Human T-cell lymphotropic virus type-I antibodies in Falashas and other ethnic groups in Israel

Seroprevalence and risk factors for human T cell lymphotropic virus type 1 and 2 infection in human immunodeficiency virus-infected patients attending AIDS referral center health units in Londrina and other communities in Paraná, Brazil

The municipality of Londrina ranks second in the number of AIDS cases in the state of Paraná, Brazil, with the Ministry of Health notified of 1070 cases from 1984 to 2002. The aim of this study was to determine the seroprevalence and risk factors for HTLV-1/2 infection in HIV-infected patients attending the AIDS Reference Center serving Londrina (and surrounding region), Paraná, Brazil. Data concerning sociodemographic conditions and risk factors were collected from 784 HIV-infected patients, using a questionnaire. Blood samples were obtained from 758 of the patients and subjected to serologic screening tests for the determination of HTLV-1/2, as well as hepatitis B virus (HBV), hepatitis C virus (HCV), and syphilis. Most patients were white (mean age, 35.9 years); 55.9% were males and 44.1% were females. The most frequent sexually transmitted disease was gonorrhea (28.5%), followed by syphilis (14.3%) and condyloma (12.2%). The major risk factors associated with the acquisition of retroviruses were sexual contact (84.8%) and intravenous drug use (IDU, 11.9%). The overall infection seroprevalence was 6.4% for HTLV-1/2, 37.2% for HBV, 21.0% for HCV, and 24.4% for syphilis. HTLV-1 and HTLV-2 infections were confirmed in 0.8 and 4.9% of patients, respectively. HIV/HTLV-1/2 coinfection was more frequent in IDUs (59.2% of cases) and was strongly associated with HCV (22.60 [95% CI, 10.35-49.35]). A weak association with HBV (2.09 [95% CI, 1.13-3.90]) and no association with syphilis were observed. The results showed that human retroviruses are circulating in southern Brazil, mainly among white people of both genders of low socioeconomic conditions and educational level. Although the sexual route was considered to be the major risk factor for HIV infection, HTLV-1/2 infection was strongly associated with IDU.

Lymphomatous presentation of CD4+/CD8+ HTLV-1-related adult T-cell leukemia/lymphoma in an Iranian woman

Adult T-cell leukemia/lymphoma (ATLL) remains an uncommon disorder outside well-defined risk groups. We describe the case of an Iranian woman, who presented with isolated meningeal relapse of diffuse large-cell lymphoma. The malignant cells coexpressed CD4 and CD8 and HTLV-1 seropositivity was confirmed. Despite combination chemotherapy disseminated lymphoma developed. Preterminally the characteristic features of ATLL were noted; hypercalcemia, with normal parathyroid hormone-related protein and vitamin D levels, and peripheral blood leukemic involvement.

Prevalence of HTLV-I antibody among two distinct ethnic groups inhabiting the Amazon region of Brazil

HTLV-I seroprevalences of 3.63% (02/55), 12.19% (10/82) and 13.88% (10/72) were demonstrated among Tiryio, Mekranoiti and Xicrin Amazonian Indians, respectively, by the Western blotting enzyme assay (WBEI). By indirect immunoelectron microscopy (IIEM), 2 Tiriyo, 9 Mekranoiti and 6 Xicrin Amerindians were reactive. Of 44 serum samples from Japanese immigrants, none reacted by any of the techniques before mentioned. One, 8 and 6 serum samples from Tiryio, Mekranoiti and Xicrin Indians, respectively, were both WBEI and IIEM positive. Our results strongly suggest that HTLV-I and/or an HTLV-I antigenic variant circulate (s) among populations living in the Amazon region of Brazil.

Low HTLV-1 seroprevalence in endemic tropical spastic paraparesis in Ethiopia

Tropical spastic paraparesis (TSP), a chronic progressive myelopathy, occurs in Ethiopia in epidemic form as neurolathyrism, while the endemic form has remained obscure. We describe the clinical features of 22 patients with TSP and the results of screening for HTLV-1 in these patients, 26 patients with other neurological disorders, 14 patients with leukaemia and 66 blood donors. The major manifestations in the patients with TSP were weakness and spasticity of the lower limbs with upper motor neurone signs and minimal sensory loss and bladder dysfunction. Two patients with TSP (9%), 2 patients with other neurological disorders (7.7%) and one patient with leukaemia and deafness were seropositive for HTLV-1. All the 66 blood donors were seronegative. Our results suggest that HTLV-1 may not play a major role in the pathogenesis of TSP in Ethiopia.

Serological and molecular survey for HTLV-I infection in a high-risk Middle Eastern group

To define the extent of human T-cell leukaemia virus (HTLV-I) infection among a group of Jewish immigrants to Israel with an increased frequency of adult T-cell leukaemia, various serological and molecular screening methods, including enzyme-linked immunosorbent assay (ELISA) for anti-HTLV-I, ELISA for antibody to recombinant HTLV-I p40tax protein, and molecular detection of infection by polymerase chain reaction (PCR) amplification of HTLV-I proviral DNA from peripheral blood mononuclear cell DNA, were used. By HTLV-I ELISA the overall rate of infection was 12% (24 of 208) among immigrants from Khurusan, northeastern Iran; no HTLV-I carriers were detected among 111 unselected Jewish immigrants from other parts of Iran. There was unexplained clustering of HTLV-I infection within a cohort of 32 elderly women of similar geographic origin in a home for old people--14 were seropositive by ELISA and 19 of 29 were positive by PCR. The findings in this newly identified high-risk population suggest that in addition to ELISA, other screening techniques may be required to detect all carriers in high-risk populations.

Adult T-cell lymphoma in Israeli patients of Iranian origin

The clinical and laboratory features of four Israeli patients with adult T-cell lymphoma-leukemia (ATL) are presented. In three of them evidence for human T-cell lymphotropic leukemia virus (HTLV-I) infection was obtained. Interestingly, all of the patients immigrated to Israel from the same regions in Iran. Except for lack of skin involvement, the clinical course was typical for ATL as described worldwide. This is the first report of ATL in an Iranian cohort. This observation suggests that Iranian patients with ATL-like illness should be studied for the presence of HTLV-I infection.

Sporadic carriers of human T-lymphotropic virus type I in northern Egypt

Sera from 3,158 individuals living in northern Egypt were tested for the presence of antibodies against human T-lymphotropic virus type I (HTLV-I) by the newly developed particle agglutination (PA) test. Ten sera gave a positive reaction in the PA test. Eight of these sera were examined further by Western blotting and all of them gave several bands corresponding to HTLV-I structural proteins. Two of the 8 sera gave positive results in the indirect immunofluorescence test. The results indicate the presence of HTLV-I carriers in this area, although at very low incidence (0.063%).

Incidence of retroviruses in some Brazilian groups

The prevalence of human T lymphotropic virus type I (HTLV-I) and human immunodeficiency virus (HIV) antibodies was evaluated in Brazil among 116 aboriginal Indians living in a pre-Amazonian region, and in 44 patients with haematological malignant disorders being treated in Rio de Janeiro. Screening for the presence of antibodies to HIV was performed routinely for 17,224 blood donors at the National Cancer Institute, Rio de Janeiro, from January 1986 to May 1987. The results demonstrated that HIV infection was not endemic among Brazilian Indians, as none of them had antibodies to HIV, in contrast with the population of Rio de Janeiro, which showed a high prevalence (0.34%) of positivity among normal individuals. In a small group of patients with haematological disease only one with acute lymphoblastic leukaemia proved to be HIV-positive, the infection having been acquired through previous blood transfusion. None of the serum samples reacted with HTLV-I, including those of 17 non-Hodgkin's lymphoma patients. HTLV-I infection does not seem to be endemic in this country, but further large scale studies are necessary, especially in patients with haematological disorders, homosexual individuals and drug users.

Possible aetiological factors in leukaemias in Africa

The hypothesis that the true incidence of c-ALL is relatively uniform throughout the world is not supported by experience in tropical Africa, where ALL is uncommon under five years of age. A high rate of spontaneous somatic mutation in pre-B cells may initiate the development of c-ALL, but its progress could be determined by (i) a leukaemogenic agent causing a second genetic event, (ii) the effects of intense antigenic barrage, either stimulating or suppressing pre-B-cell mitosis, or (iii) genetic determinants. Epidemiological patterns in populations of low, intermediate and high socio-economic status may be classified I-III with increasing incidence of diagnosed T-ALL in children over five years and c-ALL in younger children, and subclassified A and B with decreasing incidence of BL. There may be two forms of AML, one similar to that seen in industrialized countries, the other occurring at high prevalence in African children of low socio-economic status, often presenting with chloroma, and perhaps associated with immune suppression secondary to malnutrition, malaria and other intercurrent infections. Uncontrolled exposure to petroleum and other chemicals, and the use of alkylating agents in treatment of neoplasms in young patients could emerge as important causes of ANLL in Africa. There are two varieties of CLL also, one similar to that seen in the western world, the other prevalent in adults below 45 years of age, especially women: transmission of a leukaemogenic agent is postulated, to which women are more susceptible due to immunosuppression during normal pregnancy. The human population and some subhuman primates of subSaharan Africa are the largest reservoir of HTLV-1, which shows association with B-CLL over 50 years of age and ATL.

Immune impairments and antibodies to HTLVIII/LAV in asymptomatic male homosexuals in Israel: relevance to the risk of acquired immune deficiency syndrome (AIDS)

We have studied 288 Israeli asymptomatic male homosexuals (MHS) to determine the prevalence of antibodies to HTLVI and HTLVIII and their correlation with impairments of the immune system and serum interferon (IFN). Seropositivity for HTLVI, HTLVIII, or both was found in 1.4, 8.3, and 0%, respectively. Significant decreases in the total peripheral T cells, TH cells, and TH/TS ratio as well as elevated alpha IFN serum levels were found in the MHS group in comparison with normal controls. Although no difference in the prevalence of either immune derangements or elevated serum IFN was observed between HTLVIII/LAV-seropositive and HTLVIII/LAV-seronegative MHS, the decreases in total T cells, TH cells, and TH/TS ratios were significantly greater in the seropositive MHS. These results indicate that (a) immune impairments and IFN system activation occur commonly in homosexuals, precede their exposure to HTLVIII/LAV, and probably reflect this group's increased risk for AIDS and (b) HTLVIII/LAV infection of MHS aggravates further their preexisting immune impairments.

Immunoreconstitution of T-cell impairments in asymptomatic male homosexuals by thymic humoral factor (THF)

The feasibility of using Thymic Humoral Factor (THF) for immunomodulation in asymptomatic male homosexuals was evaluated in a study on fifteen subjects with T-cell impairments, selected on the basis of a 2SD reduction in T helper/inducer (T4+) cells and one additional lymphocytic defect. Following two biweekly courses of treatment, mean relative increments of T4+ (P less than 0.002), T3+ (P less than 0.02) and total lymphocyte (P less than 0.05) populations of the group receiving THF (n = 7) were significantly increased when compared to the placebo group (n = 8). In addition, a transient increase in T4+ lymphocytes was observed after the first course in the two individuals of the THF-treated group who were seropositive for HTLV-III/LAV but not in those who were seronegative. No difference was found between the groups in fluctuations of serum interferon (IFN) or proliferation of peripheral mononuclear cells to mitogens. The results of this limited trial demonstrate that THF is capable of correcting T-cell impairments that may predispose asymptomatic homosexuals to infection by HTLV-III, without affecting IFN production. These findings suggest that future strategies for AIDS prevention in high-risk groups should include institution of large controlled trials in immunodeficient, asymptomatic, HTLV-III/LAV-seronegative male homosexuals to study the potential of selective immunoreconstitution as a preventive measure against HTLV-III/LAV infection.

Spontaneous remission of Kaposi's sarcoma in an HTLV-III-negative homosexual man

Kaposi's sarcoma (KS) in homosexual men has been linked to the acquired immune deficiency syndrome (AIDS). We describe a 51-year-old homosexual man who developed extremity KS while taking corticosteroids. The KS resolved when the steroids were withdrawn. He did not have classically defined AIDS: no evidence of HTLV-III infection was found after serial ELISA and "western blot" analysis of the patient's serum nor after co-cultivation of his peripheral blood lymphocytes. This clinical observation is consistent with the hypothesis that AIDS and KS may have different etiologic agents. Corticosteroids should be used with caution in patients at risk for KS (including homosexual men) and may be complicated by the development of KS without HTLV-III-induced immunosuppression.

Human T-lymphotropic retroviruses

The first human retroviruses have been discovered during the past six years. They cause two diseases which involve disturbances of the growth of the T4 lymphocyte, a remarkably specific target cell type. This cell, which is central to the regulation of the immune system, is induced by human T-lymphotropic virus type I (HTLV-I) to excessive proliferation (leukaemia) and by HTLV-III to premature death (acquired immune deficiency syndrome, AIDS). Both also seem to be indirectly involved in several other disorders. The genetic structures of these retroviruses and the mechanisms by which they usurp host-cell functions are novel among retroviruses.