Detection of mycobacterial DNA from sputum of patients with cystic fibrosis.

BACKGROUND: Patients with cystic fibrosis (CF) are at high risk from atypical mycobacterial infections. There have been few attempts to delineate the intensity of mycobacterial infection in CF patients in Ireland. AIMS: To examine the incidence of mycobacterial DNA in an archived collection of genomic DNA extracted from the sputa of CF patients within the Northern Ireland population. METHODS: One hundred and eighty-two CF patients (66 adults and 116 children) were examined for the presence of mycobacterial DNA in their sputum by a genus specific PCR assay based on 16S rRNA, followed by direct automated sequencing of the PCR amplicons. RESULTS: One of 116 (0.9%) children and 2 of 66 adults were positive. Sequence identity revealed Mycobacterium xenopi in the paediatric patient and M. xenopi and M. chelonei in the two adult patients. False-positive results occurred in 11 patients (four adults), mainly due to Corynebacterium spp. CONCLUSIONS: There was a low prevalence of Mycobacterium spp in the CF patient population. All PCR positive results should be confirmed by direct automated sequencing and an alternative specific assay employed. Enhanced molecular screening will contribute in understanding their role as opportunistic pathogens in patients with worsening lung function.

Misidentification of a genomovar of Burkholderia cepacia by recA restriction fragment length polymorphism.

An 8 year old girl with cystic fibrosis presented with a pulmonary exacerbation from which Burkholderia cepacia was cultured. Subsequent polymerase chain reaction restriction fragment length polymorphism analysis of the recA gene suggested the presence of B cepacia Genomovar V (Burkholderia vietnamiensis); however, on subsequent sequence typing, this isolate was confirmed as B cepacia Genomovar IIIb. This report outlines the potential difficulties in the correct characterisation of the various genomovars within the B cepacia complex of organisms, which has particularly important implications for patient segregation and infection control.

Improved cultural detection of Burkholderia cepacia from sputum in patients with cystic fibrosis.

AIMS: To evaluate the sensitivity and specificity of two selective media for the isolation of Burkholderia cepacia from sputum specimens in patients with cystic fibrosis (CF). METHODS: In total, 149 expectorated sputum specimens from 113 patients with CF (32 cepacia colonised patients and 81 non-cepacia colonised patients) attending three CF centres were examined for the presence of B cepacia on two selective media: (1) MAST selective agar, a commercially available selective medium widely used in the UK and (2) BCSA (B cepacia selective agar), a new medium recently described, which is used predominantly in North America. RESULTS: Burkholderia cepacia was isolated from 53 of 149 (35.6%) specimens examined, representing 32 of 113 (28.3%) patients, using both the MAST and BCSA media. Growth was most rapid on BCSA with all (53 of 53) isolates detectable after 48 hours, compared with 50 of the 53 isolates on MAST agar, with the remaining three isolates detectable at five days. Twenty eight contaminants were identified on MAST agar and 13 on BCSA agar; mainly Alcaligenes xylosoxidans and yeast on MAST agar and Flavobacterium indologenes on BCSA medium. BCSA was equivalent to MAST agar in its ability to isolate B cepacia from patients with CF with a history of B cepacia infection. CONCLUSIONS: The increased selectivity and reduced time to detection of BCSA makes it an attractive alternative to MAST. However, its present limited commercial availability in the UK may delay its use in routine diagnostic laboratories because of complications with media preparation and quality control.

Clinical outcome after acquisition of Burkholderia cepacia in patients with cystic fibrosis.

BACKGROUND: Respiratory disease is the major cause of morbidity and mortality in cystic fibrosis (CF). The significance of Burkholderia cepacia (B. cepacia) in the pathogenesis of lung disease in CF is debated, but its exact role remains unclear. AIM: To assess the impact of respiratory tract colonisation with B. cepacia in patients with CF by measuring changes in pulmonary function and body mass index (BMI). METHODS: Three groups of patients were defined based on sputum culture isolates: Group 1 were B. cepacia and Pseudomonas aeruginosa (P. aeruginosa) positive patients; Group 2 were P. aeruginosa positive; and Group 3 were colonised with neither organism. Forced expiratory volume (FEV) and BMI were measured annually from 1987 to 1995 and the year of acquisition of P. aeruginosa or B. cepacia was recorded. RESULTS: The mean annual decrease in FEV1 was significantly different in all three groups: Group 1, -5.4 (5.1)%; Group 2, -3.9 (6.5)%; and Group 3, -1.6 (1.0)%, (p<0.05). The mean percentage decrease in FEV1 of a sub-group of Group 1 patients where the B. cepacia acquisition date was known was 6.1% per year versus 1.55% in Group 2 patients (p<0.05). CONCLUSIONS: Acquisition of B. cepacia may be a cause of, rather than a marker for, a decrease in pulmonary function.

Total energy expenditure in stable patients with cystic fibrosis.

BACKGROUND AND AIMS: Undernutrition is a common problem in patients with cystic fibrosis and is associated with a poor prognosis. The two aims of this study were to assess and compare the two main field techniques in the measurement of total energy expenditure and, secondly, to assess total energy expenditure in stable patients and compare with healthy controls. METHODS: Resting energy expenditure was measured using indirect calorimetry and total energy expenditure was measured using 24-h heart rate (HR) methodology and doubly isotopically labelled water. RESULTS: Seventeen patients, mean age 23 years and FEV(1)52% predicted and thirteen controls were recruited. Resting energy expenditure was higher in patients 0.24 (0.03) MJ/kg Fat-Free Mass (FFM) compared to controls 0.22 (0.02) MJ/kg FFM, P=0.02. Twenty-four hour heart rate underestimated total energy expenditure, 9.49 (1.85) MJ/day in patients compared to 11.69 (2.79) MJ/day using doubly labelled water. There was no difference in total energy expenditure in patients and controls using both methods, 11.69 (2.79) MJ/day compared to 11.38 (2.71) MJ/day using doubly isotopically labelled water. CONCLUSIONS: In clinically stable young adult patients with moderately severe respiratory disease total energy expenditure is comparable to that an a control population despite in increase in resting energy expenditure and both 24-h HR and doubly isotopically labelled water are suitable for use in patients with cystic fibrosis.

Clinical features associated with a delayed diagnosis of cystic fibrosis.

BACKGROUND: The majority of patients with cystic fibrosis (CF) are diagnosed in the first decade of life. In a small number of patients, the diagnosis is not made until later. OBJECTIVE: In this study, the clinical and genetic features of patients diagnosed after the age of 10 were examined. METHODS: All living patients in Northern Ireland diagnosed prior to 1983, when neonatal screening was introduced, were studied. A total of 103 patients were identified of whom 18 were diagnosed after the age of 10. The relationships between late diagnosis and clinical presentation, sputum microbiology, pancreatic sufficiency, nutritional status, genotype and distance from the regional CF centres was determined by multiple regression analysis. RESULTS: All 18 late-diagnosed patients had a sweat (chloride >70 mmol/l). Late diagnosis was significantly related to carriage of the R117H mutation (r(2) = 0.45) and pancreatic sufficiency (r(2) = 0.37). There was a weak relationship with pulmonary function (r(2) = 0.09). CONCLUSIONS: In Northern Ireland, late diagnosis in mainly associated with pancreatic function and carriage of the R117H mutation.

A review of cystic fibrosis children born to single mothers.

The purpose of this study was to examine the relationship between single parents and the health of their children with cystic fibrosis. Seventy-five children aged between 0.8 and 6.0 y were identified from our patient register; 20 of these children came from single parent families. Socioeconomic profiles were collated for each family. Retrospective medical data including, gene mutation analysis, were recorded from the hospital notes of all 75 patients. Maternal health was assessed by means of the General Health Questionnaire (28-item version). The results show that maternal age of < or = 19 y and lone parenthood were associated with higher morbidity in CF patients <6 y of age. Predicted values of the Shwachman score being lower by 4.1 and 4.3 points, respectively. A declining Shwachman score of 1.1 points/y was associated with increasing patient's age. In addition, analysis showed that the CF children of teenage mothers were 16 times more likely to have admission rates of > or = 1/y. Single mothers experienced more stress-related symptoms than those from the married group. We concluded that the young CF children of single or teenage mothers have a significantly worse clinical progress and consequently have a higher demand for hospital services. Clearly this population requires extra clinical vigilance and social support.

Retransplantation in a patient with cystic fibrosis.

A patient with cystic fibrosis is described who requested a third lung transplant. The medical and ethical issues involved are discussed.

Risk-benefit experience of ciprofloxacin use in pediatric patients in the United Kingdom.

BACKGROUND: Selection of the most appropriate therapeutic regimen in the management of an infectious disease in a small child or infant is often difficult. Many antimicrobial agents have side effects, thus stressing the importance of risk vs. benefit assessment in the younger patient population. Frequent use of an antimicrobial agent provides the practitioner with critical data regarding the relative rate and intensity of specific adverse events. In addition the benefits of therapy in terms of rapidity of cure, return to normal life and economic outcomes may also be appreciated. Oral ciprofloxacin, although not currently indicated for use in children, has been available to practitioners for > 10 years. OBJECTIVE: Compassionate use experience with ciprofloxacin for the treatment of acute, serious infections (i.e. Pseudomonas species) in pediatrics is described. RESULTS: To date ciprofloxacin has been a very useful agent for the management of serious infections in children and has been associated with little risk of permanent joint damage. CONCLUSION: These data support the use of ciprofloxacin in children in selected situations where the efficacy outweighs any considerable risk, thereby minimizing misuse and overuse of this antimicrobial agent.

Mutation characterization of CFTR gene in 206 Northern Irish CF families: thirty mutations, including two novel, account for approximately 94% of CF chromosomes.

A variety of mutation detection techniques, including restriction endonuclease digestion, allele specific oligonucleotides, and automated fluorescent sequencing, were used in the identification of 15 CFTR mutations representing 86.7% of CF chromosomes in 206 Northern Irish cystic fibrosis (CF) families. A systematic analysis of the 27 exons and intron/exon boundaries of the CFTR gene was performed using denaturing gradient gel electrophoresis (DGGE) in an attempt to characterise the 55 unknown CF mutations in 51 patients. Twenty different mutations were detected by DGGE on 30 chromosomes accounting for a further 7.3% of CF alleles. Fifteen of these mutations had not previously been found in Northern Ireland, and two are novel, M1I(G > T) and V562L. In total, 30 CFTR mutations account for 93.9% of the 412 Northern Irish CF chromosomes tested. The three major CF mutations in Northern Ireland are delta F508, G551D, and R117H with respective frequencies of 68.0%, 5.1%, and 4.1%. The efficacy of the DGGE technique was proven by the detection of 77 out of 77 control variants from all the CFTR exons. DGGE is a highly efficient and sensitive method for mutation screening especially in large genes where the mutation spectrum is known to be heterogeneous.

Comparison between a standard pancreatic supplement and a high enzyme preparation in cystic fibrosis.

This study compared the relative effectiveness of a standard pancreatic enzyme supplement ('Creon', Duphar) and a new preparation ('Pancrease HL', Cilag) containing about 3 times the lipase and more than 5 times the protease activity. Capsule dosage was adjusted to a ratio of approximately 3:1. Fat balances showed that absorption of fat did not change significantly on conversion to the new high-lipase product, and the coefficient of absorption of total energy was similarly maintained. The coefficient of protein absorption was significantly enhanced with the high enzyme preparation (P less than 0.01), which may explain the reported subjective improvement in stool odour. No adverse effects were recorded. Patient acceptability of the new compound was high; the great reduction in the number of capsules required at each meal was cited by all patients as the reason for their preference.

Increased energy expenditure in cystic fibrosis is associated with specific mutations.

1. Measurements of resting metabolic rate were made by open-circuit indirect calorimetry in 78 unrelated cystic fibrosis patients and 30 healthy control subjects. The aims of this study were: (i) to determine the range of variability in resting metabolic rate in cystic fibrosis, (ii) to relate this to pulmonary function and body size, and (iii) to investigate the hypothesis that, in cystic fibrosis, genotype exerts a significant influence on energy requirements. 2. There was no significant difference in age or body weight between patients with cystic fibrosis and control subjects. Resting metabolic rates for control subjects fell within +/- 10% of predicted values. Fifty-nine per cent of patients with cystic fibrosis had elevated resting metabolic rates (i.e. greater than 111% of predicted). Genotype analysis divided the patients with cystic fibrosis into three groups: delta F508 homozygotes, delta F508 heterozygotes and others. Patients homozygous for the delta F508 allele had a significantly higher resting metabolic rate (121% of predicted, 95% confidence interval 116-126%), compared with other genotypes (P less than 0.005). 3. There were significant differences in pulmonary function between the groups (P less than 0.005). However, after adjustment of individual resting metabolic rates for differences in pulmonary function by using analysis of covariance, resting metabolic rates remained significantly higher for delta F508 homozygotes than for other genotypes (P less than 0.05). 4. We conclude that there is a significant contribution to resting metabolic rate in cystic fibrosis associated with specific mutations that is not explained by declining pulmonary function.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of the PEP mask in cystic fibrosis.

Twenty-eight patients suffering from cystic fibrosis, with an age range of 8-21 years entered a randomised cross-over trial to study the efficacy of the Positive Expiratory Pressure (PEP) mask as a method of chest physiotherapy, both on its own and in conjunction with other physiotherapy techniques. Twenty-four of these patients completed the trial consisting of 4 treatment programmes each lasting one month and with no wash-out period between them. Five of these patients went on to a fifth programme of Forced Expiratory Technique (FET) alone. At the end of the trial, no significant difference was found between the programmes as regards growth, Shwachman score, Chrispin-Norman score or pulmonary function tests. Twenty-three patients chose to continue using the PEP mask in conjunction with FET long-term as their chest physiotherapy programme as they felt it was an effective treatment allowing increased independence, with postural drainage being kept to a minimum.

Tolerance and safety of ciprofloxacin in paediatric patients.

The Cystic Fibrosis Clinic at the Royal Belfast Hospital for Sick Children has treated 31 children with ciprofloxacin, for serious pseudomonas infection in cystic fibrosis, and carefully monitored the safety and acceptability of the drug. Initially, eight very ill children were treated on a named-patient basis, with an encouraging clinical response and few adverse effects. Children aged 10-18 years were included in a study of four consecutive exacerbations of respiratory disease, comparing (i) oral ciprofloxacin in each episode with (ii) ciprofloxacin alternating with intravenous azlocillin and tobramycin. Other children with cystic fibrosis were subsequently treated with ciprofloxacin, as the need arose. In all the groups very few adverse reactions were found; in particular only one child developed arthralgia. A total of 202 children in the UK have been treated with ciprofloxacin on a named-patient basis, and their clinicians have reported 46 adverse events that may have been drug-related. Overall ciprofloxacin appears to be safe and effective in children but concern about the possible occurrence of arthropathy remains and long term follow-up of these children may be necessary.

An unusual cause of thoracic mass.

A previously well 10 year old boy presented with scoliosis, a mass in the chest wall, and a pleural effusion. Chest radiography showed the triad of chronic consolidation, pleural effusion, and rib periostitis. Investigations confirmed thoracic actinomycosis. Tissue spread was evaluated by computed tomography. It was successfully treated with benzylpenicillin, which was later replaced by clindamycin.