Is azathioprine harmful to chronic viral hepatitis in renal transplantation? A long-term study on azathioprine withdrawal

Overview of Infections in the Immunocompromised Host

Understanding the components of the immune system that contribute to host defense against infection is key to recognizing infections that are more likely to occur in an immunocompromised patient. In this review, we discuss the integrated system of physical barriers and of innate and adaptive immunity that contributes to host defense. Specific defects in the components of this system that predispose to particular infections are presented. This is followed by a review of primary immunodeficiency diseases and secondary immunodeficiencies, the latter of which develop because of a specific illness or condition or are treatment-related. The effects of treatment for neoplasia, autoimmune diseases, solid organ and stem cell transplants on host defenses are reviewed and associated with susceptibility to particular infections. In conclusion, an approach to laboratory screening for a suspected immunodeficiency is presented. Knowledge of which host defects predispose to specific infections allows clinicians to prevent, diagnose, and manage infections in their immunocompromised patients most effectively.

Hepatitis B in transplantation

Hepatitis B has been a major challenge within the field of transplantation over the past few decades. Due to aggressive recurrence post-transplant, patients with hepatitis B have been excluded from the benefits of both solid organ and bone marrow transplants. Progress has been made, however, through an improved understanding of the biology of hepatitis B and the development of new antiviral strategies that can reliably suppress the virus. Patients with hepatitis B are now candidates for transplantation in an increasing number of circumstances. Careful pre-transplant evaluation is mandatory, together with a tailored antiviral regimen depending on the replicative status of the virus and the organ being transplanted. Minimizing steroid dose following transplantation is an important part of the strategy to reduce the risk of viral reactivation. Lamivudine has been an important development and it has assumed an increasing role in the management of these patients. As additional antivirals are developed, increasingly effective drug combinations will prevent viral recurrence as well as the emergence of drug-resistant mutants, which plagues the use of single agents. It is a rapidly evolving field and there is every reason for continued optimism.

Gastrointestinal and hepatic disorders in end-stage renal disease and renal transplant recipients

Gastrointestinal and hepatic disorders are commonly associated with end-stage renal disease, hemodialysis, and renal transplantation. Recent studies indicate that the prevalence of dyspepsia, ulcer disease, and Helicobacter pylori gastritis is not significantly different from the general population. Bleeding from angiodysplasia, however, is more common in chronic renal failure, as is gastroparesis. The prevalence of chronic hepatitis B has been dramatically reduced among hemodialysis patients since the advent of universal precautions. Response rates to hepatitis B vaccine in noninfected patients, however, are lower in these individuals. Chronic hepatitis C is found in 20% to 25% of HD patients worldwide and accounts for approximately 1% of all infected individuals. Levels of alanine aminotransferase and aspartase aminotransferase are often within normal limits but may be elevated compared with a patient's preinfection levels. Dialysis has been shown to reduce the level of hepatitis C virus viremia. Treatment is similar to non-renal failure patients, although interferon is generally not used in renal transplant recipients owing to concerns of graft failure.