Development of an HCV infection risk stratification algorithm for patients on chronic hemodialysis

The long-term impact of hepatitis C infection in kidney transplantation in the pre-direct acting antiviral era

Hepatitis C virus (HCV) infection in kidney transplantation is an important issue with effects on patient and graft survival. The current standard of care involves using oral Direct Acting Antiviral drugs. Till recently, pre-transplant treatment with interferon was the only option for treatment. We studied 677 consecutive kidney transplant recipients with HCV infection. 5.2% patients had evidence of HCV infection. 2.0% were newly detected to have HCV infection after transplant (de novo HCV group). Nearly 28.6% had negative antibody tests but positive Nucleic Acid Test at the time of diagnosis. Eighty-five percent of pre-transplant HCV-positive patients were treated with interferon-based regimens. Early virologic response was seen in 66.6%. End of treatment response was achieved by 94.1%. Sustained virologic response was seen in 81.2%. Overall, patient and graft survival were not different between HCV and control groups (log-rank P = 0.154). Comparing HCV and control groups, there was a tendency toward increased fungal (11.4% vs. 5.6%, P = 0.144) and CMV infections (25.7% vs. 17.1%, P = 0.191) in the HCV group, though it did not reach statistical significance. Eighty-percent of the interferon-treated patients suffered side effects. On comparing, the pre-transplant HCV-positive group (85% treated) with the de novo HCV group (none treated), the de novo group had significantly reduced patient survival (P = 0.020) and NODAT (35.7 vs 4.8%, P = 0.028), and a tendency toward higher CMV infections (35.7% vs 19%, P = 0.432). In addition, death and hepatic complications (decompensated liver disease, fibrosing cholestatic hepatitis) occurred only in de novo HCV group. These results highlight the need for continued post-transplant treatment of HCV positive patients. The newer anti-HCV drugs are expected to fulfill this felt-need in kidney transplantation but long-term results are awaited. This study can serve as a benchmark for future studies to compare the long-term effect of Direct Acting Antiviral drugs.

Prevalence and associations of hepatitis C viremia in hemodialysis patients at a tertiary care hospital

Hepatitis C virus (HCV) infection in hemodialysis (HD) is a significant problem. We evaluated the prevalence and associations of HCV viremia in our HD patients. All patients undergoing maintenance HD at our center were tested for HCV RNA by PCR after written informed consent. Detailed history regarding age, sex, and duration of dialysis, frequency of dialysis, blood transfusions in one year, number of dialysis centers, dialyzer reuse/fresh use, and recent laboratory data was recorded. A total of 119 patients (77 males and 42 females) were tested for HCV RNA. Thirty three (27.7%) tested positive. Duration of dialysis was significantly longer in HCV RNA positive group (P = 0.001). 45.2% of patients with duration of dialysis more than 16 months were HCV RNA positive while only 7.4% of patients with dialysis duration ≤16 months were HCV RNA positive (P < 0.001). In univariate analysis, in HCV RNA group patients, ALT, AST, and GGTP were significantly elevated and albumin was significantly lower. 39% of patients who had dialysis at more than one center were HCV RNA positive as compared to 20% for patients undergoing dialysis at single center (P = 0.024). Binary logistic regression analysis showed albumin, duration of dialysis, and serum ALT to be significant variables. Sensitivity and specificity of anti-HCV ELISA was 72.7 and 97.7%, respectively. Prevalence of HCV RNA in the HD population is 27.7%. Duration of dialysis, getting dialysis at more than one center, elevated transaminase levels, and low serum albumin are important associations for HCV RNA positivity.

Case-based reasoning support for liver disease diagnosis

OBJECTIVES

In Taiwan, as well as in the other countries around the world, liver disease has reigned over the list of leading causes of mortality, and its resistance to early detection renders the disease even more threatening. It is therefore crucial to develop an auxiliary system for diagnosing liver disease so as to enhance the efficiency of medical diagnosis and to expedite the delivery of proper medical treatment.

METHODS

The study accordingly integrated the case-based reasoning (CBR) model into several common classification methods of data mining techniques, including back-propagation neural network (BPN), classification and regression tree, logistic regression, and discriminatory analysis, in an attempt to develop a more efficient model for early diagnosis of liver disease and to enhance classification accuracy. To minimize possible bias, this study used a ten-fold cross-validation to select a best model for more precise diagnosis results and to reduce problems caused by false diagnosis.

RESULTS

Through a comparison of five single models, BPN and CBR emerged to be the top two methods in terms of overall performance. For enhancing diagnosis performance, CBR was integrated with other methods, and the results indicated that the accuracy and sensitivity of each CBR-added hybrid model were higher than those of each single model. Of all the CBR-added hybrid models, the BPN-CBR method took the lead in terms of diagnosis capacity with an accuracy rate of 95%, a sensitivity of 98%, and a specificity of 94%.

CONCLUSIONS

After comparing the five single and hybrid models, the study found BPN-CBR the best model capable of helping physicians to determine the existence of liver disease, achieve an accurate diagnosis, diminish the possibility of a false diagnosis being given to sick people, and avoid the delay of clinical treatment.

HCV infection in haemodialysed patients: a role for serum IL-10 and TGF-beta1 in liver damage?

BACKGROUND

Hepatitis C virus (HCV) infection is often clinically silent in haemodialysed (HD) patients and their immune response may modulate liver damage in HCV infection. IL-10 and TGF-beta1 could play a role in this setting as, IL-10 down-regulates hepatic fibrosis, while TGF-beta1 is a pro-fibrotic cytokine.

AIM

To evaluate the role of IL-10 and TGF-beta1 in HD/HCV+ patients.

PATIENTS

71 HD/HCV+ patients (58 with normal [HD/HCV-N] and 13 with high serum transaminases [HD/HCV-H]), 40 non-uremic patients with chronic hepatitis C (HCV+), 56 HD anti-HCV- patients and 20 healthy volunteers (H).

METHODS

IL-10 and TGF-beta1 serum levels were assessed using ELISA tests. Liver histology was assessed by Ishak's score.

RESULTS

IL-10 serum levels were significantly higher in HD patients, both HCV+ (3.7+/-0.4 pg/ml; p<0.01) and HCV- (3.8+/-0.8 pg/ml; p<0.05) than in non-uremic HCV patients (2.3+/-0.4 pg/ml). Among the HD/HCV+ patients, IL-10 serum levels were similar in HD/HCV-N and in HD/HCV-H patients. Among the HD/HCV+ patients, IL-10 serum levels were similar in those with moderate histological damage compared to those with mild damage. TGF-beta1 serum levels were significantly lower in HD patients, both HCV+ (4.6+/-0.9 ng/ml) and HCV- (6.0+/-0.9 ng/ml) than in non-uremic HCV+ patients (8.1+/-1.1 ng/ml; p<0.001 and p<0.01, respectively), but similar to the values found in H (5.3+/-0.9 ng/ml; p=n.s.). No correlation was seen between IL-10 and TGF-beta1 serum levels in any of the groups considered.

CONCLUSIONS

Patients on haemodialysis treatment to have high levels of IL-10, which remain high even when patients are anti-HCV+, whereas the opposite is true of TGF-beta1. The cytokine pattern observed in HD patients is compatible with the hypothesis explaining the relatively benign evolution of HCV-related liver disease in HD patients, and has a pathophysiological role.

Distribution of HCV genotypes in patients with end-stage renal disease according to type of dialysis treatment

The objective of this study was to investigate the effects of types of dialysis treatments on hepatitis C virus infection and the epidemiologic properties of hepatitis C virus (HCV) infection at three Baskent University hospitals, in Ankara, Adana, and Izmir, Turkey, in 655, 326, and 118 patients with end-stage renal disease, respectively. One hundred thirty patients with HCV viremia among 271 patients with end-stage renal disease seropositive for HCV were included in this cross-sectional study. HCV RNA-positive patients were classified according to the renal replacement therapies (hemodialysis or continuous ambulatory peritoneal dialysis), and viral load, transaminase levels, and distribution of genotypes were compared between these subgroups. In the continuous ambulatory peritoneal dialysis group, 26 of 165 patients (16%) were serum anti-HCV positive, and 11 of 26 patients (42%) were serum HCV RNA positive. Twenty-six percent of the patients undergoing hemodialysis were anti-HCV positive, and 49% were HCV RNA positive. The prevalence of genotype 1b was 68% and 73% for patients in the continuous ambulatory peritoneal dialysis and hemodialysis groups, respectively. No significant differences were found between the genotype 1b and the non-1b groups or between different dialysis types with regard to age and sex and serum aspartate transaminase, alanine aminotransferase, and HCV RNA levels. We conclude that HCV seropositivity may differ between different types of dialysis treatments, although viral load and genotypes may be similar in persons with end-stage renal disease and those without.

Determination of the cut-off value of serum alanine aminotransferase in patients undergoing hemodialysis, to identify biochemical activity in patients with hepatitis C viremia

BACKGROUND

Elevated liver enzymes are infrequent in patients with hepatitis C virus (HCV) infection undergoing chronic hemodialysis (HD), suggesting that the alanine aminotransferase (ALT) is a poor predictor of hepatocellular damage in this population.

OBJECTIVE

To establish a more appropriate cut-off value of ALT to identify biochemical activity due to HCV infection in HD patients.

STUDY DESIGN

A total of 217 patients, with an average age of 51.2 years, were evaluated between January and October 2002; 130 were males (60%). Serum ALT was measured by a kinetic method in five consecutive monthly blood samples, from which an average was obtained and divided by the upper limit of normal (ULN). HCV antibodies were determined using an enzyme immunoassay, the serum HCV-RNA by nested-PCR and HCV genotype by hybridization of the amplified sequence from the 5'-non-coding region. The cut-off value of ALT was obtained from a ROC curve.

RESULTS

Within the 217 patients, 18 (8.3%) were anti-HCV-positive, 17 (7.8%) of whom were also HCV-RNA-positive. Genotype distribution was: 1a=47%; 1b=18%; 3a=35%. Mean ALT/ULN (0.77+/-0.57) of the 18 anti-HCV-positive cases was higher (p<0.001) than the negative group (0.38+/-0.23). The mean ALT/ULN (0.81+/-0.57) of the 17 HCV-RNA-positive cases was also higher (p<0.0001) than the negative cases (0.37+/-0.23). The cut-off value of ALT to distinguish the anti-HCV-positive from negative patients was 0.50% or 50% of the ULN (sensitivity=67%; specificity=83%). According to the HCV-RNA, the cut-off value of ALT was 0.45% or 45% of the ULN (sensitivity=71%; specificity=80%).

CONCLUSION

Reducing the cut-off of ALT by half, enables a better identification of biochemical activity in patients with HCV infection on chronic HD.

[Identification of the cutoff value for serum alanine aminotransferase in hepatitis C screening of patients with chronic renal failure on hemodialysis]

The patients with chronic renal failure in hemodialysis present low levels of serum alanine aminotransferases. In order to establish a better cutoff value for ALT in hepatitis C screening of hemodialysis patients, the ALT levels were measured monthly in 235 patients, being excluded those that presented average above the upper limit of normality. The cutoff value was identified by construction of a ROC curve (receiver operating characteristic). Among 202 patients, 15 (7.4%) presented antibodies to hepatitis C virus (anti-HCV) and 187 (92.6%) were anti-HCV negative, with an ALT average of 0.7 and of 0.5 from ULN (p <0.0001), respectively. The better cutoff value for ALT was at 0.6 from ULN, with sensitivity of 67% and specificity of 75% in anti-HCV screening. These results suggest that ULN of ALT could be reduced for 60% from conventional limit, when we are evaluating patients with CRF in hemodialysis.

Laboratory evaluation of a fully automated chemiluminescence immunoassay for rapid detection of HBsAg, antibodies to HBsAg, and antibodies to hepatitis C virus

The performance of a fully automated, random access, enhanced chemiluminescence immunoassay (Ortho/ECi) for the detection of antibody to hepatitis C virus (HCV) (anti-HCV), HBsAg, and antibody to HBsAg (anti-HBsAg), in human serum was compared to a Abbott second-generation enzyme immunoassay (EIA 2.0). The Ortho/ECi assays employ an immunometric technique with enhanced chemiluminescence for optimal assay performance. With regard to the study of clinical laboratory performance, six groups of sera prescreened with Abbott EIAs were assayed: anti-HCV-negative samples (n = 318), anti-HCV-positive samples (n = 177), anti-HBsAg-negative samples (n = 241), anti-HBsAg-positive samples (n = 239), HBsAg-positive samples (n = 158), and HBsAg-negative samples (n = 312). Sera with discrepant results in the two serological assays were resolved by confirmatory tests. Sera with indeterminate results by one or more confirmatory tests were evaluated by reviewing medical records. The overall concordance between the Ortho/ECi assay and the Abbott EIA were 97.78, 93.54, and 97.66% for anti-HCV antibodies, anti-HBsAg antibodies, and HBsAg, respectively. After resolving the discrepancies, the specificities of the new assay for anti-HCV and anti-HBsAg antibodies and HBsAg were 98.1, 92.8, and 100%, respectively. The sensitivities of the new assay for anti-HCV, anti-HBsAg, and HBsAg were 100, 98.8, and 97.4%, respectively. In conclusion, The Ortho/ECi assays for diagnosis of HCV and hepatitis B virus (HBV) infections are highly specific and sensitive assays. The rapid turnaround time, random access, full automation, and high throughput make it an effective assay system for clinical laboratory diagnosis of HCV and HBV infections.