A cluster of cases of severe acute respiratory syndrome in Hong Kong.

BACKGROUND: Information on the clinical features of the severe acute respiratory syndrome (SARS) will be of value to physicians caring for patients suspected of having this disorder. METHODS: We abstracted data on the clinical presentation and course of disease in 10 epidemiologically linked Chinese patients (5 men and 5 women 38 to 72 years old) in whom SARS was diagnosed between February 22, 2003, and March 22, 2003, at our hospitals in Hong Kong, China. RESULTS: Exposure between the source patient and subsequent patients ranged from minimal to that between patient and health care provider. The incubation period ranged from 2 to 11 days. All patients presented with fever (temperature, >38 degrees C for over 24 hours), and most presented with rigor, dry cough, dyspnea, malaise, headache, and hypoxemia. Physical examination of the chest revealed crackles and percussion dullness. Lymphopenia was observed in nine patients, and most patients had mildly elevated aminotransferase levels but normal serum creatinine levels. Serial chest radiographs showed progressive air-space disease. Two patients died of progressive respiratory failure; histologic analysis of their lungs showed diffuse alveolar damage. There was no evidence of infection by Mycoplasma pneumoniae, Chlamydia pneumoniae, or Legionella pneumophila. All patients received corticosteroid and ribavirin therapy a mean (+/-SD) of 9.6+/-5.42 days after the onset of symptoms, and eight were treated earlier with a combination of beta-lactams and macrolide for 4+/-1.9 days, with no clinical or radiologic efficacy. CONCLUSIONS: SARS appears to be infectious in origin. Fever followed by rapidly progressive respiratory compromise is the key complex of signs and symptoms from which the syndrome derives its name. The microbiologic origins of SARS remain unclear.

Malignant mesothelioma in Hong Kong.

Malignant mesothelioma (mesothelioma) is rare. We conducted the first systematic study of the epidemiology of mesothelioma in Hong Kong from 1988 to May 2002 by reviewing medical records. Mesothelioma patients were identified from the database of 12 out of 20 hospitals that would have admitted mesothelioma patients territory-wide. These 12 hospitals served 73% of the total hospital bed-years of the 20 hospitals. We identified 67 mesothelioma patients. The estimated annual incidence was one per million, which was similar to the background incidence of one to two per million among Caucasians. Occupational history was available in 43 subjects. Three quarters of mesothelioma patients with available occupational history had occupational asbestos exposure. Restricting analysis to 48 patients with accessible medical records and using 67 occupational asbestosis patients for comparison, the epidemiology of mesothelioma in Hong Kong shares similarities with the literature: mean age of 63 years upon diagnosis, mean latency of 46 years, median survival of 9.5 months, male predominance, selective presentation among women, high prevalence among workers in ships and dockyards, predominantly epithelioid type, lower prevalence of asbestos bodies, and negative association with pleural plaques. Asbestos consumption in Hong Kong rose in the 1970s and peaked in early 1980s and late 1990s. Hong Kong may encounter an epidemic of mesothelioma in the 2010s if effective occupational asbestos control measures are not in place.

Inhibition of pyocyanin-potentiated IL-8 release by steroids in bronchial epithelial cells.

Airway epithelial cells are the first targets of environmental stimuli and local cytokines. Pyocyanin-induced synergism with interleukin (IL)-1 or tumour necrosis factor (TNF) in triggering IL-8 release has been documented previously. In this study, IL-8 mRNA and protein expression were examined in cultured human bronchial epithelial cells (BEAS-2B) stimulated with pyocyanin alone, and in combination with IL-1beta or phorbol 12,13-dibutyrate (PDBu) in the absence and presence of a group of glucocorticoids. IL-8 mRNA was measured by RT-PCR, and IL-8 protein by ELISA (cell supernatants). Pyocyanin alone produced no increase in IL-8 mRNA and release. However, pyocyanin upregulated the stimulatory effect of IL-1beta or PDBu on the release of IL-8 in a dose-dependent manner. The stimulatory effect of pyocyanin on the IL-1beta- or PDBu-stimulated IL-8 release was reduced in the presence of dexamethasone, budesonide, and fluticasone. Budesonide and fluticasone were 10-fold more potent than dexamethasone. The protein kinase C (PKC) inhibitor, Go6976, also significantly reduced the stimulatory effect of pyocyanin on IL-1beta, and PDBu increased IL-8 release. In conclusion, this study shows that PKC signal pathway seems to be involved in the pyocyanin-mediated upregulation of the IL-1beta and PDBu-induced IL-8 release in BEAS-2B cells. These findings suggest that a vicious cycle perpetuating inflammation may exist in the biologic milieu of bronchiectatic patients infected with Pseudomonas aeruginosa due to the production of pyocyanin. The priming action of pyocyanin appears to be blocked by glucocorticoids, thus providing in vitro data in support of the clinical efficacy of inhaled glucocorticoids as anti-inflammatory drugs.

Ciliary central microtubular orientation is of no clinical significance in bronchiectasis.

It has been suggested that patients with bronchiectasis might have increased central microtubular orientation angle (CMOA), which leads to poor coordination of ciliary beating, and consequently impairment of airway defence. We have employed transmission electron microscopy to assess CMOA of ciliated nasal mucosa in a cohort of 133 (81F, 56.8+/-16.1yr) stable bronchiectasis and 59 healthy subjects (30F, 49.3+/-22.1yr). There was no significant difference in CMOA between bronchiectasis (13.2 degree) and control subjects (13.0 degree, P=0.82). There was no significant difference in CMOA among patients according to the etiology of bronchiectasis, presence of nasal symptoms, or sputum status of Pseudomonas aeruginosa infection. Patients with more severe bronchiectasis, i.e. those with FEV(1) <60%, FVC <60%, or more than 4 bronchiectatic lung lobes, had significantly lower CMOA than their counterparts (P<0.05). There was no correlation between CMOA with age, 24h sputum volume, exacerbation frequency, FEV(1), FVC, or the number of bronchiectatic lung lobes (P>0.05). CMOA correlated with ciliary beat frequency (negative), and the percent of cilia showing ultrastructural or microtubular defects (P<0.05). Central microtubular orientation angle does not correlate with clinically important parameters, in contrary to the results reported by previously published smaller scale studies.

Elevated levels of transforming growth factor-beta(1) in serum of patients with stable bronchiectasis.

Bronchiectasis is a chronic inflammatory and infective airway disease characterized by irreversible dilatation of the bronchi and persistent purulent sputum. Transforming growth factor-beta(1) (TGF-beta(1)) has been found to be increased in the lungs or bronchoalveolar lavage fluid of patients with inflammatory lung diseases. However, little is known on the serum TGF-beta(1) levels in patients with bronchiectasis. We aimed to determine the serum TGF-beta(1) concentrations in 95 patients with stable bronchiectasis (63 women; mean+/-sd age, 58.9+/-14.1 years) and 68 control subjects (23 women; 48.9+/-12.8 years) by ELISA, and to correlate with clinical parameters. The serum TGF-beta(1) levels were significantly higher in bronchiectatic patients compared with control subjects (median [range], 1812.5 pg/ml [1226.4-4114.5 pg/ml] vs. 1342.4 pg/ml [940.3-2371.7 pg/ml]; P<0.001). There was, however, no correlation between serum TGF-beta(1) levels with FEV(1) (% predicted), FVC (% predicted), 24h sputum volume, the number of bronchiectatic lung lobes or total white blood cell count (P>0.05). Our findings support previous indications that TGF-beta(1) may contribute to bronchiectatic airway inflammation. Further studies on the potential mechanisms and pathogenesis implications of this elevation should also be pursued in future.

Aberrant promoter methylation in Chinese patients with non-small cell lung cancer: patterns in primary tumors and potential diagnostic application in bronchoalevolar lavage.

This study was aimed at defining patterns of aberrant gene methylation in non-small cell lung cancer (NSCLC) in Chinese patients and its use in detecting cancer cells in bronchoalveolar lavage (BAL). The methylation-specific PCR (MSP) was used to study methylation of the p16, retinoic acid receptor-beta (RARbeta), death-associated protein (DAP) kinase, and O(6)-methylguanine-DNA-methyltransferase (MGMT) genes in 75 NSCLCs [44 adenocarcinomas and 31 squamous cell carcinomas (SCCs)] and 68 BALs from suspected lung cancers. More females had adenocarcinoma than SCC (11 of 44 versus 2 of 31, P = 0.04). Aberrant methylation in at least one gene was found in 63 of 75 (84%) NSCLCs. p16, RARbeta, DAP kinase, and MGMT methylation was similar in adenocarcinoma and SCC. However, females with NSCLC showed more frequent p16 methylation than males (12 of 13 versus 36 of 62, P = 0.02), because of more frequent p16 methylation in female adenocarcinomas (10 of 11 versus 17 of 33, P = 0.02). This sexual difference was not observed in RARbeta, DAP kinase, and MGMT. At 92%, the frequency of p16 methylation in Chinese female NSCLC is one of the highest known. For BAL, MSP and cytological analysis showed concordant and discordant results in 25 of 68 and 43 of 68 samples. Of 41 MSP+/cytology- cases, 35 were eventually shown to have malignant lung lesions, 4 were at high risk but had no evidence of lung cancer, and 2 were lost to follow-up. There were two MSP-/cytology+ cases. Frequent gene methylations were seen in Chinese NSCLC patients. More frequent p16 methylation was seen in female patients. MSP is a useful molecular adjunct for cancer cell detection in BAL samples.

Exhaled and sputum nitric oxide in bronchiectasis: correlation with clinical parameters.

STUDY OBJECTIVES: Although there has been tremendous attention on endogenous nitric oxide (NO) production in many respiratory and systemic diseases, little is known on NO production in bronchiectasis. DESIGN AND SETTING: We determined exhaled and sputum NO levels in 109 patients with stable bronchiectasis (71 women; mean +/- SD age, 58.2 +/- 14.1 years) and 78 control subjects (39 women; mean age, 56.7 +/- 12.1 years) by using an automatic chemiluminescence analyzer. MEASUREMENTS AND RESULTS: There was no significant difference in exhaled NO between patients with bronchiectasis and control subjects (p = 0.11). Bronchiectasis patients with Pseudomonas aeruginosa infection had a significantly lower exhaled, but not sputum, NO levels than their counterparts and control subjects (p = 0.04 and p = 0.009, respectively). Exhaled NO correlated with 24-h sputum volume in P aeruginosa-infected patients (r = - 0.36; p = 0.002). After adjustment for sputum volume and number of bronchiectatic lung lobes, P aeruginosa-infected patients still had lower exhaled NO levels than their counterparts (p = 0.01). There was no correlation between exhaled NO with FEV(1), FVC, and the number of bronchiectatic lung lobes (p > 0.05). Sputum NO levels were not different between patients and control subjects (p = 0.64), and had no correlation with clinical parameters. CONCLUSION: Exhaled NO appears to be reduced among bronchiectasis patients with P aeruginosa infection independent of other clinical parameters, and further studies on the potential mechanisms and pathogenetic implications of this reduction should be pursued.

Validation of the Hong Kong Chinese version of the St. George Respiratory Questionnaire in patients with bronchiectasis.

STUDY OBJECTIVES: To validate the Hong Kong Chinese version of the St. George Respiratory Questionnaire (SGRQ-HK) in patients with bronchiectasis. DESIGN AND SETTING: Outpatients (93 patients; 61 women; mean age [+/- SD], 59.0 +/- 14.2 years) were assessed at baseline by the SGRQ-HK, the Hong Kong Chinese version of the 36-item short form health survey (SF-36-HK), and the hospital anxiety and depression scale (HADS). Forty randomly selected patients also were reassessed at 2 weeks for repeatability. Seventy-two patients were further reassessed at 6 months for responsiveness. MEASUREMENTS AND RESULTS: Cronbach alpha coefficients, which reflected internal consistency, were > 0.7 for all SGRQ-HK components except for symptoms (alpha = 0.59), and the intraclass correlation coefficients between baseline and the 2-week follow-up visits were between 0.80 and 0.94 (p > 0.05). SGRQ-HK component scores and total scores correlated with all the component scores of the SF-36-HK and the HADS (p < 0.02). SGRQ-HK component scores and total scores correlated with the scores of the SF-36-HK and the HADS, confirming the concurrent validity. All SGRQ-HK scores correlated negatively with FEV(1), FVC, and arterial oxygen saturation (p < 0.005), while the activity score correlated with the Karnofsky performance scale and the number of bronchiectatic lobes (p < 0.001). SGRQ-HK scores positively correlated with Borg scale scores, exacerbation frequency, and 24-h sputum volumes (p < 0.03). Patients with 24-h sputum volumes of > or = 10 mL or < 10 mL had significantly different SQRG-HK component scores and total scores (p < 0.002), although this sensitivity was not displayed by scores on the HADS or the SF-36-HK. Patients with 25% reductions in 24-h sputum volumes had significant improvements in SGRQ-HK activity scores, impact scores, and total scores (p < 0.02), but not in other quality-of-life measures or clinical parameters, indicating the responsiveness of the SGRQ-HK. CONCLUSION: The SGRQ-HK is a valid and sensitive instrument for determining quality of life in bronchiectasis patients.

Bronchoscopy of cetaceans.

Bronchoscopy is a standard diagnostic and therapeutic procedure in respiratory medicine and has been performed on many animal species. Cetaceans suffer considerable morbidity and mortality from lower respiratory tract infections, and it is very difficult to sample lower respiratory tract secretions for microbiology and other analyses. We report our experience on performing fiberoptic bronchoscopy in three bottle-nosed dolphins (Tursiops truncatus) and one false killer whale (Pseudorca crassidens), which should help other clinicians in performing bronchoscopy in cetaceans.

Capecitabine as salvage treatment for lymphoepithelioma-like carcinoma of lung.

Lymphoepithelioma-like carcinoma (LELC) of lung has previously demonstrated good clinical response to 5-fluorouracil containing chemotherapy regimen, similar to the observation in undifferentiated nasopharyngeal carcinoma. Capecitabine, which is converted into active 5-fluorouracil within tumor cells, has been found effective in colorectal, breast, and recently nasopharyngeal carcinomas. We report our experience in five patients with advanced or metastatic LELC of lung who were treated with single agent capecitabine as salvage chemotherapy. The finding of disease control in three of five patients, especially with exceptionally durable stable disease (14.8 months) in one patient, suggests the potential clinical activity of capecitabine in LELC of lung. Future studies on capecitabine-containing chemotherapy regimens in LELC of lung are warranted.

Chinese green tea ameliorates lung injury in cigarette smoke-exposed rats.

BACKGROUND: Epigallocatechin-3-gallate (EGCG), which has been shown to have potent antioxidant effect, comprises 80% of catechins in Chinese green tea. This study was to investigate whether cigarette smoke (CS) exposure would induce lung morphological changes and oxidative stress in the CS-exposed rat model, and whether Chinese green tea (Lung Chen tea with EGCG as its main active ingredient) consumption would alter oxidative stress in sera and lung leading to protection of CS-induced lung damage. METHODS: Sprague-Dawley rats were randomly divided into four groups, i.e. sham air (SA), 4% CS, 2% Lung Chen tea plus SA or 4% CS. Exposure to SA or 4% CS was performed for 1h/day for 56 days in ventilated smoking chambers. Sera and lung tissues were collected 24h after last CS exposure for histology and all biochemical assays. RESULTS: Airspace enlargement and goblet cell hyperplasia were observed after 56-day CS exposure alone, which were abolished in the presence of green tea consumption. Serum 8-isoprostane level was significantly elevated (p<0.01) as well as lung superoxide dismutase (SOD) and catalase activities in CS-exposed rats compared to SA-exposed rats (p<0.05), which returned to the levels of SA-exposed rats after Chinese green tea consumption. CONCLUSION: These results indicate that increased levels of systemic oxidative stress after CS exposure play an important role in the induction of lung damage. Chinese green tea may have the ability to suppress CS-induced oxidative stress that leads to protection of lung injury.

Lung cancer: future directions.

Increasingly, basic research is being translated into clinical benefits for patients. Recent studies have shed more light on the clinical use of targeted therapies such as tyrosine kinase and angiogenesis inhibitors, and predictive factors for their clinical benefit and their role in different clinical settings are now being elucidated. New insights into the basic biology of lung cancer hold translational promise in risk assessment, early detection, molecular staging, treatment response prediction and novel therapies. New targeted agents directed at apoptotic and developmental pathways have the potential to exploit newly discovered vulnerabilities in the basic machinery of cancer. In addition, exploration of the cancer stem cell phenomenon in lung cancer may generate new approaches to prevent recurrence in surgically respectable lung cancer, and for the long-term control of extensive disease. Molecular profiling may also allow for highly individualized prognostic, predictive and therapeutic treatment plans tailored for each patient based on the molecular diagnostic profile of their tumour. Advances in genetic susceptibility, early detection and individualized therapy based on each tumour's unique biological properties all hold promise for the future management of lung cancer.

Lymphoepithelioma-like carcinoma of the lung.

Lymphoepithelioma-like carcinoma (LELC) of the lung was first reported in 1987. In the past two decades, there have been just more than 150 cases reported in the literature. This uncommon but distinct form of non-small cell lung carcinoma has a predilection for young non-smoking Asians, without gender distinction. Histologically, it is indistinguishable from undifferentiated nasopharyngeal carcinoma. The carcinogenic role of latent Epstein-Barr virus infection in causing LELC of the lung has been evident almost exclusively in Asians compared with Caucasians. Among the reported cases, more than half were in early resectable stages (I or II) and there was a tendency for peribronchovascular spread with vascular encasement in advanced diseases. In order to establish the diagnosis of LELC of the lung, both nasopharyngeal carcinoma and lymphoma have to be excluded by endoscopic biopsy (with or without magnetic resonance imaging of the nasopharynx) and immunohistochemical staining of the biopsy samples. The mainstay of treatment for early-stage disease is curative surgical resection, whereas multimodality treatment (surgery, chemotherapy, radiotherapy) has been adopted in advanced or metastatic diseases. The overall survival is more favourable in LELC of the lung compared with non-LELC type of non-small cell lung carcinoma. Future collaborative studies especially on optimizing treatment for this uncommon malignancy are clearly warranted.

Analysis of TGF-beta(1) gene polymorphisms in Hong Kong Chinese patients with asthma.

BACKGROUND: The C-509T polymorphism of TGF-beta(1) gene has been associated with asthma and atopy in white populations. OBJECTIVE: We investigated the association between asthma and previously identified polymorphisms at C-509T and T869C of the TGF-beta(1) gene among 250 Chinese patients with asthma and 308 healthy controls in Hong Kong. METHODS: Genotyping was performed on peripheral blood genomic DNA by using PCR-RFLP. RESULTS: There were no differences in the frequencies of genotypes and alleles between patients and controls. The C-509T and T869C polymorphisms were in tight linkage disequilibrium (P < .01). Among atopic subjects, significant differences were found in genotype and allele frequencies for T869C polymorphism between patients and controls (P = .014 and P = .019, respectively), and individuals bearing the CC genotype were associated with increased risk for the development of asthma (odds ratio, 2.58; 95% CI, 1.17-5.66; P = .018) after adjusting for age, sex, and smoking status. Individuals with asthma bearing the CT genotype of the C-509T polymorphism had significantly increased risk for severe airflow obstruction compared with individuals who had mild obstruction (odds ratio, 4.00; 95% CI, 1.06-15.08; P = .035). CONCLUSION: Our results indicate that the polymorphisms at C-509T and T869C of the TGF-beta(1) gene are associated with asthma susceptibility in atopic subjects of the Hong Kong Chinese population, and the C-509T polymorphism may play a role in the pathogenesis of airflow obstruction.

Clinical value of ciliary assessment in bronchiectasis.

Although ciliary dysfunction and numerous ultrastructural defects have been described, and these could be etiologically important in the development of bronchiectasis, their correlation with relevant clinical parameters have not been systematically evaluated. We have prospectively evaluated the prevalence and clinical significance of ciliary beat frequency and ultrastructural defects of nasal respiratory mucosa obtained from 152 stable patients with idiopathic bronchiectasis (100F, 57.7 +/- 15.2 yrs) and 127 control subjects (58F, 56.0 +/- 24.2 yrs). Bronchiectasis patients had significantly slower ciliary beat frequency (p < 0.05), and a greater percent of patients had central and peripheral microtubular defects (OR 14.4, 95% CI 5.6-36.8), namely, extra peripheral microtubules, "9 + 1", "8 + 2", and compound cilia (p < 0.05), but not microtubular disarrangement, extra matrix or ciliary tail abnormalities (p > 0.05), than controls. Bronchiectasis patients also had a greater proportion of cilia with any ultrastructural microtubular defects, compound cilia, and ciliary tails than controls (p < 0.05). Ciliary beat frequency did not correlate with clinically relevant parameters (p > 0.05). However, the percent of cilia with central, but not peripheral, microtubular defects correlated with 24 h sputum volume (r = 0.40, p = 0.001, and r = -0.04, p = 0.70, respectively) and FEV1 (r = -0.24, p = 0.01, and r = 0.00, p = 0.99 respectively). Our results strongly suggest a pathogenic role for central microtubular defects in the development of idiopathic bronchiectasis.

Regression of bilateral bronchiectasis with inhaled steroid therapy.

Bronchiectasis is defined as pathological and permanent dilatation of the bronchial tree. Affected patients suffer from chronic sputum production and usually slowly progressive airway destruction as a result of continued airway infection and inflammation. Regression of bilateral bronchiectasis has never been reported in the English literature. We report the case of a 60-year-old woman with longstanding progressive idiopathic bilateral bronchiectasis whose respiratory symptoms, including sputum, rapidly disappeared after commencement of inhaled budesonide. Repeat computed tomography assessment 40 months after commencement of inhaled steroid therapy, showed partial regression of bronchial dilation and resolution of small airways sepsis. In the absence of other possible explanations for the partial resolution of the bronchiectasis, the present case suggests a possible benefit of inhaled steroid therapy in bronchiectasis.

Extrapulmonary presentation of asymptomatic pulmonary lymphangioleiomyomatosis.

Lymphangioleiomyomatosis (LAM) is a rare parenchymal lung disease, which affects young women of childbearing age and is characterized pathologically by proliferation of interstitial smooth muscle and formation of cysts in the lung. While LAM is usually predominantly a respiratory disorder, it can also initially involve other extrapulmonary organs. We report the case of a 35-year-old Chinese woman, who presented with a 4-week history of left thigh swelling which was found to be secondary to compression of pelvic veins by a mass lesion. The latter was found histologically to show LAM. Despite the patient being asymptomatic and displaying normal lung function, a thoracic high resolution CT scan showed typical features of early LAM. This case further illustrates that LAM can have multisystem involvement, and demonstrates the importance of being aware of the diagnosis in cases presenting with extrapulmonary manifestation, in order that patients are diagnosed and managed appropriately.

An indolent case of severe acute respiratory syndrome.

Severe acute respiratory syndrome (SARS) is a highly contagious and typically rapidly progressive form of atypical pneumonia, which spread from Asia to many parts of the world in early 2003. Clinical diagnosis of SARS requires the presence of unremitting fever and progressive pneumonia despite antibiotic therapy, particularly in the presence of lymphopenia and raised transaminase levels. We report the case of a woman who had undergone a successful allogeneic bone marrow transplant for acute myeloid leukemia. She presented initially with fever and a normal chest radiograph. Her indolent clinical course of SARS was punctuated by resolution of fever, but there was progressive radiologic deterioration and increasing serum antibody titer against SARS coronavirus. Treatment with oral prednisolone and ribavirin normalized her lymphopenia, altered transaminases, chest radiograph and high-resolution computed tomography appearances rapidly. Our experience should alert other clinicians in recognizing this atypical indolent presentation of SARS, to protect health care workers and the community at large and to ensure that these patients are properly treated.

Systemic oxidative and antioxidative status in Chinese patients with asthma.

BACKGROUND: Patients with asthma generate an increased amount of reactive oxygen species from peripheral blood cells. Reactive oxygen species produce many of the pathophysiologic changes associated with asthma and may contribute to its pathogenesis. OBJECTIVE: We investigated changes in antioxidant enzyme activities and oxidized glutathione (glutathione disulfide; GSSG) levels in erythrocytes from a group of healthy control Chinese subjects (n=135) and patients with asthma (n=106). METHODS: Baseline pulmonary function was measured for all subjects. Antioxidant status was evaluated by measuring erythrocyte superoxide dismutase, catalase, and glutathione peroxidase activities. Oxidative stress was also measured in terms of GSSG in erythrocytes with a kinetic microassay. RESULTS: Patients with asthma had significantly increased erythrocyte superoxide dismutase and catalase activities compared with controls (61.10 +/- 1.30 U/g hemoglobin [Hb] vs 55.51 +/- 1.82 U/g Hb [P=.018] and 0.0637 +/- 0.0021 U/g Hb vs 0.0257 +/- 0.0120 U/g Hb [P <.001] for the asthma and control groups, respectively). Conversely, erythrocyte glutathione peroxidase activity decreased (44.21 +/- 1.33 mU/g Hb vs 50.07 +/- 1.39 mU/g Hb for the asthma and control groups, respectively; P=.003). Patients with asthma also had significantly higher GSSG levels in erythrocyte hemolysates compared with controls (167.40 +/- 2.93 micromol/L vs 44.98 +/- 0.44 micromol/L for the asthma and control groups, respectively; P <.001), indicating increased oxidative stress. CONCLUSIONS: Asthma is accompanied by an alteration in systemic antioxidant status due to possible oxidative stress in this disease.