[A possible case of pulmonary infection due to Mycobacterium heckenshornense].

A 68-year-old man with emphysema was admitted with cough and bloody sputum. Chest radiography revealed infiltrative shadows in the right upper lung. Microbiologically, an acid-fast bacillus was detected in the culture of sputum (Gaffky (+)), but both tuberculosis bacillus (TB) and Mycobacterium avium complex (MAC) were negative by the PCR method. Combination chemotherapy, which included isoniazid, rifampicin, ethambutol and pyradinamide, was initiated under a tentative diagnosis of TB. His clinical symptoms and radiographic findings improved. After 4 months, the strain of acid-fast bacilli was identified as Mycobacterium xenopi by DNA-DNA hybridization (DDH) method. However, analysis of base sequences from sputum samples using 16S rDNA confirmed the identity of all tested isolates as Mycobacterium heckeshornense. M. heckeshornense could not be identified by the DDH method in Japan. When M. xenopi is detected, it is essential to perform both sequencing of 16S rDNA and a biochemical method for the purpose of distinguishing M. heckeshornense from M. xenopi.

The role of interleukin-8 in interstitial pneumonia.

OBJECTIVE: A variety of inflammatory cells accumulate in the lungs of patients with interstitial lung disease. The potential for IL-8 to be released from these cells into the lungs of patients with idiopathic interstitial pneumonia (IIP), interstitial pneumonia with collagen vascular disease (IP-CVD), sarcoidosis (SAR) and hypersensitivity pneumonitis (HP) was investigated. METHODOLOGY: IL-8 levels were assessed by enzyme-linked immunosorbent assay in BAL fluid and serum, and the expression of IL-8 in the lungs of these patients was evaluated by immunohistochemistry. RESULTS: Serum IL-8 levels were significantly elevated in patients with IIP (P < 0.05) and SAR (P < 0.01). In BAL fluid, the IL-8 level was significantly higher in patients with IIP (P < 0.05), IP-CVD (P < 0.01), SAR (P < 0.01) and HP (P < 0.01). In several cases, IL-8 level correlated with neutrophil density. The IL-8 immunopositive cells were type II pulmonary epithelial cells and alveolar and interstitial macrophages in patients with IIP and IP-CVD. CONCLUSIONS: IL-8 is likely to be a key factor in the pathogenesis of fibrosis of the lung and in lung injury.