Helen Parfrey

University of Cambridge, Cambridge, England, United Kingdom

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Publications (19)98.83 Total impact

  • Thorax 09/2013; 68(9):884-5. · 8.38 Impact Factor
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    ABSTRACT: Pulmonary fibrosis is the end stage of many diffuse parenchymal lung diseases. It is characterised by excessive matrix formation leading to destruction of the normal lung architecture and finally death. Despite an exponential increase in our understanding of potentially important mediators and mechanisms, the delineation of primary pathways has proven to be elusive.In this paper susceptibility and injurious agents such as viruses and gastroesophageal reflux and their likely role in initiating disease are discussed. Further topics that are elaborated are candidate ancillary pathways, including immune mechanisms, oxidative and endoplasmic reticulum stress, activation of the coagulation cascade and the potential role of stem cells. The paper will try to provide the reader with an integrated view on the current knowledge and attempts to provide a road map for future research.It is important to explore robust models of overall pathogenesis, reconciling a large number of clinical and scientific observations. We believe that the integration of current data into a "big picture" overview of fibrogenesis is essential for the development of effective antifibrotic strategies. The latter will likely consist of a combination of agents targeting a number of key pathways.
    European Respiratory Journal 05/2013; 41(5):1207-18. · 6.36 Impact Factor
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    ABSTRACT: BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a fatal condition with limited treatment options. However, in a previous small study, co-trimoxazole was found to be beneficial. METHODS: In a double-blind multicentre study, 181 patients with fibrotic idiopathic interstitial pneumonia (89% diagnosed as definite/probable IPF) were randomised to receive co-trimoxazole 960 mg twice daily or placebo for 12 months in addition to usual care. Measurements were made of forced vital capacity (FVC) (primary endpoint), diffusing capacity of carbon monoxide (Dlco) and EuroQol (EQ5D)-based utility, 6-minute walk test (6MWT) and Medical Research Council (MRC) dyspnoea score (secondary endpoints). All-cause mortality and adverse events were recorded (tertiary endpoints). RESULTS: Co-trimoxazole had no effect on FVC (mean difference 15.5 ml (95% CI -93.6 to 124.6)), Dlco (mean difference -0.12 mmol/min/kPa (95% CI 0.41 to 0.17)), 6MWT or MRC dyspnoea score (intention-to-treat analysis). The findings of the per-protocol analysis were the same except that co-trimoxazole treatment resulted in a significant improvement in EQ5D-based utility (mean difference 0.12 (95% CI 0.01 to 0.22)), a reduction in the percentage of patients requiring an increase in oxygen therapy (OR 0.05 (95% CI 0.00 to 0.61)) and a significant reduction in all-cause mortality (co-trimoxazole 3/53, placebo 14/65, HR 0.21 (95% CI 0.06 to 0.78), p=0.02)) compared with placebo. The use of co-trimoxazole reduced respiratory tract infections but increased the incidence of nausea and rash. CONCLUSIONS: The addition of co-trimoxazole therapy to standard treatment for fibrotic idiopathic interstitial pneumonia had no effect on lung function but resulted in improved quality of life and a reduction in mortality in those adhering to treatment.ISRCTN22201583.
    Thorax 11/2012; · 8.38 Impact Factor
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    Thorax 10/2012; 67(11):938-40. · 8.38 Impact Factor
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    ABSTRACT: Pleuroparenchymal fibroelastosis (PPFE) is a rare condition characterised by predominantly upper lobe pleural and subjacent parenchymal fibrosis, the latter being intra-alveolar with accompanying elastosis of the alveolar walls. The aim of this study was to review cases fulfilling published imaging and histological criteria, and identify any common clinical features that may suggest an underlying aetiology for a condition that has previously been regarded as idiopathic. Of 12 patients (seven females, median age 57 yrs), the presenting symptoms were shortness of breath (11 out of 12 patients) and dry cough (six out of 12 patients). Seven patients reported recurrent infections during the course of their disease. Five demonstrated nonspecific autoantibody positivity. Two patients had a family history of interstitial lung disease (ILD). High-resolution computed tomography features of lung disease remote from the pleuroparenchymal changes were present in six out of 12 patients (coexistent fibrosis, n=5; bronchiectasis, n=1). Of seven patients with tissue sampled from the lower lobes, four patients showed less intense PPFE changes (one with additional features of hypersensitivity pneumonitis) and three showed usual interstitial pneumonia. PPFE is a distinct clinicopathological entity, with clinical data suggesting a link to recurrent pulmonary infection. Genetic and autoimmune mechanisms may also contribute to the development of these changes. PPFE may also present with more diffuse involvement than previously reported, and coexist with different patterns of ILD.
    European Respiratory Journal 03/2012; 40(2):377-85. · 6.36 Impact Factor
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    ABSTRACT: Rituximab (RTX), a B-cell depleting mAb, has been reported to cause pulmonary toxicity in many patients. As the use of this biologic is increasing, we have undertaken a systematic review of the literature to gauge the nature and extent of non-infection-related RTX-induced lung disease. A systematic literature review was undertaken to document all reported cases of RTX-associated interstitial lung disease (RTX-ILD), evaluating the epidemiological, clinical, radiological, histopathological, laboratory and management data from the available primary sources. The search was conducted using PubMed, the Cochrane Library and EMBASE up to June 2010 using the terms RTX in the advanced search option without limitations and all relevant publications reviewed manually. In addition, unpublished data from the Food and Drug Administration, the European Medicines Agency and the manufacturer (Roche) were evaluated to complement this search. Identified articles were included if they displayed a potential relationship between the administration of RTX and ILD following exclusion of other likely causes. A total of 121 cases of potential RTX-ILD were identified from 21 clinical studies/trials, 30 case reports and 10 case series. The most common indication for RTX was diffuse large B-cell lymphoma. RTX-ILD occurred more frequently in male patients and was most common during the fifth and sixth decades of life. In most cases, RTX was part of combination chemotherapy, but in 30 (24.7%) cases it was given as monotherapy. The mean and median number of cycles of RTX before disease onset was four, but cases following the first cycle or as late as the 12th cycle were also identified. The mean time of onset, from the last RTX infusion until symptom development or relevant abnormal radiological change was 30 days (range 0-158 days). Abnormal radiological findings were similar in all patients, with diffuse bilateral lung infiltrates apparent on chest radiographs and/or thoracic CT. Hypoxaemia was seen in all cases and pulmonary function tests were uniformly abnormal with a characteristic diffusion capacity deficit and restrictive ventilatory pattern. RTX-ILD was fatal in 18 cases. ILD is a rare but potentially fatal complication of RTX therapy. This diagnosis should be considered in any patient who develops respiratory symptoms or new radiographic changes while receiving this biologic agent.
    Rheumatology (Oxford, England) 12/2011; 51(4):653-62. · 4.24 Impact Factor
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    ABSTRACT: Lung disease is commonly encountered in rheumatological practice either as a manifestation of the underlying condition or as a consequence of using disease-modifying therapies. This has been particularly apparent with the TNF-α antagonists and exacerbations of interstitial lung disease (ILD). In view of this, we undertook a review of the current literature to identify non-infectious pulmonary complications associated with the newer biologic agents used for the treatment of rheumatic conditions. A systematic literature review (SLR) was conducted using PubMed, the Cochrane Library and EMBASE for reviews, meta-analyses, clinical studies and randomized controlled trials, case studies and series, published up to June 2010 using the terms rituximab (RTX), certolizumab, golimumab (GOL), tocilizumab (TCZ) and abatacept in the advanced search option without limitations. In addition, abstracts from International Rheumatology conferences and unpublished data from the Food and Drug Administration, the European Medicines Agency and drug manufacturers were used to complement our search. References were reviewed manually and only those articles that suggested a potential relationship between the biological agent and lung toxicity, following exclusion of other causes, were included. Reported non-infectious pulmonary adverse events with TCZ included a fatal exacerbation of RA-associated ILD, new-onset ILD, idiopathic pulmonary fibrosis and allergic pneumonitis, as well as three cases of microbiological culture-negative pneumonia. Although RTX had a higher incidence of pulmonary toxicity, only 7 of the 121 cases reported involved rheumatological diseases. GOL treatment was associated with four cases of non-infectious pulmonary toxicity and two cases of pneumonia with negative microbiological studies. There were no episodes of pulmonary toxicity identified for either certolizumab or abatacept. Our results highlight an association between the use of newer biologic agents (TCZ, RTX and GOL) and the development of non-infectious parenchymal lung disease in patients with RA. Post-marketing surveillance and biologic registries will be critical for detecting further cases of ILD and improving our understanding of the pathophysiology of this process. As the use of these drugs increases, clinicians must remain vigilant for potential pulmonary complications and exercise caution in prescribing biologic therapies, particularly to rheumatological patients with pre-existing ILD.
    Rheumatology (Oxford, England) 12/2011; 50(12):2297-305. · 4.24 Impact Factor
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    ABSTRACT: Idiopathic pulmonary fibrosis (IPF) is a chronic progressive disease of unknown aetiology. It has a very poor prognosis and no effective treatment. There are two major barriers to the development of novel treatments in IPF: an incomplete understanding of its pathogenesis and the fact that current models of the disease are poorly predictive of therapeutic response. Recent studies suggest an important role for the alveolar epithelium in the pathogenesis of IPF. However, practical limitations associated with isolation and culture of primary alveolar epithelial cells have hampered progress towards further elucidating their role in the pathogenesis of the disease or developing disease models that accurately reflect the epithelial contribution. The practical limitations of primary alveolar epithelial cell culture can be divided into technical, logistical and regulatory hurdles that need to be overcome to ensure rapid progress towards improved treatment for patients with IPF. To develop a strategy to facilitate alveolar epithelial cell harvest, retrieval and sharing between IPF research groups and to determine how these cells contribute to IPF, a workshop was organised to discuss the central issues surrounding epithelial cells in IPF (ECIPF). The central themes discussed in the workshop have been compiled as the proceedings of the ECIPF.
    Thorax 06/2011; 67(2):179-82. · 8.38 Impact Factor
  • Rheumatology (Oxford, England) 01/2011; 50(5):992-4. · 4.24 Impact Factor
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    ABSTRACT: The serpinopathies result from point mutations in members of the serine protease inhibitor or serpin superfamily. They are characterized by the formation of ordered polymers that are retained within the cell of synthesis. This causes disease by a "toxic gain of function" from the accumulated protein and a "loss of function" as a result of the deficiency of inhibitors that control important proteolytic cascades. The serpinopathies are exemplified by the Z (Glu342Lys) mutant of α₁-antitrypsin that results in the retention of ordered polymers within the endoplasmic reticulum of hepatocytes. These polymers form the intracellular inclusions that are associated with neonatal hepatitis, cirrhosis, and hepatocellular carcinoma. A second example results from mutations in the neurone-specific serpin-neuroserpin to form ordered polymers that are retained as inclusions within subcortical neurones as Collins' bodies. These inclusions underlie the autosomal dominant dementia familial encephalopathy with neuroserpin inclusion bodies or FENIB. There are different pathways to polymer formation in vitro but not all form polymers that are relevant in vivo. It is therefore essential that protein-based structural studies are interpreted in the context of human samples and cell and animal models of disease. We describe here the biochemical techniques, monoclonal antibodies, cell biology, animal models, and stem cell technology that are useful to characterize the serpin polymers that form in vivo.
    Methods in enzymology 01/2011; 501:421-66. · 1.90 Impact Factor
  • Thorax 08/2010; 65(8):665-7. · 8.38 Impact Factor
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    ABSTRACT: We describe the case of a 71-year-old man with idiopathic pulmonary fibrosis (usual interstitial pneumonia (UIP) pattern) diagnosed on clinical, radiological and lung function criteria, in accordance with the American Thoracic Society/European Respiratory Society consensus criteria (2000), who had been in close proximity to three atmospheric nuclear bomb blasts during military service in 1957. He does not have clubbing and clinically and radiologically his lung disease is stable. He also has bladder carcinoma and carotid arteriosclerosis, both recognised consequences of radiation injury. This is the first reported case of UIP in a nuclear test veteran. Awareness of this potential association is important given the current attempts of the British Nuclear Test Veterans Association to gain compensation for claimed injuries.
    Case Reports 01/2010; 2010.
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    ABSTRACT: The Z variant of alpha1-antitrypsin (Z-AT) is present in 4% of Northern Europeans and is associated with liver cirrhosis and emphysema. Polymers accumulate within the hepatocyte and the subsequent plasma deficiency of AT renders the lungs susceptible to proteolysis and early onset emphysema. We have previously demonstrated that the Phe-Leu-Glu-Ala-Ile-Gly (6 mer) peptide specifically binds to Z-AT and inhibits polymerization. Here we present the first detailed biochemical study of the purified Z-AT-6 mer binary complex. Biochemical studies indicated that this complex was inactive as a proteinase inhibitor and the peptide annealed to beta-sheet A of Z-AT. Removal of the N-acetyl terminus of the 6 mer peptide did not affect the peptide's ability to prevent polymer formation. However, the nonacetylated 6 mer-Z-AT complex dissociated at a rate 2.75 x faster than the acetylated 6 mer-Z-AT complex to yield an active inhibitor; Koff 5.5 +/- 1.07 versus 2.0 +/- 0.25 10(6) s(-1), respectively. These biochemical data indicate a potential therapeutic approach whereby polymerization is prevented in the liver, with the gradual release of the peptide from the binary complex restoring proteinase inhibitory function within the tissues. Thus, it raises the novel prospect of ameliorating both the cirrhosis and the emphysema associated with Z-AT.
    American Journal of Respiratory Cell and Molecular Biology 09/2004; 31(2):133-9. · 4.15 Impact Factor
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    D A Lomas, H Parfrey
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    ABSTRACT: The molecular basis of alpha(1)-antitrypsin deficiency is reviewed and is shown to be due to the accumulation of mutant protein as ordered polymers within the endoplasmic reticulum of hepatocytes. The current goals are to determine the cellular response to polymeric alpha(1)-antitrypsin and to develop therapeutic strategies to block polymerisation in vivo.
    Thorax 07/2004; 59(6):529-35. · 8.38 Impact Factor
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    ABSTRACT: Conformational diseases are caused by a structural rearrangement within a protein that results in aberrant intermolecular linkage and tissue deposition. This is typified by the polymers that form with the Z deficiency variant of alpha 1-antitrypsin (Glu-342 --> Lys). These polymers are retained within hepatocytes to form inclusions that are associated with hepatitis, cirrhosis, and hepatocellular carcinoma. We have assessed a surface hydrophobic cavity in alpha1-antitrypsin as a potential target for rational drug design in order to prevent polymer formation and the associated liver disease. The introduction of either Thr-114 --> Phe or Gly-117 --> Phe on strand 2 of beta-sheet A within this cavity significantly raised the melting temperature and retarded polymer formation. Conversely, Leu-100 --> Phe on helix D accelerated polymer formation, but this effect was abrogated by the addition of Thr-114 --> Phe. None of these mutations affected the inhibitory activity of alpha 1-antitrypsin. The importance of these observations was underscored by the finding that the Thr-114 --> Phe mutation reduced polymer formation and increased the secretion of Z alpha 1-antitrypsin from a Xenopus oocyte expression system. Moreover cysteine mutants within the hydrophobic pocket were able to bind a range of fluorophores illustrating the accessibility of the cavity to external agents. These results demonstrate the importance of this cavity as a site for drug design to ameliorate polymerization and prevent the associated conformational disease.
    Journal of Biological Chemistry 08/2003; 278(35):33060-6. · 4.65 Impact Factor
  • Helen Parfrey, Ravi Mahadeva, David A Lomas
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    ABSTRACT: alpha(1)-Antitrypsin is a member of the serine proteinase inhibitor (serpin) superfamily and a potent inhibitor of neutrophil elastase. The most important deficiency variant of alpha(1)-antitrypsin arises from the Z mutation (Glu342Lys). This mutation perturbs the protein's tertiary structure to promote a precise, sequential intermolecular linkage that results in polymer formation. These polymers accumulate within the endoplasmic reticulum of the hepatocyte forming inclusion bodies that are associated with neonatal hepatitis, juvenile cirrhosis and adult hepatocellular carcinoma. The resultant secretory defect leads to plasma deficiency of alpha(1)-antitrypsin. This exposes lung tissue to uncontrolled proteolytic attack from neutrophil elastase, culminating in alveolar destruction. Thus, the Z alpha(1)-antitrypsin homozygote is predisposed to developing early onset basal, panacinar emphysema. In this review, we summarise the current understanding of the pathobiology of alpha(1)-antitrypsin deficiency and the associated liver cirrhosis and emphysema. We show how this knowledge has led to the development of novel therapeutic approaches to treat this condition.
    The International Journal of Biochemistry & Cell Biology 08/2003; 35(7):1009-14. · 4.15 Impact Factor
  • Helen Parfrey, Ravi Mahadeva, David A. Lomas
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    ABSTRACT: α1-Antitrypsin is a member of the serine proteinase inhibitor (serpin) superfamily and a potent inhibitor of neutrophil elastase. The most important deficiency variant of α1-antitrypsin arises from the Z mutation (Glu342Lys). This mutation perturbs the protein’s tertiary structure to promote a precise, sequential intermolecular linkage that results in polymer formation. These polymers accumulate within the endoplasmic reticulum of the hepatocyte forming inclusion bodies that are associated with neonatal hepatitis, juvenile cirrhosis and adult hepatocellular carcinoma. The resultant secretory defect leads to plasma deficiency of α1-antitrypsin. This exposes lung tissue to uncontrolled proteolytic attack from neutrophil elastase, culminating in alveolar destruction. Thus, the Z α1-antitrypsin homozygote is predisposed to developing early onset basal, panacinar emphysema. In this review, we summarise the current understanding of the pathobiology of α1-antitrypsin deficiency and the associated liver cirrhosis and emphysema. We show how this knowledge has led to the development of novel therapeutic approaches to treat this condition.
    The International Journal of Biochemistry & Cell Biology 01/2003; 35(7):1009-1014. · 4.15 Impact Factor
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    ABSTRACT: alpha1-Antitrypsin (alpha1-AT) is the most abundant circulating proteinase inhibitor. The Z variant results in profound plasma deficiency as the mutant polymerizes within hepatocytes. The retained polymers are associated with cirrhosis, and the lack of circulating protein predisposes to early onset emphysema. We have investigated the role of the naturally occurring solute trimethylamine N-oxide (TMAO) in modulating the polymerization of normal M and disease-associated Z alpha1-AT. TMAO stabilized both M and Z alpha1-AT in an active conformation against heat-induced polymerization. Spectroscopic analysis demonstrated that this was due to inhibition of the conversion of the native state to a polymerogenic intermediate. However, TMAO did not aid the refolding of denatured alpha1-AT to a native conformation; instead, it enhanced polymerization. These data show that TMAO can be used to control the conformational transitions of folded alpha1-AT but that it is ineffective in promoting folding of the polypeptide chain within the secretory pathway.
    American Journal of Respiratory Cell and Molecular Biology 07/2001; 24(6):727-32. · 4.15 Impact Factor
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    ABSTRACT: � 1 -Antitrypsin ( � 1 -AT) is the most abundant circulating pro- teinase inhibitor. The Z variant results in profound plasma de- ficiency as the mutant polymerizes within hepatocytes. The retained polymers are associated with cirrhosis, and the lack of circulating protein predisposes to early onset emphysema. We have investigated the role of the naturally occurring sol- ute trimethylamine N -oxide (TMAO) in modulating the poly- merization of normal M and disease-associated Z � 1 -AT. TMAO stabilized both M and Z � 1 -AT in an active conformation against heat-induced polymerization . Spectroscopic analysis demonstrated that this was due to inhibition of the conver- sion of the native state to a polymerogenic intermediate. How- ever, TMAO did not aid the refolding of denatured � 1 -AT to a native conformation; instead, it enhanced polymerization. These data show that TMAO can be used to control the conforma- tional transitions of folded � 1 -AT but that it is ineffective in promoting folding of the polypeptide chain within the secre- tory pathway. Conformational disorders arise when a protein undergoes