The glucocorticosteroid, budesonide, partially blocks histamine release from human lung tissue in vitro

Targeted inhibition of allergen-induced histamine production by neutrophils

Histamine is a critical inflammatory mediator in allergic diseases. We showed in a previous work that neutrophils from allergic patients produce histamine in response to allergens to which the patients were sensitized. Here, we investigate the molecular mechanisms involved in this process using peripheral blood neutrophils. We challenged these cells in vitro with allergens and analyzed histamine release in the culture supernatants. We also explored the effect of common therapeutic drugs that ameliorate allergic symptoms, as well as allergen-specific immunotherapy. Additionally, we examined the expression of histidine decarboxylase and diamine oxidase, critical enzymes in the metabolism of histamine, under allergen challenge. We show that allergen-induced histamine release is dependent on the activation of the phosphoinositide 3-kinase, mitogen-activated protein kinase p38, and extracellular signal-regulated kinase 1/2 signaling pathways. We also found a contribution of the phosphatase calcineurin to lesser extent. Anti-histamines, glucocorticoids, anti-M3-muscarinic receptor antagonists, and mainly β₂ -receptor agonists abolished the allergen-dependent histamine release. Interestingly, allergen-specific immunotherapy canceled the histamine release through the downregulation of histidine decarboxylase expression. Our observations describe novel molecular mechanisms involved in the allergen-dependent histamine release by human neutrophils and provide new targets to inhibit histamine production.

Budesonide/formoterol in the treatment of asthma

Budesonide/formoterol is a combination of an inhaled corticosteroid plus a long-acting beta(2)-agonist available as a dry-powder inhaler for the indication of asthma and chronic obstructive pulmonary disease in various countries outside of the USA and as a pressurized metered-dose inhaler in the USA for the indication of asthma. Clinical studies have shown that budesonide/formoterol is significantly more effective than an equivalent or higher dose of budesonide or fluticasone propionate alone in patients with moderate-to-severe disease, and at least as effective as its two components administered via separate inhalers in asthmatics with predominantly moderate to severe persistent disease. Budesonide/formoterol is effective when administered both once or twice daily. Adjustable maintenance dosing with budesonide/formoterol has been shown to provide equivalent or better asthma control with a significantly lower amount of study drug use compared with fixed dosing. The rapid onset of action of budesonide/formoterol, predominantly due to formoterol, as well as its favorable dose-response, has prompted budesonide/formoterol to be used as both a maintenance and reliever medication, referred to as the Symbicort maintenance and reliever therapy (SMART) dosing regimen in several countries. Use of this approach has resulted in studies evaluating SMART, demonstrating significantly lower rates of exacerbations and reliever medication use compared with fixed-dosing regimens in asthma.

Oral budesonide and ursodeoxycholic acid for treatment of primary biliary cirrhosis: results of a prospective double-blind trial

BACKGROUND & AIMS

Ursodeoxycholic acid (UDCA) is used for treatment of primary biliary cirrhosis. Previous studies showed that, compared with UDCA monotherapy, bile salts plus prednisolone had no further effect on laboratory data but improved liver histology. Thirty percent of these patients had prednisolone-related side effects. Budesonide is a glucocorticoid with a high receptor affinity and a high first-pass metabolism. In this study we investigated whether budesonide and UDCA are superior to UDCA monotherapy.

METHODS

A 2-year prospective, controlled double-blind trial was performed. Twenty patients (mainly with early-stage disease) were treated with UDCA at a dose of 10-15 mg/kg daily in addition to 3 mg budesonide 3 times daily (group A), and 19 patients (1 dropped out for personal reasons) were treated with UDCA plus placebo (group B). Liver biopsy specimens were taken before, after 12 months, and at the end of study. Glucose tolerance tests, serum cortisol levels, and adrenocorticotropin-stimulated cortisol secretion were assessed at regular intervals. Bone mass density was measured by dual-energy photon absorptiometry.

RESULTS

Compared with pretreatment values, liver enzyme and immunoglobulin M and G levels decreased significantly in both groups. Improvement in group A was significantly more pronounced (P < 0.05) than in group B. Titers of antimitochondrial antibodies did not change. In group A, the point score of liver histology improved by 30.3%; in group B, it deteriorated by 3.5% (P < 0.001). Changes in bone mineral density after 2 years were -1.747% in group A and -0.983% in group B (P = 0.43). Budesonide had little influence on the hypothalamic-pituitary-adrenal axis. One patient in group A had budesonide-related side effects; in 3 patients in group B, complications of liver disease developed.

CONCLUSIONS

Combination therapy with UDCA and budesonide is superior to UDCA and placebo.

Effects of topical nasal steroids on human respiratory mucosa and human granulocytes in vitro

Human respiratory mucosa and human granulocytes were exposed to topical nasal steroids in vitro. The preparations containing benzalkonium chloride and benzalkonium chloride alone destroyed the mucosa within 10 days. The same preparations also inhibited human neutrophil actin polymerization, degranulation and oxidative burst in vitro in a time and concentration dependent manner. Preparations without benzalkonium chloride, as well as the steroid compounds themselves, did not have these effects. It is concluded that benzalkonium chloride has toxic effects on human respiratory mucosa and human neutrophils in vitro.

The effect of two months of treatment with inhaled budesonide on bronchial responsiveness to histamine and house-dust mite antigen in asthmatic children

We studied the effect of 2 months of treatment with budesonide (BUD) (Pulmicort), an inhaled corticosteroid, on the bronchial hyperresponsiveness to house-dust mite antigen (BHR-HDM) and to histamine (BHR-H). We also investigated whether BUD started 20 to 24 h after the development of a late asthmatic reaction (LAR) would influence the antigen-induced increase in nonspecific bronchial hyperresponsiveness to BHR-H. Thirty-one children with mild asthma who were atopic to HDM were randomized double blind into two parallel groups. Fifteen patients inhaled 0.2 mg BUD three times a day. Sixteen inhaled placebo in a similar way. Treatment began 20 to 24 h after antigen exposure and continued for 2 months. BHR-H and BHR-HDM were measured prior to and at the end of treatment. BHR-H was also determined 3 days after each antigen provocation. In the children receiving BUD, mean BHR-H and mean BHR-HDM were decreased approximately twofold after 2 months. No increase in BHR-H was observed after 3 days in the BUD group, irrespective of whether a LAR occurred. In patients in whom BUD treatment was withheld after the second antigen provocation, the protective effect of BHR-H was abolished. We conclude that 2 months of treatment with an inhaled corticosteroid causes a decrease in BHR-H and BHR-HDM. When an inhaled corticosteroid is administered 20 to 24 h after antigen provocation, It may protect against the antigen-induced increase in BHR-H. After treatment is discontinued, the protective effect wears off rapidly.

Dexamethasone does not inhibit the release of mediators from human mast cells residing in airway, intestine, or skin

Glucocorticoids are potent anti-inflammatory drugs that are widely used in the treatment of allergic disorders. Their actions are often species specific or cell-type specific. Previous studies have demonstrated that glucocorticoids inhibit mediator release from mast cells derived from the peritoneum of mouse or rat and from guinea pig lung, but not those residing in human lung parenchymal tissue. In the present study, we have analyzed the effect of overnight culture with dexamethasone (10(-6) to 10(-7)M) on the subsequent IgE-dependent release of mediators from human mast cells derived from airway tissue, intestine, and skin. Airway tissue was passively sensitized with antigen-specific, IgE-rich serum during the culture period and subsequently challenged with ragweed antigen E. Skin and intestinal mast cells were challenged with anti-IgE. Histamine and immunoreactive LTC4 and PGD2 release was monitored in all experiments. Prostaglandin E release was quantitated in the experiments using airway tissue. Dexamethasone treatment failed to inhibit the release of mast cell mediators from all three tissues, but it inhibited the antigen-induced release of immunoreactive PGE from other cells residing in airway tissue. These results confirm earlier studies of the effects of glucocorticoids on human lung parenchymal mast cells, but contrast with the inhibitory effects of steroids observed in murine mast cells and human basophils.