HTLV-1 provirus load in peripheral blood lymphocytes of HTLV-1 carriers is diminished by green tea drinking.

Human T-cell lymphotropic virus type 1 (HTLV-1) is causatively associated with adult T-cell leukemia (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Since a high level of HTLV-1 provirus load in circulating lymphocytes is thought to be a risk for ATL and HAM/TSP, diminution of HTLV-1 provirus load in the circulation may prevent these intractable diseases. Our previous study (Jpn J Cancer Res 2000; 91: 34-40) demonstrated that green tea polyphenols inhibit in vitro growth of ATL cells, as well as HTLV-1-infected T-cells. The present study aimed to investigate the in vivo effect of green tea polyphenols on HTLV-1 provirus load in peripheral blood lymphocytes on HTLV-1 carriers. We recruited 83 asymptomatic HTLV-1 carriers to examine HTLV-1 provirus DNA with or without administration of capsulated green tea extract powder. Thirty-seven subjects were followed up for 5 months by measuring HTLV-1 provirus load after daily intake of 9 capsules of green tea extract powder per day (equivalent to 10 cups of regular green tea), and 46 subjects lived ad libitum without intake of any green tea capsule. The real-time PCR quantification of HTLV-1 DNA revealed a wide range of variation of HTLV-1 provirus load among asymptomatic HTLV-1 carriers (0.2-200.2 copies of HTLV-1 provirus load per 1000 peripheral blood lymphocytes). Daily intake of the capsulated green tea for 5 months significantly diminished the HTLV-1 provirus load as compared with the controls (P = 0.031). These results suggest that green tea drinking suppresses proliferation of HTLV-1-infected lymphocytes in vivo.

HLA-DRB1*1602 allele is positively associated with HPV cervical infection in Bolivian Andean women.

Incidence of cervical cancer is high among Bolivian Andean women. Human papillomavirus (HPV) infection is known as the major risk factor of cervical cancer. The host immune system plays an important role in the outcome of HPV infection and associated malignancies. In order to study the immunogenetic background of Bolivian Andean women with regard to HPV infection status, we compared HLA class I and class II allele frequencies between 37 HPV positive and 68 HPV negative Bolivian women. Demographic variables, including distribution of Andean ethnicities, were similar in both groups. Comparison of HLA class I allele frequencies between both groups indicated no significant difference. In contrast, HLA class II DRB1*1602 allele, an Amerindian allele, was significantly higher in the HPV positive women compared with HPV negative controls (chi(2) = 5.2, p < 0.05, odds ratio = 3.17; 95% confidence interval = 1.4-8.8). HPV types present in the HPV positive group were HPV-18, -16, -31, -33, and -58. These results suggest that HLA class II DRB1*1602 may confer susceptibility to infection with genetically related HPV types. This is the first report of an HLA class II association with HPV infection in an Andean population.

High Prevalence of HBV in Tibet, China.

Hepatitis B virus (HBV), distributed throughout the world, is classified into seven geographically separated genotypes designated A to G. Since the prevalence of HBV infection in isolated ethnic Tibetan populations in China, and the HBV genotypes involved have been hither to remained unclear, we collected 262 blood samples from four isolated villages in the east and west regions of Tibet. The prevalence of HBV infection was estimated by EIA for HBV Ag and HBV Ab. The HBV genotypes were determined by a PCR-microwell plate hybridization method using plasma DNA. The prevalence of HBV Ag and HBV Ab positives was 19.1% (50/262 cases) and 29.0% (76/262 cases), respectively. We detected only the C genotype (20/20 cases), this being known as a predominant type of HBV among Mongoloid populations in Asia. The results revealed, for the first time, that Tibetan villagers have a high rate of infection with HBV of C genotype, in line with the available data for chronic hepatitis and liver cancer.

Human Papillomavirus Infection among Bolivian Amazonian Women.

Cervical cancer is the most common malignancy among women in Latin America. Human papilloma virus infection is known to be an important risk factor. However, HPV infection among Bolivian women has not yet been fully evaluated. The present study aimed to investigate HPV infection among women living in a rural region of the Bolivian Amazon. Cervical swab samples were collected from 151 healthy women in three Amazonian villages. From every woman, two samples were collected by cotton swab; one for cytological examination and the other for ethanol-preservation of cervical epithelial cells for HPV DNA testing. High molecular DNA was extracted from the ethanol-preserved cervical epithelial cells and tested for HPV DNA by a PCR-RFLP protocol. Ethanol-preserved cervical epithelial cells remained suitable for DNA isolation and PCR amplification of human b-globin and HPV E6/E7 genes, 25 days after sample collection in the field. HPV-31, HPV-58 and HPV-6 were detected in the studied population. The overall prevalence of HPV infection among Bolivian Amazonian women was 8.0%. Neither dual nor multiple HPV infections were found in any of the positive samples. This is the first report of HPV prevalence and type distribution among Bolivian Amazonian women. Our new method for preservation of cervical epithelial cells in ethanol may be useful for viro-epidemiological studies in rural areas.

Human leukocyte antigen class II alleles associated with human T cell lymphotropic virus type I infection and adult T-vell leukemia/lymphoma in a black population

BACKGROUND: Human T-cell lymphotropic virus type I (HTLV-I) is linked to adult T-cell luekemia/lymphoma (ATL) and HTLV-I associated myelopathy (HAM; also known as tropical spastic paraparesis [TSP]), a chronic neurodegenerative disorder. Worldwide, several million HTLV-I carriers are at risk for disease, with an estimated lifetime cumulative risk of 1 percent-5 percent. However, the determinants of disease progression are relatively unknown. We studied human leukocyte antigens (HLA class II) that have been implicated in the pathogenesis of HTLV-I related diseases. METHODS: We analyzed HLA class II alleles among asymptomatic HTLV-I carriers (n = 45), patients with ATL (n = 49) or HAM/TSP (n = 54), and HTLV-I seronegative control subjects (n = 51). All participants were of African descent and were enrolled in epidemiologic studies conducted at the University of the West Indies, Kingston, Jamaica. We used standard microlymphocytotoxicity assays for HLA antigen serotyping and polymerase chain reaction-based methods to examine HLA class II DRB1 and DQB1 alleles. RESULTS: Two antigens determined by serotyping DR15 and DQ1, occurred at significantly increased frequency among HTLV-I carriers compared with seronegative control subjects (42 percent versus 22 percent for DR15 [odds ratio [OR] = 2.7; 95 percent confidence interval [CI] - 1.0-7.2] and 78 percent versus 53 percent for DQ1 [OR = 3.1; 95 percent CI= 1.2-8.5]). Asymptomatic carriers were shown to have and HLA class II allele distribution similar to that of patients with ATL, and the frequencies of the alleles DRB1*1501, DRB1*1101, and DQB1*0602 were significantly increased among patients with ATL compared with patients with HAM/TSP. CONCLUSIONS: These data suggest that host genetic background is an important factor in determining weather HTLV-I carriers develop either ATL or HAM/TSP.(AU)

HLA DRBI *DQB1* haplotype in HTLV-I-associated familial infective dermatitis may predict development of HTLV-I-associated myelopathy/tropical spastic paraparesis

A possible causal association between infective dematitis and HTLV-I infection was reported familial infective dematitis (ID) occurring in a 26-year-old mother and her 9-year-old son. The mother was first diagnosed with ID in 1969 at the age of 2 years in the Dermatology Unit at the University Hospital of the West indies (U.H.W.I.) in Jamaica. The elder of her 2 sons was diagnosed with ID at the age of 3 years, also at U.H.W.I. Both mother and son are HTLV-I-seropositive. A second, younger son, currently age 2 years, is also HTLV-I-seropositive, but without clinical evidence of ID. Major hitocompatibility complex (MHC), class II, human leucocyte antigen (HLA) genotyping documented a shared class II haplotype, DRB*DQBI* (1101-0301), in the mother and her 2 sons. This same haplotype has been described among Japanese patients with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP), and has been associated with a possible pathologically heightened immune repsonse to HTLV-I infection. The presence of this haplotype in these familial ID cases with clinical signs of HAM/TSP may have contributed to their risk for development of HAM/TSP. The unaffected, HTLV-I seropositive younger son requires close clinical follow-up. (AU)

Distribution of HLA and haplotypes of Colombian and Jamaican black populations

To investigate the genetic background of the black populations of Colombia and Jamaica, we determined HLA types of 78 Colombian and 98 Jamaican blacks from 2 different socioeconomic groups (Jamaican #1 and Jamaican #2) and estimated the frequencies of HLA genes and haplotypes. A phylogenetic tree based on the HLA gene frequencies revealed that Jamaican #1 and Jamaican #2 were distinct from each other, Jamaican #1 being closely related to Colombian blacks and the Jamaican #2 being closely related to Senegalese and Zairean populations. Three-locus haplotypes of Colombian and Jamaican #1 blacks were an admixture between Africans and Caucasians or South American Indians while Jamaican #2 blacks were relatively homogeneous and appeared to conserve African lineages. The major five-locus HLA haplotypes were not shared among Colombian, Jamaican #1 and Jamaican #2 blacks. These results indicated that the black populations of Colombia and Jamaica were originated from African blacks and admixed variably with Caucasians and South Americans Indians to make genetic subpopulations in Colombia and Jamaica. (AU)