Photodynamic therapy: Inception to application in breast cancer.

Photodynamic therapy (PDT) is already being used in the treatment of many cancers. This review examines its components and the new developments in our understanding of its immunological effects as well as pre-clinical and clinical studies, which have investigated its potential use in the treatment of breast cancer.

Hepatitis C virus and organ transplantation.

Hepatitis C virus (HCV) is both the leading cause of cirrhosis and hepatic failure leading to liver transplantation and a cause of chronic hepatitis in approximately 10% of all transplant recipients. Beginning 5-10 years or more posttransplant, HCV causes progressive liver disease in a significant fraction of infected individuals and contributes to an increased incidence of opportunistic infection and hepatocellular carcinoma. The existence of multiple genotypes of HCV with differing biologic behaviors and the generation of antigenic diversity of the virus (quasispecies) during the course of infection, limit the capacity of the immune system to generate protective immunity. Antiviral therapy with interferon-alpha is effective in only a minority of transplant patients, and since allografts from HCV infected donors are quite efficient in transmitting the virus, great attention is paid to the appropriate use of organs from HCV-positive donors. At present, these organs should be particularly targeted for patients in emergent need of lifesaving heart, liver, or lung transplants. Issues requiring further investigation include the impact of viral superinfection on HCV-infected recipients of organs from HCV-infected donors and the use of such organs in seronegative patients who are older, diabetic, or highly sensitized, for whom quality of life issues may outweigh the long-term impact of HCV infection.

The impact of pretransplantation hepatitis C infection on the outcome of renal transplantation.

Controversy exists regarding the impact of pretransplantation HCV infection on the outcome of renal transplantation. We compared the prevalence of posttransplantation liver disease and graft and patient survival among kidney transplant recipients with and without anti-HCV at the time of transplantation. Pretransplantation sera from 103 randomly selected recipients of kidneys from anti-HCV-negative donors were tested for anti-HCV using a second generation ELISA. Twenty-three (22%) were positive for anti-HCV and 80 (78%) were negative. Anti-HCV-positive recipients had a longer time on dialysis (P = 0.003) and had a higher number of previous transplants (P = 0.01). Further, 61% of anti-HCV-positive patients had a history of liver disease compared with 13% of anti-HCV-negative patients (P < 0.001). HCV RNA was detected in the pretransplantation serum in 61% of anti-HCV positive recipients compared with 5% of anti-HCV-negative recipients (P < 0.001). Clinical follow-up on both anti-HCV-positive and -negative patients was obtained until December, 1993. Median posttransplantation follow-up among recipients with anti-HCV prior to transplantation (45 months) was shorter (P = 0.05) than that for recipients without anti-HCV (66 months). For recipients with anti-HCV prior to transplantation, the relative risk of posttransplantation liver disease was 5.0 (95% confidence intervals of 2.4 to 10.5); the relative risk of graft loss was 1.3 (95% confidence intervals of 0.6 to 2.6); the relative risk of death was 3.3 (95% confidence intervals of 1.4 to 7.9), and the relative risk of death due to sepsis was 9.9 (95% confidence intervals of 2.6 to 38.3). The results of this study demonstrate that pretransplantation HCV infection is associated with an increased risk of liver disease and death after renal transplantation. These results raise the question of whether anti-HCV-positive patients on dialysis should be offered renal transplantation as opposed to continuing dialysis.