BCR-ABL-mediated upregulation of PRAME is responsible for knocking down TRAIL in CML patients.

Tumor necrosis factor-related apoptosis-inducing ligand-TNFSF10 (TRAIL), a member of the TNF-α family and a death receptor ligand, was shown to selectively kill tumor cells. Not surprisingly, TRAIL is downregulated in a variety of tumor cells, including BCR-ABL-positive leukemia. Although we know much about the molecular basis of TRAIL-mediated cell killing, the mechanism responsible for TRAIL inhibition in tumors remains elusive because (a) TRAIL can be regulated by retinoic acid (RA); (b) the tumor antigen preferentially expressed antigen of melanoma (PRAME) was shown to inhibit transcription of RA receptor target genes through the polycomb protein, enhancer of zeste homolog 2 (EZH2); and (c) we have found that TRAIL is inversely correlated with BCR-ABL in chronic myeloid leukemia (CML) patients. Thus, we decided to investigate the association of PRAME, EZH2 and TRAIL in BCR-ABL-positive leukemia. Here, we demonstrate that PRAME, but not EZH2, is upregulated in BCR-ABL cells and is associated with the progression of disease in CML patients. There is a positive correlation between PRAME and BCR-ABL and an inverse correlation between PRAME and TRAIL in these patients. Importantly, knocking down PRAME or EZH2 by RNA interference in a BCR-ABL-positive cell line restores TRAIL expression. Moreover, there is an enrichment of EZH2 binding on the promoter region of TRAIL in a CML cell line. This binding is lost after PRAME knockdown. Finally, knocking down PRAME or EZH2, and consequently induction of TRAIL expression, enhances Imatinib sensibility. Taken together, our data reveal a novel regulatory mechanism responsible for lowering TRAIL expression and provide the basis of alternative targets for combined therapeutic strategies for CML.

Ommexecha virens (Thunberg, 1824) and Descampsacris serrulatum (Serville, 1831) (Orthoptera, Ommexechidae): karyotypes, constitutive heterochromatin and nucleolar organizing regions.

Chromosomes of Ommexecha virens and Descampsacris serrulatum (Ommexechidae) were analyzed through conventional staining, C-banding, base specific fluorochromes, silver nitrate impregnation (AgNO3), and fluorescent in situ hybridization (FISH) with probe for 45S rDNA. The two species presented diploid number 2n= 23,X0 in males and acrocentric autosomes, except the pair one that presented submetacentric morphology. The X chromosome has distinct morphology in the two analyzed species, being a medium acrocentric in Ommexecha virens and large submetacentric in Descampsacris serrulatum. The C-banding revealed pericentromeric blocks of constitutive heterochromatin (CH) in all the chromosomes of Descampsacris serrulatum. For Ommexecha virens it was evidenced that the blocks of CH are preferentially located in the pericentromeric area (however some bivalents presents additional blocks) or in different positions. The staining with CMA3/DA/DAPI showed GC rich CH blocks (CMA3+) in some chromosomes of the two species. The nucleolar organizer regions (NORs) were located in the bivalents L2, S9, S10 of Ommexecha virens and M5, M6, M7, S11 of Descampsacris serrulatum. The FISH for rDNA showed coincident results with the pattern of active NORs revealed by AgNO3. This work presents the first chromosomal data, obtained through differential cytogenetics techniques in Ommexechidae, contributing to a better characterization of karyotypic evolution for this grasshopper family.

Acute kidney injury in AIDS: frequency, RIFLE classification and outcome

The objective of the present study was to evaluate the characteristics of acute kidney injury (AKI) in AIDS patients and the value of RIFLE classification for predicting outcome. The study was conducted on AIDS patients admitted to an infectious diseases hospital inBrazil. The patients with AKI were classified according to the RIFLE classification: R (risk), I (injury), F (failure), L (loss), and E (end-stage renal disease). Univariate and multivariate analyses were used to evaluate the factors associated with AKI. A total of 532 patients with a mean age of 35 ± 8.5 years were included in this study. AKI was observed in 37 percent of the cases. Patients were classified as "R" (18 percent), "I" (7.7 percent) and "F" (11 percent). Independent risk factors for AKI were thrombocytopenia (OR = 2.9, 95 percentCI = 1.5-5.6, P < 0.001) and elevation of aspartate aminotransferase (AST) (OR = 3.5, 95 percentCI = 1.8-6.6, P < 0.001). General mortality was 25.7 percent and was higher among patients with AKI (40.2 vs17 percent, P < 0.001). AKI was associated with death and mortality increased according to RIFLE classification - "R" (OR 2.4), "I" (OR 3.0) and "F" (OR 5.1), P < 0.001. AKI is a frequent complication in AIDS patients, which is associated with increased mortality. RIFLE classification is an important indicator of poor outcome for AIDS patients.

Acute kidney injury in AIDS: frequency, RIFLE classification and outcome.

The objective of the present study was to evaluate the characteristics of acute kidney injury (AKI) in AIDS patients and the value of RIFLE classification for predicting outcome. The study was conducted on AIDS patients admitted to an infectious diseases hospital inBrazil. The patients with AKI were classified according to the RIFLE classification: R (risk), I (injury), F (failure), L (loss), and E (end-stage renal disease). Univariate and multivariate analyses were used to evaluate the factors associated with AKI. A total of 532 patients with a mean age of 35 ± 8.5 years were included in this study. AKI was observed in 37% of the cases. Patients were classified as "R" (18%), "I" (7.7%) and "F" (11%). Independent risk factors for AKI were thrombocytopenia (OR = 2.9, 95%CI = 1.5-5.6, P < 0.001) and elevation of aspartate aminotransferase (AST) (OR = 3.5, 95%CI = 1.8-6.6, P < 0.001). General mortality was 25.7% and was higher among patients with AKI (40.2 vs17%, P < 0.001). AKI was associated with death and mortality increased according to RIFLE classification - "R" (OR 2.4), "I" (OR 3.0) and "F" (OR 5.1), P < 0.001. AKI is a frequent complication in AIDS patients, which is associated with increased mortality. RIFLE classification is an important indicator of poor outcome for AIDS patients.

Prediction of significant liver fibrosis in kidney transplant patients with chronic hepatitis C virus infection: the TX-3 index.

HCV infection is highly prevalent among kidney transplant (KT) recipients. The natural history and management of these patients are controversial. We sought to assess the diagnostic value of noninvasive markers of liver fibrosis in KT HCV-infected patients. This cross-sectional study included 102 KT individuals with positive HCV-RNA. Bivariate and multivariate analyses were used to identify variables associated with significant fibrosis (METAVIR > or = F2). Significant fibrosis was observed in 20 patients (20%). Time after transplantation, AST level, and platelet count were identified as independent predictors of significant fibrosis. Based on the regression model, a simplified index was devised. The AUROC for the TX-3 model was 0.867 +/- 0.081 (0.909, when adjusted by DANA). Values < or =4.0 of TX-3 showed a NPV of 97% and scores >9.6 exhibited a PPV of 71%. If biopsy indication was restricted to scores in the intermediate range of TX-3, this could have been correctly avoided in 68% of cases. The APRI score provided a correct diagnosis in only 47 individuals (46%) and exhibited lower diagnostic indices for both cutoffs, as compared to the TX-3 index. Comparison of AUROCs showed a trend towards superior diagnostic accuracy for TX-3 over APRI, although the difference between AUROCs did not reach statistical significance (0.867 +/- 0.053 vs 0.762 +/- 0.066, respectively, P = 0.064). In conclusion, significant liver fibrosis can be reliably predicted in KT HCV-infected subjects by simple and widely available parameters. If additional studies confirm our results, this model might obviate the requirement for a liver biopsy in a significant proportion of those patients.

Anti-hepatitis C virus-positive blood donors: are women any different?

We sought to assess clinical, epidemiological, biochemical, serological and histological characteristics of anti-hepatitis C virus (HCV)-positive female blood donors and compare them with men. As women are frequently the minority among blood donors, studies evaluating this population usually reflect characteristics of male gender. This retrospective study included 380 blood donors with confirmed positive anti-HCV. The mean age was 36.9 +/- 11.3 years and 33.2% were women. Compared with men, female donors showed higher prevalence of prior transfusion of blood products (P = 0.031) and lower prevalence of intravenous drug use (P = 0.001) and alcohol abuse (P < 0.001). Women exhibited lower medians of alanine aminotransferase (P < 0.001) and gamma-glutamyltransferase (P < 0.001). They also showed higher platelet count (P < 0.001) and prothrombin activity (P = 0.049), and a lower frequency of antibody against core antigen of hepatitis B virus (anti-HBc) positivity (P = 0.032). A higher proportion of spontaneous viral clearance (P = 0.001) and a lower frequency of viraemia (P < 0.001) were observed among women. On liver biopsy, women had lower prevalence of fibrosis stage > or = 2. Multivariate analysis identified age (OR = 1.050, 95% CI: 1.019-1.081, P = 0.001) and anti-HBc positivity (OR = 2.184, 95% CI: 1.010-4.722, P = 0.047) as independent predictors of significant fibrosis. Female blood donors presented higher prevalence of spontaneous viral clearance as well as biochemical and histological evidence of less advanced liver disease. These findings could be because of intrinsic characteristics of female gender or secondary to associated factors such as younger age or anti-HBc positivity.

Serum levels of YKL-40 and hyaluronic acid as noninvasive markers of liver fibrosis in haemodialysis patients with chronic hepatitis C virus infection.

Hepatitis C virus (HCV) infection is highly prevalent among end-stage renal disease (ESRD) patients undergoing haemodialysis and it is an important cause of morbidity and mortality in this population. The aim of this study was to evaluate the diagnostic value of YKL-40 and hyaluronic acid (HA) as noninvasive markers of liver fibrosis in 185 ESRD HCV-infected patients. Significant liver fibrosis was defined as METAVIR F2, F3 or F4 stages. Significant fibrosis was observed in 45 patients (24%). By univariate analysis, higher levels of YKL-40, HA, aspartate aminotransferase (AST), alanine aminotransferase (ALT) and gamma-glutamyltransferase (GGT) as well as reduced platelet count were associated with fibrosis. However, by multivariate analysis, only AST (P = 0.001), platelet count (P = 0.004) and HA (P = 0.042) were independently associated with significant fibrosis. For the prediction of significant fibrosis, the areas under receiver operating characterictic curve (AUROC) of the regression model (0.798) was significantly higher than the AUROC of YKL-40 (0.607) and HA (0.650). No difference was noted between the AUROC of the regression model and AST to platelet ratio index (APRI) (0.787). Values <8.38 of the regression model showed a negative predictive value of 94% and scores >or=9.6 exhibited a positive predictive value of 65%. If biopsy indication was restricted to scores in the intermediate range of the regression model, it could have been correctly avoided in 61% of the cases. In conclusion, APRI and a model based on AST, platelet count and HA showed better accuracy than YKL-40 and HA (when used solely) for the prediction of significant fibrosis in ESRD HCV-infected patients.

Conversion of CD95 (Fas) Type II into Type I signaling by sub-lethal doses of cycloheximide.

CD95 (Fas/Apo-1)-mediated apoptosis was shown to occur through two distinct pathways. One involves a direct activation of caspase-3 by large amounts of caspase-8 generated at the DISC (Type I cells). The other is related to the cleavage of Bid by low concentration of caspase-8, leading to the release of cytochrome c from mitochondria and the activation of caspase-3 by the cytochrome c/APAF-1/caspase-9 apoptosome (Type II cells). It is also known that the protein synthesis inhibitor cycloheximide (CHX) sensitizes Type I cells to CD95-mediated apoptosis, but it remains contradictory whether this effect also occurs in Type II cells. Here, we show that sub-lethal doses of CHX render both Type I and Type II cells sensitive to the apoptogenic effect of anti-CD95 antibodies but not to chemotherapeutic drugs. Moreover, Bcl-2-positive Type II cells become strongly sensitive to CD95-mediated apoptosis by the addition of CHX to the cell culture. This is not the result of a restraint of the anti-apoptotic effect of Bcl-2 at the mitochondrial level since CHX-treated Type II cells still retain their resistance to chemotherapeutic drugs. Therefore, CHX treatment is granting the CD95-mediated pathway the ability to bypass the mitochondria requirement to apoptosis, much alike to what is observed in Type I cells.

Lack of impact of hepatitis C virus coinfection in end-stage renal disease patients with hepatitis B virus infection.

INTRODUCTION: Hepatitis B virus (HBV) and hepatitis C virus (HCV) coinfection results in more severe forms of liver disease in nonuremic patients; however, the impact of HCV coinfection is not clearly known in end-stage renal disease (ESRD) patients with HBV infection. We sought to determine the impact of HCV coinfection in HBV-infected ESRD patients. PATIENTS AND METHODS: The HBsAg-positive ESRD patients evaluated between March 1999 and May 2003 were divided into two groups: group B, HBV infection alone, and group BC, HBV-HCV coinfection (anti-HCV-positive). Both groups were compared regarding epidemiological, laboratory, and histological findings. A liver biopsy was obtained in cases with evidence of viral replication and/or elevated alanine aminotransferase. RESULTS: One hundred patients (73% men) with mean age of 42 +/- 11 years (55 patients in group B and 45 in group BC) were studied. Comparison between groups showed a difference in time on hemodialysis and duration of infection, which were higher in group BC (P < .001 and P = .001, respectively) and in history of blood transfusion, which was also more frequent in group BC (P = .04). Liver biopsies, obtained from 15 patients in group B and 28 patients in group BC, showed no difference in frequency of septal fibrosis (60% in group B vs 48% in group BC, P = .46) or interface hepatitis (73% vs 71%, P = .99). CONCLUSIONS: HBV-HCV coinfection was related to a longer time on hemodialysis, longer duration of infection, and history of blood transfusion. Contrary to nonuremic patients, HCV coinfection was not associated with more severe forms of liver disease in ESRD patients.

Neutrophils as a specific target for melatonin and kynuramines: effects on cytokine release.

A growing body of evidence suggests that the pineal hormone, melatonin, has immunomodulatory properties, although very little is known about its effect on leukocytes. Therefore, we aimed to investigate the effect of melatonin and its oxidation product N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK) on cytokine production by neutrophils and peripheral blood mononuclear cells (PBMCs). AFMK (0.001-1 mM) inhibits the lipopolysaccharide (LPS)-mediated production of tumor necrosis factor-alpha (TNF-alpha) and interleukin-8 (IL-8) more efficiently in neutrophils than PBMCs. Moreover, the inhibitory activity of AFMK is stronger than that of melatonin. Interestingly, monocytes efficiently oxidize melatonin to AFMK. We conclude that neutrophils are one of the main targets for melatonin and that at least part of the effects described for melatonin on immune cells may be due to its oxidation product, AFMK. We also consider that the oxidation of melatonin may be an important event in the cross-talking between neutrophils and monocytes.

Prevalence of previous hepatitis A virus infection in renal transplant patients with hepatitis C: evidence of persistent anti-hepatitis A virus immune response.

Data concerning the prevalence of hepatitis A virus (HAV) infection among kidney transplant recipients are scarce. There is little information concerning natural immunity acquired after acute HAV infection. In most renal transplant recipients, anti-HAV antibodies are not detectable after vaccination; it is reasonable to suppose that immunosuppressive therapy interferes with the immunity. The objective of this study was to evaluate, in an endemic area, the prevalence of anti-HAV immunoglobulin (Ig)G in renal transplant recipients with chronic hepatitis C virus (HCV) infection. The prevalence of anti-HAV IgG was assessed in 40 HCV-positive renal transplant recipients. This group showed a 90% prevalence of previous HAV infection. These findings suggest that in an endemic area, the prevalence of previous HAV infection is high, even among immunosuppressed patients. HAV antibodies acquired after natural infection are detectable even after the onset of immunosuppressive therapy. These data should be considered when renal transplant recipients are considered for HAV vaccination. Prevaccination screening of renal transplant recipients must follow the same guidelines as those for immunocompetent subjects.

Interferon-alpha receptor 1 mRNA expression in peripheral blood mononuclear cells is associated with response to interferon-alpha therapy of patients with chronic hepatitis C

Interferon (IFN)-alpha receptor mRNA expression in liver of patients with chronic hepatitis C has been shown to be a response to IFN-alpha therapy. The objective of the present study was to determine whether the expression of mRNA for subunit 1 of the IFN-alpha receptor (IFNAR1) in peripheral blood mononuclear cells (PBMC) is associated with the response to IFN-alpha in patients with chronic hepatitis C. Thirty patients with positive anti-HCV and HCV-RNA, and abnormal levels of alanine aminotransferase in serum were selected and treated with IFN-alpha2b for one year. Those with HBV or HIV infection, or using alcohol were not included. Thirteen discontinued the treatment and were not evaluated. The IFN-alpha response was monitored on the basis of alanine aminotransferase level and positivity for HCV-RNA in serum. IFNAR1-mRNA expression in PBMC was measured by reverse transcription-polymerase chain reaction before and during the first three months of therapy. The results are reported as IFNAR1-mRNA/á-actin-mRNA ratio (mean ñ SD). Before treatment, responder patients had significantly higher IFNAR1-mRNA expression in PBMC (0.67 ñ 0.15; N = 5; P < 0.05) compared to non-responders (0.35 ñ 0.17; N = 12) and controls (0.30 ñ 0.16; N = 9). Moreover, IFNAR1-mRNA levels were significantly reduced after 3 months of treatment in responders, whereas there were no differences in IFNAR1 expression in non-responders during IFN-alpha therapy. Basal IFNAR1-mRNA expression was not correlated with the serum level of alanine and aspartate aminotransferases or the presence of cirrhosis. The present results suggest that IFNAR1-mRNA expression in PBMC is associated with IFN-alpha response to hepatitis C and may be useful for monitoring therapy in patients with chronic hepatitis C.

Interferon-alpha receptor 1 mRNA expression in peripheral blood mononuclear cells is associated with response to interferon-alpha therapy of patients with chronic hepatitis C.

Interferon (IFN)-alpha receptor mRNA expression in liver of patients with chronic hepatitis C has been shown to be a response to IFN-alpha therapy. The objective of the present study was to determine whether the expression of mRNA for subunit 1 of the IFN-alpha receptor (IFNAR1) in peripheral blood mononuclear cells (PBMC) is associated with the response to IFN-alpha in patients with chronic hepatitis C. Thirty patients with positive anti-HCV and HCV-RNA, and abnormal levels of alanine aminotransferase in serum were selected and treated with IFN-alpha 2b for one year. Those with HBV or HIV infection, or using alcohol were not included. Thirteen discontinued the treatment and were not evaluated. The IFN-alpha response was monitored on the basis of alanine aminotransferase level and positivity for HCV-RNA in serum. IFNAR1-mRNA expression in PBMC was measured by reverse transcription-polymerase chain reaction before and during the first three months of therapy. The results are reported as IFNAR1-mRNA/beta-actin-mRNA ratio (mean +/- SD). Before treatment, responder patients had significantly higher IFNAR1-mRNA expression in PBMC (0.67 +/- 0.15; N = 5; P < 0.05) compared to non-responders (0.35 +/- 0.17; N = 12) and controls (0.30 +/- 0.16; N = 9). Moreover, IFNAR1-mRNA levels were significantly reduced after 3 months of treatment in responders, whereas there were no differences in IFNAR1 expression in non-responders during IFN-alpha therapy. Basal IFNAR1-mRNA expression was not correlated with the serum level of alanine and aspartate aminotransferases or the presence of cirrhosis. The present results suggest that IFNAR1-mRNA expression in PBMC is associated with IFN-alpha response to hepatitis C and may be useful for monitoring therapy in patients with chronic hepatitis C.

Bcr-Abl-mediated resistance to apoptosis is independent of constant tyrosine-kinase activity.

Bcr-Abl is one of the most potent antiapoptotic molecules and is the tyrosine-kinase implicated in Philadelphia (Ph) chromosome-positive leukemia. It is still obscure how Bcr-Abl provides the leukemic cell a strong resistance to chemotherapeutic drugs. A rational drug development produced a specific inhibitor of the catalytic activity of Bcr-Abl called STI571. This drug was shown to eliminate Bcr-Abl-positive cells both in vitro and in vivo, although resistant cells may appear in culture and relapse occurs in some patients. In the study described here, Bcr-Abl-positive cells treated with tyrosine-kinase inhibitors such as herbimycin A, genistein or STI571 lost their phosphotyrosine-containing proteins, but were still extremely resistant to apoptosis. Therefore, in the absence of tyrosine-kinase activity, Bcr-Abl-positive cells continue to signal biochemically to prevent apoptosis induced by chemotherapeutic drugs. We propose that secondary antiapoptotic signals are entirely responsible for the resistance of Bcr-Abl-positive cells. Precise determination of such signals and rational drug development against them should improve the means to combat Ph chromosome-positive leukemia.

In vitro-induced antibody production in chronic hepatitis C virus infection.

The objectives of the present study were to assess the in vitro-induced anti-hepatitis C virus (HCV) antibody production (IVIAP) in relation to the clinical, biochemical, virologic and histologic variables of patients with HCV infection. The study included 57 patients (60% males) with HCV infection (anti-HCV and HCV-RNA positive). Alanine aminotransferase (ALT) was elevated in 89% of the patients. Mean viral load was 542,241 copies/ml and histology of the liver showed chronic hepatitis in 27/52 (52%) and cirrhosis in 11/52 (21%) patients. IVIAP levels were determined by immunoenzymatic assay at median absorbance of 0.781 at 450 nm. IVIAP was negative in 14% of the patients. When groups with IVIAP levels above and below the median were compared, high IVIAP levels were associated with the male sex, elevated ALT levels and more advanced disease stage. After logistic regression analysis, advanced histologic damage to the liver remained as the only independent variable associated with elevated IVIAP levels. Using a receiver operator characteristic curve, the best cut-off level for IVIAP was established (= 1.540), with 71% sensitivity and 94% specificity for the detection of more advanced disease stages (grades 3 and 4). These findings are consistent with the participation of immunological mechanisms in the genesis of the hepatic lesions induced by HCV and indicate that the IVIAP test may be useful as a noninvasive marker of liver damage either alone or in combination with other markers.

In vitro-induced antibody production in chronic hepatitis C virus infection

The objectives of the present study were to assess the in vitro-induced anti-hepatitis C virus (HCV) antibody production (IVIAP) in relation to the clinical, biochemical, virologic and histologic variables of patients with HCV infection. The study included 57 patients (60 percent males) with HCV infection (anti-HCV and HCV-RNA positive). Alanine aminotransferase (ALT) was elevated in 89 percent of the patients. Mean viral load was 542,241 copies/ml and histology of the liver showed chronic hepatitis in 27/52 (52 percent) and cirrhosis in 11/52 (21 percent) patients. IVIAP levels were determined by immunoenzymatic assay at median absorbance of 0.781 at 450 nm. IVIAP was negative in 14 percent of the patients. When groups with IVIAP levels above and below the median were compared, high IVIAP levels were associated with the male sex, elevated ALT levels and more advanced disease stage. After logistic regression analysis, advanced histologic damage to the liver remained as the only independent variable associated with elevated IVIAP levels. Using a receiver operator characteristic curve, the best cut-off level for IVIAP was established (= 1.540), with 71 percent sensitivity and 94 percent specificity for the detection of more advanced disease stages (grades 3 and 4). These findings are consistent with the participation of immunological mechanisms in the genesis of the hepatic lesions induced by HCV and indicate that the IVIAP test may be useful as a noninvasive marker of liver damage either alone or in combination with other markers

Evaluation of an enzyme immunoassay for hepatitis C virus antibody detection using a recombinant protein derived from the core region of hepatitis C virus genome

This study was undertaken to evaluate an enzyme immunoassay (EIA) for hepatitis C virus antibody detection (anti-HCV), using just one antigen. Anti-HCV EIA was designed to detect anti-HCV IgG using on the solid-phase a recombinant C22 antigen localized at the N-terminal end of the core region of HCV genome, produced by BioMérieux. The serum samples diluted in phosphate buffer saline were added to wells coated with the C22, and incubated. After washings, the wells were loaded with conjugated anti-IgG, and read in a microtiter plate reader (492 nm). Serum samples of 145 patients were divided in two groups: a control group of 39 patients with non-C hepatitis (10 acute hepatitis A, 10 acute hepatitis B, 9 chronic hepatitis B, and 10 autoimmune hepatitis) and a study group consisting of 106 patients with chronic HCV hepatitis. In the study group all patients had anti-HCV detected by a commercially available EIA (Abbott(r)), specific for HCV structural and nonstructural polypeptides, alanine aminotransferase elevation or positive serum HCV-RNA detected by nested-PCR. They also had a liver biopsy compatible with chronic hepatitis. The test was positive in 101 of the 106 (95 percent) sera from patients in the study group and negative in 38 of the 39 (97 percent) sera from those in the control group, showing an accuracy of 96 percent. According to these results, our EIA could be used to detect anti-HCV in the serum of patients infected with hepatitis C virus.

Significance of the presence of antibodies against hepatitis C virus in asymptomatic blood donors

In order to determine the significance of anti-hepatitis C virus (anti-HCV) antibodies in blood donors, 46 consecutive asymptomatic individuals were recruited at the blood bank of Hospital Sao Paulo, Sao Paulo, Brazil. They were submitted to an interview to collect epidemiological data and to clinical examination and blood samples were obtained for biochemical, serological and virological analysis. All patients were followed for a minimum period of six months and those with abnormal mean alanine aminotransferase (ALT) levels were submited to a liver biopsy after giving informed consent. Hepatitis C virus RNA (HCVRNA) was detected by the polymerase chain reaction (PCR) in 22/46 (47.8 per cent) patients and this finding was associated with parenteral risk factors (P = 0.03) and ethanol abuse (P - 0.03). HCVRNA positivity was also associated with abnormal levels of ALT (P<0.001) and gamma-glutamyl transpeptidase (gamma-GT) (P=0.01). Abnormal ALT levels were a good marker of viremia, with 86.4 per cent sensitivity and 79.2 per cent specificity. Twenty-three patients with elevated mean ALT levels were submitted to a liver biopsy and histopathological changes were observed in 17 of them (73.9 per cent). HCVRNA positivity was associated with severe forms of hepatic disease (chronic hepatitis and cirrhosis). These results indicate the need for a judicious evaluation of all anti-HCV-positive blood donors, including clinical examination, biochemical tests and liver histology when ALT is persistently elevated.