Alveolar, but not bronchial nitric oxide production is elevated in cystic fibrosis

Exhaled nitric oxide (NO) remains a promising non-invasive marker for measuring inflammation in lung diseases. In cystic fibrosis (CF), exhaled NO measured at a single expiratory flow has been found to be normal or low. However, this measure cannot localize the anatomical site of NO production. The aims of this study were to apply a multiple-flow NO analysis to compare alveolar NO concentration and bronchial NO flux in CF children with healthy controls. Twenty-two children with CF and 17 healthy controls had exhaled NO measured at four different expiratory flows to calculate bronchial NO flux and alveolar NO concentration. Median (range) alveolar NO concentration was 2.2 (0.6-5.6) ppb for children with CF and 1.5 (0.4-2.6) ppb for healthy controls. Median (range) bronchial NO flux was 445 (64-1,256) pL/sec for children with CF and 509 (197-1,913) pL/sec for healthy controls. Children with CF had a significantly higher alveolar NO concentration, but no significant difference in bronchial NO flux compared to healthy children. In conclusion, children with CF have increased alveolar NO production, but not bronchial NO flux compared to healthy controls. The distal airway is a major site of inflammation in CF, and measuring alveolar NO may be a marker of distal inflammation in this disease.     

Exhaled carbon monoxide is not elevated in patients with asthma or cystic fibrosis.

Increased levels of exhaled carbon monoxide (fractional concentration of CO in expired gas (FE,CO)), measured with an electrochemical sensor, have been reported in patients with inflammatory airway disorders, such as asthma, rhinitis and cystic fibrosis. This study aimed to evaluate these findings by using a fast-response nondisperse infrared (NDIR) analyser, and to compare these measurements with the fractional concentration of nitric oxide in exhaled air (FE,NO). Thirty-two steroid-na?ve asthmatics, 24 steroid-treated asthmatics (16 patients with allergic rhinitis, nine patients with cystic fibrosis), and 30 nonsmoking healthy controls were included. CO measurements with the NDIR analyser were performed simultaneously with nitric oxide (NO) analysis (chemiluminescence technique). After 15 s of breath-hold, single-breath exhalations over 10 s were performed at two flow rates and end-tidal plateau concentrations were registered. An electrochemical CO sensor was used independently with an exhalation to residual volume, after a 15 s breath-hold. None of the two CO analysers gave a significant increase in FE,CO in the groups of patients with inflammatory airway disorders compared to controls. FE,NO was significantly elevated in steroid-na?ve asthmatics and subjects with allergic rhinitis, but not in steroid-treated asthmatics and subjects with cystic fibrosis. Reducing exhalation flow rate by 50% gave a two-fold increase in FE,NO, while FE,CO was unaffected. A significant increase was seen in FE.CO, but not in FE,NO, when comparing with and without a 10 s breath-hold. In conclusion, the fractional concentration of carbon monoxide in expired gas was not increased in any of the patient groups, while the fractional concentration of nitric oxide in expired gas was significantly elevated in patients with steroid-na?ve asthma and allergic rhinitis. Moreover, carbon monoxide was unaffected by flow rate but increased with breath-hold, suggesting an origin in the alveoli rather than the conducting airways.     

Prostaglandins E2 and E2 alpha are elevated in saliva of cystic fibrosis patients

Several products of arachidonic acid metabolism were assayed in whole saliva of patients with cystic fibrosis, a disease affecting primarily the exocrine glands. The levels of prostaglandins (PG) E2 and F2 alpha were elevated fourfold in patients with cystic fibrosis, compared with a control group (mean +/- SEM for PGE2 1.13 +/- 0.22 vs 0.37 +/- 0.08 ng/ml saliva, p less than 0.005; and for PGE2 alpha 0.84 +/- 0.27 vs 0.17 +/- 0.03 ng/ml saliva, p less than 0.025). The levels of PGI2, hydroxyeicosatetraenoic acids, and leukotrienes showed no significant differences between the two groups. These changes were not present in individuals heterozygous for the cystic fibrosis gene. Study of appropriate control groups suggested that the changes that we observed in patients with cystic fibrosis could not be attributed to their lung disease or to the medications these patients were receiving. Our findings indicate that metabolism of arachidonic acid is abnormal in cystic fibrosis.     

Elevated vascular endothelial growth factor is correlated with elevated erythropoietin in stable, young cystic fibrosis patients

Angiogenesis is an important mechanism of airway remodeling in lung disease. We previously demonstrated that serum vascular endothelial growth factor (VEGF) is elevated in cystic fibrosis (CF) patients and declines with therapy for pulmonary exacerbation. We hypothesized that VEGF is elevated early in the course of CF and is associated with markers of tissue hypoxia. A prospective, single-visit evaluation of thirty stable infants and children with CF was performed. Serum was analyzed for VEGF and for other markers of tissue hypoxia (erythropoietin (EPO), insulin-like growth factor binding protein-1 (IGFBP-1)) and for inflammatory mediators (IL-1 beta, IL-6, IL-8, and tumor necrosis factor alpha (TNFα)) using Meso Scale multi-spot serum immunoassays. Measurements were correlated between assay groups; and with age in months and pulmonary function (FEV0.5 or FEV1). VEGF, EPO, TNFα and IL-8 were elevated compared to published normative values. VEGF levels were not significantly correlated with any inflammatory mediators. However, VEGF correlated with EPO (r=0.505; P<0.05). There was no correlation between lung function and markers of inflammation or tissue hypoxia. VEGF is elevated in young, stable infants and children suggesting angiogenesis as a contributing mechanism for early lung disease in CF. VEGF elevation does not show significant correlation with inflammatory mediators known to be increased in CF, but is significantly correlated with EPO levels. We propose that VEGF elevation and angiogenesis contribute to early lung disease and may result from a direct tissue hypoxia pathway in CF.     

Myeloperoxidase and protein oxidation in the airways of young children with cystic fibrosis

Cystic fibrosis (CF) is characterized by considerable oxidative stress. However, it is not known whether oxidative stress is an important feature early in this disease. We have investigated a group of infants and young children with CF to establish whether oxidants are produced in their airways. Bronchoalveolar lavage fluid (BALF) was assayed for myeloperoxidase as a measure of neutrophilic inflammation, and 3-chlorotyrosine as a biomarker of the potent oxidant hypochlorous acid, which is formed by myeloperoxidase. Protein carbonyls were also measured as a nonspecific indicator of reactive oxidant production. Myeloperoxidase and 3-chlorotyrosine levels in BALF from children with CF were 10- and fivefold higher, respectively, than in disease control subjects. There was a strong correlation between myeloperoxidase and 3-chlorotyrosine. Myeloperoxidase levels were fourfold higher in children with infections in their airways. Median protein carbonyls were elevated by only twofold compared with disease control subjects, but some children had extremely high levels of protein oxidation. We conclude that hypochlorous acid is produced early in CF and that it is a candidate for precipitating the fatal decline in lung function associated with this disease. Also, there must be other sourcesof oxidants because protein carbonyls were not related to either inflammation or infection.     

Colonic wall thickening is related to age and not dose of high strength pancreatin microspheres in children with cystic fibrosis

OBJECTIVE: Colonic fibrosis causing stricture is a recently described complication in cystic fibrosis (CF). Studies have suggested that ultrasound evidence of bowel thickening predicts this complication and that it is prevalent among children receiving large doses of high-strength pancreatin preparations. We performed ultrasound studies on our patients to look for evidence of bowel wall thickening or early stricture. METHOD: Detailed colonic ultrasounds were carried out in 33 children with CF including 25 who had been receiving high-strength pancreatin (Creon 25,000) continuously for 3 years at the time of study. RESULTS: Median lipase intake was 19 330 U/kg/day (range 0-59 880 U/kg/day) and median protease intake was 387 U/kg/day (range 0-1170 U/kg/day). The combined thickness of mucosa, sub-mucosa and muscle layers was measured in ascending, transverse and descending colon using a 7.5 MHz transducer. Measurements were also made in nine healthy controls. There was no relationship between enzyme dosage and colon thickness but simple regression identified a significant relationship (P < 0.001) between age and maximum colon thickness in all three areas. The colon of CF children was up to 50% thicker than in controls. CONCLUSIONS: Thickening of the order described elsewhere did not occur among any of the children studied. The results suggest that the most important factor determining the thickness of the CF colon is age.     

C-reactive protein is not a useful indicator of intermittent bacterial colonization in early lung disease of patients with cystic fibrosis

C-reactive protein (CRP) is a general marker of the systemic inflammatory response to bacterial infection. Serial measurement of CRP is useful in monitoring respiratory exacerbations in patients with cystic fibrosis (CF) and chronic infection with Pseudornonas aeruginosa. We hypothesized that regular monitoring of CRP in young children with CF prior to colonization with P. aeruginosa might provide an objective guide to the need for antibiotic treatment. Twenty-two children were studied prospectively over a 6 month period. We measured CRP every 2 months and at the beginning and end of respiratory exacerbations. In samples taken when the children were well, median CRP was 0.45 μg/mL compared with 1.92 μg/mL when they were symptomatic with positive culture results (P < 0.05). Despite this difference there was considerable overlap between CRP levels for infected and noninfected patients. A CRP value of >1.82 μg/mL (the upper 95% confidence interval for a control group of well children without CF) had a sensitivity of 49% and a specificity of 83% in determining a symptomatic exacerbation. We conclude that in this group of patients CRP measurements were of little value in monitoring respiratory exacerbations in patients who become intermittently infected with either Haernophilus influenzae or Staphylococcus aureus. Pediatr Pulmonol. 1994; 17:6–10 . © 1994 Wiley-Liss, Inc.     

Safety and efficacy of recombinant alpha(1)-antitrypsin therapy in cystic fibrosis

Neutrophil elastase (NE) is thought to be the most important protease which damages the cystic fibrosis (CF) lung. Attempts have been made to suppress this activity using the plasma-derived inhibitor, alpha(1)-antitrypsin (AAT). In this pilot study, the safety and efficacy of inhaled recombinant human AAT (rAAT) as a treatment for CF were investigated. Thirty-nine patients participated in a prospective, double-blinded, randomized, placebo-controlled phase II trial to examine the effect of rAAT (500, 250, and 125 mg) on sputum NE activity. Sputum myeloperoxidase (MPO), interleukin-8, tumor necrosis factor receptors, sputum and plasma NE/AAT complexes, and safety parameters were also measured. Subjects were randomized to receive nebulized treatment once a day for 4 weeks, followed by 2-4 weeks with no study treatment, and then a 2-week rechallenge phase. Trends toward a reduction in NE activity were observed in patients treated with 500 mg and 250 mg of rAAT compared to placebo. Sputum NE/AAT complex and MPO levels were lower on rAAT compared to placebo. No major adverse events and, in particular, no allergic reactions to rAAT were observed. Although significant differences between rAAT and placebo for sputum NE activity were not observed, some improvements were found for secondary efficacy variables. This study demonstrated that nebulized rAAT is safe and well-tolerated, but has a limited effect on NE activity and other markers of inflammation.     

Serum vascular endothelial growth factor is elevated in cystic fibrosis and decreases with treatment of acute pulmonary exacerbation

Chronic bacterial infection and neutrophilic inflammation characterize cystic fibrosis (CF) pulmonary disease. In many disorders, inflammation and angiogenesis are codependent phenomena. We previously noted excessive angiogenesis in CF tissues and elevated vascular endothelial growth factor (VEGF) in random serum samples from subjects with CF. To further explore this finding, we measured serum VEGF in 38 subjects with stable CF and in 25 subjects with other pulmonary diseases. Mean VEGF was elevated in both groups compared with reference values, but it was higher in CF: 403 +/- 280 versus 255 +/- 169 pg/ml, p = 0.02. VEGF was negatively correlated with FEV(1) in CF, r = -0.51, p = 0.007. To assess the effect of airway infection on VEGF, 10 subjects with CF were studied before and after intravenous antibiotic therapy for pulmonary exacerbation. VEGF levels decreased with antibiotic therapy, from 537 +/- 220 to 259 +/- 176 pg/ml, p = 0.001. We conclude that circulating VEGF is increased in subjects with CF and other inflammatory pulmonary disorders. In CF, VEGF elevation is related to airway infection. We speculate that increased circulating VEGF is related to chronic inflammation, which is robust in CF. Elevated circulating VEGF may result in tissue angiogenesis, furthering the progression of pulmonary disease.     

Fidarestat (SNK-860), a potent aldose reductase inhibitor,normalizes the elevated sorbitol accumulation in erythrocytes of diabetic patients

Sorbitol accumulation in nerves has been regarded as one of the major causes of diabetic neuropathy. In this study, fidarestat (SNK-860; 1 mg daily), a potent new aldose reductase inhibitor (ARI), or the commercially available ARI epalrestat (150 mg daily), was administered for 4 weeks to 58 Type 2 diabetic patients. Treatment with these drugs had no effect on glycemic control, judging from plasma glucose and HbA(1c) levels. However, fidarestat treatment normalized the elevated sorbitol content of erythrocytes under fasting as well as postprandial conditions. In contrast, the effect of epalrestat was minimal. There were no major side effects with fidarestat. Thus, fidarestat is considered to be a potent and promising ARI, possibly useful for both preventing and treating diabetic neuropathy. Further studies are needed to clarify how much the occurrence and progression of diabetic neuropathy are inhibited by normalizing sorbitol elevation with fidarestat treatment.     

SCH-C (SCH 351125), an orally bioavailable, small molecule antagonist of the chemokine receptor CCR5, is a potent inhibitor of HIV-1 infection in vitro and in vivo

We describe here the identification and properties of SCH-C (SCH 351125), a small molecule inhibitor of HIV-1 entry via the CCR5 coreceptor. SCH-C, an oxime-piperidine compound, is a specific CCR5 antagonist as determined in multiple receptor binding and signal transduction assays. This compound specifically inhibits HIV-1 infection mediated by CCR5 in U-87 astroglioma cells but has no effect on infection of CXCR4-expressing cells. SCH-C has broad and potent antiviral activity in vitro against primary HIV-1 isolates that use CCR5 as their entry coreceptor, with mean 50% inhibitory concentrations ranging between 0.4 and 9 nM. Moreover, SCH-C strongly inhibits the replication of an R5-using HIV-1 isolate in SCID-hu Thy/Liv mice. SCH-C has a favorable pharmacokinetic profile in rodents and primates with an oral bioavailability of 50-60% and a serum half-life of 5-6 h. On the basis of its novel mechanism of action, potent antiviral activity, and in vivo pharmacokinetic profile, SCH-C is a promising new candidate for therapeutic intervention of HIV infection.     

Retrospective review of the effects of rhDNase in children with cystic fibrosis

Trials of rhDNase in mixed groups of adults and children with cystic fibrosis (CF) have demonstrated improvements in lung function and well-being. This has led to many pediatric CF patients receiving regular rhDNase therapy although their response to treatment may not be the same as that seen in adults. We have retrospectively reviewed the effects of rhDNase during the first year of therapy in 65 children receiving the drug at two tertiary referral centers. Outcome measures included changes in lung function, oxygen saturation, use of intravenous antibiotics, and subjective improvement. Median baseline lung function (% of predicted) was 45% for forced expiratory volume in 1 second (FEV₁) and 58% for forced vital capacity (FVC). At 3–4 months following initiation of therapy the group demonstrated median (95% CI) increases of 14.2% (95% CI 7.3; 21.1%) in FEV₁ and 7% (0; 14%) in FVC. Within this wide scatter of responses, one-quarter of children deteriorated, but almost 50% showed significant improvements of > 10%. A similar pattern was seen at 9 months, with median increases for the group of 11.1% (0; 18.8%) in FEV₁ and 5.6% (0; 17%) in FVC, again with approximately one-third of the group deteriorating and one-half improving significantly. Intravenous antibiotic use decreased significantly. Almost all the children (89%), including those with a fall in lung function, described subjective improvement. There were no predictive markers at baseline of a good response to the drug. However, there was a good correlation between lung function response at 3 months and that at 6, 9, and 12 months. Thus, children respond to rhDNase at least as well as adults, and a therapeutic trial is justified in those over 5 years with significantly impaired lung function. Response is highly variable, making careful individual assessment mandatory. Baseline characteristics are not useful in predicting those children who will respond well to treatment, but long-term response to the drug can be predicted on the basis of spirometric improvement at 3 months. Therefore, this would be a useful time period for a therapeutic trial. Pediatr Pulmonol. 1997; 23:243–248. © 1997 Wiley-Liss, Inc.     

YKL-39 (chitinase 3-like protein 2), but not YKL-40 (chitinase 3-like protein 1), is up regulated in osteoarthritic chondrocytes

OBJECTIVE: To investigate quantitatively the mRNA expression levels of YKL-40, an established marker of rheumatoid and osteoarthritic cartilage degeneration in synovial fluid and serum, and a closely related molecule YKL-39, in articular chondrocytes. METHODS: cDNA array and online quantitative polymerase chain reaction (PCR) were used to measure mRNA expression levels of YKL-39 and YKL-40 in chondrocytes in normal, early degenerative, and late stage osteoarthritic cartilage samples. RESULTS: Expression analysis showed high levels of both proteins in normal articular chondrocytes, with lower levels of YKL-39 than YKL-40. Whereas YKL-40 was significantly down regulated in late stage osteoarthritic chondrocytes, YKL-39 was significantly up regulated. In vitro both YKLs were down regulated by interleukin 1beta. CONCLUSIONS: The up regulation of YKL-39 in osteoarthritic cartilage suggests that YKL-39 may be a more accurate marker of chondrocyte activation than YKL-40, although it has yet to be established as a suitable marker in synovial fluid and serum. The decreased expression of YKL-40 by osteoarthritic chondrocytes is surprising as increased levels have been reported in rheumatoid and osteoarthritic synovial fluid, where it may derive from activated synovial cells or osteophytic tissue or by increased matrix destruction in the osteoarthritic joint. YKL-39 and YKL-40 are potentially interesting marker molecules for arthritic joint disease because they are abundantly expressed by both normal and osteoarthritic chondrocytes.