Israel Medical Association Journal

Background: Epidemiological studies in different parts of the world have revealed controversial results on the association between hepatitis C virus infection and non-Hodgkin’s lymphoma. This discrepancy suggests that HCV[1] lymphotropism or its effect on host lymphocytes may be influenced by regional and racial factors, as well as by genomic variations.

Objective: To determine the prevalence of HCV infection in patients with lymphoproliferative disorders diagnosed and treated in our institute in Israel.

Methods: A total of 212 consecutive patients (95 males and 117 females) treated in our hematology outpatient clinic between August 1997 and September 1999 was screened for anti-HCV antibodies and hepatitis B surface antigen. HCV infection was confirmed by the presence of HCV RNA in the serum. The prevalence of HCV in patients with lymphoproliferative disorders was compared to a control group of patients with myeloproliferative disorders and myelodysplastic syndromes.

Results: HCV infection was more prevalent in the group of LPD[2] patients than in the control group, but this finding was not statistically significant. The prevalence of HCV among LPD patients was 7.8%, while that in the group with myeloproliferative and myelodysplastic disorders was 1.19% and in the general population 0.64%. Among the different classes of LPD, a significant association with HCV infection was established only in patients with diffuse large B cell lymphoma. Furthermore, HCV infection was significantly more prevalent than HBV infection in the LPD group, but not in the myeloproliferative and myelodysplastic disorders group.

Conclusions: Our finding of a significant association between HCV infection and diffuse large B cell lymphoma leads us to suggest that anti-HCV antibodies be performed routinely in such subjects.  

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 [1]LPD = lymphoproliferative disorders

[2] HCV = hepatitis C virus

Background: Following the recent drought in Ethiopia, the Jewish Agency, aided by the Israel Ministry of Foreign Affairs, launched a medical relief mission to a rural district in Ethiopia in May-August 2000.

Objectives: To present the current medical needs and deficiencies in this representative region of Central Africa, to describe the mission’s mode of operation, and to propose alternative operative modes.

Methods: We critically evaluate the current local needs and existing medical system, retrospectively analyze the mission’s work and the patients’ characteristics, and summar­ize a panel discussion of all participants and organizers regarding potential alternative operative modes.

Results: An ongoing medical disaster exists in Ethiopia, resulting from the burden of morbidity, an inadequate health budget, and insufficient medical personnel, facilities and supplies. The mission operated a mobile outreach clinic for 3 months, providing primary care to 2,500 patients at an estimated cost of $48 per patient. Frequent clinical diagnoses included gastrointestinal and respiratory tract infections, skin and ocular diseases (particularly trachoma), sexually trans­mitted diseases, AIDS, tuberculosis, intestinal parasitosis, malnutrition and malaria.

Conclusions: This type of operation is feasible but its overall impact is marginal and temporary. Potential alternative models of providing medical support under such circum­stances are outlined.
 

Mixed cryoglobulinemia is a systemic vasculitis described as a triad characterized by purpura, weakness and arthralgias. Since the first description of the disease in 1964 by Meltzer and Franklin our understanding of its pathogenesis has increased considerably. The striking association of the disease with hepatitis C virus infection was initially noted in 1990. Since then, the disease has gained growing attention among investigators involved in the study of autoimmune systemic disorders because it represents one of the most intriguing models of autoimmunity triggered by a virus. Nonetheless, a number of answered questions still remain to be resolved and are reviewed in this article.

Background: Hepatitis B is a major problem worldwide. Israel has intermediate endemicity for hepatitis B virus, and an annual carrier rate of 1-3%.

Objective: To evaluate both the prevalence of HBV infection among family members of HBV carriers and the competence of family practitioners in performing a compre­hensive assessment.

Methods: A total of 152 HB surface antigen-positive blood donors were discovered in our subdistrict during the years 1993-97. Their family physicians were questioned regarding the patients' family members. Specific information on 85 spouses and 200 children was also obtained.

Results: Among the 85 married carriers, 5 of the spouses (5.9%) were found to be HBsAg positive. None of the 200 children was HB5Ag positive. We found that in a third (n=52) of the patients, the sexual partner had never been tested by a primary care physician. Patients were not routinely tested for HB e antigen or anti-HBe antibodies. Neither the parents nor the siblings had undergone any serological evaluation. How­ever, most family members of the carriers had received an HBV vaccine from their family physicians.

Conclusions: Our findings show that horizontal transmis­sion of HBV among spouses of HBV carriers still exists. We did not find any vertical transmission, probably due to male predominance and previous vaccination. Family physicians should be trained to perform an extensive serological evalua­tion of family members of patients with chronic HBV infection, including parents and siblings, and should vaccinate sero­negative family members.

Objectives: To compare risk behavior between subjects attending anonymous and confidential clinics for human immunodeficiency virus testing, and to assess whether anonymous testing results in a higher accrual of persons at risk for HIV.

Methods: An anonymous questionnaire that addressed sociodemographic and risk behavior aspects was administered to 140 subjects attending an anonymous clinic and 124 attending a confidential clinic in the Tel Aviv area. A logistic regression analysis was used to compare the effects of various behavioral factors on the probability of attending each clinic.

Results: Chronological age, age at first sexual intercourse and the percent of married subjects were similar in both clinics. However, there was a significant difference in the sex ratio and in educational attainment (85.0% versus 55.6% were males, P< 0.001 and 58% vs. 34% had over 12 years of education, P<0.001, in the anonymous and confidential clinics respectively).

There was a striking difference between the two clinics with regard to sexual experience characteristics: of the subjects reaching the anonymous clinic 21.4% were homosexual and 10.0% bisexual versus a total of 2.6% in the confidential clinic. A logistic regression analysis, comparing the effects of various behavioral factors on the probability of attending each clinic showed that gender (male), high education, homosexuality, number of partners and sexual encounter with sex workers were the strongest predictors for selecting anonymous HIV examination.

Conclusions: Individuals at high risk for HIV, such as homosexuals and bisexuals, prefer to attend an anonymous clinic.
 

Cancer is a multi-step disease involving a series of genetic alterations that result in the loss of control of cell proliferation and differentiation. Such genetic alterations could emerge from the activation of oncogenes and the loss or malfunctioning of tumor suppressor gene activity. Our understanding of cancer has greatly increased through the use of DNA tumor viruses and their transforming proteins as a biological tool to decipher a cascade of events that lead to deregulation of cell proliferation and subsequent tumor formation. For the past ten years our laboratory has focused on the molecular biology of the human neurotropic papovavirus, JCV. This virus causes progressive multifocal Ieukoencephalopathy, a fatal neuro­degenerative disease of the central nervous system in immunocompromised patients. JCV is a common human virus that infects more than 80% of humans but does not induce any obvious clinical symptoms. The increased incidence of acquired immune deficiency syndrome and the use of immunosuppressive chemotherapy have dramatically raised the incidence of PML. The coincidental occurrence of malignant astrocytes and oligodendrocytes in PML patients, coupled with the induction of glioblastoma in JCV-intected non­human primates, provides intriguing speculation on the association between JCV and CNS malignancies. In this report we discuss clinical data and laboratory observations pointing to the direct involvement of JCV in cancer.

Background: The transfer of therapeutic genes into malignant brain tumors has been the subject of intense pre­clinical and clinical research in recent years. Most approaches have used direct intratumoral placement of a variety of vectors and genes, such as retroviruses or adenoviruses carrying drug-susceptibility genes, modified replication-competent herpes virus, and several vectors carrying tumor suppressor genes such as the p53 gene. However, clinical results have so far been disappointing, mainly due to the limited ability to effectively distribute the genetic material into the target cell population. Accordingly, alternative delivery approaches into the central nervous system, e.g., intravascular, are under investigation. Genetic vectors administered intravascularly are unlikely to penetrate the blood-brain barrier and transfer a gene into brain or tumor parenchyma. However, intravascular delivery of vectors may target endothelial cells lining the blood vessels of the brain. Since endothetial cells participate in a variety of physiological and pathological processes in the brain, their modulation by gene transfer may be used for a variety of therapeutic purposes. Angiogenically stimulated endothelial cells within tumors replicate rapidly and hence may become targets for retroviral-mediated gene transfer.

Objective: To assess the anti-tumor effect of transferring a drug-susceptibility gene into endothelial cells of the tumor vasculature.

Methods: As a model for this approach we delivered concentrated retroviral vectors carrying a drug-susceptibility gene via the internal carotid artery of rats with malignant brain tumors. The safety and efficacy of this approach, without and with subsequent treatment with a pro-drug (ganciclovir). was evaluated.

Results: No acute or long-term toxicity was observed after intraarterial infusion of the vector. Treatment with ganciclovir resulted in variable hemorrhagic necrosis of tumors, indicating preferential transduction of the angiogenically stimulated tumor vasculature. This was accompanied by severe toxicity caused by subarachnoid hemorrhage and intracerebral hemorrhage in vascular territories shared by the tumor and adjacent brain.

Conclusion: The data indicate that endothelial cells can be targeted by intraarterial delivery of retroviral vectors and can be used for devising new gene therapy strategies for the treatment of brain tumors.

Background: A previous study on Hodgkin's lymphoma in southern Israel found that Bedouin patients had an increased rate of Epstein-Barr virus expression in their tumor cells.

Objectives: To determine the influence of the patients' communities on the pattern of disease in HL.

Methods: We compared the clinical features, demographic data, stage at diagnosis, treatment modality and outcome, as well as laboratory findings, in four community-based subgroups. These groups comprised kibbutz residents (n=11), Bedouin (n=19), new immigrants from the former USSR (n=22), and town-dwellers (n=82).

Results: The Bedouin patients differed significantly from the new immigrants and town-dwellers, particularly regarding the rate of EBV sequences in the tumor tissues, and a poorer response to treatment. The kibbutz patients did not differ significantly from the other populations regarding most of the parameters studied, but showed an intermediate expression of EBV antigens compared to Bedouin patients and the rest of the cohort.

Conclusions: This study indicates that HL may behave differently in different population groups in a given geographic area. Notably, the Bedouin patients showed markedly different clinical and biological patterns of this malignancy. 

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HL= Hodgkin's lymphoma

EBV= Epstein-Barr virus

Background: Chickenpox is a highly contagious childhood infection caused by varicella zoster virus, a virus of the herpes family. Although a mild and self-limiting disease in otherwise healthy children, chickenpox can be a complicated and even life-threatening disease in adults, pregnant women and immunosuppressed individuals. Among infants whose mothers had varicella during the first trimester of pregnancy, 2-3% will develop a congenital VZV syndrome that includes a combination of scarring, limb deformation, central nervous system impairment and ocular injury. In 1974, a live attenuated virus vaccine against VZV was developed in Japan and has been thoroughly tested for safety, efficacy and long-term effects. In March 1995 the vaccine was licensed in the U.S. for use in healthy children only.

Objectives: To determine the rate of immunity to VZV in young Israeli adults.

Methods: On the assumption that a randomly picked sample of 18-year-old army recruits in Israel is representative of the general Jewish population, 900 sera samples were taken for 3 years (1985,1988,1992). The sera were analyzed for IgG to VZV with a commercial ELISA kit using microwells coated with VZV antigens.

Results: A total of 98% of the samples tested positive for VZV antibodies. The difference in serologic values between the recruitment years was not statistically significant.

Conclusion: The majority of the Israeli population reaches adulthood already immunized against VZV, with immigrants having slightly lower immunity rates. Nonetheless, a few dozen cases of chickenpox are diagnosed in the IDF annually. These data should be taken into account when a vaccination program is devised. Should such a program be implemented, it would be interesting to repeat the serosurvey for comparison. A shift in the peak occurrence age might necessitate the administration of a booster vaccine at an older age.

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VZV= varicella zoster virus

IDF= Israel Defense Forces