Hepatitis B and C virus infections in the immune compromised

N-6 Substituted Deoxygenated Derivatives of L-like 5'-Noraristeromycin

Several N-6 substituted derivatives (4-11) of (+)-4'-deoxy-5'-noraristeromycin (2) and its unsaturated counterpart (3) have been prepared. The derivatives are designed to systematically vary the hydrophobic/hydrophilic balance of the lead compounds. These compounds were evaluated against a large number of viruses but, no significant antiviral activity was observed. Also, no cytotoxicity to host cells was found.

Immunopathogenesis of hepatitis B persistent infection: implications for immunotherapeutic strategies

It has been shown that cellular immunity, especially by cytotoxic T lymphocytes (CTLs), NK cells and NK-T cells, plays a central role in the control of virus infection. In addition, CD4+ T cells facilitate both CTL and B-cell responses. Hyporesponsiveness of HBV-specific T cells in peripheral blood has been shown in patients with chronic HBV infection. Interferon and nucleos(t)ide analogs, such as lamivudine, adefovir, entecavir and tenofovir, are the currently available treatments. Unfortunately, the efficacy of nucleos(t)ide analogs is limited by viral reactivation by the emergence of escaped mutants in cases of prolonged treatment. Therefore, immunotherapy is one of the significant options to eradicate or control HBV replication without drugs. The aim of immunotherapies is to decrease the levels of viral replication and to eradicate infected hepatocytes. For this reason, new strategies for immunotherapies by vaccination target not only the induction or stimulation of CD4+ and CD8+ T cell responses, but also the induction of proinflammatory cytokines capable of controlling viral replication. We will review the immunopathogenesis of persistent HBV infection, especially focusing on the mechanisms of immune suppression. Then we will review the immunotherapy for HBV persistent infection.

Efficacy of accelerated hepatitis B vaccination program in patients being actively treated for hematologic malignancies

BACKGROUND

The goal of this study was to conduct an accelerated vaccination program and to determine its efficacy in patients susceptible to hepatitis B virus (HBV) receiving chemotherapy because of their hematologic malignancies.

METHODS

Over a one-year period, a total of 327 patients who were diagnosed as having a hematologic malignancy were serologically analyzed in terms of HBV infection. Of those found to be susceptible to HBV infection, a total of 42 patients consisting of 16 females and 26 males were enrolled in the accelerated vaccination program. All the patients were administered a 20-microg yeast-derived recombinant hepatitis B vaccine on days 0, 14, and 28. Anti-HBs titers above 10IU/l at 1 and 3 months after the final dose were accepted as protective.

RESULTS

A total of 146 (44.6%) patients were susceptible to HBV, while 13 (4.0%) were carriers, 28 (8.6%) were vaccinated, and 113 (34.5%) had had a previous HBV infection. A total of 42 patients (16 females and 26 males, mean age 34.5+/-10.9 years) were enrolled in the vaccination program. Overall, 23.8% (10/42) of the patients in the program had developed anti-HBs at one month after the last vaccination.

CONCLUSIONS

Poor results obtained by different vaccination programs suggest the need for alternative strategies to prevent the disease.

Renal Fanconi syndrome and myopathy after liver transplantation: drug-related mitochondrial cytopathy?

Advances in the field of transplantation provide a better quality of life and allow more favorable conditions for growth and development in children. However, combinations of different therapeutic regimens require consideration of potential adverse reactions. We describe a 15-yr-old girl who had orthotopic liver transplantation because of Wilson's disease. Tacrolimus, MMF, and steroids were given as immunosuppressant. Lamivudine was added because of de nova hepatitis B infection during her follow-up. Three yr after transplantation she developed renal Fanconi syndrome with severe metabolic acidosis, hypophosphatemia, glycosuria, and aminoaciduria. Although tacrolimus was suspected to be the cause of late post-transplant renal acidosis and was replaced by sirolimus, acidosis, and electrolyte imbalance got worse. Proximal muscle weakness has developed during her follow-up. Fanconi syndrome, as well as myopathy, is well recognized in patients with mitochondrial disorders and caused by depletion of mtDNA. We suggest that our patient's tubular dysfunction and myopathy may have resulted from mitochondrial dysfunction which is triggered by tacrolimus and augmented by lamivudine.

Changing mortality rates and causes of death for HIV-infected individuals living in Southern Alberta, Canada from 1984 to 2003

OBJECTIVES

To examine changes over a 2-year period in both the mortality rate and the causes of death in a geographically defined HIV-infected population.

METHODS

A database search of primary care information for the dates and causes of death for all patients documented with HIV infection and living in Southern Alberta between 1984 and 2003 was undertaken. Sociodemographic and clinical characteristics were obtained. Causes of death were then individually confirmed by reviewing the patients' hospital charts, autopsy reports, or death certificates and coded using the International Classification of Diseases, 9th Revisions. AIDS deaths were reconciled with Public Health Reports. The time span was divided into pre-highly active antiretroviral therapy (HAART) (1984-1996) and current HAART (1997-2003) periods.

RESULTS

Between 1984 and 2003, there were 560 deaths in the 1987 individuals living with HIV infection in Southern Alberta. Of these, 436 deaths (78%) occurred pre-HAART and 124 (22%) in the current HAART period. The crude mortality rate declined from 117 deaths per 1000 patient-years pre-HAART to 24 in the current HAART period. In the pre-HAART era, 90% of all deaths were AIDS related whereas only 67% were AIDS related in the current HAART era. The leading causes of AIDS deaths were AIDS multiple causes (31%), Mycobacterium avium complex (18%), Pneumocystis pneumonia (10%) and non-Hodgkin's lymphoma (7%). The proportion of non-AIDS related deaths increased from 7% pre-HAART to 32% in the current HAART era. Accidental deaths, including drug overdose (29%), suicide (7%) and violence (3%), hepatic disease (19%), non-AIDS related malignancies (19%), and cardiovascular disease (16%) accounted for the majority of non-AIDS related deaths. No deaths directly caused by drug toxicity were found. Overall, 21% of patients who died were antiretroviral (ARV)-naive. A total of 14% of patients dying from AIDS were ARV-naive in contrast to 35% dying from non-HIV related conditions. Of all those dying from AIDS, 23% died<3 months after their initial diagnosis, reflecting late presentation. In the current HAART era, 87% of patients who died from AIDS were extensively treated, reflecting HAART treatment failures due mostly to multiclass drug resistance (42%), inexorable disease progression despite ARV (32%), lack of ability or interest to be maintained on a lifelong HAART programme (21%) and, rarely, drug intolerance (<1%).

CONCLUSIONS

Deaths from AIDS-related causes have decreased significantly, but deaths from non-AIDS related conditions have increased, both as an absolute number of deaths and as a proportion of all deaths in HIV-infected patients. The increasing age of the HIV population, and the increased mean CD4 count, increased proportion of intravenous drug users, increased hepatitis B virus and hepatitis C virus coinfection rate, and increased history of smoking seen in our population also influenced the mortality rate and causes of death. These factors must also be considered in projecting future trends in mortality of an HIV-infected population.

Advances in hepatitis B and C

PURPOSE OF REVIEW

Hepatitis B and C infections are prevalent around the world and a major health burden due to the associated complications of hepatic fibrosis, cirrhosis and hepatocellular carcinoma which occur in the context of chronic infection. Significant advances are being made in assessing and treating infected patients and recent studies are now targeting patients who have failed to respond to previous treatments or who have associated co-morbidities. The purpose of this article to review the recent literature on the subject of hepatitis B and C infections with particular focus on new treatment options, new approaches in patients who have previously failed therapy and in those who have co-morbidity.

RECENT FINDINGS

A large number of studies have been carried out investigating the roles of varying doses, targeting treatment in particular groups and new treatment options in patients infected with hepatitis B and C. Several key findings such as the value of prolonging treatment in patients with genotype 1 hepatitis C infection, the use of pegylated interferon in chronic hepatitis B infection and the emergence of new treatments such as adefovir for resistant hepatitis B infection, as well as treatment of patients co-infected with hepatitis C and human immunodeficiency virus, have dominated the recent literature. Patients in particular groups such as those who have had liver transplantation or who are immunosuppressed have also received added attention.

SUMMARY

Hepatitis B and C infections are the focus of much current attention with particular regard to new and emerging treatment options which are becoming increasingly focused on varying patient groups.