Circulating carbon monoxide level is elevated after sleep in patients with obstructive sleep apnea.

BACKGROUND: Patients with obstructive sleep apnea (OSA) have an increased risk of cardiovascular morbidity. This study aimed to determine circulating carbon monoxide (CO) levels, which have been suggested to be a marker of cardiovascular risk in patients with OSA. METHODS: Venous blood samples were obtained from 35 patients with OSA and 17 age-matched, healthy control subjects before and after polysomnography. Concentrations of venous CO and serum heme oxygenase (HO)-1 were determined by gas chromatography and enzyme-linked immunosorbent assay, respectively. RESULTS: Circulating CO levels in OSA patients were significantly increased in the morning, but not in the evening. The change in CO level, which was defined as a gap between the presleep and postsleep CO levels, correlated with apnea-hypopnea index and hypoxia duration as a percentage of total sleep time. No difference was found in serum HO-1 levels between OSA patients and control subjects. Treatment with continuous positive airway pressure (CPAP) resulted in normalization of the postsleep CO level. CONCLUSIONS: The postsleep circulating CO level is helpful for assessing the clinical severity of OSA. Moreover, treatment of OSA with CPAP can potentially reduce the risk of the disease associated cardiovascular events.

[A case of systemic lupus erythematosus presenting with jaundice and lupus pneumonia].

A 27-year-old Japanese woman was referred to our hospital for acute hepatitis in April 2002. She had been suffering from low grade fever and fatigue for a week. She also presented with dyspnea. On admission, ALT and AST were 857 U/l and 473 U/l respectively. Urine protein was 2 g/day. Chest radiograph showed bilateral infiltrative shadow and pleural effusion. She developed jaundice and her level of total bilirubin was increased to 9.6 mg/dl on May 9. Antibodies to hepatitis viruses were not detected. Testing for antimitochondrial antibodies, antismooth muscle antibodies, and antiribosomal P antibodies showed all negative. However, antinuclear antibodies were positive at titer 1:160 and anti-double stranded DNA antibodies were 130 U/ml. A diagnosis of systemic lupus erythematosus was made and oral administration of 60 mg/day prednisolon was started on May 10. Serum levels of ALT, AST and bilirubin were reduced to within normal range and pulmonary lesions were also improved. We conclude that this is a rare case of systemic lupus erythematosus presenting with acute hepatitis and jaundice.

[Case of rheumatoid arthritis presenting with pulmonary tuberculosis].

A 72-year-old man who had been suffering from rheumatoid arthritis for 25 years developed pulmonary tuberculosis after treatment with infliximab. He had been receiving this treatment since December 2003. Forty-six days later, a fever developed and the patient was hospitalized on February 3, 2004. Chest radiography and chest CT showed an infiltrative shadow with cavity formation. Mycobacterium tuberculosis was detected in the sputum. Infliximab is a monoclonal antibody toward tumor necrosis factor alpha (TNFalpha). It has been reported that infliximab increases the risk of tuberculosis in patients with rheumatoid arthritis in Europe and North America. This is the first case of pulmonary tuberculosis in a patient treated with infliximab in Japan.