The MHC class I-related receptor, FcRn, plays an essential role in the maternofetal transfer of gamma-globulin in humans

The transfer of maternal gamma-globulin (IgG) provides the neonate with humoral immunity during early life. In humans, maternal IgG is transported across the placenta during the third trimester of pregnancy. The expression of the MHC class I-related receptor, FcRn, in the human placenta suggests that this Fc receptor might be involved in the delivery of maternal IgG, but direct evidence to support this is lacking. In the current study an ex vivo placental model has been used to analyze the maternofetal transfer of a recombinant, humanized (IgG1) antibody in which His435 has been mutated to alanine (H435A). In vitro binding studies using surface plasmon resonance indicate that the mutation ablates binding of the antibody to recombinant mouse and human FcRn. Relative to the wild-type antibody, the H435A mutant is deficient in transfer across the placenta. Significantly, the mutation does not affect binding to Fc gamma RIII, an FcR that has been suggested in earlier studies to mediate the transfer of maternal IgG. The analyses demonstrate that binding of an IgG to FcRn is a prerequisite for transport across the perfused placenta. FcRn therefore plays a central role in the maternofetal delivery of IgG and this has implications for the use of protein engineering to improve the properties of therapeutic antibodies.

Functional expression of the MHC class I-related receptor, FcRn, in endothelial cells of mice

Our recent data indicate that the MHC class I-related receptor, FcRn, plays a role in regulating serum IgG levels, in addition to its known role in transferring IgG from mother to young. In the current study, the distribution of FcRn in adult mice has been investigated using several approaches. First, tissue distribution of anti-FcRn F(ab')2, murine IgG1 and recombinant, IgG1-derived Fc-hinge fragments has been analyzed, and these FcRn binding proteins localize predominantly in skin and muscle with lesser amounts in liver and adipose tissue. Second, histochemical analyses of muscle and liver with anti-FcRn F(ab')2 indicate that FcRn is expressed in the endothelium of small arterioles and capillaries, but not in larger vessels such as the central vein and portal vasculature. Third, immunoprecipitation and immunofluorescence studies of cultured murine endothelial cells show that functional FcRn is expressed in these cells, and is located within vesicular structures in the cytosol and not on the membrane. Taken together the data demonstrate that FcRn is expressed in functionally active form in endothelial cells, indicating that these cells are a possible site at which serum IgG homeostasis is maintained.

Interim analysis of the Stockholm III trial of preoperative radiotherapy regimens for rectal cancer

BACKGROUND

To address issues regarding the fractionation of radiotherapy (RT) and timing of surgery for rectal cancer, a multicentre trial has randomized patients to preoperative short-course RT with two different intervals to surgery, or long-course RT with delayed surgery. The present interim analysis assessed feasibility, compliance and complications after RT and surgery.

METHODS

Some 303 patients were randomized to either short-course RT (5 x 5 Gy) and surgery within 1 week (group 1), short-course RT and surgery after 4-8 weeks (group 2) or long-course RT (25 x 2 Gy) and surgery after 4-8 weeks (group 3).

RESULTS

Demographic data were similar between groups and there were few protocol violations (5.0-6 per cent). Eight patients (2.6 per cent) developed radiation-induced acute toxicity. There were no significant differences in postoperative complications between groups (46.6, 40.0 and 32 per cent in groups 1, 2 and 3 respectively; P = 0.164). Patients receiving short-course RT with surgery 11-17 days after the start of RT had the highest complication rate (24 of 37).

CONCLUSION

Compliance was acceptable and severe acute toxicity was low, irrespective of fractionation. Short-course RT with immediate surgery had a tendency towards more postoperative complications, but only if surgery was delayed beyond 10 days after the start of RT.

REGISTRATION NUMBER

NCT00904813 (http://www.clinicaltrials.gov).

Increasing the serum persistence of an IgG fragment by random mutagenesis

The major histocompatibility complex (MHC) class I-related receptor FcRn is involved in regulating serum gammaglobulin (IgG) levels in mice. With the aim of increasing the serum half-life of a recombinant murine Fc gamma 1 fragment, the affinity for binding to FcRn at pH 6.0 has been increased by random mutagenesis of Thr252, Thr254, and Thr256 followed by selection using bacteriophage display. These residues were chosen as they are in proximity to the FcRn-IgG (Fc) interaction site. Two mutants with higher affinity (due to lower off-rates) than the wild-type Fc have been isolated and analyzed in pharmacokinetic studies in mice. The mutant with the highest affinity has a significantly longer serum half-life than the wild type fragment, despite its lower off-rate from FcRn at pH 7.4. The results provide support for the involvement of FcRn in the homeostasis of serum IgGs in mice. The indications that a homologous FcRn regulates IgG levels in humans suggest that this approach has implications for increasing the serum persistence of therapeutic antibodies.

Macrophage-secreted myogenic factors: a promising tool for greatly enhancing the proliferative capacity of myoblasts in vitro and in vivo

In this work we set out to determine if the murine macrophage J774 cell line can be used to produce myogenic growth factors. Activated J774 macrophages were grown in serum-free conditions. The macrophage-conditioned medium (MCM) was then used to treat cultures of primary myoblasts and regenerating muscle tissue, in vitro and in vivo respectively. MCM activity in vitro was tested by analyzing the expression of muscle-specific transcription factors, in parallel with the proliferation and differentiation rates of the cells. The macrophage-secreted factors greatly enhanced the proliferative potential of both rat and human primary myoblasts and were found to be highly muscle-specific. In vivo, MCM administration markedly enhanced the regenerative processes in damaged muscles. The ability to produce large amounts of macrophage-secreted myogenic factor(s) in the absence of serum holds great promise for its biochemical characterization and successive application in therapeutic protocols, both for ex vivo gene therapy and for muscle repair.

Association of SV40 with human tumours

SV40 was discovered as a contaminant of poliovirus vaccines that were inadvertently administered to millions of people in Europe and the United States between 1955 and 1963. Shortly afterwards, SV40 was proven to be oncogenic in rodents and capable of transforming human and animal cells in vitro. The possibility that SV40 might cause tumours in humans thus became a subject of scientific and public interest and scrutiny. However, largely due to a lack of significant epidemiological evidence, interest in assessing SV40's potential carcinogenic role in humans diminished. Recently, many laboratories have reported the presence of SV40-like DNA in a high proportion of human mesotheliomas, ependymomas and osteosarcoma (the three main types of tumours caused by virus in hamsters), renewing the question whether SV40 might be a human tumour virus. Molecular data from these studies are reviewed to re-evaluate the potential role of SV40 as a human carcinogen.

Increased anticoagulant response to low-molecular-weight heparin in plasma from patients with advanced cirrhosis

INTRODUCTION

Cirrhotic patients may present thrombotic complications that warrant anticoagulant therapy. However, the efficacy of low-molecular-weight heparin (LMWH) in this clinical setting is still unclear.

AIMS/METHODS

To evaluate the in vitro effect of LMWH on thrombin generation (TG) in cirrhotic patients at different stages of liver disease. Thirty cirrhotics (10 Child Pugh A, 10 Child Pugh B and 10 Child Pugh C), 10 subjects with inherited type 1 antithrombin (AT) defect and 10 healthy controls were studied. TG was determined at baseline and with anti-Xa levels after the addition of enoxaparin at 0.35 and 0.7 U anti-Xa mL. The endogenous thrombin potential (ETP) ratio at 0.35 and 0.7 U anti-Xa mL was obtained by dividing ETP with LMWH by ETP at baseline.

RESULTS

Mean AT levels in all cirrhotic subgroups and in patients with AT deficiency were significantly lower than in controls. The 0.35 ETP ratio was significantly lower in cirrhotic patients than in controls (0.26 ± 0.1 vs. 0.48 ± 0.1, P < 0.001) and the reduction paralleled the severity of liver disease, in spite of the concomitant decrease in AT and anti-Xa activity. AT-deficient subjects showed a significantly increased 0.35 ETP ratio compared with both cirrhotic patients and controls (0.69 ± 1 vs. 0.26 ± 0.1, P < 0.001, and vs. 0.48 ± 0.1, P = 0.04 respectively). LMWH at 0.7 U anti-Xa mL completely inhibited TG in 9/30 cirrhosis patients with more advanced liver disease (Child Pugh B and C), whereas complete TG abolition was seen in only 1/10 controls.

CONCLUSIONS

Cirrhotic patients show an increased response to LMWH, which correlates with the severity of liver disease, in spite of reduced AT and anti-Xa activity levels. Thrombin generation may be a useful tool to monitor the response to LMWH in cirrhotic patients.

A new nephritogenic streptococcus

A local milk-borne outbreak of 85 cases of sore throat with cervical lymphadenitis, a third of whom later developed acute glomerulonephritis as a complication, is described. Renal involvement was shown by Volhard's criteria, filtered fraction data and renal biopsy findings. From lymph-node biopsies from patients, from the pharyngeal exudate of patients and carriers, and from three samples of cow's milk, 16 strains of beta-haemolytic streptococci of Lancefield group C, type zooepidemicus subtype lactose-positive, were isolated.

The aetiological role of the streptococcus isolated in this outbreak was confirmed by autoserodiagnosis (precipitation tests with Lancefield's antigens and patients' sera) which in this case proved more valuable than antistreptolysin-O titration as evidence of infection.

Two of the 85 patients, 7 months after the acute phase of illness, show nephrotic oedema and hypertension as chronic sequelae.

We are pleased to express our gratitude to Dr M. T. Parker and Dr W. R. Maxted for much advice, and confirmation of our serological and biochemical findings.

Localization of the site of the IgG molecule that regulates maternofetal transmission in mice

Site-directed mutagenesis of a recombinant Fc hinge fragment has recently been used to localize the site of the mouse IgG1 (mIgG1) molecule that is involved in the intestinal transfer of recombinant Fc hinge fragments in neonatal mice. This site encompasses Ile-253, His-310, Gln-311, His-433 and Asn-434, localized at the CH2-CH3 domain interface and overlapping with the staphylococcal protein A-binding and catabolic sites. In the present study, the effect of these mutations on the maternofetal transfer of Fc hinge fragments has been studied. Experiments to analyze transfer of radiolabeled Fc hinge fragments from the circulation of 15-18 day pregnant mice to fetuses in utero demonstrate that the mutations affect the maternofetal transmission in a way that correlates closely with the effects of the mutations on intestinal transfer and catabolism. The studies indicate that the neonatal Fc receptor, FcRn, is involved in transcytosis across both yolk sac and neonatal intestine in addition to the regulation of IgG catabolism.

Hepatitis C virus infection is a risk factor for gallstone disease: a prospective hospital-based study of patients with chronic viral C hepatitis

We evaluated the prevalence and the risk factors for gallstone disease in patients with chronic hepatitis C infection. We investigated 453 consecutively admitted patients with chronic infection with hepatitis C virus (HCV) (cirrhosis excluded) and 879 patients without liver disease (October 2006-April 2007). Gallstone disease was diagnosed if gallstones were present at ultrasonography or if there had been a previous cholecystectomy. Variables evaluated were age, gender, gallstone heredity, body mass index, waist circumference, parity, serum lipids, fatty liver, arterial hypertension, diabetes mellitus and metabolic syndrome (International Diabetes Federation criteria). Informed consent was obtained from all patients. We found that 88 of 453 (19%) patients with chronic HCV hepatitis (age 50.1 +/- 11.7 years) and 153 of 879 (17%) controls (age 60.6 +/- 12.6 years) had gallstone disease (GD). Abdominal obesity (OR = 2.108, 95% CI 1.287-3.452) and steatosis (OR = 3.699, 95% CI 2.277-6.008) were risk factors for GD in HCV patients. Gallstone heredity, dyslipidaemia, type 2 diabetes mellitus and metabolic syndrome increased the risk for GD in controls vs HCV patients. Our study shows that even HCV patients with chronic hepatitis but not cirrhosis have an increased prevalence of gallstones. Compared with controls, gallstones are present in HCV patients at a younger age and are associated with central obesity and liver steatosis, but not with gallstone heredity, dyslipidaemia, diabetes mellitus or metabolic syndrome. Although we could not establish a temporal relationship, the association between HCV infection and gall stone disease is real and appears to be causally linked, at least in predisposed individuals (obese and with liver steatosis).

Homozygous F5 deep-intronic splicing mutation resulting in severe factor V deficiency and undetectable thrombin generation in platelet-rich plasma

BACKGROUND

Coagulation factor (F) V deficiency is associated with a bleeding tendency of variable severity, but phenotype determinants are largely unknown. Recently, we have shown that three patients with undetectable plasma FV and mild bleeding symptoms had sufficient residual platelet FV to support thrombin generation in platelet-rich plasma (PRP). Therefore, we hypothesized that FV-deficient patients with severe bleeding manifestations may lack platelet FV.

OBJECTIVES

To characterize a FV-deficient patient with a severe bleeding diathesis.

PATIENTS/METHODS

We performed FV mutation screening and functional studies in a 31-year-old male (FV:C < 1%) with umbilical bleeding at birth, recurrent hemarthrosis and muscle hematomas, and a recent intracranial hemorrhage.

RESULTS

The proband was homozygous for a deep-intronic mutation (F5 IVS8 +268A→G) causing the inclusion of a pseudo-exon with an in-frame stop codon in the mature F5 mRNA. Although platelet FV antigen was detectable by immunoprecipitation followed by Western blotting, no FV activity could be demonstrated in the proband's plasma or platelets with a prothrombinase-based assay. Moreover, no thrombin generation was observed in PRP triggered with 1-50 pm tissue factor (even in the presence of platelet agonists), whereas an acquired FV inhibitor was excluded. Clot formation in the proband's whole blood, as assessed by thromboelastometry, was markedly delayed but not abolished.

CONCLUSIONS

This is the first report of a pathogenic deep-intronic mutation in the F5 gene. Our findings indicate that the minimal FV requirement for viability is extremely low and suggest that thrombin generation in PRP may predict bleeding tendency in patients with undetectable plasma FV.

Non-invasive ménage à trois for the prediction of high-risk varices: stepwise algorithm using lok score, liver and spleen stiffness

BACKGROUND & AIMS

Liver stiffness (LS), spleen stiffness (SS) and serum markers have been proposed to non-invasively assess portal hypertension or oesophageal varices (EV) in cirrhotic patients. We aimed to evaluate the performance of a stepwise algorithm that combines Lok score with LS and SS for diagnosing high-risk EV (HREV) and to compare it with other already-validated non-invasive methods.

METHODS

We performed a cross-sectional study including 136 consecutive compensated cirrhotic patients with various aetiologies, divided into training (90) and validation (46) set. Endoscopy was performed within 6 months from inclusion for EV screening. Spleen diameter was assessed by ultrasonography. LS and SS were measured using Fibroscan. Lok score, platelet count/spleen diameter ratio, LSM-spleen diameter to platelet ratio score and oesophageal varices risk score (EVRS) were calculated and their diagnostic accuracy for HREV was assessed. The algorithm classified patients as having/not-having HREV. Its performance was tested and compared in both groups.

RESULTS

In the training set, all variables could select patients with HREV with moderate accuracy, the best being LSPS (AUROC = 0.818; 0.93 sensitivity; 0.63 specificity). EVRS, however, was the only independent predictor of HREV (OR = 1.521; P = 0.032). The algorithm correctly classified 69 (76.66%) patients in the training set (P < 0.0001) and 36 (78.26%) in the validation one. In the validation group, the algorithm performed slightly better than LSPS and EVRS, showing 100% sensitivity and negative predicted value.

CONCLUSION

The stepwise algorithm combining Lok score, LS and SS could be used to select patients at low risk of having HREV and who may benefit from more distanced endoscopic evaluation.

Increased lactate dehydrogenase activity is dispensable in squamous carcinoma cells of origin

Although numerous therapeutic strategies have attempted to target aerobic glycolysis to inhibit tumor progression, these approaches have not resulted in effective clinical outcomes. Murine squamous cell carcinoma (SCC) can be initiated by hair follicle stem cells (HFSCs). HFSCs utilize aerobic glycolysis, and the activity of lactate dehydrogenase (Ldh) is essential for HFSC activation. We sought to determine whether Ldh activity in SCC is critical for tumorigenesis or simply a marker of the cell type of origin. Genetic abrogation or induction of Ldh activity in HFSC-mediated tumorigenesis shows no effect on tumorigenesis as measured by number, time to formation, proliferation, volume, epithelial to mesenchymal transition, gene expression, or immune response. Ldha-null tumors show dramatically reduced levels of glycolytic metabolites by metabolomics, and significantly reduced glucose uptake by FDG-PET live animal imaging. These results suggest that squamous cancer cells of origin do not require increased glycolytic activity to generate cancers.

Most tumours are characterized by increased aerobic glycolytic activity. Here the authors show that elevated  aerobic glycolysis is not essential for cancer initiation by testing the effect of lactate dehydrogenase depletion on the ability of hair follicle stem cells (HFSCs) to form squamous cell carcinoma (SCC) in mouse genetic models.

Two or more synchronous combination of noninvasive tests to increase accuracy of liver fibrosis assessement in chronic hepatitis C; results from a cohort of 446 patients

BACKGROUND

The prediction of fibrosis is an essential part of the assessment and management of patients with chronic liver disease. Non-invasive tests (NITs) have a number of advantages over the traditional standard of fibrosis assessment by liver biopsy, including safety, cost-effectiveness, and widespread accessibility.

OBJECTIVES

The aim of this study was to determine the accuracy of certain biomarkers and transient elastography (TE) alone or in combination to predict the stage of liver fibrosis in chronic hepatitis C (CHC). Also, we examined whether the combination of certain biomarkers and TE could increase the diagnostic accuracy of liver fibrosis assessment.

PATIENTS AND METHOD

A total of 446 patients who were previously diagnosed with CHC were included in the study. In the study group, 6 blood-based scores (APRI, Forns, Fib-4, Hepascore, FibroTest, and Fibrometer) were calculated, and TE was performed to validate the stage of fibrosis, compared with liver biopsy (LB) as the standard.

RESULTS

Significant fibrosis (F ≥ 2) was predicted with an AUROC of 0.727, 0.680, 0.714, 0.778, 0.688, 0.797, and 0.751 for the APRI, Forns, Fib-4, FibroTest, Hepascore, and Fibrometer scores and TE (Fibroscan), respectively. Severe fibrosis (F ≥ 3) was predicted, with AUROCs ranging between 0.705 and 0.811 for Hepascore and Fibrometer, respectively. Of the biomarkers, Fibrometer had the highest AUROC value in predicting both significant and severe fibrosis. The combination of APRI or FIB-4 with Fibrometer increased the diagnostic accuracy for significant fibrosis (from 69.07 to 82.27 for APRI, P = 0.001 and from 57.74 to 81.33, P = 0.001 for Fib-4). Combining APRI or Fib-4 with TE also increased the diagnostic accuracy (from 69.07 to 80.70%, P = 0.001 for APRI and from 57.74 to 81.33%, P = 0.001 for Fib-4) for significant fibrosis. The association that included Fibrotest was also reliable for the improvement of diagnostic accuracy. These combinations were more accurate or the assessment of severe fibrosis.

CONCLUSIONS

The synchronous association between a simple, inexpensive score and a complex but expensive score or TE increases the diagnostic accuracy of non-invasive methods for the assessment of liver fibrosis stage.

Does a liquid supplement improve energy and protein consumption in nursing home residents?

One popular strategy to improve the acceptance and efficacy of oral liquid supplements in long-term care is dispensing them during the medication pass, although few studies support its effectiveness. This study evaluated the impact of a supplement medication pass program on energy and nutrient consumption and weight in nursing home residents. Findings indicate that residents maintained their prestudy weight and had a 29% decrease in supplement energy intake, a 19% increase in food energy intake, and a 17% decrease in net energy intake (supplement plus food). Supplement and food protein intake remained stable. Over longer periods, this reduced energy consumption could lead to weight loss, so routine monitoring and periodic evaluations of resident intake (both food and supplement) are recommended to ensure residents are receiving and consuming adequate amounts of daily energy and nutrients.

Impaired health-related quality of life in Romanian patients with chronic viral hepatitis before antiviral therapy

BACKGROUND AND AIM

Chronic hepatitis is a disabling condition leading to impairment of a patient's quality of life. We investigated the impact of chronic viral hepatitis on health-related quality of life. The relationship between transaminase level and score in the quality-of-life questionnaire was also investigated.

METHODS

We studied 66 patients with chronic viral hepatitis (27 with hepatitis B, 38 with hepatitis C, 1 with hepatitis B+C; 32 men, 34 women) naive to any previous antiviral therapy. All had high levels of transaminases. Patients with chronic disease or those using drugs to modify their quality of life were discarded. The control group consisted of 36 healthy volunteers (17 men, 19 women). Both groups completed the Short Form 36 health survey, with the exception of the items concerning bodily pain.

RESULTS

Significant differences between the two groups for every domain of quality of life (physical functioning, role physical, mental health, role emotional, social functioning, vitality and general health) were recorded. We found no significant correlation between the level of transaminases and any item of the health-related quality-of-life questionnaire. In hepatitis B patients, several quality-of-life scores (general health, social functioning, mental health) were better than in hepatitis C patients.

CONCLUSIONS

Patients with chronic viral hepatitis not receiving antiviral therapy have an impaired quality of life as estimated by the Short Form 36 health survey.

Creating a career ladder for nursing assistants in long-term care

This article describes the development, implementation, and evaluation of a career ladder for certified nursing assistants in long-term care. A career ladder is an effective way to maximize the use of unlicensed workers without changing the skill mix (eg, no loss of licensed nursing positions) and allow the licensed nurse more time to perform higher-level clinical tasks, such as assessments, patient education, and documentation. Implementation of an unlicensed worker career ladder also can improve nursing assistant retention.

Two or more synchronous combination of noninvasive tests to increase accuracy of liver fibrosis assessement in chronic hepatitis C; results from a cohort of 446 patients

BACKGROUND

The prediction of fibrosis is an essential part of the assessment and management of patients with chronic liver disease. Non-invasive tests (NITs) have a number of advantages over the traditional standard of fibrosis assessment by liver biopsy, including safety, cost-effectiveness, and widespread accessibility.

OBJECTIVES

The aim of this study was to determine the accuracy of certain biomarkers and transient elastography (TE) alone or in combination to predict the stage of liver fibrosis in chronic hepatitis C (CHC). Also, we examined whether the combination of certain biomarkers and TE could increase the diagnostic accuracy of liver fibrosis assessment.

PATIENTS AND METHOD

A total of 446 patients who were previously diagnosed with CHC were included in the study. In the study group, 6 blood-based scores (APRI, Forns, Fib-4, Hepascore, FibroTest, and Fibrometer) were calculated, and TE was performed to validate the stage of fibrosis, compared with liver biopsy (LB) as the standard.

RESULTS

Significant fibrosis (F ≥ 2) was predicted with an AUROC of 0.727, 0.680, 0.714, 0.778, 0.688, 0.797, and 0.751 for the APRI, Forns, Fib-4, FibroTest, Hepascore, and Fibrometer scores and TE (Fibroscan), respectively. Severe fibrosis (F ≥ 3) was predicted, with AUROCs ranging between 0.705 and 0.811 for Hepascore and Fibrometer, respectively. Of the biomarkers, Fibrometer had the highest AUROC value in predicting both significant and severe fibrosis. The combination of APRI or FIB-4 with Fibrometer increased the diagnostic accuracy for significant fibrosis (from 69.07 to 82.27 for APRI, P = 0.001 and from 57.74 to 81.33, P = 0.001 for Fib-4). Combining APRI or Fib-4 with TE also increased the diagnostic accuracy (from 69.07 to 80.70%, P = 0.001 for APRI and from 57.74 to 81.33%, P = 0.001 for Fib-4) for significant fibrosis. The association that included Fibrotest was also reliable for the improvement of diagnostic accuracy. These combinations were more accurate or the assessment of severe fibrosis.

CONCLUSIONS

The synchronous association between a simple, inexpensive score and a complex but expensive score or TE increases the diagnostic accuracy of non-invasive methods for the assessment of liver fibrosis stage.

Molecular requirements for T cell recognition by a major histocompatibility complex class II-restricted T cell receptor: the involvement of the fourth hypervariable loop of the Valpha domain

The role of two central residues (K68, E69) of the fourth hypervariable loop of the Valpha domain (HV4alpha) in antigen recognition by an MHC class II-restricted T cell receptor (TCR) has been analyzed. The TCR recognizes the NH2-terminal peptide of myelin basic protein (Ac1-11, acetylated at NH2 terminus) associated with the class II MHC molecule I-Au. Lysine 68 (K68) and glutamic acid 69 (E69) of HV4alpha have been mutated both individually and simultaneously to alanine (K68A, E69A). The responsiveness of transfectants bearing wild-type and mutated TCRs to Ac1-11-I-Au complexes has been analyzed in the presence and absence of expression of the coreceptor CD4. The data demonstrate that in the absence of CD4 expression, K68 plays a central role in antigen responsiveness. In contrast, the effect of mutating E69 to alanine is less marked. CD4 coexpression can partially compensate for the loss of activity of the K68A mutant transfectants, resulting in responses that, relative to those of the wild-type transfectants, are highly sensitive to anti-CD4 antibody blockade. The observations support models of T cell activation in which both the affinity of the TCR for cognate ligand and the involvement of coreceptors determine the outcome of the T cell-antigen-presenting cell interaction.

The FibroTest value in discriminating between insignificant and significant fibrosis in chronic hepatitis C patients. The Romanian experience

AIM

To assess the diagnostic value of FibroTest to discriminate between insignificant and significant fibrosis in order to avoid the liver biopsy currently used for selection of chronic hepatitis C patients eligible for antiviral therapy.

PATIENTS AND METHODS

A retrospective study was carried out in 206 chronic hepatitis C patients with liver biopsy performed before starting antiviral therapy and concomitant serum stored at -80 degrees C. Liver fibrosis was evaluated according to the METAVIR scoring system on a scale of F0 to F4. Biochemical markers assessed were: alpha 2 macroglobulin (alpha 2-MG), apolipoprotein A1 (Apo-A1), haptoglobin (Hapto), gamma-glutamyltransferase (GGT), total bilirubin (TB). The FibroTest score was computed after adjusting for age and gender. Predictive values and ROC curves were used to assess the accuracy of FibroTest results.

RESULTS

Alpha 2-MG, apo-A1, Hapto and gender were independent predictors for significant fibrosis. For FibroTest the observed area under ROC (ObAUROC) for the discrimination between minimal or no fibrosis (F0-F1) and significant fibrosis (F2-F4) was 0.782 (+/- 95 CI: 0.716-0.847) for a cutoff value 0.47. The sensitivity (Se), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV) of the FibroTest to differentiate significant from insignificant fibrosis were 80.2; 63.2; 78.9 and 65.8, respectively. The adjusted AUROC (AdAUROC) according to the prevalence of each individual stage of fibrosis was 0.856.

CONCLUSION

FibroTest could be an alternative to biopsy in most patients with chronic hepatitis C. It requires a strict adherence and observance of the technical recommendations for the assays of biochemical markers in order to avoid analytical variability.