A comparison of epidemiologic, histologic, and virologic studies on Hodgkin's disease in western Kenya and Nagasaki, Japan.

Rapid progress in molecular technologies has enabled the detection of several oncogenic viruses in various types of tumors. The pathogenesis of Hodgkin's disease is suggested to have a strong association with Epstein-Barr virus (EBV). However, Hodgkin's disease related to EBV shows a wide geographic variation in epidemiology. These variations among different populations suggest an interaction of environmental factors and a direct role of EBV infection. Therefore, we performed a comparative study on epidemiologic, histologic, and virologic features of Hodgkin's disease among those in the western part of Kenya and in Nagasaki, Japan. The age distribution of Hodgkin's disease showed a distinct peak in the 0-9-year-old age group in Kenya, and a higher and lower peak in the 60-69- and 30-39-year-old age groups, respectively, in Japan. The most common subtype of Hodgkin's disease in both countries was mixed cellularity, followed by nodular sclerosis, lymphocyte depletion, and lymphocyte predominance. Mixed cellularity showed a significantly high prevalence among Kenyan children nine years of age or younger. Using the in situ hybridization method, EBV-encoded RNA (EBER-1) was detected in 79% of the Kenyan cases and 59% of the Japanese cases, with the mixed cellularity subtype showing a strong correlation with EBER-1. There was 100% positivity in both countries in those less than nine years old. These results suggest that EBV plays a more direct role in the pathogenesis of Hodgkin's diseases in Kenya, especially in cases among young children and also in Japanese children. Environmental and/or genetic factors may have a role, in addition to EBV, in the pathogenesis of Hodgkin's disease, especially in Nagasaki, Japan.

Short report: herpes-like DNA sequences in African-endemic and acquired immunodeficiency syndrome-associated Kaposi's sarcoma.

Recently, the unique nucleic acid closely related to the herpes-like sequences has been found in acquired immunodeficiency syndrome (AIDS)-associated Kaposi's sarcoma (KS). We have confirmed the presence of herpes-like DNA sequences in six cases of AIDS-associated KS and three of the nine cases of African-endemic KS in adults, but not in eight cases of KS in children from the same area. These sequences were seen in a histologically early stage of KS. Our results suggest that herpes-like DNA sequences may play an important role in the pathogenesis of AIDS-associated KS.

The pattern of pediatric solid malignant tumors in western Kenya, east Africa, 1979-1994: an analysis based on histopathologic study.

This study analyzed histopathologic specimens of 600 pediatric solid malignant tumors seen during the period 1979-1994 at the histopathology laboratories of the Rift Valley Provincial General Hospital in Nakuru, the Nyanza Provincial General Hospital in Kisumu, and the Uasin Gishu Hospital in Eldoret in western Kenya. The crude incidence rate of each malignancy per 100,000 children per year was calculated. The patterns of malignancies were examined with a focus on tumor incidence, age, sex, geographic, and ethnic distribution to relate the tumors to putative environmental and genetic causative factors. The six common tumors were Burkitt's lymphoma (33.5%), non-Hodgkin's lymphoma (21.8%), retinoblastoma (11.5%), Kaposi's sarcoma (6.1%), nephroblastoma (4.5%), and Hodgkin's disease (4.1%). Significantly high crude incidence rates for lymphomas and Kaposi's sarcoma showed a characteristic ethnogeographic distribution. The majority of the tumors were found concentrated around Lake Victoria and showed decreasing occurrence as one moved towards the semi-arid and highland areas. We concluded that environmental factors seem to play a major role in childhood tumors in western Kenya.