Postrenal transplant malignancies in a living-related donor program: 13-year experience--an update

Seroprevalence of Human herpesvirus 8 (HHV-8) and incidence of Kaposi's sarcoma in Iran

Seroepidemiological surveys show that the prevalence of human herpesvirus 8 (HHV-8) infection mostly varies in various geographical areas and reflects the local incidence of classic and endemic KS, being widespread in sub-Saharan Africa and Mediterranean countries and uncommon in the USA and Northern Europe. In the Middle East only few populations, such as Ashkenazi and Sephardic groups in Israel, have been adequately evaluated for HHV-8 seroprevalence. Among Iranian population a striking higher seroprevalence of HHV8 has been reported among haemodialysis (16.9%), renal transplant recipients (25%) and HIV (45.7%) patients compared to blood donors (2%). Kaposi's sarcoma (KS) is the rarest cancer in Iran, with an annual age-standardized incidence varying from 0.10 to 0.17 per 100,000 in males and from 0.06 to 0.08 per 100,000 in females. KS, however, is one of the most important malignancies in Iranian renal transplanted patients affecting up to 2.4% of organ recipients. The epidemiology of HHV8 and KS in Iran needs further evaluation. While the high prevalence of HHV-8 antibodies in HIV positive and haemodialysis individuals may be attributed to high-risk sexual behavior and polytransfusions, respectively, unknown determinants may be responsible for high seroprevalence of HHV8 and high incidence of KS in solid organ recipients. A global survey on HHV8 seroprevalence in Iran is mandatory to define co-factors associated with HHV8 infection and KS risk in the general Iranian population and in specific patient groups.

Donor-derived human herpes virus 8-related Kaposi's sarcoma in renal allograft ureter

We present a case of human herpes virus 8 (HHV8)-associated Kaposi sarcoma (KS) occurring in a renal allograft ureter from a male donor. The female patient presented with a rising creatinine due to ureteric obstruction, and subsequent histological examination of the excised tumor revealed a KS. The tumor tested positive for HHV8 antigen and, using in situ hybridization to identify X and Y chromosomes, we were able to demonstrate that the tumor was of male origin. In the absence of any other KS lesions, this suggested that the tumor arose due to reactivation of latent HHV8 in the donor tissue, permitted by the recipient's immunosuppression. The patient was managed by a gradual reduction in immunosuppression and there has been no subsequent recurrence of the tumor. KS in renal transplantation is discussed in detail including the possible utility of pre-transplant HHV8 screening.

Racial and ethnic variations in incidence and pattern of malignancies after kidney transplantation

Malignancies are a well-recognized complication of renal transplantation. Although the problem is well studied in developed countries, less is known about it in developing countries. Although geographic and ethnic variations have been alluded to in several reports, to our knowledge the subject has not been investigated formally. From April 1976 through March 1999, 41 (7.6%) patients were diagnosed with cancer among a heterogeneous population of renal allograft recipients treated at our institution in Cape Town, South Africa. The incidence of malignancies was comparable in white and nonwhite patients. However, squamous cell cancer and basal cell cancer of the skin (in that order) were the most common cancers in white patients, in whom they occurred exclusively. On the other hand, Kaposi sarcoma was the most common cancer in nonwhite renal allograft recipients, in whom it accounted for almost 80% of all cancers. Review of the world literature suggests that posttransplant cancers are less common in developing countries; Kaposi sarcoma is the most common lesion, with few exceptions. Malignant lymphomas are also more common in developing countries. The impact of different immunosuppressive regimens is controversial. In general, cyclosporine is not associated with a significant increase in the incidence of cancer after renal transplantation, although the time to the first cancer may be reduced. In our experience, the pattern of posttransplant cancers in white and nonwhite patients living in the same geographic region epitomizes the world experience of the disease and suggests that genetic factors, rather than geography, are the more important determinants of cancer development after renal transplantation.

Treatment results in renal transplant recipients with non-Hodgkin's lymphoma

The purpose of this study was to investigate the incidence of non-Hodgkin's lymphoma (NHL), response to treatment, and survival time in renal transplant recipients at our center who developed this form of neoplasia. Between October 1985 and August 2002, 1077 renal transplantations were carried out at our center. The incidence of NHL after transplantation was 1.1% (12/1077). All patients had their immunosuppressive doses reduced after they were diagnosed with NHL. Complete remission was achieved in eight cases, and five of these individuals were still alive at the time of writing. The circumstances for each of the three deaths in this group were as follows: (1) progressive gastric adenocarcinoma 9 years after being diagnosed with NHL, (2) stage III NHL cured with chemotherapy, but died of infection 2 years after NHL diagnosis, and (3) recurrent intestinal lymphoma, with death during second line chemotherapy. Of the five survivors in the remission group, one had to return to hemodialysis. The four patients who did not enter remission all died. The median time from transplantation to diagnosis of NHL was 66 months. At the time of writing, the median survival time for the eight patients who achieved complete remission was 41.5 months. The study showed that treatment of localized disease (skin or intestinal NHL) with surgery and/or radiotherapy/chemotherapy leads to complete remission and long survival times; however, patients in remission are at risk for other causes of death.