Hepatitis B surface antigen (HBSAg) in peritoneal fluid of HBSAg carriers undergoing peritoneal dialysis

Detection and genetic characterization of domestic cat hepadnavirus in cats with cavitary effusions

After the identification of the novel domestic cat hepadnavirus (DCH) in 2018, its potential pathogenetic role in feline hepatic diseases has been suggested. Following the detection of DCH in a cat's serum and peritoneal effusion, the aim of this study was to retrospectively investigate the presence of DCH in cats with and without cavitary effusions along with DCH presence in effusions. Stored serum and effusion samples from cats with and without effusions admitted to the Veterinary Teaching Hospital of Lodi (Italy) in 2020-2022 were included based on results of hematobiochemical parameters. Effusions were classified based on cytological and physicochemical findings. The likelihood of liver damage was estimated based on clinical and laboratory findings. Samples were tested for DCH presence by quantitative PCR (qPCR). Positive samples were subjected to whole genome sequencing and phylogenetic analysis. DCH was detected in both serum and peritoneal effusion samples of 2/72 (2.8%) enrolled cats, included in the group with effusions (2/33; 6.1%), with one cat showing inflammatory and the other non-inflammatory effusion. Both DCH-positive cats belonged to the group with a likelihood of liver damage (2/22, 9.1%). Phylogeny showed that the DCH sequences from this study clustered with the prototypic Australian strain but were not included in the clade with other Italian DCH sequences. Results suggest the circulation of different DCH variants in Italy and show the presence of DCH in effusion samples from DCH-positive cats, mirroring the presence of HBV in body fluids from HBV-infected humans. Further studies are still recommended to define the pathogenic role of DCH in cats.

Hepatitis B related dilemmas in the renal unit

Testing for hepatitis B in dialysis patients is routine, but newer and more sensitive detection methods mean that there is sometimes confusion around viral loads and occult infection. There are frequently difficult choices surrounding isolation and treatment. Here we describe the use of HBV serology and DNA testing in decisions around patients with end-stage renal disease. We also suggest isolation decisions based on our current understanding of the virus and its infectivity.

Identification of Hepatitis C Virus RNA in Peritoneal Dialysis Fluid of Patients with Viremia

Background

The potential risk for transmission of hepatitis C virus (HCV) by peritoneal dialysis (PD) has been studied previously, with conflicting results.

Methods

To assess whether HCV crosses the peritoneal membrane, the following determinations were performed in 16 patients (7 males, 9 females; mean age 41.8 years; mean time on PD 14 ± 15 months) undergoing PD: serum anti-HCV using second-generation enzyme-linked immunosorbent assay (ELISA), serum and PD fluid HCV RNA by nested polymerase chain reaction, HCV genotyping by restriction fragment length polymorphism, and serum HCV load by branched DNA assay.

Results

Anti-HCV was positive in 10 patients. Serum HCV RNA was positive in 7 anti-HCV-positive patients and negative in all anti-HCV-negative patients. Fluid HCV RNA was detected in 5 (71.4%) patients testing positive for serum HCV RNA and in none testing negative for serum HCV RNA. Serum HCV genotype was 1a in 3 patients and 1b in 4; PD fluid HCV genotype was 1a in 1 patient and 1b in 4. Genotypes in serum and fluid were concordant when both were positive. Serum viral load ranged from nondetectable by the quantitative method to 5.1 MEq genome/mL in patients with fluid infection, and 1.05 MEq and 29 MEq genome/mL in the remaining 2 patients without detectable HCV in PD fluid.

Conclusions

HCV crosses the peritoneal membrane and may be detected in the dialysate of PD patients with proven viremia. Although our study population was small for firm conclusions to be drawn, this passage does not seem to depend upon the serum viral load. Our data support the notion that PD fluid needs careful handling and local disinfection to prevent possible spreading of viruses, in the institutional and the domestic environments.

Hepatitis B Virus Infection in the Dialysis Population: Current Perspectives

One of the major advances in the management of patients on regular dialysis has been the control of the spread of hepatitis B virus (HBV) infection in dialysis units. The rate of HBsAg positive patients on regular dialysis in the developed world is currently low, but outbreaks of HBV continue to occur. The diffusion of HBV in dialysis units in developing countries is higher, although available information is not abundant. There are limited data on the natural history of HBV in the dialysis population; they support a detrimental effect of HBV on survival in dialysis patients. The HBV viral load in HbsAg-positive dialysis patients appears low and stable over time and numerous mechanisms have been posited to explain it. Several assays for detecting HBV DNA in serum are available but they should not be used for purposes of routine screening within dialysis units. The epidemiology and clinical significance of occult HBV infection in the dialysis population needs to be addressed adequately - this remains an area of active research. Recent recommendations for the management of HBsAg chronic carriers on maintenance dialysis have been issued. No controlled trials for the treatment of hepatitis B with either interferon or lamivudine in dialysis patients are currently available.

Outcomes of hepatitis B surface antigenaemia in patients with incident end-stage renal disease

AIM

Hepatitis B virus (HBV) infection is an important risk factor for morbidity and mortality in the general population. However, limited data are available on the progression of HBV infection in patients with end-stage renal disease (ESRD), and available data are controversial. Therefore, we investigated the association between hepatitis B surface antigen (HBsAg) seropositivity and mortality in patients with incident ESRD.

METHODS

All adult patients (≥18 years of age) starting dialysis for ESRD from January 2000 to December 2011 were included. A total of 1090 patients with ESRD were analyzed. HBsAg-positive patients were paired 1:6 with HBsAg-negative patients using propensity score matching.

RESULTS

Eighty one (7.4%) patients were HBsAg positive. No differences in the survival rates of the HBsAg-positive and HBsAg-negative patients with ESRD were detected in either the entire cohort or the propensity score matched cohort. No differences in survival were detected between the groups of HBsAg-positive patients based on the hepatitis B envelope antigen, hepatitis B envelope antibody, HBV DNA status, or use of antiviral agents. No difference in mortality was found between the haemodialysis (HD) and peritoneal dialysis (PD) subgroups among HBsAg-positive patients.

CONCLUSION

Our results suggest that hepatitis B surface antigenaemia is not related to increased mortality in patients with incident ESRD. Survival of HBsAg-positive patients undergoing PD was comparable to that of patients undergoing HD.

Development and treatment of peritonitis in continuous ambulatory peritoneal dialysis

The main complication of continuous ambulatory peritoneal dialysis is peritonitis. This paper reviews its causes and treatment.

Review article: Hepatitis B and dialysis

The incidence of hepatitis B virus (HBV) infection in dialysis populations has declined over recent decades, largely because of improvements in infection control and widespread implementation of HBV vaccination. Regardless, outbreaks of infection continue to occur in dialysis units, and prevalence rates remain unacceptably high. For a variety of reasons, dialysis patients are at increased risk of acquiring HBV. They also demonstrate different disease manifestations compared with healthy individuals and are more likely to progress to chronic carriage. This paper will review the epidemiology, modes of transmission and diagnosis of HBV in this population. Prevention and treatment will be discussed, with a specific focus on strategies to improve vaccination response, new therapeutic options and selection of patients for therapy.

Kinetics of hepatitis B virus load and haemodialysis: a prospective study

The control of the spread of hepatitis B virus (HBV) infection within dialysis units has been an important goal in the management of patients on regular dialysis but infected patients continue to enter the dialysis system. It is evident that HBV viraemia in hepatitis B surface antigen (HBsAg)-positive patients on dialysis is low but it remains unclear whether haemodialysis per se can contribute to viral load reduction in such patients. HBV DNA was determined in 40 HBsAg-positive patients on maintenance haemodialysis immediately before and at the end of a 4-h haemodialysis session. The same measurements were repeated 48 and 72 h later. Twenty (50%) of 40 HBsAg-positive patients had detectable HBV DNA in serum. Detectable HBV DNA in serum was not predicted by demographic, clinical or biochemical parameters. HBV load decreased in the majority of patients after haemodialysis, although the difference was not significant (29 390 +/- 48 820 vs 23 862.8 +/- 4 350 copies/mL, NS). There was a strong relationship between mean HBV DNA levels before dialysis and absolute reduction of HBV DNA during haemodialysis sessions (r = 0.75, P = 0.0001). No difference occurred in the magnitude of change in HBV DNA titre when comparing cellulosic to synthetic membranes. Haemodialysis per se leads to a reduction in HBV load in HBsAg-chronic carriers on maintenance dialysis. This phenomenon could explain the low viral loads in these patients. Prospective studies are in progress to identify the mechanisms responsible for reduction in HBV load during haemodialysis.

Hepatitis B virus infection and the dialysis patient

Prevention of nosocomial transmission of hepatitis B virus (HBV) has been a signal achievement in the management of chronic kidney disease. The rate of serum hepatitis B surface antigen (HBsAg) seropositivity in patients on maintenance hemodialysis in the developed world is currently low (0-10%) but outbreaks of acute HBV infection continue to occur in this setting. The prevalence of HBV infection within dialysis units in developing countries appears higher (2-20%) based on relatively few reports. Although data are limited, HBV infection in dialysis population diminishes survival; HBV viral load in HBsAg-positive dialysis patients is reportedly low and stable over time. Updated recommendations for the management of HBsAg chronic carriers on maintenance dialysis have been issued. No rigorously controlled treatment trials for treatment of hepatitis B with either interferon or lamivudine therapy in dialysis patients are currently available.

Low HBV-DNA levels in end-stage renal disease patients with HBeAg-negative chronic hepatitis B

In end-stage renal disease patients treated by hemodialysis with HBeAg-negative chronic hepatitis B virus (HBV) infection, the evaluation of the presence of viral replication is essential in the assessment for renal transplantation. Data on HBV viral load, prevalence of precore mutations, as well as the influence of HCV coinfection on HBV-DNA levels in this group of patients is scarce. The aim of this study was to determine the HBV viral load in HBsAg-positive/HBeAg-negative hemodialysis patients; to compare HBV-DNA levels between isolated HBV infection carriers and HBV-HCV coinfected patients, and to evaluate the prevalence of precore mutations in these patients. Fifty hemodialysis patients with chronic HBeAg-negative HBV infection were studied. Viral load was determined by PCR (Amplicor HBV Monitor-Roche). The detection of precore mutations was made by sequencing. Of a total of 50 patients, 76% were male, with a mean age of 44 +/- 11 years. Anti-HCV was positive in 56% of patients. HBV-DNA was undetectable in 58% of patients; 24% had HBV-DNA <10,000 copies/ml, 12% between 10,000-100,000 copies/ml, and only 6% had HBV-DNA >100,000 copies/ml. There was no difference in the viral load of patients infected only by HBV and HBV-HCV co-infected patients (P = 0.96). Precore mutations were detected in only 8% of cases. In conclusion, hemodialysis patients with HBeAg-negative HBV infection had a low viral load. Precore mutations were infrequent and the presence of anti-HCV has not influenced the levels of HBV-DNA.

Biological dynamics of hepatitis B virus load in dialysis population

BACKGROUND

Control of the spread of hepatitis B virus (HBV) infection in dialysis units has been one of major advances in the management of end-stage renal disease. However, the natural history of HBV in dialysis patients remains unclear. The aim of this study is to measure monthly HBV viral load (HBV DNA) in a large cohort (n = 29) of hepatitis B surface antigen (HBsAg)-positive chronic dialysis patients during 12 months.

METHODS

HBV DNA was measured using the Amplicor HBV Monitor Test (Roche Diagnostics, Branchburg, NJ), an in vitro assay using polymerase chain reaction nucleic acid amplification and DNA hybridization for the quantitative measurement of HBV DNA in serum.

RESULTS

We observed three HBV DNA patterns: (1) patients persistently positive by Amplicor HBV Monitor Test (persistent HBV DNA; 7 of 29 patients; 24.1%), (2) individuals with alternatively positive and negative results (intermittent HBV DNA; 18 of 29 patients; 62.1%), and (3) patients persistently negative by Amplicor HBV Monitor Test (4 of 29 patients; 13.8%). HBV viral load was greater in patients with persistent compared with intermittent HBV DNA (persistently HBV DNA positive; 2.686 x 10(4) copies/mL; 95% confidence interval [CI], 5.2499 x 10(4) to 1.8158 x 10(4)copies/mL) versus intermittently HBV DNA positive (1.071 x 10(3) copies/mL; 95% CI, 8.524 x 10(3) to 4.09 x 10(2) copies/mL; P = 0.0001). In the entire group, HBV load at study entry was low and did not change versus the end of follow-up.

CONCLUSION

Three patterns of HBV viremia in dialysis patients over time were assessed; HBV load was not high and was relatively stable. HBsAg-positive patients who were intermittently HBV DNA positive had less HBV viral load than persistently HBV DNA-positive patients. Periodic testing for HBV DNA to assess the virological status of HBsAg-positive dialysis patients is recommended.

Infections in patients undergoing peritoneal dialysis

Considering experience acquired in the past years, it seems as though physicians have reached a plateau in the frequency of peritonitis. A peritonitis rate of 1 every 2 patient years may be acceptable. Further reduction of this peritonitis rate will require inordinately large efforts on all fronts. One will have to consider what are the acceptable costs and risks of peritonitis in patients on peritoneal dialysis. New developments in catheter technology, improved connections, better understanding of patient selection and training programs, improved diagnostic and therapeutic methods in the management of peritonitis, and understanding of the infectious and immune processes are eagerly awaited developments.

Disposal of dialysate in HIV-positive patients: an update

One of the concerns with the use of peritoneal dialysis in human immunodeficiency virus (HIV)-positive patients is disposal of the peritoneal effluents. This article reviews survival characteristics of HIV in dialysate effluents and current disinfectant strategies.

The risk of hepatitis B infection among health professionals in the United States: a review

Many physicians, dentists, and allied health personnel sustain occupational exposures to blood and other body fluids that increase their risk of contracting type B viral hepatitis. Overall, the risk of hepatitis B among persons employed in health-related fields is estimated to be approximately four times that in the general adult population. Studies on the incidence of infection and the prevalence of hepatitis B serologic markers have further defined risk in specific occupational categories and work activities. Physicians and dentists are five to ten times more likely than the general adult population to experience hepatitis B infection. Infection rates ten or more times above the average have often been characteristic of surgeons, patient care personnel in dialysis units and institutions for the mentally handicapped, and clinical laboratory workers having frequent contact with blood samples.