Serum hepatitis B core-related antigen is more accurate than hepatitis B surface antigen to identify inactive carriers, regardless of hepatitis B virus genotype

OBJECTIVES

To investigate whether hepatitis B surface antigen (HBsAg) and hepatitis B core-related antigen (HBcrAg) levels are useful to identify inactive carriers among HBeAg-negative patients infected by different hepatitis B virus (HBV) genotypes.

METHODS

In all, 202 consecutive HBeAg-negative patients with chronic hepatitis B, 135 inactive carriers and 67 with HBV activity, were prospectively followed for 1 year.

RESULTS

In HBeAg-negative patients, HBsAg levels differed across the different genotypes (p <0.001). The highest levels were observed in genotypes F or H (4.2 ± 0.6 logIU/mL), followed by genotype E (3.4 ± 1.1 logIU/mL), genotype A (3.4 ± 0.8 logIU/mL), and the lowest in genotype D (2.7 ± 1.1 logIU/mL). Variations in HBsAg levels were similar in inactive carriers and patients with HBV activity. HBsAg <3 logIU/mL showed good performance for identifying genotype D inactive carriers: 76% of genotype D inactive carriers met this cut-off versus ≤31% for genotypes A, E, F or H. However, in patients with genotype A, HBsAg levels ≤3.7 logIU/mL better classified inactive carriers. The combination of a single measurement of HBcrAg ≤3 logU/mL plus HBV DNA ≤2000 IU/mL yielded a positive predictive value and diagnostic accuracy >85% in all HBV genotypes, except genotype H or F, with values of 62.5% and 72.7%, respectively, for the two parameters.

CONCLUSIONS

HBsAg levels varied across genotypes in HBeAg-negative patients. HBsAg levels <3 logIU/mL were only useful for identifying genotype D inactive carriers. A single HBcrAg measurement ≤3 logU/mL plus HBV DNA ≤2000 IU/mL was highly accurate for identifying inactive carriers, regardless of their HBV genotype.

Hepatitis B virus quasispecies evolution after liver transplantation in patients under long-term lamivudine prophylaxis with or without hepatitis B immune globulin

AIMS

To investigate an optimal long-term prophylactic strategy for prevention of hepatitis B virus (HBV) recurrence after liver transplantation, we conducted a randomized study of 29 transplant recipients receiving a short course of hepatitis B immune globulin (HBIg) + lamivudine (LAM), followed by randomization to long-term prophylaxis with LAM with or without HBIg.

METHODS

The efficacy and safety, and impact on survival and HBV recurrence of these 2 prophylactic regimens were compared over a mean period of 10 years. In patients with viral recurrence, the HBV quasispecies in the surface/polymerase region were studied by ultra-deep pyrosequencing (UDPS).

RESULTS

The 10-year survival rate was 76% and was not affected by the type of prophylaxis. Four patients had hepatitis B surface antigen (HBsAg) recurrence within the first 48 months after orthotopic liver transplantation (OLT). HBsAg-positive and -negative patients showed similar mean survival times, with no differences between the 2 regimens. Low HBV DNA levels were transiently detected in 32% of HBsAg-negative patients. UDPS showed major changes after OLT in the HBV quasispecies of patients with viral recurrence, which may be explained by a "bottleneck" effect of OLT together with prophylactic therapy.

CONCLUSION

Long-term survival after OLT in end-stage chronic hepatitis B patients was good with both prophylactic strategies. However, low, transient HBV DNA levels were detected even in the absence of HBsAg, showing the importance of continuing HBV prophylaxis.

Early predictors of antiviral treatment response in liver transplant recipients with recurrent hepatitis C genotype 1

The success of current antiviral treatment for hepatitis C virus (HCV) recurrence in liver transplant (LT) recipients remains limited. We aimed at evaluating the value of IL28B genotype and early viral kinetics to predict response to standard treatment in the transplant setting. We retrospectively evaluated 104 LT recipients treated for HCV genotype 1 recurrence between 2001 and 2010. Baseline variables, including IL28B genotype, and early viral kinetics were compared among patients who did or did not achieve a sustained virological response (SVR). Logistic regression analyses of candidate variables were conducted to generate a reliable predictive model based on the minimum set of variables. Twenty-nine (28%) achieved an SVR. On multivariate analysis, the magnitude of HCV RNA decline at 4 weeks (OR: 3.74, 95% CI: 1.64-9.39; P = 0.003) and treatment compliance (OR: 35.27, 95% CI: 3.35-365.54; P = 0.003) were the only independent predictors of SVR. Favourable recipient IL28B genotype significantly correlates with virological response at week 4 (OR 3.23; 95% CI, 1.12-9.15; P = 0.03). By logistic regression analysis, a model including donor age, recipient rs12979860 genotype and viral load at 4 weeks showed the best predictive value for SVR with an area under the receiver operating curve of 0.861. Favourable recipient IL28B genotype strongly correlates with the viral response at week 4 which is the strongest predictor of response. The combination of recipient IL28B genotype and donor age with the week 4 response reliably estimates the probability of SVR early on-treatment and may facilitate therapeutic strategies incorporating new antiviral agents.

Main mutations in the hepatitis B virus basic core promoter (A1762T/G1764A) before HBeAg loss are markers that identify patients who will require long-term treatment

BACKGROUND

Some patients continue to have detectable HBV-DNA levels with liver disease progression after hepatitis B e antigen (HBeAg) loss. It is important to identify these patients, candidates for long-term treatment.

AIMS

To evaluate hepatitis B virus (HBV) genotype and the main mutations in the basic core promoter (BCP, A1762T/G1764A) and precore (G1896A) sequences as markers of persistent HBV-DNA after HBeAg loss.

METHODS

We analysed 60 serum samples from 20 Caucasian, HBeAg-positive, chronic hepatitis B patients, who lost HBeAg and were followed-up longitudinally. HBV genotype and precore and BCP mutations were determined before, at the time of, and after HBeAg loss.

RESULTS

After HBeAg loss, eight (40%) patients continued to have undetectable HBV-DNA and 12 (60%) had persistent HBV-DNA (median level 4.7 log(10) copies/mL). The presence of BCP mutations prior to therapy was the only variable associated with persistently detectable viraemia (P = 0.017). Four patients with genotype A and no mutations in the BCP region experienced hepatitis B surface antigen (HBsAg) loss after a mean period of 35 months from baseline.

CONCLUSIONS

Main BCP mutations in HBeAg-positive patients are useful markers to identify patients who will not have sustained virological suppression after HBeAg loss and therapy discontinuation and could benefit from long-term treatment.

Results of a case-detection programme for 1-antitrypsin deficiency in COPD patients

Alpha1-antitrypsin (alpha1-AT) deficiency is an underdiagnosed condition in patients with chronic obstructive pulmonary disease (COPD). The present authors have conducted a nationwide case detection programme of alpha1-AT deficiency in unselected patients with COPD using dried blood spots. The first phase analysed samples from 971 patients by determining alpha1-AT concentrations and identifying the deficient Z allele by genotyping using rapid real-time PCR. The second phase analysed 1,166 samples with alpha1-AT concentrations and identified both the S and the Z allele, but only in samples with low alpha1-AT concentrations. A total of eight (0.37%) individuals with the severe deficiency PiZZ were detected. In addition, three patients were identified with the PiSZ genotype in the second phase (0.3%). The global cost of the programme was 41,512, which represents 19.42 per sample and 5,189 per PiZZ detected. A sensitivity analysis demonstrated that performing Z genotype to all samples would have resulted in increased costs of 28 per sample and 7,479.5 per PiZZ case identified. In conclusion, a case detection programme of alpha1-antitrypsin deficiency in patients with chronic obstructive pulmonary disease using dried blood spots is feasible and at a reasonable cost per case detected. Diagnostic yield and costs depend largely on inclusion criteria and the protocol for processing of samples.

[Screening program for alpha-1 antitrypsin deficiency in patients with chronic obstructive pulmonary disease, using dried blood spots on filter paper]

Alpha-1 antitrypsin (AAT) deficiency is an under-diagnosed disease and screening programs have therefore been recommended for patients with chronic obstructive pulmonary disease (COPD). We present the results of the pilot phase of a screening program for AAT deficiency in order to evaluate the technique used, the procedures for transporting samples and the results obtained. Over a period of one month, five centers collected samples from all COPD patients for whom plasma concentrations of AAT or Pi phenotype had not yet been determined. Capillary blood spots were dried on filter paper and then sent by surface mail to a central laboratory for study. An immunonephelometric assay was used to determine AAT and DNA phenotyping was done by use of a Light Cycler. Samples were analyzed from 86 COPD patients (76 men, 10 women) with a mean age of 68.2 years. AAT deficiency was ruled out for 74 patients (86%) who had concentrations above the cutoff established, although one of them was MZ heterozygote by genotype. Among the 12 remaining patients (13.9%), only two also had a Z allele. The rest were individuals with concentrations below the established threshold and no evidence of a Z allele (10 patients, 11.6%). The Z allele frequency observed (3/172; 1.74%) was very similar to that found in the general population. The results of this pilot study allowed us to confirm that the method used to collect samples worked well. The sampling method is applicable, easy and well-accepted by participating physicians. It allowed AAT concentrations and Z allele deficiency to be determined. The method correlates well with standard techniques used for samples in whole blood.

Influence of deficient alpha1-anti-trypsin phenotypes on clinical characteristics and severity of asthma in adults

Severe alpha1-anti-trypsin (AAT) deficiency implies a high risk of pulmonary emphysema development. The possible relationship between partial deficiencies of this enzyme and bronchial asthma remains controversial. The objective of this study was to ascertain the distribution of AAT phenotypes in a non-selected asthmatic patient population. Across-sectional study on a sample of 111 patients with asthma was carried out. Demographic and clinical variables were collected with serum IgE concentrations, plasma eosinophil number and serum AAT concentrations determined, together with the Pi phenotype. Asthma was mild in 36 (32.4%) patients, moderate in 45 (40.5%) and severe in 30 (27%). No differences were observed in eosinophil count or serum IgE or AAT concentrations among patients with different degrees of severity. Twenty-two (19.8%) asthmatics with deficient phenotypes for AAT were identified, distributed equally in all severity stages of the disease. No significant differences were found in clinical and functional characteristics, or in asthma morbidity between PiMM and PiMS patients or the heterozygote group (PiMS and PiMZ). Eosinophil count and IgE concentrations did not differ significantly between asthmatics with normal phenotype and heterozygotes. In conclusion, the distribution of AAT phenotypes in asthmatic patients did not differ from that found in the general population. Heterozygote phenotypes for the deficiency do not appear to confer greater severity or different clinical expression of asthma in adults.

[Usefulness of the quantification of the alpha-1 serous protein band in the screening of alpha-1-antitrypsin deficiency]

BACKGROUND

Population studies indicate that alpha-1-antitrypsin (AAT) deficiency is an under diagnosed disease. Although alpha-1 serum protein is widely known to accompany AAT deficiency, the diagnostic utility of measuring the alpha-1 band to screen for this condition has not been assessed in the literature.

SUBJECTS AND METHOD

Electropherograms with alpha-1 band widths under the reference values were collected over a period of 3 months. The Pi phenotype of AAT was identified for these sera by isoelectric point determination. The phenotypes were compared to those obtained for the population of the same geographic area (n = 440). The alpha-1 band reference values were obtained from 73 healthy individuals with no Pi phenotype deficiency. Moreover, the alpha-1 band was also measured for a group of 17 PiZZ deficient patients.

RESULTS

We analyzed 7,305 electropherograms. One hundred four individuals (1.4%) without hypoproteinemia had alpha-1 readings below reference (set at 2.3%). The phenotypes in this group were 25 PiMM (24%), 52 PiMS (54%), 13 PiMZ (12.5%) and 5 PiSS 5 (5%). The odds ratios (CI 95%) in comparison with the normal population were, respectively, 0.10 (0.16-0.06); 4.58 (2.97-7.04); 4.35 (2.09-9.04) and 5.51 (1.66-18.16) (p < 10-5 in all cases except PiSS, which was p < 0.05). The levels for PiZZ patients were 1.4% +/- 0.3% (range 1.0%-2.1%).

CONCLUSIONS

Three times fewer subjects with a normal PiMM phenotypes are found among individuals with low alpha-1 band serum protein levels, and many more of such individuals are carriers of Z allele heterozygotes. Alpha-1 band readings in patients with AAT deficiency (PiZZ phenotype) have alpha-1 values below reference. Measuring alpha-1 protein is an easy technique, within the expertise of any laboratory, and may be very useful for screening for AAT deficiency in patients with chronic respiratory diseases.

[Quantitative determination of HBV-DNA in chronic hepatitis B: comparison of three methods]

The aim of this study was to evaluate a technique of quantitative determination of DNA-HBV in serum, bDNA Quantiplex, in a series of 90 patients with chronic HBV infection: 75 with chronic hepatitis B (24 HBeAg positive and 51 with anti-HBe) and 15 asymptomatic carriers of HBV (anti-HBe positive). The results were related to DNA-HBV determination by hydridation techniques in dot-blot and PCR. DNA-HBV was detected by the Quantiplex bDNA technique in 61 (81%) of the 75 patients with chronic hepatitis B, in 24 (100%) of the 24 HBeAg positive patients and in 37 (72%) of the 51 anti-HBe positive (p < 0.05) patients and in none of the asymptomatic HBV carriers. The median of DNA-HBV concentration was 4,000 pg/ml in the hepatitis HBeAg and 71 pg/ml in the ati-HBe positive (p < 0.05). A significant relation was observed between the ALT value and the DNA-HBV concentration (p < 0.05). DNA-HBV by dot-blot was positive in 22 (29%) of the chronic hepatitis B and in none of the asymptomatic HBV carriers. DNA-HBV was not observed by dot-blot in 39 patients positive for DNA-HBV by the Quantiplex bDNA technique. DNA-HBV by PCR was identified in 65 (87%) of the chronic hepatitis B and in one of the asymptomatic HBV carriers. The sensitivity of the Quantiplex bDNA technique (98% versus the PCR technique) is much greater than that observed with dot-blot. In conclusion, the determination of DNA-HBV by the Quantiplex bDNA technique may be considered a good method for evaluating the viremia and degree of viral replication in patients with chronic hepatitis B.

[Molecular characterization of two variants of alpha-1-antitrypsin deficiency: PI Mpalermo and PI Plovel]

BACKGROUND

Alpha 1 antitrypsin (AAT) is a highly polymorphic protein, having more than 75 different variants. In this work two rare AAT deficient variants were characterized by DNA study.

PATIENTS AND METHODS

Members of three generations of two separate families were studied. In family 1, the index case was affected with pulmonary emphysema and presented AAT deficiency (23 mg/dl). In family 2, the index case had a normal pulmonary function, an AAT serum level of 72 mg/dl and a phenotype heterozygous for an AAT variant migrating in the P variant region. The AAT variants were characterized by polymerase chain reaction amplification of the coding exons and direct sequencing of the amplification products.

RESULTS

Direct DNA sequencing from a member of family 1 demonstrates that in the exon II of the normal M1 (Val213) allele there was a 3-bp deletion (TTC), corresponding to Phe51 or Phe52. This mutation is characteristic of the Pl Mpalermo variant. In our study, Pl Mpalermo was detected in six members of three generations of this same family. Sequencing of exon III in a member of family 2, identified in the common M1 (Val213) allele a single base substitution of GAT-GTT, with the resulting amino acid change Asp256 for Val256. This mutation characterizes the Pl Plovel allele. The Pl Plovel was also detected in nine members of five others independent families. All of them have AAT serum levels between 80 and 102 mg/dl. None of the studied subjects had clinical evidence of lung disease.

CONCLUSIONS

The results of our study show the presence of the two AAT deficient variants in Spain and suggest that the Pl Plovel variant might be more common than expected.

[Study of HLA-II antigens in chronic hepatitis C and B and in acute hepatitis B]

The aim of this study was to analyze the variability of the HLA-II system in a series of patients with chronic hepatitis B, chronic hepatitis C and acute hepatitis B to know whether there is any relationship between the polymorphism of the HLA system, the different types of hepatitis and the evolution of the infection. HLA-II antigens were determined by a PCR technique in serum samples of 24 controls, 22 cases of chronic hepatitis C, 38 cases of chronic hepatitis B and 11 with acute hepatitis B. The prevalence of the HLA-DR4 antigen was lower in the cases of chronic hepatitis B (10.5%) and C (13.6%) than in the controls (33.3%), particularly the DRB1*0401 allele (p = NS). The prevalence of HLA-DR6 was similar in chronic hepatitis B (42.1%) and acute hepatitis B (45.5%). Predominance of the DRB1*1301 and DRB1*1302 alleles were, however, observed in acute hepatitis B (36.4%) versus chronic hepatitis B (13%). These data suggest that immunologic factors such as HLA antigens may influence in the susceptibility to infection by HBV and HCV. The use of PCR techniques which discriminate between the different alleles of the HLA antigens may provide better knowledge of the immune response.

[Study of the frequency of different phenotypes of alpha-1-antitrypsin in a population of Barcelona]

BACKGROUND

Severe alpha-1-antitrypsin (AAT) deficiency is caused by homozygous inheritance of gene Z, and is associated with a high risk of developing pulmonary emphysema. Determination of frequencies of different genes associated with the deficiency (especially S and Z) gives a clue to estimate the number of individuals homozygous PiZZ, carrying a high risk for pulmonary disease, in any given population.

PATIENTS AND METHODS

Pi phenotypes of 440 healthy individuals were determined by means of isoelectrofocusing in polyacrylamide gel. Seric values of AAT were determined by immunonephelometry. Mean age of participants was 30 years (range 18-49 yrs.). Results are compared with other published series.

RESULTS

Distribution of phenotypes was: PiMM 333 individuals (75%), PiMS 84 (19%), PiMZ 14 (3%), PiSS 4 (0.9%), PiM 3 (0.6%), PiMF 1 (0.2%), PiMP 1 (0.2%). The corresponding gene frequencies were Pi*M 87%, Pi*S 10.4%, and Pi*Z 1.5%. Normal values of AAT (phenotype PiMM) established in our laboratory were 116-232 mg/dl (21-41 micromol/I) (mean +/- 2 SD). According to Hardy-Weinberger equation, expected frequency of PiZZ individuals in our area would be 225 per million.

CONCLUSIONS

The frequency of Z gen individuals observed in our study is one of the highest in the Iberian Peninsula, but lower than the frequency in northern Europe. According to these results, AAT deficiency (PiZZ) is not a rare condition in contrast with the small number of patients diagnosed. The gen frequency of the S variant is higher than that of the rest of Europe, and similar to others found in some Spanish populations.

Hepatitis E virus infection in acute hepatitis in Spain

In order to study the prevalence of hepatitis E virus (HEV) infection in developed countries, IgG and IgM anti-HEV were determined in serum samples from 382 patients with acute viral hepatitis (244 hepatitis A, 48 hepatitis B and/or D, and 90 non-A, non-B, non-C hepatitis), 76 healthy subjects, 55 hemophiliacs and 50 patients on hemodialysis. IgG anti-HEV antibodies were detected and confirmed by a synthetic peptide-based EIA in 5 (5.6%) non-A, non-B, non-C acute hepatitis, in 3 (6.5%) B and D acute hepatitis, in 10 (4%) acute A hepatitis, in 3 (5.5%) of 54 healthy adults in none of the hemophiliacs and in 3 (6%) patients on hemodialysis. IgM anti-HEV antibodies were only detected in two cases of acute hepatitis B and/or D. Analysis of serial serum samples demonstrated IgG anti-HEV seroconversion in 3 of the 18 confirmed cases; one of them was also positive for IgM anti-HEV. All 3 acute anti-HEV-positive hepatitis cases occurred in adults, were community-acquired (two of them were intravenous drug addicts) and had a self-limited course. These results demonstrate that HEV is a minor cause of acute hepatitis in Spain. A similar low rate of IgG anti-HEV antibodies was detected in patients with different diseases, suggesting that HEV has a very low epidemiological impact. An apparent association of HEV infection with hepatitis B and D suggests a possible parenteral transmission of a mainly enteral pathogen.

Synthesis of a non-radioactive hepatitis B virus DNA probe from human serum by the polymerase chain reaction

A method for synthesizing probes for detecting hepatitis B virus DNA in serum was developed. It uses DNA extracted from the serum of an hepatitis B virus carrier as target, and digoxigenin-11-dUTP incorporated in DNA sequences during the polymerase chain reaction as tracer. Using a spot hybridization assay, the sensitivity and specificity of the digoxigenin-labelled DNA probe were compared with two standard hepatitis B virus DNA probes, synthesized with cloned hepatitis B virus DNA and labelled either with digoxigenin or 32P by random priming. Data obtained from the three methods showed an excellent correlation. Thus, hepatitis B virus DNA extracted from human serum and labelled by polymerase chain reaction may be considered a suitable alternative to cloned DNA. It provides reliable probes and eliminates the need for facilities and personnel dedicated to the manipulation of clones. These advantages will allow a wider application of hepatitis B virus DNA testing in clinical practice.

[A study of 158 cases of acute delta hepatitis]

We have prospectively studied 158 cases of acute hepatitis delta observed during the last 7 years in a general hospital. Among them 136 were male and 22 female. The mean age was 22.7 years with a range between 16 and 61 years. The epidemiologic factors were drug addiction by parenteral route in 145 cases (92%), sexual transmission in 5 (3%), post transfusional in 2 (1%) and unknown in 6 (4%). With respect to the delta type infection, 105 cases (66%) were coinfections with type B and delta, and 53 patients had a type delta superinfection (34%). The clinical course was a fulminant hepatitis in three cases (two cases of coinfection B and delta an one case of delta superinfection), and an acute benign hepatitis in 155 patients. The follow-up of 118 patients revealed that 96% of coinfections by type B and delta evolved to the chronicity showing findings of active chronic hepatitis or hepatic cirrhosis. It should be noted that in 4 cases of superinfection delta type (11%) the HBsAg was negative after several months of positivity. In these patients the level of transaminases normalized and the hepatic histology evidenced alterations of chronic active hepatitis (2 cases) and hepatic cirrhosis (2 cases) without identification of tissular delta antigen.