[The mechanism of airway inflammation in eosinophilic bronchitis and cough variant asthma].

OBJECTIVE: To explore the characteristics of airway inflammatory cells, cytokines and inflammatory mediators in eosinophilic bronchitis (EB) and cough variant asthma (CVA) patients and to elucidate the underlying mechanism of distinct airway inflammation between EB and CVA. METHODS: This study included 15 patients with EB (EB group), 15 patients with cough variant asthma (CVA, CVA group), 14 patients with bronchial asthma (asthma group) and 14 healthy controls (healthy group). Percentage of eosinophils (EOS) in sputum induced by hypertonic saline was detected by FACS. The percentage of CD(69)(+) EOS stimulated by interleukin-5 (IL-5) and interferon γ (IFN-γ) was also detected by FACS. The expression of leukotriene C4 synthase (LTC4S) and prostaglandin-endoperoxide synthase-2 (PTGS2) mRNA in sputum was measured by real-time PCR and the concentration of leukotriene C4 (LTC4) and prostaglandin E2 (PGE2) in sputum was measured by ELISA. RESULTS: The percentage of EOS in induced sputum was 15.8 ± 3.2 (EB group), 13.0 ± 2.7 (CVA group) and 11.6 ± 4.5 (asthma group), respectively, which were significantly higher than 1.0 ± 0.4 in the healthy group. The difference was significant and the t value was 16.31, 15.23 and 14.21 respectively (P < 0.05). After stimulated by IL-5 and IFN-γ, the percentage of CD(69)(+) EOS in induced sputum was 1.5 ± 0.4 and 1.5 ± 0.5 (EB group), 1.4 ± 0.4 and 1.4 ± 0.3 (CVA group) and 1.42 ± 0.72 and 1.37 ± 0.46 (asthma group) respectively. There was no statistical significance between these 3 groups, but when compared with 0.4 ± 0.2 and 0.4 ± 0.1 in healthy group, the difference was significant (P < 0.05). The expression of IL-5 mRNA and protein in induced sputum of EB group, CVA group and asthma group were higher than the healthy group and the difference was all statistically different (P < 0.05), but there was no statistical significance between EB group, CVA group and asthma group. The expression of IFN-γ mRNA and protein in induced sputum of each group was not different when compared with healthy group (P > 0.05). The concentration of PGE2 in induced sputum of EB group was(839 ± 69) ng/L, which was higher than (33 ± 8) ng/L of CVA group, (25 ± 6) ng/L of asthma group and (24 ± 8) ng/L of healthy group (all P < 0.01). There was no statistical difference between CVA group, asthma group and healthy group. The expression of PTGS2 in induced sputum of EB group increased significantly; when compared with CVA group, asthma group and healthy group, the difference was significant (all P < 0.01). The concentration of LTC4 in induced sputum of EB group, CVA group and asthma group was all higher than the healthy group (all P < 0.05). The expression of LTC4S mRNA of EB group, CVA group and asthma group was also higher than the healthy group (all P < 0.05). The expression of LTC4S mRNA and LTC4 in the EB group was higher than that in the CVA group and the asthma group (P < 0.05). The value of LTC4/PGE2 in the CVA group and the asthma group was higher than that in the EB group (t = 8.7 and 13.1, P < 0.05). CONCLUSION: These data suggest that the difference in airway function observed in subjects with eosinophilic bronchitis and CVA (or asthma) may be due to the results of differences in PGE(2) production and an imbalance between the production of bronchoconstrictor LTC(4) and bronchoprotective PGE(2) lipid mediators.

Clinical evaluation of oral levofloxacin 500 mg once-daily dosage for treatment of lower respiratory tract infections and urinary tract infections: a prospective multicenter study in China.

Levofloxacin (LVFX), a fluoroquinolone agent, has a broad spectrum that covers Gram-positive and -negative bacteria and atypical pathogens. It demonstrates good clinical efficacy in the treatment of various infections, including lower respiratory tract infections (LRTIs) and urinary tract infections (UTIs). To evaluate the efficacy and safety of oral LVFX 500 mg once daily, a large open-label clinical trial was conducted in 1266 patients (899 with LRTIs and 367 with UTIs) at 32 centers in China. In the per-protocol population, the clinical efficacy rate (cure or improvement) at 7 to 14 days after the end of treatment was 96.4% (666/691) for LRTIs and 95.7% (267/279) for UTIs. In 53 patients diagnosed with atypical pneumonia the treatment was effective. The bacteriological efficacy rate was 96.6% (256/265) for LRTIs and 93.3% (126/135) for UTIs. The eradication rate of the causative pathogens was 100% (33/33) for Haemophilus influenzae and 96.0% (24/25) for Streptococcus pneumoniae in LRTIs, and 94.1% (80/85) for Escherichia coli in UTIs. The overall efficacy rates were 89.3% (617/691) for LRTIs and 87.8% (245/279) for UTIs. The incidence of drug-related adverse events (ADRs) was 17.3% (215/1245), and the incidence of drug-related laboratory abnormalities was 15.7% (191/1213). Common ADRs were dizziness, nausea, and insomnia. Common laboratory abnormalities included "WBC decreased", "alanine aminotransferase (ALT) increased", "aspartate aminotransferase (AST) increased", and "lactate dehydrogenase (LDH) increased". All of these events were mentioned in the package inserts of fluoroquinolones including LVFX, and most events were mild and transient. Thirty-four patients (2.7%) were withdrawn from the study because of the ADRs. No new ADRs were found. This study concluded that the dosage regimen of LVFX 500 mg once daily was effective and tolerable for the treatment of LRTIs and UTIs.