar Proteinosis in Korean Population

Idiopathic pulmonary alveolar proteinosis (PAP) is a rare disorder in which lipoproteinaceous material accumulates within alveoli. There were few reports on Asian populations with idiopathic PAP. We retrospectively reviewed 38 patients with idiopathic PAP in Korea. We assessed clinical features, therapeutic efficacy and outcomes of whole lung lavage in patients with idiopathic PAP. The mean age at diagnosis was 52 yr. Eighty six percent of patients were symptomatic at diagnosis. Dyspnea and cough were the most common symptoms. Crackles were the most common physical examination finding. On pulmonary function test, a mild restrictive ventilatory defect was common, with a predicted mean forced vital capacity (FVC) of 77% and forced expiratory volume in one second (FEV1) of 84.6%. Diffusing capacity was disproportionately reduced at 67.7%. Arterial blood gas analysis revealed hypoxemia with a decreased PaO2 of 69.0 mmHg and an increased D(A-a)O2 of 34.2 mmHg. After whole lung lavage, PaO2, D(A-a)O2 and DLCO were significantly improved, but FVC and total lung capacity (TLC) were not different. This is the first multicenter study to analyze 38 Korean patients with idiopathic PAP. The clinical features and pulmonary parameters of Korean patients with idiopathic PAP are consistent with reports in other published studies. Whole lung lavage appears to be the most effective form of treatment.