The effect of the weather on pulmonary exacerbations and viral infections among adults with cystic fibrosis

The effect of changes in the weather on the respiratory health of patients with cystic fibrosis (CF) is unclear. We conducted a prospective study to determine the impact of climate and season on the incidence of viral respiratory infections (VRI) and pulmonary exacerbations (PEx) among adults with CF. Between December 2010 and April 2012, 98 adults with CF were followed for 12 months. Polymerase chain reaction assays for nine viruses were performed on sputum, nose and throat swabs every 2 months and additionally at onset of PEx. Hourly temperature and relative humidity measurements were recorded throughout the study. Statistical analysis utilized generalized estimating equation (GEE) models. Pre-specified criteria for VRI and PEx were met at 29% and 37% of visits, respectively. Rhinovirus accounted for 72% of identified viruses. Incidence of rhinovirus peaked in autumn while non-rhinovirus VRI peaked in winter. Rhinovirus was associated with increased mean temperatures (OR 1.07; p = 0.001), while non-rhinovirus VRI was associated with lower mean temperatures (OR 0.87; p < 0.001). PEx occurred frequently throughout the study with no clear seasonal pattern observed. There was no significant association between climate variables and the incidence of either PEx or antibiotic prescription. There is a seasonal pattern to VRI in adults with CF. The incidence of VRI but not PEx is associated with changes in ambient temperature.

Inflammatory and immunological biomarkers are not related to survival in adults with Cystic Fibrosis

BACKGROUND

Chronic Pseudomonas aeruginosa pulmonary infection is associated with a decline in lung function and reduced survival in people with Cystic Fibrosis (CF). Damaging inflammatory and immunological mediators released in the lungs can be used as markers of chronic infection, inflammation and lung tissue damage.

METHODS

Clinical samples were collected from CF patients and healthy controls. Serum IgG and IgA anti-Pseudomonas antibodies, sputum IL-8 and TNFα, plasma IL-6 and urine TNFr1 were measured by ELISA. Sputum neutrophil elastase (NE), cathepsin S and cathepsin B were measured by spectrophotometric and fluorogenic assays. The relationship between IgG and IgA, inflammatory mediators and long-term survival was determined.

RESULTS

IgG and IL-6 positively correlated with mortality. However, multivariate analysis demonstrated that after adjusting for FEV(1), IgG was not independently related to mortality. A relationship was observed between IgG and IL-6, TNFα, TNFr1 and between IgA and IL8, cathepsin S and cathepsin B.

CONCLUSIONS

These data indicate that biomarkers of inflammation are not independent predictors of survival in people with CF.

Differing perspectives of sputum and its expectoration: a qualitative study involving patients with cystic fibrosis and physiotherapists

Sputum specimens are frequently requested from individuals with chronic suppurative conditions such as cystic fibrosis (CF). For a proportion of people, expectorating sputum can be difficult. Our goal was to explore the potential barriers and facilitators to expectorating sputum from the perspective of those with CF and physiotherapists involved in their care. Eighteen interviews were conducted with people who have CF and three focus groups with physiotherapists. Data were recorded, transcribed verbatim, and analysed using a framework approach. Variation emerged in perceptions between physiotherapists and people with CF in terms of sputum's impact on everyday life and the importance of its role in managing the condition. These differences were reflected in the following themes: (1) seepage of bodily boundaries, (2) discrediting nature of sputum, (3) embodied representation of chronic illness, and (4) non-production as a decisional balance. Differing views between participants could have arisen from the personal nature of sputum for people with CF, whilst physiotherapists may see sputum specimens as a necessary part of holistic management of this condition. Education could assist individuals in overcoming some of the barriers associated with expectorating, but physiotherapists may have to individualise the collection of sputum, recognising not everyone will be at ease with this procedure.

Sputum issues as defined by patients with cystic fibrosis: a qualitative investigation

OBJECTIVES

Patients with cystic fibrosis (CF) are asked to provide a sputum sample at clinic to test for potentially harmful pathogens. However, some appear to struggle with this request. Research into the difficulties experienced by these patients is lacking. This study set out to explore this issue in depth, using a qualitative research approach.

METHODS

Semi-structured interviews were conducted with 18 patients identified as having difficulties with sputum by the physiotherapists involved in their care. Framework analysis was applied to collected data.

RESULTS

An overarching concept derived from the interview material was a concern about sputum coming to be a defining feature of identity. This was reflected in the following four themes: (1) being seen as dirty because sputum is socially vilified as thus; (2) sputum exposing an invisible condition; (3) sputum acting as a reminder of having CF; (4) being seen as sputum producers by practitioners.

DISCUSSION

Patients' difficulties with expectorating sputum were multifaceted and included psychosocial and physical factors. Practitioners need to appreciate that for some people, a request for sputum can cause significant discomfort. Individualized interventions to assist these patients may prove helpful.

Association of airway cathepsin B and S with inflammation in cystic fibrosis

Irreversible tissue damage within the cystic fibrosis (CF) lung is mediated by proteolytic enzymes during an inflammatory response. Serine proteinases, in particular neutrophil elastase (NE), have been implicated however, members of the cysteine proteinase family may also be involved. The aim of this study was to determine cathepsin B and S levels in cystic fibrosis (CF) sputum and to assess any relationship to recognized markers of inflammation such as sputum NE, interleukin-8 (IL-8), tumor necrosis factor alpha (TNF-alpha), urine TNF receptor 1 (TNFr1), plasma IL-6, and serum C-reactive protein (CRP). Proteinase activities were measured in the sputum of 36 clinically stable CF patients using spectrophotometric and fluorogenic assays. Immunoblots were also used to confirm enzyme activity data. All other parameters were measured by ELISA. Patients had a mean age of 27.2 (8.2) years, FEV. of 1.6 (0.79) L and BMI of 20.7 (2.8). Both cathepsin B and S activities were detected in all samples, with mean concentrations of 18.0 (13.5) microg/ml and 1.6 (0.88) microg/ml, respectively and were found to correlate not only with each other but with NE, TNF-alpha and IL-8 (in all cases . < 0.05). Airway cathepsin B further correlated with circulatory IL-6 and CRP however, no relationship for either cathepsin was observed with urine TNFr1. This data indicates that cathepsin B and S may have important roles in the pathophysiology of CF lung disease and could have potential as markers of inflammation in future studies.

A novel solution for severe urinary incontinence in women with cystic fibrosis

BACKGROUND

To explore whether Tension-free Vaginal Tape offers a solution for women with cystic fibrosis who suffer from severe stress incontinence.

METHODS

Four adults with cystic fibrosis were formally assessed by gynaecological and urological specialists, prior to hospital admission for surgery.

RESULTS

The procedure was tolerated well by all patients. In three, leakage ceased completely. The fourth patient experienced considerable improvement in symptoms.

CONCLUSIONS

Tension-free Vaginal Tape is a safe, effective and worthwhile solution for stress incontinence in females with cystic fibrosis.

Objective measurement of cough during pulmonary exacerbations in adults with cystic fibrosis

BACKGROUND

Little is known about cough frequency in adults with cystic fibrosis (CF). This study aimed to determine (1) daytime and overnight cough rates in patients with CF at the beginning and end of a course of antibiotics for treatment of an exacerbation; (2) the relationship between cough frequencies and standard clinical measures of disease; and (3) the relationship between objective cough rates and the subjective assessment of cough.

METHODS

Nineteen adult patients admitted with a pulmonary exacerbation performed daytime and overnight sound recordings on admission; 13 had repeat recordings prior to discharge. Coughs were manually quantified in cough seconds (time spent coughing). Patients subjectively scored their cough using a visual analogue scale (VAS) and numerical score. Lung function, C-reactive protein (CRP) levels, and sputum weights were recorded.

RESULTS

Cough rates fell substantially with treatment; median fall in cough rate was 51.3% (IQR 32.3-77.5) (p<0.001) for daytime and 72.2% (28.6-90.1) (p = 0.049) for overnight. Multivariate regression analyses showed that forced expiratory volume in 1 second and CRP levels predicted overnight cough rates on admission. On discharge, sputum volume predicted daytime cough rates. Only the change in overnight VAS correlated with the change in objective cough rates.

CONCLUSIONS

The cough rate significantly decreases with treatment of a pulmonary exacerbation in adults with CF. Lung function, sputum volume, and CRP influences the cough rate, with the effects differing from day to night and between admission and discharge. Subjective reporting of a nocturnal cough may indicate a pulmonary exacerbation of CF in adults.

Clinical and economic choices in the treatment of respiratory infections in cystic fibrosis: Comparing hospital and home care

BACKGROUND

A cost-effectiveness evaluation comparing home-based and hospital-based treatment with intravenous antibiotics for respiratory exacerbations in adults with cystic fibrosis (CF) has not been previously undertaken.

METHODS

The study was conducted in a UK adult CF centre from a health service perspective. Clinical outcome and resource use data were obtained from a retrospective one-year study and combined with unit cost data in an incremental economic analysis. The primary outcome measure was percentage change in FEV(1); "effectiveness" was defined as maintenance of baseline average FEV(1) over the one-year study period.

RESULTS

116 patients received 454 courses of intravenous antibiotics. At the end of 1 year, there had been a mean percentage decline in FEV(1) compared with baseline average for home-treated patients but an improvement for hospital-treated patients (Tukey's HSD mean difference 10.1%, 95% CI 2.9 to 17.2, p = 0.003). Treatment was deemed "effective" in more hospital (58.8%) than home (42.6%) patients. The cost of hospital treatment was higher than home treatment (mean difference 9,005 pounds, 95% CI 3,507 to 14,700, p<0.001). The mean ICER was 46,098 pounds (2.5th and 97.5th percentiles -374,044 and 362,472).

CONCLUSIONS

Hospital treatment was more effective but more expensive than home treatment. Potential methods to improve outcome at home should be considered but these may have resource implications.

Symptoms, lactate and exercise limitation at peak cycle ergometry in adults with cystic fibrosis

The purpose of this study was to investigate symptoms, lactate accumulation and limiting factors at peak exercise in cystic fibrosis (CF) patients. In total, 104 CF adults attending an adult CF centre and 27 controls performed progressive cycle ergometry to a symptom-limited maximum. Measurements taken at peak exercise included: heart rate, ventilation, oxygen uptake, carbon dioxide output, oxygen saturation and blood lactate. Symptom scores of perceived breathlessness and muscle effort were recorded using Borg scales. The CF subjects had a lower mean body mass index, forced expiratory volume in one second (FEV(1)) and peak oxygen uptake than controls. Peak lactate concentrations were very similar to controls (mean+/-sd 6.8+/-2.0 mmol x L(-1) versus 7.4+/-1.0 mmol x L(-1)). Symptom scores were no different to controls for either breathlessness (4.5+/-2.0 versus 4.3+/-1.0) or perceived muscle effort (6.1+/-2.0 versus 6.5+/-1.0), with higher scores for muscle effort than breathlessness in both groups. In addition, peak ventilation was lower than the predicted maximum, and high peak heart rates were recorded supporting nonpulmonary factors as important in limiting peak exercise. Peak oxygen uptake was correlated with FEV(1). Comparison of CF subjects with mild or moderate pulmonary disease and controls revealed similar exercise responses. In contrast, those CF patients with severe lung disease (FEV(1) <40% predicted) had significantly higher breathlessness, lower muscle effort scores, lower peak lactate, lower peak heart rate and a mean ventilation exceeding predicted, thus confirming that ventilation was the major factor limiting exercise. In conclusion, cystic fibrosis subjects have a reduced peak exercise capacity, but their exercise response is similar to controls in generating high blood-lactate concentrations and symptoms of muscle effort in excess of dyspnoea. Nonpulmonary factors influence peak performance more in those without severe disease.

Individualised unsupervised exercise training in adults with cystic fibrosis: a 1 year randomised controlled trial

BACKGROUND

Short term studies of exercise training have shown benefits in cystic fibrosis. Transferring exercise programmes to the community and sustaining them long term is a challenge for the patient. The effectiveness of an individualised unsupervised home based exercise programme was examined in adults with cystic fibrosis over a 1 year period.

METHODS

Subjects were randomised to undertake three sessions per week of upper and lower body exercise based on individualised preferences (n = 30) or to a control group (n = 18). They were evaluated at baseline and at 12 months. The primary outcome measure was improved fitness as assessed by change in blood lactate concentration at the end of an identical constant work rate for both arm and leg ergometric testing. Secondary outcome measurements were heart rate and pulmonary function.

RESULTS

For leg exercise, significant differences were seen at 12 months between the active and control groups in the mean (SE) change in blood lactate levels (-0.38 (0.23) mmol/l v 0.45 (0.25) mmol/l, p<0.05) and heart rate (-4.8 (2.5) bpm v 3.4 (2.5) bpm, p<0.05), confirming a training effect. For arm ergometry there was no change in lactate levels at 12 months but there was a significant difference in forced vital capacity (46 (72) ml v -167 (68) ml, p<0.05).

CONCLUSIONS

A training effect, as measured by a reduction in lactate levels and heart rate, can be achieved with unsupervised individualised home exercise in adults with cystic fibrosis. A benefit to pulmonary function was observed and together these findings suggest that exercise programmes should be encouraged as an important component of care in cystic fibrosis.

Quality of life in cystic fibrosis: the impact of gender, general health perceptions and disease severity

BACKGROUND

Disease progression in cystic fibrosis (CF) is marked by deterioration across a number of physiological systems. In addition, there is evidence that females have a worse prognosis than males. The current work assesses the impact of both these factors on health related quality of life (HRQoL).

METHODS

Two hundred and twenty-three adolescents and adults completed the cystic fibrosis quality of life (CFQoL) questionnaire with a further 185 approached and not responding by non-completion of the questionnaire. The CFQoL is divided into nine domains: physical, social, treatment, chest symptoms, emotional functioning, concerns for the future, relationships, body image, and career. Measurement of objective clinical status included, body mass index (BMI), and percentage of predicted forced expiratory volume in one second (FEV1). General health perceptions (GHP) were also measured.

RESULTS

Patients were sub-divided by gender and disease severity (mild > 70% FEV1, moderate 40-69% and severe < 40%). Factorial analysis of variance indicated significant main effects for FEV1 (F = 587.98, P < or = 0.001) and BMI (F = 17.29, P < or = 0.001) as a function of disease severity. Post hoc tests revealed significant two-group differences for FEV1 and BMI between disease severity groups. No differences were observed for gender across FEV1 or BMI. Differences emerged across most CFQoL domains for disease severity, with the exception of concerns for the future, which was consistently low throughout. Gender differences emerged for chest symptoms, emotional functioning, concerns for the future, body image and career. With the exception of body image, females exhibited poorer HRQoL. Pearson correlations indicated that females' perception of health was more closely related to clinical status than males.

CONCLUSIONS

Disease severity has an impact on HRQoL in adolescents and adults with CF. Some differences emerged between males and females, with females generally reporting poorer HRQoL. Evidence indicated that males and females perceived their health status differently, with females having a more accurate perception of objective clinical health status.

Burkholderia cenocepacia and Burkholderia multivorans: influence on survival in cystic fibrosis

INTRODUCTION

Burkholderia cepacia infection has been associated with a poor prognosis for patients with cystic fibrosis (CF). It is now recognised that organisms classified as B cepacia comprise a number of distinct genomic species each known as a genomovar of the B cepacia complex (BCC). The outcome of infection for CF patients with individual genomovars is unknown. The clinical outcome of infection with the two most commonly isolated genomovars (B cenocepacia and B multivorans) was studied at a specialist CF centre between 1982 and 2003.

METHODS

The numbers of patients who progressed from initial to chronic infection were assessed. Control groups were created by matching patients with chronic BCC infection by percentage forced expiratory volume in 1 second with patients with Pseudomonas aeruginosa infection. Outcome measures were survival time, deaths from "cepacia syndrome", rate of decline in spirometry and body mass index (BMI), and treatment requirements.

RESULTS

Forty nine patients had an initial infection with either B multivorans (n = 16) or B cenocepacia (n = 33); 8/16 and 31/33, respectively, developed chronic infection (p<0.001). Deaths from "cepacia syndrome" occurred in both BCC groups. Patients with B cenocepacia infection had a shorter survival than patients with P aeruginosa infection (p = 0.01). There was no difference in survival between CF patients infected with B multivorans and P aeruginosa. There were no observed differences in changes in spirometry and BMI or treatment requirements between the BCC groups and respective controls.

CONCLUSION

In CF, the genomovar status of BCC may influence both the likelihood of progression from initial to chronic infection and the overall survival of the patients.

Validation of the SF-36 for the assessment of quality of life in adolescents and adults with cystic fibrosis

BACKGROUND

Generic health-related quality of life measures are often applied to disease groups without assessment of their psychometric properties. The current work assesses the properties of the Short Form 36-item (SF-36) questionnaire in a British sample of adolescents and adults with cystic fibrosis (CF).

METHODS

Two hundred and twenty-three adolescents and adults with CF completed the SF-36 with a further 185 approached and not responding by non-completion of the questionnaire. The structure and internal reliability of the instrument was assessed by principal components analysis, Cronbach alpha coefficients and item to domain correlations. Differences between disease severity groups were assessed by analysis of variance.

RESULTS

Factor analysis of the SF-36 scores broadly confirmed domain structures for the SF-36. Cronbach alpha coefficients were high (range 0.82-0.91) and item-to-same domain correlations were stronger than item-to-unrelated domain correlations. Examination of differences between mild, moderate and severe disease states revealed four significant main effects for: physical functioning, role limitation due to physical functioning, general health perceptions and energy and vitality. The analysis also revealed the presence of numerous ceiling effects across domains.

CONCLUSIONS

The domain structure of the SF-36 was demonstrated to be robust. However, the discriminatory ability of the measure was disappointing. The presence of ceiling effects and the low frequency of differences between intermediate disease severity groups indicated that the SF-36 was not discriminatory with respect to mild disease states or progression of illness.

Inflammatory related changes in bone mineral content in adults with cystic fibrosis

BACKGROUND

Proinflammatory cytokines stimulate osteoclast activity and this could lead to increased bone resorption in patients with cystic fibrosis. The aim of this study was to determine whether markers of systemic inflammation are related to changes in bone mineral content (BMC) in adults with cystic fibrosis.

METHODS

Total body BMC was assessed by dual energy x ray absorptiometry in 100 patients (54 male) of mean (SD) age 25.6 (7.1) years and forced expiratory volume in 1 second (FEV(1)) 61.8 (24.1)% predicted on recruitment to the study and 1 year later. Blood was also taken at these time points to measure markers of systemic inflammation.

RESULTS

After 1 year BMC had reduced by 16.1 (62.1) g, p = 0.01; (0.6 (2.8)%). The change in BMC was related to mean levels of interleukin (IL)-6 (r(s) = -0.39, p<0.001) and C reactive protein (r(s) = -0.34, p = 0.002), intravenous antibiotic use (r(s) = -0.27, p = 0.006) and oral corticosteroid use (r(s) = -0.20, p = 0.045). Urinary markers of osteoclast activity were also related to IL-6 (r(s) = 0.27, p = 0.02). Multiple linear regression revealed that IL-6 (coefficient -2.2 (95% CI -3.4 to -1.0) per pg/ml, p = 0.001), colonisation with Burkholderia cepacia (coefficient -46.8 (95% CI -75.5 to -18.1), p = 0.002), and annual change in BMI (coefficient 15.4 (95% CI 3.6 to 27.2) per kg/m(2), p = 0.011) were independently significant predictors of annual change in BMC.

CONCLUSIONS

These data suggest a pathophysiological mechanism by which chronic pulmonary infection results in bone loss in patients with cystic fibrosis.

Long term clinical outcome of home and hospital intravenous antibiotic treatment in adults with cystic fibrosis

BACKGROUND

Several studies have suggested that clinical outcomes in adults with cystic fibrosis (CF) are equivalent after home and hospital treatment with intravenous antibiotics, but these studies were small and selective and only considered one course of treatment.

METHODS

A retrospective longitudinal study was performed to compare the clinical outcome over a period of 1 year of all patients attending the Manchester Adult CF Unit who received intravenous antibiotics at home or in hospital. The primary outcome measure was percentage change in forced expiratory volume in 1 second (FEV(1)) at the end of the 1 year period. Baseline "best" and "average" FEV(1) values were established for each patient for the year before the study. The secondary outcome measures were percentage changes in forced vital capacity (FVC) and body weight.

RESULTS

A total of 116 patients received 454 courses of intravenous antibiotics. At the end of 1 year there had been a mean percentage decline in FEV(1) compared with the baseline "average" for patients treated mostly at home but an improvement in patients treated mostly in hospital (Tukey's HSD mean difference 10.1%, 95% CI 2.9 to 17.2, p = 0.003). For all patients there was a mean percentage decline in FEV(1) from the baseline "best" value. For each course of treatment the mean percentage improvements in FEV(1) at the end of the course from the start of the course were significantly higher for patients treated in hospital than for those treated at home.

CONCLUSIONS

Clinical outcome, as defined by spirometric parameters and body weight, was better after a course of treatment in hospital than after home treatment, and this benefit was maintained over 1 year of treatment. The results suggest that patients treated at home need closer supervision.

Treatment of urinary incontinence in cystic fibrosis

BACKGROUND

Urinary incontinence (UI) is a newly recognised problem in cystic fibrosis. Whilst prevalence is well documented, there are no reports of assessment and treatment of the problem.

METHODS

A previous study reports the prevalence of UI in women with CF to be 51/75 (68%). Nineteen women subsequently requested help for the problem and were referred to a physiotherapist specialising in women's health. A digital assessment was performed to measure pelvic floor muscle strength and endurance. An individualised programme of pelvic floor muscle exercises (PFME) was taught based on the assessment. A questionnaire addressed issues of assessment and treatment.

RESULTS

12 women were assessed. The median (range) age, FEV1% predicted and BMI were 20.9 (19.3-46.1) years, 45.9 (14.8-82.7) and 20.5 (16.1-26.0), respectively. The median strength of the pelvic floor muscle was moderate (Oxford Scale grade 3) with a hold time (endurance) of 5 s. At reassessment (median time 13.1 weeks), there was an improvement in endurance (P = 0.04), with no change in strength. This was supported by a subjective improvement in symptoms. Patients found the exercises were difficult to perform, difficult to fit into their treatment programme and adherence was poor.

CONCLUSIONS

PFME are effective at improving endurance and reducing leakage over the short-term. Women are reluctant to be assessed and the CF team should provide support and encouragement with treatment. Long-term outcome and the mechanisms of UI in this group of patients need further evaluation.

Inflammatory markers in cystic fibrosis patients with transmissiblePseudomonas aeruginosa

Chronic Pseudomonas aeruginosa infection in cystic fibrosis (CF) leads to a damaging host inflammatory response. There are an increasing number of reports of P. aeruginosa cross-infection at CF centres. The clinical significance of acquisition of a transmissible strain for patients who already harbour P. aeruginosa is unclear. In this study, levels of inflammatory markers in clinically stable adult CF patients who harbour transmissible and sporadic strains of P. aeruginosa have been compared. Patients with CF and chronic P. aeruginosa infection were grouped into those who harbour a transmissible P. aeruginosa and those who harbour their own sporadic strains. Total white cell and differential counts, sputum neutrophil elastase (NE), interleukin (IL)-8, tumour necrosis factor (TNF)-alpha, plasma IL-6 and NE/alpha1-antitrypsin complexes, serum C-reactive protein, and urine TNF receptor 1 were all measured in clinically stable patients 4-6 weeks following completion of intravenous antibiotic therapy. The two groups (both n=20) were well matched for per cent predicted forced expiratory volume in one second, per cent predicted forced vital capacity and body mass index. There were no significant differences in levels of white cell counts or inflammatory markers between the two groups. At times of clinical stability, cystic fibrosis patients infected with transmissible Pseudomonas aeruginosa do not have a heightened inflammatory response above that of those harbouring sporadic strains.

Identification of airborne dissemination of epidemic multiresistant strains of Pseudomonas aeruginosa at a CF centre during a cross infection outbreak

BACKGROUND

Chronic Pseudomonas aeruginosa infection is a major cause of morbidity and mortality for individuals with cystic fibrosis (CF). P aeruginosa cross infection outbreaks have recently been reported at CF holiday camps and specialist centres. The mechanism of cross infection is unknown. A study was performed to look for the presence of epidemic strains of P aeruginosa in the environment of a CF centre during a cross infection outbreak and to examine their potential modes of spread between patients.

METHODS

Microbiological sampling of the environment of the CF facility was performed, including room air sampling. Individual P aeruginosa strains were identified by bacterial fingerprinting. The typing patterns were compared with those of epidemic strains responsible for cross infection among the patients.

RESULTS

Epidemic P aeruginosa strains were isolated from room air when patients performed spirometric tests, nebulisation, and airway clearance, but were not present in other areas of the inanimate environment of the CF centre.

CONCLUSIONS

Aerosol dissemination may be the most important factor in patient-to-patient spread of epidemic strains of P aeruginosa during recent cross infection outbreaks at adult CF centres.

Increased treatment requirements of patients with cystic fibrosis who harbour a highly transmissible strain of Pseudomonas aeruginosa

BACKGROUND

A group of patients who harbour the same highly transmissible strain of Pseudomonas aeruginosa were identified at a cystic fibrosis (CF) centre. Isolates of this strain display a number of unusual phenotypic features including resistance to most typical antipseudomonal antibiotics. A study was undertaken to see if there was a difference in treatment requirements between CF patients with chronic infection with their own unique P aeruginosa strains (group 1) and those who harbour a highly transmissible strain (group 2).

METHODS

Data on treatment requirements for the year 2000 were collected from the case records of CF patients with chronic P aeruginosa infection who had received inpatient treatment. Patients co-infected with Burkholderia cepacia or other highly transmissible strains of P aeruginosa were excluded.

RESULTS

There were 2/56 and 3/22 deaths in groups 1 and 2, respectively; these patients were excluded from the analysis. No difference was found between the two groups for mean age, % predicted forced expiratory volume in 1 second (FEV(1)), % predicted forced vital capacity (FVC), and body mass index. Patients in group 2 had a greater median (range) number of intravenous antibiotic days (60 (17-216) v 33 (4-237) days; p=0.01), inpatient days (39 (7-183) v 16 (1-172) days; p<0.01), and inpatient episodes (3 (1-9) v 2 (1-6); p<0.01), and more respiratory exacerbations (mean (SD) 8.2 (3.4) v 6.1 (3.2); p=0.01).

CONCLUSIONS

Patients who harbour the highly transmissible P aeruginosa strain have a greater treatment burden than patients with CF who harbour their own unique strains. These findings support the need for microbiological surveillance for highly transmissible P aeruginosa and the implementation of infection control measures to prevent cross infection.

A prospective study of change in bone mineral density over one year in adults with cystic fibrosis

BACKGROUND

Low bone mineral density (BMD) is prevalent in adults with cystic fibrosis. To identify appropriate therapeutic strategies and the optimal time for intervention, it is necessary to document the natural history of cystic fibrosis related low BMD.

METHODS

114 adults with cystic fibrosis underwent bone densitometry a median (25-75% interquartile range) of 12 (12-13) months after initial assessment of bone density. BMD was measured in the lumbar spine, femoral neck, total hip, and distal forearm on recruitment to the trial and at follow up.

RESULTS

In patients <or=24 years of age (n=55, mean (SD) age 19.5 (2.6) years) in whom an annual increase in BMD would normally be expected, BMD increased by a mean (95% CI) 2.9% (1.6 to 4.2) per year in the distal forearm (p<0.001), but decreased by 2.5% (95% CI -3.8 to -1.2) per year in the femoral neck (p<0.001) and by 2.2% (95% CI -3.3 to -1.0) per year in the total hip (p<0.001). In patients >or=25 years of age (n=59, mean (SD) age 30.3 (5.4) years) in whom no annual change in BMD would normally be expected, BMD decreased by 1.9% (95% CI -2.9 to -0.8) per year in the femoral neck (p<0.001), by 1.5% (95% CI -2.4 to -0.6) per year in the total hip (p=0.001), and by 0.8% (95% CI -1.5 to -0.1) per year in the distal forearm (p=0.026). There was no significant annual change in lumbar spine BMD in either patient cohort.

CONCLUSIONS

Reduced rates of bone accretion and accelerated rates of bone loss explain the high prevalence of low BMD in adults with cystic fibrosis.

Identification of an immunodominant drug efflux pump in Burkholderia cepacia

Burkholderia cepacia, a major pathogen amongst individuals with cystic fibrosis (CF), is intrinsically resistant to most clinically available antibiotics. We report the identification of an immunodominant antigen in CF patients infected with B. cepacia, a multidrug-resistance efflux pump called BcrA. The bcrA gene encodes a 46 kDa peptide with 14 potential alpha-helices that belongs to the major facilitator superfamily of drug transporters. A recombinant Escherichia coli strain was constructed containing the bcrA gene, which resulted in a four-fold increase in resistance to tetracycline and an eight-fold increase in resistance to nalidixic acid. These results demonstrate that the bcrA gene is part of a drug efflux system that is potentially a major contributor to the high-level antibiotic resistance observed in B. cepacia and thus a potential target for novel therapeutics.

PCR-based detection and identification of Burkholderia cepacia complex pathogens in sputum from cystic fibrosis patients

PCR amplification of the recA gene followed by restriction fragment length polymorphism (RFLP) analysis was investigated for the rapid detection and identification of Burkholderia cepacia complex genomovars directly from sputum. Successful amplification of the B. cepacia complex recA gene from cystic fibrosis (CF) patient sputum samples containing B. cepacia genomovar I, Burkholderia multivorans, B. cepacia genomovar III, Burkholderia stabilis, and Burkholderia vietnamiensis was demonstrated. In addition, the genomovar identifications determined directly from sputum were the same as those obtained after selective culturing. Sensitivity experiments revealed that recA-based PCR could reliably detect B. cepacia complex organisms to concentrations of 10(6) CFU g of sputum(-1). To fully assess the diagnostic value of the method, sputum samples from 100 CF patients were screened for B. cepacia complex infection by selective culturing and recA-based PCR. Selective culturing identified 19 samples with presumptive B. cepacia complex infection, which was corroborated by phenotypic analyses. Of the culture-positive sputum samples, 17 were also detected directly by recA-based PCR, while 2 samples were negative. The isolates cultured from both recA-negative sputum samples were subsequently identified as Burkholderia gladioli. RFLP analysis of the recA amplicons revealed 2 patients (12%) infected with B. multivorans, 11 patients (65%) infected with B. cepacia genomovar III-A, and 4 patients (23%) infected with B. cepacia genomovar III-B. These results demonstrate the potential of recA-based PCR-RFLP analysis for the rapid detection and identification of B. cepacia complex genomovars directly from sputum. Where the sensitivity of the assay proves a limitation, sputum samples can be analyzed by selective culturing followed by recA-based analysis of the isolate.

Spread of a multiresistant strain of Pseudomonas aeruginosa in an adult cystic fibrosis clinic

We initiated a prospective surveillance study to investigate possible Pseudomonas aeruginosa cross-infection in our cystic fibrosis centre. We characterised isolates by pyocin typing and pulsed-field gel electrophoresis. 22 (14%) of 154 patients with chronic P aeruginosa had isolates with similar and new pyocin and pulsed-field gel electrophoresis types. The shared isolates showed unusual phenotypic features: they were non-pigmented, non-motile, and resistant to a number of antipseudomonal antibiotics. Cross-infection by a multiresistant P aeruginosa strain has therefore occurred in patients attending our cystic fibrosis centre. We recommend microbiological surveillance in other cystic fibrosis centres.

Questionnaire survey of urinary incontinence in women with cystic fibrosis

Cystic fibrosis is an inherited disease characterised by the production of infected secretions, and it requires lifelong daily treatment by airway clearance. We knew that some women attending our clinic for adults with cystic fibrosis leaked urine when performing airway clearance or spirometry, but they were dismissive during discussion and were rarely forthcoming about the problem. This study was designed to determine the prevalence of urinary incontinence in women with cystic fibrosis, to establish the importance of the problem as perceived by the patients, and to identify those women who wanted help.

Effect of intravenous pamidronate on bone mineral density in adults with cystic fibrosis

BACKGROUND

Low bone mineral density (BMD) is prevalent in adults with cystic fibrosis. The aim of this study was to assess the effect of intravenous pamidronate on BMD in these subjects.

METHODS

Patients were invited to participate if they had a BMD Z score of -2 or less in the lumbar spine, proximal femur, or distal forearm. Patients were randomised to receive either 30 mg intravenous pamidronate every 3 months + 1 g calcium daily (pamidronate group) or 1 g calcium daily (control group). All pancreatic insufficient patients were prescribed oral vitamin D supplements.

RESULTS

After 6 months of treatment the pamidronate group (n=13) showed a significant increase in absolute BMD compared with the control group (n=15) in the lumbar spine (mean difference 5.8% (CI 2.7% to 8.9%)) and total hip (mean difference 3.0% (CI 0.3% to 5.6%)). However, the pamidronate group showed a reduction in BMD compared with the control group in the distal forearm (mean difference -1.7% (CI -3.7% to 0.3%)). The use of pamidronate was associated with a high incidence of bone pain in non-corticosteroid treated individuals.

CONCLUSION

Intravenous pamidronate increases axial BMD in adults with cystic fibrosis, but the high incidence of bone pain associated with this treatment might limit its use.

Burkholderia cepacia: current clinical issues, environmental controversies and ethical dilemmas

Burkholderia cepacia is a plant phytogen and is known as a hardy and versatile organism. Over the past two decades it has emerged as a pathogen in the cystic fibrosis (CF) community, with devastating effects. Pulmonary colonisation can lead to an accelerated decline in lung function. In some cases, it causes a rapid and progressive pneumonic illness termed "cepacia syndrome", which is untreatable and fatal. B. cepacia is inherently resistant to multiple antibiotics and highly transmissible and virulent strains have been identified. CF patients colonised with the organism have to be segregated from their peers to try to prevent cross-infection. However, the pathogenicity of B. cepacia is not limited to CF. Other groups, such as individuals with chronic granulomatous disease and immunocompromised patients are vulnerable and it has caused disease in healthy individuals. However, the agricultural and petrochemical industries are attempting to exploit properties of B. cepacia for use as a biopesticide and biodegradation agent. This article provides an up to date review of clinically based literature on the Burkholderia cepacia complex, highlighting clinical management issues for both cystic fibrosis and non-cystic fibrosis patients. The article also addresses the potential conflict between medicine and agriculture on plans to reintroduce strains of Burkholderia cepacia back into the environment.

Association of alpha(1)-antichymotrypsin deficiency with milder lung disease in patients with cystic fibrosis

BACKGROUND

Cystic fibrosis (CF) is characterised by an excess of free proteinases that destroy lung tissue. Despite this, previous studies have shown that patients with CF with a mild deficiency variant of the proteinase inhibitor alpha(1)-antitrypsin have less, rather than more, severe pulmonary disease. Alpha(1)-antichymotrypsin is another important serine proteinase inhibitor that protects the lung against proteolytic attack, and point mutations in the alpha(1)-antichymotrypsin gene that result in plasma deficiency are associated with chronic obstructive pulmonary disease.

METHODS

The effect of alpha(1)-antichymotrypsin deficiency and the -15 alpha(1)-antichymotrypsin signal peptide genotype on lung function was assessed in patients with CF.

RESULTS

One hundred and fifty seven patients with CF were screened and 10 were identified with a plasma deficiency of alpha(1)-antichymotrypsin (plasma concentration <0.2 g/l). In a multivariate analysis these individuals had significantly less severe lung disease than those who had normal or raised levels of alpha(1)-antichymotrypsin: forced expiratory volume in one second (FEV(1)) 69.9% predicted versus 53. 2% predicted (p=0.04) and chest radiographic score of 7.2 versus 9.7 (p=0.03) for those with and without alpha(1)-antichymotrypsin deficiency, respectively. The -15 signal peptide genotype did not affect plasma levels, but the -15 Ala/Ala signal peptide genotype was over-represented in individuals with CF compared with healthy blood donor controls.

CONCLUSION

These data indicate that deficiency of alpha(1)-antichymotrypsin is associated with less severe pulmonary disease in patients with CF, and support our previous observations that mild genetic deficiency of a proteinase inhibitor is associated with an improved outcome.

Burkholderia gladioli: recurrent abscesses in a patient with cystic fibrosis

We describe a case of an adult patient with cystic fibrosis who developed chronic pulmonary infection and multiple episodes of soft tissue abscesses with Burkholderia gladioli; this organism should be added to the list of potential pathogens for individuals with cystic fibrosis.

Perceived body image and eating behavior in young adults with cystic fibrosis and their healthy peers

Treatment aimed at achieving an ideal nutritional status is an integral part of the management of patients with cystic fibrosis (CF). Emphasis is continually placed upon dietary intake and weight. The effects of this on eating behavior and self-perceptions are unclear. This work compared male and female CF adults with a healthy male and female control population with regard to (a) clinical variables, (b) actual, perceived, and desired body shape/body mass index (BMI), and (c) body satisfaction, eating behaviors and attitudes, and self-esteem. Clinical data were recorded for 221 adults with CF and 148 healthy controls. All subjects completed BMI Charts (perception of body weight/BMI), the Eating Attitudes Test, and scales of body satisfaction and self-esteem. CF patients had poorer lung function and nutritional status than controls. Control males accurately perceived their body shape/BMI and were content with it, whereas CF males viewed their BMI as greater than it actually was and desired to be much heavier. Control females viewed their body shape/BMI as less than it actually was and desired to be even slimmer, in comparison with CF females, who perceived their BMI as less than it actually was but were happy with their perceived shape/weight. Control subjects, especially females, dieted to a greater extent and were more preoccupied with food (with binge eating and intended vomiting) than CF patients. Conversely, those with CF reported greater pressure from others to eat than did controls. More problems with food/eating behavior were associated with less body satisfaction and reduced self-esteem. In comparison with a healthy control population, the perceptions and behaviors of CF adults relating to eating, weight, and body image are not abnormal. Indeed, females with CF have fewer problems than their healthy peers.

Development of a disease specific health related quality of life measure for adults and adolescents with cystic fibrosis

BACKGROUND

Health related quality of life (HRQoL) measurement is important in determining the impact of disease on daily functioning and subsequently informing interventions. In cystic fibrosis (CF) generic HRQoL measures have been employed but these may not be sufficiently specific. The aim of the current work was to develop and validate a disease specific HRQoL measure for adults and adolescents with cystic fibrosis.

METHODS

Areas of concern to adults and adolescents with CF were identified by unstructured interviews, self-administered questionnaires, consultation with multidisciplinary specialist staff, a review of the relevant literature, and examination of other HRQoL measures. Items for the questionnaire were generated on the basis of this process. Continued evaluation and development of the Cystic Fibrosis Quality of Life (CFQoL) questionnaire was undertaken by a process of statistical analysis and continued feedback from patients. The full testing and validation of the CFQoL questionnaire took place over four phases: (1) initial item generation and testing of a preliminary questionnaire, (2) testing and validation of the second version of the questionnaire, (3) test-retest reliability of a third and final version of the questionnaire, and (4) sensitivity testing of the final version of the questionnaire.

RESULTS

Nine domains of functioning were identified using principal components analysis with varimax rotation. Internal reliability of the identified domains was demonstrated using Cronbach alpha coefficients (range 0.72-0.92) and item to total domain score correlations. Concurrent validity (range r = 0.64-0.74), discriminatory ability between different levels of disease severity, sensitivity across transient changes in health (effect size range, moderate d = 0.56 to large d = 1.95), and test-retest reliability (r = 0.74-0.96) were also found to be robust.

CONCLUSIONS

The CFQoL questionnaire is a fully validated disease specific measure consisting of 52 items across nine domains of functioning which have been identified by, and are of importance to, adolescents and adults with cystic fibrosis. This measure will be useful in clinical trials and longitudinal studies.