Pulmonary Mycobacterium avium complex infection associated with the IVS8-T5 allele of the CFTR gene.

BACKGROUND: The T5 allele in intron 8 (IVS8) on specific haplotype backgrounds (e.g., long TG repeats) causes abnormal splicing in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, and is also known to be associated with chronic airway diseases. OBJECTIVE: To investigate the role of CFTR variations for susceptibility to pulmonary Mycobacterium avium complex (MAC) infection. PARTICIPANTS: Three hundred patients with pulmonary MAC infection (72 males, 228 females; mean age at onset 61.6 + or - 12.4 years) took part in this study. Diagnosis of MAC infection was based on American Thoracic Society criteria. Clinical profiles were collected and blood samples were genotyped for TG repeats, poly-T and M470V polymorphisms. RESULTS: We found significantly higher T5 frequency in MAC patients than in healthy controls from our own study (0.035 and 0.005, respectively, P = 0.023) and other reports. Homozygote for the T5 allele was found in two MAC patients. All T5 alleles were associated with longer TG repeats, the TG12 or TG13 allele. Seventeen of the 21 T5 alleles appeared to be associated with the V470 allele. Other polymorphisms did not show any significant differences in frequency. CONCLUSIONS: These findings suggest that the IVS8 5T allele might be involved in susceptibility to pulmonary MAC infection.

Time-course of Toll-like receptor 2 expression, as a predictor of recurrence in patients with bacterial infectious diseases.

The clinical course of bacterial infectious diseases is often variable, especially in elderly patients. Thus, new biological markers have been sought to predict the disease outcome. Recent studies have revealed that Toll-like receptor (TLR) 2 and/or TLR4 on circulating monocytes are significantly up-regulated in bacterial infections. However, the lack of reliable quantification methods hampers extensive study on the modulation of these molecules in response to the patient's clinical condition. In this study, we developed a new quantitative flow cytometric analysis system for TLR2. We then carried out a longitudinal study on TLR2 expression levels on monocytes from patients suffering from bacterial infectious diseases during and after antibiotic treatment. The clinical outcome divided 37 patients into 'cure' (n = 24) and 'recurrence' (n = 13) groups. A significant difference between the two groups was recognized in the TLR2 levels just after antibiotic treatment (antibody-binding sites/cell, 4395 +/- 784 versus 5794 +/- 1484, P < 0.001). The risk of recurrence was associated significantly with TLR2 (P < 0.001), but not C-reactive protein (P = 0.351) levels assayed during the first remission. Furthermore, antibiotic effectiveness was associated inversely with TLR2 levels during antibiotic administration (P < 0.001). Taken together, TLR2 expression levels on monocytes provide critical information for planning treatment against bacterial infectious diseases.

[Serological diagnosis of pulmonary tuberculosis and nontuberculous pulmonary mycobacteriosis].

OBJECTIVE: The present study was undertaken to evaluate the utility of the serodiagnosis of pulmonary tuberculosis and nontuberculous pulmonary mycobacteriosis by ELISA using a Pathozyme-Myco kit (Myco kit) and a Pathozyme-TB complex kit (TB kit) (OMEGA Diagnostics Ltd.). STUDY POPULATION: The subjects comprised 256 healthy volunteers (HV, healthy hospital employees), 66 patients with sputum-positive active pulmonary tuberculosis (apTB), 14 patients with healed pulmonary tuberculosis (hpTB), 24 patients with nontuberculous pulmonary mycobacteriosis (NTM) and 32 patients with pulmonary diseases other than mycobacteriosis. RESULTS: 1) The serum IgG antibody titers determined with the Myco kit were significantly higher in the apTB group (p < 0.01), the hpTB group (p < 0.01), and the NTM group (p < 0.01) than those in the HV and the other pulmonary disease group. At a cut-off value of the mean + 2SD of the values obtained in the HV, the positive rate was 47.0% in patients with apTB, 50.0% in those with NTM, 21.4% in those with hpTB, 3.1% in those with other pulmonary diseases, and 1.6% in the HV. Analysis of ROC curves showed that the HV and the pulmonary mycobacteriosis group (apTB and NTM) were best distinguished by a cut-off value of -0.280 OD (log), with the sensitivity and the specificity being 83.3% and 78.5%, respectively. It was impossible to distinguish apTB from NTM. 2) The serum IgG antibody titers determined with the TB kit were significantly higher in the apTB group than those in the HV (p < 0.01), the NTM group (p < 0.05) and the other pulmonary disease group (p < 0.01). No significant difference was observed between the HV and the patients with NTM or those with other pulmonary diseases. Although the positive rate of the test was low in the apTB group (42.4%), there was a significant difference between apTB and NTM (12.5%) (p < 0.05), suggesting that apTB could be distinguished from NTM. 3) Since the serum antibody titers determined by the Myco kit showed no significant difference between apTB and NTM, and there was also no difference in the positivity between the two diseases, we performed serologic examination using the Myco kit to detect both diseases as pulmonary mycobacteriosis. After diagnosing pulmonary mycobacteriosis by the Myco kit, we then used the TB kit to separate apTB from NTM. In this case, the sensitivity and specificity of the test were 55.6% and 85.7%, respectively. Better methods should be developed to distinguish apTB from nontuberculous mycobacteriosis.

State-dependent modification of ATP-sensitive K+ channels by phosphatidylinositol 4,5-bisphosphate.

With inside-out patch recordings in ventricular myocytes from the hearts of guinea pigs, we studied ATP-sensitive K+ (K(ATP)) channels activated by phosphatidylinositol 4,5-bisphosphate (PIP2) with respect to sensitivity to ATP when in either a rundown state (RS) or a non-rundown state (NRS). Rundown of K(ATP) channels was induced by exposure either to ATP-free solution or to ATP-free solution containing 19 microM Ca2+. Exposure of membrane patches to 10 microM PIP2 reactivated channels with both types of rundown. The reactivation by PIP2 did not require ATP in the bath. The IC50 of channels recovered from RS and before the rundown was 37.1 and 31.1 microM, respectively. PIP2 irreversibly increased the mean current when the channel was in the NRS. This was associated with a shift of IC50 to 250.6 microM after PIP2 exposure. PIP2 activates NRS K(ATP) channels by decreasing their sensitivity to ATP, whereas PIP2 reactivates RS-K(ATP) channels independently of ATP without changing ATP sensitivity.

On the mechanism of ADP-induced alteration of sulphonylurea sensitivity in cardiac ATP-sensitive K(+) channels.

1. To study the mechanism of regulation of sulphonylurea sensitivity in ATP-sensitive K(+) (K(ATP)) channels, we used the inside-out patch clamp technique in guinea-pig ventricular myocytes. 2. In the absence of nucleotides, the half maximal concentration of tolbutamide inhibition of K(ATP) channels (IC(50)) was 0.4 mM, and it decreased to 0.1 mM when 0.1 mM ATP was added. 3. Increasing the ADP concentration from 0 to 0.1 and 0.3 mM in the absence of ATP shifted the IC(50) from 0.4 to 5.3 and 11.4 mM, respectively. Increasing the ADP concentration further to 1 and 3 mM conversely reduced the IC(50) to 9.5 and 4.4 mM, respectively. 4. In the absence of Mg(2+) and ADP, the IC(50) was calculated to 16.6 mM which was found to be less, 12.3, 5.1 and 2.5 mM, respectively, when the ADP concentration was increased to 0.1, 0.3 and 1 mM. 5. The IC(50)s for tolbutamide obtained at various concentrations of ADP in the presence of Mg(2+) were best fitted by equations reflecting a model that assumed two binding sites for ADP; one is a high affinity site that reduces the sensitivity to the sulphonylurea, while the other is a low affinity site that increases such sensitivity. Dissociation constants calculated for ADP to sites 1 and 2 were 2.6 microM and 46.7 mM, respectively. In the absence of Mg(2+), data were fitted by equations corresponding to a single site model (site 2); the dissociation constant for ADP was 25.0 mM. 6. It is concluded that ADP modifies tolbutamide sensitivity by binding to two sites. The high affinity site is strongly Mg(2+)-dependent, whereas the low affinity site is Mg(2+)-independent.

[Significance of serum surfactant protein-D (SP-D) level in patients with pulmonary tuberculosis].

Elevated levels of serum surfactant protein-D (SP-D) have been previously reported in patients with idiopathic pulmonary fibrosis (IPF) and pulmonary alveolar proteinosis. To determine whether the same change is seen in other pulmonary diseases, especially pulmonary tuberculosis (TB), we measured the serum SP-D levels in active pulmonary TB (smear and/or culture: positive), acute interstitial pneumonia (AIP), IPF, acute exacerbation of IPF, hypersensitivity pneumonitis (HP), pneumoconiosis, bronchiectasis, and bacterial pneumonia by an enzyme-linked immunosorbent assay using monoclonal antibodies to human lung SP-D, and compared them with those of healthy elderly subjects over 50 years of age. The SP-D level in the healthy elderly subjects was 57.6 +/- 38.4 ng/ml (mean +/- SD, n = 287). The levels in patients with active pulmonary TB (140.6 +/- 18.2 ng/ml, n = 49), AIP (1,021 ng/ml, n = 1), IPF (307.0 +/- 180.7 ng/ml, n = 42), acute exacerbation of IPF (817.7 +/- 283.6 ng/ml, n = 3), and HP (716.6 +/- 548.8 ng/ml, n = 4) were significantly higher than those in the healthy elderly controls (p < 0.05), whereas those of pneumoconiosis, bronchiectasis, and bacterial pneumonia, 121.9 +/- 92.8 ng/ml (n = 8), 93.9 +/- 72.9 ng/ml (n = 11), and 72.7 +/- 3.4 ng/ml (n = 4), respectively, showed no significant difference with the controls. In active pulmonary TB, the percentage of patients whose serum SP-D levels were over 134.6 ng/ml (mean + 2SD of healthy elderly controls) was 34.7%, and therefore we considered the serum SP-D level was not useful for the diagnosis of pulmonary TB. However, it was significantly higher in the patients with cavity formation than in those without (p < 0.05), and there was a significant positive correlation between the serum SP-D level and the number of tubercle bacilli in the sputum (r = 0.416, p = 0.00165), erythrocyte sedimentation rate at 1 hr (r = 0.489, p < 0.01), and CRP level (r = 0.383, p = 0.003). These findings suggest that the serum SP-D level is a useful indicator of the disease activity in pulmonary TB.

[Suspected leiomyosarcoma of the trachea].

A 73-year-old women was admitted to our hospital because of dyspnea, bloody sputum, and an apparent intratracheal tumor. A chest X-ray film from August 1991 showed a sharply circumscribed soft-tissue density in the trachea at the level of the aortic arch. By March 1993 the tumor had grown from 15 mm to 20 mm in diameter. A chest CT scan and fiberoptic bronchoscopy showed an intratracheal tumor that occupied 80% to 90% of the tracheal lumen. The tumor was resected on March 26, 1993. Histopathological study revealed a suspected leiomyosarcoma of the trachea. Only 18 cases of leiomyosarcoma of the trachea have previously been reported worldwide. We know of only 3 previous reports of the case of suspected leiomyosarcoma of the trachea in Japan.

[Pneumonitis due to Hangeshashin-to].

A 72-year-old woman was admitted to our hospital because of dyspnea and abnormal shadows on a chest X-ray film. The X-ray film revealed diffuse reticular and patchy shadows in both lung fields. Drug-induced pneumonitis was suspected, and all drug treatment was stopped. The symptoms were relieved and the X-ray findings improved markedly. In bronchoalveolar lavage fluid, the lymphocyte percentage was high and the CD4/CD8 ratio was low. Microscopic examination of open-lung biopsy specimens showed pneumonitis, dominant lymphocyte invasion within peribronchiolar and alveolar interstitia. The result of leukocyte migration inhibition test was positive for Hangeshashin-to and Byakkokaninjin-to, and lymphocyte stimulation test was positive for Hange, an ingredient of Hangeshashin-to. Based on these findings, we diagnosed as pneumonitis induced by Hangeshashin-to. To our knowledge, there has been no previous report of pulmonary hypersensitivity induced by Hangeshashin-to in Japan.