Survival following lung volume reduction procedures: results from the UK Lung Volume Reduction (UKLVR) registry.

INTRODUCTION: Lung volume reduction surgery (LVRS) and endobronchial valve (EBV) placement can produce substantial benefits in appropriately selected people with emphysema. The UK Lung Volume Reduction (UKLVR) registry is a national multicentre observational study set up to support quality standards and assess outcomes from LVR procedures at specialist centres across the UK. METHODS: Data were analysed for all patients undergoing an LVR procedure (LVRS/EBV) who were recruited into the study at participating centres between January 2017 and June 2022, including; disease severity and risk assessment, compliance with guidelines for selection, procedural complications and survival to February 2023. RESULTS: Data on 541 patients from 14 participating centres were analysed. Baseline disease severity was similar in patients who had surgery n=244 (44.9%), or EBV placement n=219 (40.9%), for example, forced expiratory volume in 1 s (FEV1) 32.1 (12.1)% vs 31.2 (11.6)%. 89% of cases had discussion at a multidisciplinary meeting recorded. Median (IQR) length of stay postprocedure for LVRS and EBVs was 12 (13) vs 4 (4) days(p=0.01). Increasing age, male gender and lower FEV1%predicted were associated with mortality risk, but survival did not differ between the two procedures, with 50 (10.8%) deaths during follow-up in the LVRS group vs 45 (9.7%) following EBVs (adjusted HR 1.10 (95% CI 0.72 to 1.67) p=0.661) CONCLUSION: Based on data entered in the UKLVR registry, LVRS and EBV procedures for emphysema are being performed in people with similar disease severity and long-term survival is similar in both groups.

The evolving role of MDCT in the assessment of patients with chronic obstructive pulmonary disease.

The purpose of this article is to educate the reader in the value a radiologist can offer in the multidetector (MD) CT assessment of patients with chronic obstructive pulmonary disease (COPD). MDCT can identify patients in whom treatments such as lung volume reduction surgery or newer endobronchial therapies may be of benefit. We will also discuss important and under-recognised associated cardiorespiratory disease, which may be incidentally identified.

An association between Type 2 diabetes and alpha-antitrypsin deficiency.

AIMS: Alpha(1)-Antitrypsin (AAT) is a serine protease inhibitor which recently has been shown to prevent Type 1 diabetes development, to prolong islet allograft survival and to inhibit pancreatic B-cell apoptosis in vivo. It has also been reported that Type 1 diabetic patients have significantly lower plasma concentrations of AAT, suggesting the potential role of AAT in the pathogenesis of Type 1 diabetes. We have investigated whether plasma AAT levels are altered in Type 2 diabetes. METHODS: The study included patients with Type 2 diabetes (n = 163) and non-diabetic control subjects matched for age, sex and smoking habits (n = 158) derived from the population-based Malmö Diet and Cancer study. Plasma samples were analysed for AAT concentration and phenotype and serum glucose, insulin, C-reactive protein and lipid levels were measured. Glycated haemoglobin was also measured. RESULTS: In the diabetic group, the women had higher mean plasma AAT levels than men (P < 0.05). The mean plasma AAT levels did not differ between diabetic and control subjects. However, the number of individuals with low AAT levels (< 1.0 mg/ml) was 50% higher in the diabetic group (P < 0.05) and the frequency of AAT deficiency genotypes was 50% higher (NS) in diabetic compared with control subjects. In the group of diabetic patients with AAT < 1 mg/ml, AAT directly correlated with systolic blood pressure (P = 0.048) and inversely correlated with waist-hip ratio (P = 0.031). CONCLUSIONS: Our results provide evidence that deficiency of AAT may be associated with an increased risk of developing Type 2 diabetes.

Chronic obstructive pulmonary disease * 3: Experimental animal models of pulmonary emphysema.

The use of genetically manipulated mice together with traditional animal studies are steadily increasing our knowledge of the factors important in determining alveolar formation and destruction in emphysema. A review of the animal models used to study emphysema is presented.

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.

Clinical and radiological characteristics of lung disease in inflammatory bowel disease.

The pulmonary associations of inflammatory bowel disease (IBD) are poorly characterized. The clinical, physiological and high-resolution computed tomographic thorax characteristics of the lung disease in patients with IBD presenting with respiratory symptoms are described. Detailed clinical information was obtained and standard pulmonary physiological tests and thorax high-resolution computed tomography performed on 14 patients with ulcerative colitis (UC) and three with Crohn's disease (CD), 10 male, aged 38-83 yrs. Respiratory symptoms had been present for 2-50 yrs and extraintestinal manifestations were present in three (17.6%). Normal pulmonary physiology (six patients) was associated with the high resolution computed tomographic changes of bronchiectasis, mosaic perfusion and air trapping suggestive of obliterative bronchiolitis and a pattern of centrilobular nodules and branching linear opacities ("tree in bud" appearance) suggestive of either cellular bronchiolitis or bronchiolectasis with mucoid secretions. Bronchiectasis was found in 13 patients (11 UC, 2 CD), 11 had air trapping and five had a "tree in bud" appearance on computed tomography. One patient had a predominantly peripheral reticular pattern at the lung bases similar to that found in cryptogenic fibrosing alveolitis and one patient had a mixed reticular and ground-glass pattern in the midzones with a patchy distribution in the central and peripheral portions of the lungs with air trapping. Eleven patients (three with alveolitis) exhibited a clinical and/or physiological response to steroids. Pulmonary abnormalities in ulcerative colitis and Crohn's disease can present years after the onset of the bowel disease and can affect any part of the lungs. Early recognition is important as they can be strikingly steroid-responsive.

Anti-neutrophil cytoplasmic antibodies (ANCA) against bactericidal/permeability-increasing protein (BPI) and cystic fibrosis lung disease.

Persistent infection with Pseudomonas aeruginosa and inflammatory mechanisms play an important role in cystic fibrosis (CF) lung disease. ANCA against BPI, a potent host defence protein with anti-bacterial and anti-endotoxin properties, have been described in CF. We have assessed the relationship of anti-BPI antibodies to pulmonary disease severity in 148 CF subjects. IgA and IgG anti-BPI antibodies were found in 55.4% and 70.3% of CF patients, respectively, and higher levels were strongly associated with colonization with P. aeruginosa (P = 0.001 and 0.039 for IgA and IgG antibodies, respectively). IgA and IgG anti-BPI antibodies were independently associated with more severe lung disease as assessed by chest radiograph score (P = 0.023) and a significantly lower forced expiratory volume in 1 s (FEV1)% (P = 0.01). The pathophysiological relevance of the autoantibodies was investigated further by determining their epitope specificity and their effect on bacterial phagocytosis in vitro. Both isotypes of anti-BPI antibodies were specific for the C-terminus of BPI shown recently to be important for BPI-mediated opsonization, and in vitro affinity-purified anti-BPI antibodies significantly reduced BPI-induced phagocytosis of Escherichia coli compared with controls. These data indicate that anti-BPI autoantibodies are associated with colonization with P. aeruginosa and worse lung disease in CF. The inhibition of bacterial phagocytosis suggests that these autoantibodies may contribute to the persistence of P. aeruginosa in the CF lung and so play a role in perpetuating CF lung damage.

Metastatic endometrial stromal sarcoma masquerading as pulmonary lymphangioleiomyomatosis.

A 39 year old female presented with bilateral pneumothoraces and interstitial shadowing on chest x ray. A diagnosis of lymphangioleiomyomatosis was made following an open lung biopsy. Over the next eight years she developed respiratory failure leading to single lung transplantation but she died in the immediate postoperative period. Necropsy examination and review of the previous open lung biopsy revealed multiple pulmonary metastases from a low grade endometrial stromal sarcoma of the uterus. This case high-lights the importance of an accurate diagnosis before transplantation.

Heteropolymerization of S, I, and Z alpha1-antitrypsin and liver cirrhosis.

The association between Z alpha1-antitrypsin deficiency and juvenile cirrhosis is well-recognized, and there is now convincing evidence that the hepatic inclusions are the result of entangled polymers of mutant Z alpha1-antitrypsin. Four percent of the northern European Caucasian population are heterozygotes for the Z variant, but even more common is S alpha1-antitrypsin, which is found in up to 28% of southern Europeans. The S variant is known to have an increased susceptibility to polymerization, although this is marginal compared with the more conformationally unstable Z variant. There has been speculation that the two may interact to produce cirrhosis, but this has never been demonstrated experimentally. This hypothesis was raised again by the observation reported here of a mixed heterozygote for Z alpha1-antitrypsin and another conformationally unstable variant (I alpha1-antitrypsin; 39Arg-->Cys) identified in a 34-year-old man with cirrhosis related to alpha1-antitrypsin deficiency. The conformational stability of the I variant has been characterized, and we have used fluorescence resonance energy transfer to demonstrate the formation of heteropolymers between S and Z alpha1-antitrypsin. Taken together, these results indicate that not only may mixed variants form heteropolymers, but that this can causally lead to the development of cirrhosis.

A kinetic mechanism for the polymerization of alpha1-antitrypsin.

The mutation in the Z deficiency variant of alpha1-antitrypsin perturbs the structure of the protein to allow a unique intermolecular linkage. These loop-sheet polymers are retained within the endoplasmic reticulum of hepatocytes to form inclusions that are associated with neonatal hepatitis, juvenile cirrhosis, and hepatocellular carcinoma. The process of polymer formation has been investigated here by intrinsic tryptophan fluorescence, fluorescence polarization, circular dichroic spectra and extrinsic fluorescence with 8-anilino-1-naphthalenesulfonic acid and tetramethylrhodamine-5-iodoacetamide. These biophysical techniques have demonstrated that alpha1-antitrypsin polymerization is a two-stage process and have allowed the calculation of rates for both of these steps. The initial fast phase is unimolecular and likely to represent temperature-induced protein unfolding, while the slow phase is bimolecular and associated with loop-sheet interaction and polymer formation. The naturally occurring Z, S, and I variants and recombinant site-directed reactive loop and shutter domain mutants of alpha1-antitrypsin were used to demonstrate the close association between protein stability and rate of alpha1-antitrypsin polymerization. Taken together, these data allow us to propose a kinetic mechanism for alpha1-antitrypsin polymer formation that involves the generation of an unstable intermediate, which can form polymers or generate latent protein.

Identification of DNA polymorphisms associated with the V type alpha1-antitrypsin gene.

alpha1-Antitrypsin (alpha1-AT) is a highly polymorphic protein. The V allele of alpha1-AT has been shown to be associated with focal glomerulosclerosis (FGS) in Negroid and mixed race South African patients. To identify mutations and polymorphisms in the gene for the V allele of alpha1-AT in five South African patients with FGS nephrotic syndrome DNA sequence analysis and restriction fragment length polymorphisms of the coding exons were carried out. Four of the patients were heterozygous for the BstEII RFLP in exon III [M1(Val213)(Ala213)] and one patient was a M1(Ala213) homozygote. The mutation for the V allele was identified in exon II as Gly-148 (GGG)-->Arg (AGG) and in all patients was associated with a silent mutation at position 158 (AAC-->AAT). The patient who was homozygous for (Ala213) also had a silent mutation at position 256 in exon III (GAT-->GAC) which was not present in any of the other four patients. Although the V allele of alpha1-AT is not associated with severe plasma deficiency, it may be in linkage disequilibrium with other genes on chromosome 14 that predispose to FGS. Furthermore, the associated silent mutation at position 158 and the Ala213 polymorphism are of interest, as these could represent an evolutionary intermediate between the M1(Ala213) and M1(Val213) subtypes.

Bronchiectasis in association with coeliac disease.

A 48 year old woman presented with a history of fatigue, regular sputum production, and wheeze. High resolution computed tomographic scanning of the thorax demonstrated widespread bronchiectasis. Coeliac disease was diagnosed on the basis of an iron deficiency anaemia, subtotal villous atrophy on small bowel biopsy, and raised anti-gliadin and antiendomysial antibodies. The temporal relationship of the bronchiectasis and coeliac disease, and the subsequent stabilisation of her clinical symptoms and improvement in pulmonary physiology following treatment with inhaled corticosteroids, suggests a relationship between the two conditions which may be due to immunological mechanisms.

Alpha1-antitrypsin deficiency alleles and the Taq-I G-->A allele in cystic fibrosis lung disease.

Cystic fibrosis (CF) is characterized by progressive and ultimately fatal pulmonary disease although there are notable variations in clinical features. This heterogeneity is thought to lie outside the cystic fibrosis transmembrane regulator (CFTR) gene locus and may stem from deficiencies in the antiproteinase screen that protects the lung from proteolytic attack. One hundred and fifty seven patients were recruited from two UK CF centres. The serum concentrations of alpha1-antitrypsin, alpha1-antichymotrypsin and C-reactive protein (CRP) were determined and patients were screened for the common S and Z deficiency alleles of alpha1-antitrypsin and the G-->A mutation in the 3' noncoding region of the alpha1-antitrypsin gene (Taq-I G-->A allele). Alpha1-antitrypsin deficiency phenotypes were detected in 20 (16 MS, 1 S and 3 MZ) out of 147 unrelated tested CF patients and were, surprisingly, associated with significantly better lung function (adjusted mean forced expiratory volume in one second (FEV1) 62.5% of predicted for deficient group and 51.1% pred for normal alleles; p=0.043). The Taq-I G-->A allele was found in 21 out of 150 unrelated patients and had no significant effect on CF lung disease or on levels of alpha1-antitrypsin during the inflammatory response. We show here that, contrary to current thinking, common mutations of alpha1-antitrypsin that are associated with mild to moderate deficiency of the protein predict a subgroup of cystic fibrosis patients with less severe pulmonary disease. Moreover, the Taq-I G-->A allele has no effect on serum levels of alpha1-antitrypsin in the inflammatory response, which suggests that the previously reported association of the Taq-I G-->A allele with chronic obstructive pulmonary disease is not mediated by its effect on the serum level of alpha1-antitrypsin.

Clinical outcome in relation to care in centres specialising in cystic fibrosis: cross sectional study.

OBJECTIVES: To assess the effect on clinical outcome of managing paediatric and adult patients with cystic fibrosis at specialised cystic fibrosis centres. DESIGN: Cross sectional study. SETTING: Two adult cystic fibrosis centres in the United Kingdom. SUBJECTS: Patients from an adult cystic fibrosis centre in Manchester were subdivided into those who had received continuous care from paediatric and adult cystic fibrosis centres (group A), and those who had received paediatric care in a centre not specialising in cystic fibrosis followed by adult care in a cystic fibrosis centre (group B). Group C were referrals to the new adult cystic fibrosis centre in Cambridge who had received neither paediatric nor adult centre care for their cystic fibrosis. MAIN OUTCOME MEASURES: Body mass index (weight (kg)/height (m2)), lung function (forced expiratory volume in one second (FEV1 percentage of predicted)), the Northern chest x ray film score, and age at colonisation with Pseudomonas aeruginosa. RESULTS: A prominent stepwise increase in body mass index was associated with increasing amounts of care at a cystic fibrosis centre; 18.3, 20.2, and 21.3 for groups C, B, and A respectively (P<0.001). Improved nutritional status was correlated with a higher FEV1 and better (lower) chest x ray film scores; r=0. 52 and -0.45 respectively (P<0.001 for both). CONCLUSION: These findings provide the first direct evidence that management of cystic fibrosis in paediatric and adult cystic fibrosis centres results in a better clinical outcome, and strongly supports the provision of these specialist services.

Alpha-1 antitrypsin deficiency alleles and severe cystic fibrosis lung disease.

BACKGROUND: Alpha-1 antitrypsin (alpha 1-AT) is the most abundant proteinase inhibitor within the lung. We have recently reported the surprising observation that cystic fibrosis patients with mild to moderate deficiency of alpha 1-antitrypsin have significantly better pulmonary function than non-deficient patients. This study may have been biased as it did not include the most severely affected patients who have died in childhood or those who have undergone orthotopic lung transplantation. The prevalence of alpha 1-antitrypsin deficiency alleles in this most severely affected group of patients with cystic fibrosis was therefore assessed. METHODS: DNA was obtained from neonatal blood spots from children with cystic fibrosis who had died from pulmonary disease and from formalin fixed lung tissue from transplanted cystic fibrosis patients. The common S and Z deficiency alleles of alpha 1-AT were sought by amplification mutagenesis of the appropriate region of the alpha 1-AT gene followed by restriction enzyme digestion with Xmn I and Taq I, respectively. RESULTS: Seventy-nine patients were identified (seven dead, 72 transplanted). Two patients (2.5%) were heterozygous for the Z allele of alpha 1-AT and four (5.1%) were heterozygous for the S allele. This is not significantly different from the incidence in the normal population of 4% and 8% for the S and Z alleles, respectively. CONCLUSIONS: These data support previous findings that deficiency of alpha 1-AT is not associated with more severe pulmonary disease in cystic fibrosis and may be associated with milder lung disease. Further work is needed to clarify the mechanisms underlying the progressive lung damage in cystic fibrosis.