Corticosteroids in chronic bronchitis

Multiplicity of Glucocorticoid Action in Inhibiting Allograft Rejection

Glucocorticoids (GCs) are used as immunosuppressive and antiinflammatory agents in organ transplantation and in treating autoimmune diseases and inflammatory disorders. GCs were shown to exert their antiproliferative effects directly through blockade of certain elements of an early membrane-associated signal transduction pathway, modulation of the expression of select adhesion molecules, and by suppression of cytokine synthesis and action. GCs may act indirectly by inducing lipocortin synthesis, which in turn, inhibits arachidonic acid release from membrane-bound stores, and also by inducing transforming growth factor (TGF)-β expression that subsequently blocks cytokine synthesis and T cell activation. Furthermore, by preferentially inhibiting the production of Th1 cytokines, GCs may enhance Th2 cell activity and, hence, precipitate a long-lasting state of tolerance through a preferential promotion of a Th2 cytokine-secreting profile. In exerting their antiproliferative effects, GCs influence both transcriptional and posttranscriptional events by binding their cytosolic receptor (GR), which subsequently binds the promoter region of cytokine genes on select DNA sites compatible with the GCs responsible elements (GRE) motif. In addition to direct DNA binding, GCs may also directly bind to, and hence antagonize, nuclear factors required for efficient gene expression, thereby markedly reducing transcriptional rate. The pleiotrophy of the GCs action, coupled with the diverse experimental conditions employed in assessing the GCs effects, indicate that GCs may utilize more than one mechanism in inhibiting T cell activation, and warrant careful scrutiny in assigning a mechanism by which GCs exert their antiproliferative effects. © 1998 Elsevier Science Inc.

An alternate mechanism of glucocorticoid anti-proliferative effect: promotion of a Th2 cytokine-secreting profile

Glucocorticoids (GCs) are used as immunosuppressive and anti-inflammatory agents in organ transplantation and in treating autoimmune diseases and inflammatory disorders and they exert their effects by several mechanisms, the most significant of which is inhibition of cytokine production and action. Recent reports suggested that GCs inhibit cytokine expression indirectly through promotion of a T helper cell type 2 (Th2) cytokine-secreting profile, thereby resulting in preferential blockade of pro-inflammatory monokine and T helper cell type 1 (Th1) cytokine expression. The target of GCs appeared to be monocytes macrophages, whereby altered regulation of interleukin (IL)-1/IL-1 receptor antagonist (IL-1ra), coupled with profound blockade of IL-12 synthesis and inhibition of interferon (IFN)-gamma-induced major histocompatibility complex (MHC) class II expression, lead to a preferential cognate stimulation of Th2 cells at the expense of Th1 cells. It is possible that this may have involved the expansion of a Th2-cell pool or, in addition, frank stimulation of uncommitted naive CD4 + T cells toward the Th2 lineage. In addition, GCs may have blocked Th1 cytokine expression, thereby inhibiting ongoing Th1 cytokine secretion, and consequently provided for the unimpeded production of Th2 cytokines. Collectively, this indicates that, in exerting their anti-proliferative effects, GCs act indirectly by altering Th1/Th2 cytokine balance, blocking the (pro-inflammatory) Th1 program and favoring the (anti-inflammatory) Th2 program.

Improving outcomes in elderly patients with asthma

Although often regarded as a disease of childhood, asthma is common in elderly people. Although recent figures show a decline over the past few years in the number of asthma deaths in children and younger adults, the same is not true of older adults, in whom most asthma deaths occur. Differences between asthma in young and old patients are seen not only in response to treatment. The nonspecific presentation of asthma in elderly adults means that the diagnosis of asthma is difficult to make. In addition, research suggests that physicians are reluctant to use spirometry and measurement of reversibility when investigating respiratory symptoms in old people. This leads to a tendency to label breathless or wheezy elderly patients as having chronic obstructive pulmonary disease (COPD) rather than asthma. In turn, patients with a diagnosis of COPD are less likely to be treated with bronchodilators and corticosteroids. Treatment guidelines for the management of asthma in children and younger adults may need to be adapted when applied to older patients. Reduced perception of bronchoconstriction may lead to underuse of bronchodilators prescribed 'as required'. The bronchodilator response to beta2-agonists is attenuated as part of the normal aging process, and other groups of bronchodilator medications should be considered. Inhaler technique can be a particular problem in elderly patients with asthma, requiring careful choice of inhaler device. However, the frequent presence of multiple pathology and multiple medication in this age group enhances the risk of adverse effects from oral preparations, and so the inhaled route should be preferred wherever possible. Underestimation of the severity of an acute exacerbation of asthma by both patient and doctor has been suggested as a contributory factor to poor outcome in older people. Since the cardiovascular responses to hypoxia and bronchoconstriction tend to diminish with increasing age, objective measures of asthma severity (peak flow monitoring and blood gas estimation) are essential in this age group.

Role of glucocorticoid in the upregulation of type I interleukin-1 receptor mRNA expression in hepatocytes of endotoxin-administrated mice

The interleukin-1 (IL-1) signal is transduced through type I IL-1 receptor (IL-1RI). We have recently reported that lipopolysaccharide (LPS) upregulated IL-1RI mRNA expression in mouse liver in vivo and that IL-1 and IL-6 directly upregulated IL-1RI mRNA expression in primary cultured mouse hepatocytes. Glucocorticoid (GC) has been reported to increase IL-1 binding to the cell surface and the expression level of IL-1R mRNA in a variety of cell types. As serum GC level is elevated in an inflammatory response, we evaluated the role of GC in LPS-induced upregulation of IL-1RI mRNA in the mouse liver. When LPS was administered to adrenalectomized (ADX) mice, IL-1RI mRNA was upregulated at a level comparable to those of untreated or sham-operated mice. A high dose of dexamethasone (Dex), however, caused upregulation of the mRNA. When primary cultured mouse hepatocytes were treated with Dex, only a weak upregulation of IL-1RI mRNA was observed. However, Dex in combination with IL-1 or IL-6 markedly enhanced the IL-1RI mRNA expression. A marked upregulation of the mRNA was also induced by treatment with a combination of IL-1 and IL-6 in the absence of Dex, reflecting the observation in ADX mice. These results suggest that the upregulation of IL-1RI mRNA in response to LPS is induced by the interaction of IL-1 and IL-6 and that GC augments their effect.

Inhaled budesonide therapy for patients with stable COPD

A significant minority of patients with COPD have favorable response to corticosteroid treatment. In addition, the benefit of corticosteroid treatment may be outweighed by the side effects. Long-term administration of inhaled steroids is a safe means of treatment. We hypothesized that treatment with high-dose inhaled budesonide would improve clinical symptoms and pulmonary function in subjects with COPD, and that the response to inhaled beta 2-agonist will serve to individualize steroid responders. We compared a 6-week course of 800 micrograms/d inhaled budesonide with placebo, separated by 4 weeks when no medication was taken, in a double-blind crossover trial, in 8 patients responding to inhaled beta 2-agonist, and in 22 nonresponders with stable COPD. In six of eight "responders to beta 2-agonist," there was a significant improvement in the FEV1 (defined as > or = 20%) following inhaled budesonide, as compared with placebo. In the 22 "nonresponders to beta 2-agonist," there was no significant improvement in the mean FEV1 (1.41 +/- 0.1 L before, and 1.61 +/- 0.1 L after treatment) with inhaled budesonide or placebo. Over the 6-week course of treatment by either budesonide or placebo, the nonresponders reported similar beta 2-agonist consumption (4.8 +/- 0.2 and 5.0 +/- 0.1 puffs per patient per day, respectively). However, there was a significant difference between the two periods of treatment in the responders as for the mean daily number of beta 2-agonist inhalations (2.4 +/- 0.1 in the budesonide period as compared with 5.3 +/- 0.1 in the placebo period; p < 0.005). We conclude that treatment with inhaled steroids improved spirometry data and inhaled beta 2-agonist consumption in about 25% of patients with stable COPD, and this rate is increased to about 75% in patients who respond to beta 2-agonist inhalation.

A comparison of the effects of prednisolone and mianserin on ventilatory, exercise and psychometric parameters in patients with chronic obstructive pulmonary disease

There is controversy as to whether effects on mood play a role in mediating the response to corticosteroids in chronic obstructive pulmonary disease (COPD). If alterations in mood are important, it is conceivable that psychotropic drugs such as mianserin might produce similar responses to prednisolone in patients with COPD. Twelve patients age 62.5 y, with FEV1 29% of predicted and < 15% reversibility to salbutamol completed a randomised, double-blind crossover study. After an initial three week placebo run-in period patients received three weeks of prednisolone 40 mg daily or mianserin 60-90 mg daily with an intervening three week placebo washout period. Full respiratory function tests, bicycle ergometry and 6 minute walks were performed before and after the run-in and at the end of each period. Psychological and functional assessments were also made at each visit. Prednisolone significantly increased FVC, maximum ventilation (VEmax) and maximum heart rate (HRmax) compared with placebo, with mean for the difference of 0.25 l, 2.56 l.min-1 and 12 beats.min-1 respectively. FVC, maximum oxygen uptake (VO2max) and HRmax were also significantly increased with prednisolone compared with mianserin. Anxiety scores were significantly lower with prednisolone compared with placebo. In contrast, mianserin had no significant effects on lung function, exercise or psychological parameters compared with placebo. The improvements in ventilation, exercise and anxiety scores following treatment with prednisolone were not reproduced by mianserin, suggesting that the effects of prednisolone in COPD are unlikely to be due to alterations in mood.

Effects of high dose inhaled beclomethasone dipropionate, 750 micrograms and 1500 micrograms twice daily, and 40 mg per day oral prednisolone on lung function, symptoms, and bronchial hyperresponsiveness in patients with non-asthmatic chronic airflow obstruction

BACKGROUND

The effect of treatment with inhaled corticosteroids in patients with non-asthmatic chronic airflow obstruction is still disputed. Whether any physiological improvements seen are accompanied by changes in bronchial responsiveness and symptoms and quality of life is also still unclear.

METHODS

A sequential placebo controlled, blinded parallel group study investigating the effect of three weeks of treatment with inhaled beclomethasone dipropionate (BDP), 750 micrograms or 1500 micrograms twice daily, and oral prednisolone, 40 mg per day, was carried out in 105 patients with severe non-asthmatic chronic airflow obstruction (mean age 66 years, mean forced expiratory volume in one second (FEV1) 1.05 litres [40% predicted], geometric mean PD20 0.52 mumol). End points assessed were FEV1, forced vital capacity (FVC), and peak expiratory flow (PEF), bronchial responsiveness to inhaled histamine, and quality of life as measured by a formal quality of life questionnaire.

RESULTS

Both doses of BDP produced equivalent, small, but significant improvements in FEV1 (mean 48 ml), FVC (mean 120 ml), and PEF (mean 12.4 l/min). The addition of oral prednisolone to the treatment regime in two thirds of the patients did not produce any further improvement in these parameters. Inhaled BDP produced a treatment response in individual patients (defined as an improvement in FEV1, FVC, or mean PEF of at least 20% compared with baseline values) more commonly than placebo (34% v 15%). The two doses of BDP were equally effective in this respect and again no further benefit of treatment with oral prednisolone was noted. Treatment with BDP for up to six weeks did not affect bronchial responsiveness to histamine. Small but significant improvements were seen in dyspnoea during daily activities, and the feeling of mastery over the disease.

CONCLUSIONS

High dose inhaled BDP is an effective treatment for patients with chronic airflow obstruction not caused by asthma. Both objective and subjective measures show improvement. Unlike asthma, no improvement in bronchial responsiveness was detected after six weeks of treatment.

Steroid trials in the assessment of reversibility of air flow limitation: a survey of current clinical practice of chest physicians

To evaluate how steroid trials are currently used in the assessment of reversibility of air flow limitation, a postal questionnaire was sent to 355 consultant members of the British Thoracic Society working in England and Wales; 253 questionnaires were returned (71% response rate). Two respondents did not undertake steroid trials; of the remaining 251, 75% prescribed 30-40 mg oral prednisolone, with the commonest treatment period being 2 weeks. A high dose steroid inhaler was sometimes used as an alternative by 31% of respondents. Although 71% of respondents made lung function measurements on several occasions before starting steroids and 76% made measurements during treatment, 78% assessed patients on only one occasion at the end of the trials to ascertain its outcome. Weight, blood pressure and glycosuria were measured less frequently after the steroid treatment compared to the pre-trial period. Blood glucose and serum electrolytes were infrequently measured both before and after treatment. Wide variations exist in steroid trial regimens and current practice may neither provide definitive evidence of treatment benefit nor an adequate safeguard for patients against potential side-effects.

An analysis of sequential physiologic changes in hypoxic cor pulmonale during long-term oxygen therapy

Physiologic changes were studied retrospectively in 37 patients with hypoxic cor pulmonale who died during long-term oxygen therapy (LTOT). The subjects were assessed during periods of clinical stability for each year on LTOT. At the onset of treatment, their mean age (+/- SEM) was 60.0 +/- 1.3 years, and at the time of death, they were aged 65.0 +/- 1.3 years. The median duration of LTOT was five years. For each year leading up to death, mean values of FEV1, PaO2, and PaCO2 were obtained. A rate of decline of FEV1 of 73 +/- 10 ml/yr was observed, and this was accompanied by a decline in PaO2 of 0.47 +/- 0.01 kPa/yr. Patients died with a mean FEV1 of 0.55 +/- 0.04 L and a PaO2 of 5.1 +/- 0.2 kPa. A small rise in PaCO2 occurred, on average 0.25 +/- 0.09 kPa/yr, throughout the study, but accelerating in many cases during the three years before death. Hypoxic cor pulmonale appears to be associated with a rapid deterioration in airway function, a steady decline in PaO2, and a slow rise in PaCO2 during the years leading up to death. These physiologic changes measured in a stable clinical state while breathing air appear to occur in spite of LTOT. The LTOT may merely prevent death from episodes of severe hypoxemia while the pathophysiologic changes in the lung progress. Hence the benefit to be expected from LTOT is only temporary. Generally, those patients with lower levels of FEV1 will obtain diminishing clinical benefit, inversely related to the severity of airflow obstruction at the time of commencement of LTOT.

Corticosteroid trials in non-asthmatic chronic airflow obstruction: a comparison of oral prednisolone and inhaled beclomethasone dipropionate

One hundred and twenty seven adults considered on clinical grounds to have non-asthmatic chronic airflow obstruction entered a randomised, double blind, placebo controlled, crossover trial comparing the physiological response to inhaled beclomethasone dipropionate 500 micrograms thrice daily with oral prednisolone 40 mg a day, both given for two weeks. One hundred and seven patients completed the study. Response was assessed as change in FEV1 and FVC measured on the last treatment day, and as change in mean peak expiratory flow (PEF) over the final seven days of treatment from home PEF recordings performed five times daily. A full response to treatment was defined as an increase in FEV or FVC, or an increase in mean daily PEF over the final seven days of treatment, of at least 20% from baseline values. An improvement in one measurement of at least 15%, or of 10% in any two measurements, was defined as a partial treatment response. Response to placebo showed a significant order effect, suggesting a carry over effect of active treatment of at least three weeks. Response to active treatment was therefore related to initial baseline values, and compared with placebo by considering responses in the first treatment phase only. A full response to oral prednisolone (16/38) was significantly more common than to placebo (3/35). The number of full responses to inhaled beclomethasone (8/34) did not differ significantly from the number responding to oral prednisolone or placebo in the first treatment phase, though full and partial responses to inhaled beclomethasone (12/34) were significantly more common than those to placebo (4/35). When all three treatment phases were considered 44/107 patients showed a full response to one or both forms of corticosteroid treatment, a response to prednisolone (39) occurring more frequently than to inhaled beclomethasone (26). Only 21 of the 44 responders showed a response to both forms of treatment. Inhaled beclomethasone dipropionate 500 micrograms thrice daily was inferior to oral prednisolone 40 mg per day, but better than placebo, in producing improvement in physiological measurements in patients thought to have nonasthmatic chronic airflow obstruction. It was, however, an effective alternative in over half of those showing a response to prednisolone.

Bronchial responsiveness, lung mechanics, gas transfer, and corticosteroid response in patients with chronic airflow obstruction

Thirty patients with stable chronic airflow obstruction receiving regular bronchodilator treatment were studied to determine whether the level of bronchial responsiveness, transfer factor for carbon monoxide (TLCO), or the mechanical properties of the lung predicted a bronchodilator response to oral corticosteroid treatment. Before treatment mean (SD) FEV1 was 48% (16%) of the predicted value (% pred); the geometric mean concentration of methacholine required to produce a 20% fall in FEV1 (PC20) was 0.44 (range 0.07-3.32) mg/ml; and TLCO was 59% (21%) predicted. The exponential constant (k) defining the shape of the static volume-pressure curve was 146% (66%) predicted and pulmonary conductance relative to predicted lung volume at a transpulmonary pressure of 5 cm H2O (sGL5) was 72% (37%) predicted. After prednisolone treatment (0.6 mg kg-1 day-1 for two weeks) FEV1 increased by 8% (19%) (p less than 0.05) and daily mean peak flow (PEF) by 3% (10%) (p less than 0.01) over pretreatment values. Three patients had an increase in FEV1 of more than 30%, two of whom had sputum eosinophilia (p less than 0.05). The three were among the 13 patients with a reduced sGL5. The increase in FEV1 did not correlate with initial PC20 (r = 0.16), k (r = -0.12), or TLCO (r = -0.14). Thus measurements of bronchial responsiveness, lung distensibility, and TLCO did not predict corticosteroid response in patients with stable chronic airflow obstruction. Patients with sputum eosinophilia or reduced pulmonary conductance may be more likely to respond.

Corticosteroids in stable chronic obstructive pulmonary disease: reappraisal of efficacy

Although systemic corticosteroids are widely used in treating stable chronic obstructive pulmonary disease (COPD), the evidence for their efficacy is still disputed. To reappraise this evidence, the authors used a new analytic strategy in which the 14 available randomized clinical trials were evaluated according to a methodologic "review of systems" and an examination of the statistical precision of the outcome results. Although none of the trials satisfied all of the methodologic criteria for both validity and clinical pertinence, the trials finding steroids efficacious were generally better designed and more statistically precise than trials failing to show efficacy. The authors propose a set of five main methodologic guidelines that require a stable baseline state, a crossover design with suitable washout, adequate doses of corticosteroids, pragmatic designs, and comprehensive choices of outcome events. Attention to these guidelines can help improve both design and evaluation for future trials of systemic steroids for stable COPD.

The diagnosis and treatment of adults with obstructive airways disease in general practice

Two hundred and one patients diagnosed by their general practitioners as having asthma and 113 as having chronic bronchitis were compared by symptomatology and airways reversibility. Though the majority of patients given these two diagnoses could be separated by symptom complex, in about one-third such differentiation was difficult. There was no significant difference in bronchodilator reversibility between the asthmatics and chronic bronchitics. Nine out of 15 (60%) asthmatics and four out of 18 (22%) chronic bronchitics responded by 15% or more to a course of oral corticosteroid drugs. The majority of corticosteroid responders had been undertreated. The problems arising from the poor correlation between airways reversibility and symptomatic diagnosis are discussed.