Amb a 1 isoforms: Unequal siblings with distinct immunological features.

BACKGROUND: Ragweed pollen represents a major allergy risk factor. Ragweed extracts contain five different isoforms of the major allergen Amb a 1. However, the immunological characteristics of Amb a 1 isoforms are not fully investigated. Here, we compared the physicochemical and immunological properties of three most important Amb a 1 isoforms. METHODS: After purification, the isoforms were physicochemically characterized, tested for antibody binding and induction of human T-cell proliferative responses. Their immunological properties were further evaluated in vitro and in vivo in a mouse model. RESULTS: Amb a 1 isoforms exhibited distinct patterns of IgE binding and immunogenicity. Compared to Amb a 1.02 or 03 isoforms, Amb a 1.01 showed higher IgE-binding activity. Isoforms 01 and 03 were the most potent stimulators of patients' T cells. In a mouse model of immunization, Amb a 1.01 induced higher levels of IgG and IgE antibodies when compared to isoforms 02 and 03. Interestingly, ragweed-sensitized patients also displayed an IgG response to Amb a 1 isoforms. However, unlike therapy-induced antibodies, sensitization-induced IgG did not show IgE-blocking activity. CONCLUSION: The present study showed that naturally occurring isoforms of Amb a 1 possess different immunogenic and sensitizing properties. These findings should be considered when selecting sequences for molecule-based diagnosis and therapy for ragweed allergy. Due to its high IgE-binding activity, isoform Amb a 1.01 should be included in diagnostic tests. In contrast, due to their limited B- and T-cell cross-reactivity patterns, a combination of different isoforms might be a more attractive strategy for ragweed immunotherapy.

Birch pollen immunotherapy inhibits anaphylaxis to the cross-reactive apple allergen Mal d 1 in mice.

BACKGROUND: Cross-reactive apple allergy is a common co-morbidity of birch pollen allergy, caused by the presence of a Bet v 1 homologue allergen in apple, Mal d 1. Treatment of tree pollen hay fever by immunotherapy is well established, but its effect on the accompanying apple allergy is debated. OBJECTIVE: To establish a mouse model of birch pollen induced cross-reactivity to Mal d 1 and investigate the effect of birch pollen immunotherapy on the cross-reactivity to Mal d 1. METHODS: Respiratory allergy was induced in Balb/c mice by intraperitoneal exposure to alum-adsorbed birch pollen extract (BPE) in combination with short or prolonged intranasal exposure to BPE. To evaluate the response to Mal d 1, mice were exposed intraperitoneally to Mal d 1. Immunoglobulin responses and cytokine production by splenocytes were measured by ELISA. Allergic symptoms were evaluated by measuring airway hyper-reactivity and hypothermia as a surrogate marker for anaphylaxis. Immunotherapy was performed subcutaneously with alum-adsorbed BPE. RESULTS: Mice exposed to BPE develop cross-reactive IgE to Mal d 1. Early after exposure to BPE, this response is still weak and does not yet translate into anaphylaxis. Interestingly, later re-challenge with BPE increased cross-reactivity to a level where Mal d 1 exposure induced anaphylaxis. Cross-sensitization can also be induced by systemic Mal d 1 exposure. Birch pollen immunotherapy significantly reduced the anaphylactic response of mice to Mal d 1. CONCLUSION & CLINICAL RELEVANCE: A mouse model mimicking birch pollen induced cross-reactivity to Mal d 1 was successfully established. In this model, birch pollen immunotherapy significantly ameliorated the anaphylaxis induced by Mal d 1. Our experimental data suggest that boosting of Mal d 1 recognizing immunoglobulins by BP SCIT is important for the amelioration of apple allergy in human.

Tree pollen allergens-an update from a molecular perspective.

It is estimated that pollen allergies affect approximately 40% of allergic individuals. In general, tree pollen allergies are mainly elicited by allergenic trees belonging to the orders Fagales, Lamiales, Proteales, and Pinales. Over 25 years ago, the gene encoding the major birch pollen allergen Bet v 1 was the first such gene to be cloned and its product characterized. Since that time, 53 tree pollen allergens have been identified and acknowledged by the WHO/IUIS allergen nomenclature subcommittee. Molecule-based profiling of allergic sensitization has helped to elucidate the immunological connections of allergen cross-reactivity, whereas advances in biochemistry have revealed structural and functional aspects of allergenic proteins. In this review, we provide a comprehensive overview of the present knowledge of the molecular aspects of tree pollen allergens. We analyze the geographic distribution of allergenic trees, discuss factors pivotal for allergic sensitization, and describe the role of tree pollen panallergens. Novel allergenic tree species as well as tree pollen allergens are continually being identified, making research in this field highly competitive and instrumental for clinical applications.

Allergen hybrids - next generation vaccines for Fagales pollen immunotherapy.

BACKGROUND: Trees belonging to the order of Fagales show a distinct geographical distribution. While alder and birch are endemic in the temperate zones of the Northern Hemisphere, hazel, hornbeam and oak prefer a warmer climate. However, specific immunotherapy of Fagales pollen-allergic patients is mainly performed using birch pollen extracts, thus limiting the success of this intervention in birch-free areas. OBJECTIVES: T cells are considered key players in the modification of an allergic immune response during specific immunotherapy (SIT), therefore we thought to combine linear T cell epitope-containing stretches of the five most important Fagales allergens from birch, hazel, alder, oak and hornbeam resulting in a Fagales pollen hybrid (FPH) molecule applicable for SIT. METHODS: A Fagales pollen hybrid was generated by PCR-based recombination of low IgE-binding allergen epitopes. Moreover, a structural-variant FPH4 was calculated by in silico mutagenesis, rendering the protein unable to adopt the Bet v 1-like fold. Both molecules were produced in Escherichia coli, characterized physico-chemically as well as immunologically, and tested in mouse models of allergic sensitization as well as allergy prophylaxis. RESULTS: Using spectroscopic analyses, both proteins were monomeric, and the secondary structure elements of FPH resemble the ones typical for Bet v 1-like proteins, whereas FPH4 showed increased amounts of unordered structure. Both molecules displayed reduced binding capacities of Bet v 1-specific IgE antibodies. However, in a mouse model, the proteins were able to induce high IgG titres cross-reactive with all parental allergens. Moreover, prophylactic treatment with the hybrid proteins prevented pollen extract-induced allergic lung inflammation in vivo. CONCLUSION: The hybrid molecules showed a more efficient uptake and processing by dendritic cells resulting in a modified T cell response. The proteins had a lower IgE-binding capacity compared with the parental allergens, thus the high safety profile and increased efficacy emphasize clinical application for the treatment of Fagales multi-sensitization.

Historical epidemiology of hepatitis C virus (HCV) in selected countries.

Chronic infection with hepatitis C virus (HCV) is a leading indicator for liver disease. New treatment options are becoming available, and there is a need to characterize the epidemiology and disease burden of HCV. Data for prevalence, viremia, genotype, diagnosis and treatment were obtained through literature searches and expert consensus for 16 countries. For some countries, data from centralized registries were used to estimate diagnosis and treatment rates. Data for the number of liver transplants and the proportion attributable to HCV were obtained from centralized databases. Viremic prevalence estimates varied widely between countries, ranging from 0.3% in Austria, England and Germany to 8.5% in Egypt. The largest viremic populations were in Egypt, with 6,358,000 cases in 2008 and Brazil with 2,106,000 cases in 2007. The age distribution of cases differed between countries. In most countries, prevalence rates were higher among males, reflecting higher rates of injection drug use. Diagnosis, treatment and transplant levels also differed considerably between countries. Reliable estimates characterizing HCV-infected populations are critical for addressing HCV-related morbidity and mortality. There is a need to quantify the burden of chronic HCV infection at the national level.

Strategies to manage hepatitis C virus (HCV) disease burden.

The number of hepatitis C virus (HCV) infections is projected to decline while those with advanced liver disease will increase. A modeling approach was used to forecast two treatment scenarios: (i) the impact of increased treatment efficacy while keeping the number of treated patients constant and (ii) increasing efficacy and treatment rate. This analysis suggests that successful diagnosis and treatment of a small proportion of patients can contribute significantly to the reduction of disease burden in the countries studied. The largest reduction in HCV-related morbidity and mortality occurs when increased treatment is combined with higher efficacy therapies, generally in combination with increased diagnosis. With a treatment rate of approximately 10%, this analysis suggests it is possible to achieve elimination of HCV (defined as a >90% decline in total infections by 2030). However, for most countries presented, this will require a 3-5 fold increase in diagnosis and/or treatment. Thus, building the public health and clinical provider capacity for improved diagnosis and treatment will be critical.

The present and future disease burden of hepatitis C virus (HCV) infection with today's treatment paradigm.

The disease burden of hepatitis C virus (HCV) is expected to increase as the infected population ages. A modelling approach was used to estimate the total number of viremic infections, diagnosed, treated and new infections in 2013. In addition, the model was used to estimate the change in the total number of HCV infections, the disease progression and mortality in 2013-2030. Finally, expert panel consensus was used to capture current treatment practices in each country. Using today's treatment paradigm, the total number of HCV infections is projected to decline or remain flat in all countries studied. However, in the same time period, the number of individuals with late-stage liver disease is projected to increase. This study concluded that the current treatment rate and efficacy are not sufficient to manage the disease burden of HCV. Thus, alternative strategies are required to keep the number of HCV individuals with advanced liver disease and liver-related deaths from increasing.

Differences in the intrinsic immunogenicity and allergenicity of Bet v 1 and related food allergens revealed by site-directed mutagenesis.

BACKGROUND: Birch pollen allergies are frequently associated with adverse reactions to various fruits, nuts, or vegetables, described as pollen-food syndrome (PFS) and caused by cross-reactive IgE antibodies primarily directed against Bet v 1. Specific immunotherapy (SIT) represents an effective treatment for inhalant allergies; however, successful birch pollen SIT does not correlate well with the amelioration of concomitant food allergies. METHODS: As vaccine candidates, apple Mal d 1 as well as hazelnut Cor a 1 derivatives were designed by in silico backbone analyses of the respective allergens. The proteins were produced by site-directed mutagenesis as fold variants of their parental allergens. Because Mal d 1 and Cor a 1 form cysteine-mediated aggregates, nonaggregative cysteine to serine mutants were also generated. The proteins were characterized physicochemically, immunologically, and in in vivo models with or without adjuvant. RESULTS: The structurally modified proteins showed significantly decreased IgE binding capacity. Notably, both in vivo models revealed reduced immunogenicity of the hypoallergenic fold variants. When formulated with alum, the monomeric cysteine mutants induced a similar immune response as the aggregated parental allergens, which is in contrast with data published on Bet v 1. CONCLUSION: These findings lead to the suggestion that the Bet v 1 structure has unique intrinsic properties, which could account for its high allergenicity. Obviously, these characteristics are not entirely shared with its food homologues from apple and hazelnut. Thus, it is important to tackle pollen-related food allergies from different angles for the generation of effective vaccine candidates to treat birch PFS.

Female mate-choice drives the evolution of male-biased dispersal in a social mammal.

Dispersal has a significant impact on lifetime reproductive success, and is often more prevalent in one sex than the other. In group-living mammals, dispersal is normally male-biased and in theory this sexual bias could be a response by males to female mate preferences, competition for access to females or resources, or the result of males avoiding inbreeding. There is a lack of studies on social mammals that simultaneously assess these factors and measure the fitness consequences of male dispersal decisions. Here we show that male-biased dispersal in the spotted hyaena (Crocuta crocuta) most probably results from an adaptive response by males to simple female mate-choice rules that have evolved to avoid inbreeding. Microsatellite profiling revealed that females preferred sires that were born into or immigrated into the female's group after the female was born. Furthermore, young females preferred short-tenured sires and older females preferred longer-tenured sires. Males responded to these female mate preferences by initiating their reproductive careers in groups containing the highest number of young females. As a consequence, 11% of males started their reproductive career in their natal group and 89% of males dispersed. Males that started reproduction in groups containing the highest number of young females had a higher long-term reproductive success than males that did not. The female mate-choice rules ensured that females effectively avoided inbreeding without the need to discriminate directly against close kin or males born in their own group, or to favour immigrant males. The extent of male dispersal as a response to such female mate preferences depends on the demographic structure of breeding groups, rather than the genetic relatedness between females and males.

Characterisation and validation of an enzyme-immunoassay for the non-invasive assessment of faecal glucocorticoid metabolites in cheetahs (Acinonyx jubatus).

The non-invasive measurement of adrenocortical function in cheetahs is an important tool to assess stress in captive and free-ranging individuals, because stress has been suggested to be one of the causes of poor reproductive performance of captive cheetahs. We tested four enzyme immunoassays (EIA) in two captive cheetahs in Germany using adrenocorticotropic hormone (ACTH) challenges and identified the corticosterone-3-CMO EIA to be most sensitive to the increase in faecal glucocorticoid metabolite (fGCM) concentrations after the ACTH challenge. This EIA performed also well in five captive cheetahs in South Africa. The fGCM concentrations across all seven cheetahs increased within 24h by 681% compared to the baseline levels prior to ACTH. Storage of faecal samples at 0-4°C did not strongly affect fGCM concentrations within 24h, simplifying sample collection when immediate storage at -20°C is not feasible. The two cheetahs in Germany also received an injection of [(3)H]cortisol to characterise fGCMs in faecal extracts using high-performance liquid chromatography (HPLC) immunograms. HPLC fractions were measured for their radioactivity and immunoreactive fGCM concentrations with the corticosterone-3-CMO EIA, respectively. The results revealed a polar peak of radiolabelled cortisol metabolites co-eluting with the major peak of immunoreactive fGCMs. Thus, our EIA measured substantial amounts of fGCMs corresponding to the radioactive peaks. The peaks were of higher polarity than native cortisol and corticosterone, suggesting that the metabolites were conjugated, which was confirmed by solvolysis of the HPLC fractions. Our results show that the corticosterone-3-CMO EIA is a reliable tool to assess fGCMs in cheetahs.

Prevalence and clinical significance of GB virus type C/hepatitis G virus coinfection in patients with chronic hepatitis C undergoing antiviral therapy.

Coinfection with GBV-C/HGV in patients with chronic hepatitis C (CHC) may influence clinical course and response rates of antiviral therapy. Aim of the study was to investigate the prevalence of GBV-C/HGV/HCV coinfection and its influence on outcome of interferon/ribavirin combination therapy. Three hundred and four patients with CHC [m/f = 211/93, age: 42 (18-65)] were investigated. HGV RNA detection was performed by polymerase chain reaction prior to and 6 months after the end of antiviral therapy. HGV/HCV coinfection could be identified in 37/304 (12.2%) patients with intravenous drug abuse as the most common source of infection (N = 21, (56.8%)). The predominant HCV genotype in coinfected individuals was HCV-3a (HCV-3a: 51.4%, HCV-1: 37.8%, HCV-4: 10.8%). HGV coinfection was more prevalent in patients infected with HCV-3 compared to HCV-1 or HCV-4 [19/45 (42.2%) vs. 14/185 (7.6%) vs. 4/52 (7.7%), P < 0.01]. Patients with HGV/HCV coinfection were younger [35 (18-56) vs. 43 (19-65), years; P < 0.01], and advanced fibrosis (F3-F4) was less frequent (22.2% vs. 42.9%, P < 0.05). A sustained virological response was achieved more frequently in HGV/HCV coinfected patients [26/37 (70.3%)] than in monoinfected patients [120/267 (44.9%), P < 0.01]. HGV RNA was undetectable in 65.7% of the coinfected patients at the end of follow-up. Intravenous drug abuse seems to be a major risk factor for HGV coinfection in patients with chronic hepatitis C. Coinfection with HGV does not worsen the clinical course of chronic hepatitis C or diminish response of HCV to antiviral therapy. Interferon/ribavirin combination therapy also clears HGV infection in a high proportion of cases.

Effect of virtual endoscopy simulator training on performance of upper gastrointestinal endoscopy in patients: a randomized controlled trial.

BACKGROUND: Skills in gastrointestinal endoscopy mainly depend on experience and practice. Patients upon whom trainees perform their first endoscopic examinations are likely to suffer more discomfort and prolonged procedures. Training on endoscopy simulators may reduce the time required to reach competency in patient endoscopy. PATIENTS AND METHODS: Residents in internal medicine without experience of endoscopy were randomized to a group who trained on a simulator before conventional training (group S) or one that received conventional training only (group C) before starting upper gastrointestinal endoscopy in patients. After endoscopy, discomfort and pain were evaluated by patients, who were blind to the beginners' training status. Results in terms of time, technique (intubation, pyloric passage, J-maneuver), and diagnosis of pathological entities were evaluated by experts. RESULTS: From 2003 to 2007, 28 residents were enrolled. Comparing group S with group C in their first ten endoscopic examinations in patients, time taken to reach the duodenum (239 seconds (range 50 - 620) vs. 310 seconds (110 - 720; P < 0.0001) and technical accuracy ( P < 0.02) were significantly better in group S. Diagnostic accuracy did not differ between the groups. Fourteen residents (7 simulator-trained, 7 not simulator-trained) continued endoscopy training. After 60 endoscopic examinations, investigation time was still shorter in group S. Technical and diagnostic accuracy improved during on-patient training in both groups; here differences between groups were no longer observable. There were no significant differences in discomfort and pain scores between the groups after 10 and after 60 endoscopies. Discomfort and pain were higher than for endoscopy performed by experts. CONCLUSION: This randomized controlled trial shows that virtual simulator training significantly affects technical accuracy in the early and mid-term stages of endoscopic training. It helps reduce the time needed to reach technical competency, but clinically the effect is limited. Simulator training could be useful in an endoscopy training curriculum but cannot replace on-patient training.

Hepatocellular carcinoma in long-term sustained virological responders following antiviral combination therapy for chronic hepatitis C.

Antiviral treatment results in a sustained virologic response (SVR) in 50-75% of patients with chronic hepatitis C. Long-term follow up studies have observed ongoing SVR in the overwhelming majority of them. Thus chronic hepatitis C is considered 'cured' if an SVR is achieved. Consequently, it is expected that in sustained virologic responders long-term complications of hepatatic C virus (HCV) related chronic liver disease including hepatocellular carcinoma are eliminated or have a decreased incidence. We report on five patients (three from Austria, two from USA) who developed hepatocellular carcinoma during follow up (3-6 years) after achieving SVR. During follow up and at diagnosis all were HCV-RNA neg. None of the patients had other liver diseases. One patient presented with bilateral adrenal metastasis, the remaining four with large hepatic tumours. Three patients were noncirrhotic at the start of treatment at the time of tumour diagnosis. Successful antiviral treatment in HCV patients does not prevent development of hepatocellular carcinoma even in non-cirrhotic livers. Long-term follow up of patients with SVR is mandatory and should include surveillance for hepatocellular carcinoma.

Efficacy and safety of antiviral therapy in patients with Crohn's disease and chronic hepatitis C.

BACKGROUND: Efficacy and safety of antiviral combination therapy in patients with Crohn's disease (CD) and chronic hepatitis C (CHC) is presently not established and consequently CHC is rarely treated in CD patients. AIM: To analyse the efficacy and tolerability of antiviral interferon/ribavirin therapy in patients with CHC and CD. METHODS: Eleven HCV-infected CD patients received either 3 x 1.5 microg/kg/week interferon-alpha-2b or 180 microg/week peginterferon-alpha-2a (PEGASYS; Roche, Basel, Switzerland) as monotherapy (n = 1) or in combination with 800-1200 mg/day ribavirin (COPEGUS; Roche) (n = 10) for 24-54 weeks according to HCV-genotype and initial response respectively. Eight patients were under CD-specific therapy. RESULTS: Five (46%) patients (HCV-1: a = 3; HCV-2: n = 0; HCV-3: n = 1; unknown: n = 1) achieved a sustained virological response, three (27%) patients relapsed, three (27%) were nonresponders (all GT 1b). At baseline, the Harvey--Bradshaw Index was 0 (0-8) [median (range)], increased on antiviral therapy to 4 (1-15) (P = 0.005) and decreased to baseline level 0 (0-6) after 6-month follow-up. CONCLUSIONS: This preliminary experience demonstrates that treatment of CHC in patients with CD is comparable to the treatment of CHC in those without CD. However, gastrointestinal symptoms may be temporarily exacerbated and haemopoietic growth factors may be required.

Reduction of atherosclerotic nanoplaque formation and size by Ginkgo biloba (EGb 761) in cardiovascular high-risk patients.

Coating a silica surface with the isolated lipoprotein receptor proteoheparan sulfate (HS-PG) from arterial endothelium and vascular matrices and adding both the atherogenic VLDL/IDL/LDL lipid fraction in its native composition and Ca(2+) ions, we could observe in vitro the earliest stages of atherosclerotic plaque development by ellipsometric techniques (patent EP 0 946 876). This so-called nanoplaque formation is represented by the ternary aggregational complex of the HS-PG receptor, lipoprotein particles and calcium ions. The model was validated in several clinical studies on statins in cardiovascular high-risk patients. In eight patients who had undergone an aortocoronary bypass operation, the reduction of atherosclerotic nanoplaque formation amounted to 11.9+/-2.5% (p<0.0078) and of nanoplaque size to 24.4+/-8.1% (p<0.0234), respectively, after a 2-month therapy with Ginkgo biloba extract (2x 120 mg daily, EGb 761). Additionally, superoxide dismutase (SOD) activity was upregulated by 15.7+/-7.0% (p<0.0391), the quotient oxLDL/LDL lowered by 17.0+/-5.5% (p<0.0234) and lipoprotein(a) concentration decreased by 23.4+/-7.9% (p<0.0234) in the patients' blood. The concentration of the vasodilating substances cAMP and cGMP was augmented by 37.5+/-9.1% (p<0.0078) and 27.7+/-8.3% (p<0.0156), respectively. A multiple regression analysis between the patients' VLDL/IDL/LDL lipoprotein fraction applied in the ellipsometry measurements as well as the further risk factors oxLDL/LDL and Lp(a) on the one hand and changes in nanoplaque formation on the other hand reveals a basis for a mechanistic explanation of nanoplaque reduction under ginkgo treatment. The atherosclerosis inhibiting effect is possibly due to an upregulation in the body's own radical scavenging enzymes and an attenuation of the risk factors oxLDL/LDL and Lp(a).

The intracellular domain of the human protocadherin hFat1 interacts with Homer signalling scaffolding proteins.

The cadherin superfamily protein Fat1 is known to interact with the EVH1 domain of mammalian Ena/VASP. Here we demonstrate that: (i) the scaffolding proteins Homer-3 and Homer-1 also interact with the EVH1 binding site of hFat1 in vitro, and (ii) binding of Homer-3 and Mena to hFat1 is mutually competitive. Endogenous Fat1 binds to immobilised Homer-3 and endogenous Homer-3 binds to immobilised Fat1. Both, endogenous and over-expressed Fat1 exhibit co-localisation with Homer-3 in cellular protrusions and at the plasma membrane of HeLa cells. As Homer proteins and Fat1 have been both linked to psychic disorders, their interaction may be of patho-physiological importance.

Long-term follow-up of chronic hepatitis C patients with sustained virological response to various forms of interferon-based anti-viral therapy.

BACKGROUND: Combination anti-viral therapy achieves a sustained virological response (defined as HCV-RNA negativity 6 months after the end of therapy) of 56% of patients with chronic hepatitis C. Little is known about long-term durability of HCV-RNA negativity in patient treated with pegylated interferon. AIM: To evaluate the durability of virologic response in patients with sustained virological response to anti-viral therapy treated at our centre. METHODS: A total of 187 sustained virological responses (50% genotype 1, 42% genotype 2 or 3 and 8% genotype 4; 20% with cirrhosis) with a follow-up of >12 months post-therapy were studied. Twelve patients received monotherapy with interferon-alpha2a or -2b. One hundred and seventy-five received combination therapy with ribavirin and standard interferon-alpha (n = 73) or pegylated interferon-alpha2a or 2b (n = 102). Qualitative serum HCV-RNA was tested by COBAS AMPLICOR HCV test, v2.0. RESULTS: Median follow-up time was 29 months (range 12-172). Recurrence of HCV infection was not observed in any of the 187 sustained virological responders. Alanine aminotransferase values were normal in 90% and two patients showed minimal elevation of alpha-fetoprotein levels. CONCLUSIONS: No recurrence of HCV infection was seen in any patient. Thus, long-term prognosis in chronic hepatitis C patients with a sustained virological response to therapy with pegylated interferon +/- ribavirin is promising, but long-term studies need to continue.

Centrilobular necrosis in autoimmune hepatitis: a histological feature associated with acute clinical presentation.

AIMS: The characteristic histological feature of autoimmune hepatitis (AIH) is interface hepatitis with predominant portal lymphoplasmacytic necroinflammatory infiltration. Centrilobular necrosis (CN), reminiscent of toxic or circulatory liver injury, has been reported in AIH. The aim of this study was to assess the frequency of CN in patients with AIH and its correlation with laboratory and clinical data. METHODS: Liver biopsies were obtained from 114 patients (90 women, 24 men, mean (SD) age 45.4 (19.4) years) with AIH and were evaluated under code by a single pathologist according to the modified Knodell score. RESULTS: CN was found in 20 (17.5%) patients with virtually unaffected portal areas in four cases. Patients with AIH with CN had a higher total hepatic activity index (median (range) 11 (6 to 15) v 5 (2 to 10)) and presented less frequently with cirrhosis (10% v 38%). Patients with CN had a higher frequency of acute onset (87% v 32%), higher bilirubin (median (range) 12.0 (0.43 to 40.0) v 1.9 (0.36 to 46)) and higher ALT levels (median (range) 25.6 (2.7 to 63.9) v 7.2 (0.7 to 62.6)), than did patients with AIH without centrizonal injury. CONCLUSION: CN with sparing of the portal areas represents a rare histological pattern in AIH. CN is associated with an acute clinical presentation and might reflect an early lesion preceding portal involvement. Recognition of this particular histological appearance enables early diagnosis of AIH and a timely initiation of immunosuppressive therapy.

Interaction of immobilized phosphofructokinase with soluble muscle proteins.

Selected glycolytic enzymes (including phosphoglucose isomerase, aldolase, glyceraldehyde phosphate dehydrogenase, enolase, pyruvate kinase and lactate dehydrogenase), as well as glycogen phosphorylase, creatine kinase, and adenylate kinase, bound to phosphofructokinase immobilized on an agarose gel. The affinity of phosphofructokinase to these various proteins differed, with phosphorylase exhibiting the strongest binding. Binding was reversed either by: (1) elution with high-ionic-strength buffer (0.4 M KCl); (2) the addition of a 5-10 mM concentration of ATP; or (3) high concentrations of fructose 6-phosphate (5 mM).