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We evaluated the fourth-generation HIV screening assay VIDAS HIV DUOII (DUOII) based on ELFA for simultaneous detection of anti-HIV-1 and anti-HIV-2 antibodies and HIV-1 p24 antigen through comparison with other HIV antigen-antibody detection assays. Materials were 1228 HIV-negative specimens, 95 HIV-antibody-positive specimens, and HIV commercial panels. The specificity of DUOII was 99.8% and sensitivity 100%, detecting all of HIV-1 group M subtype A, B, B', C, D, A/E, F, G, B/D, HIV-1 group O, and HIV-2. The sensitivity test to HIV-1 p24 antigen was 5pg/ mL, higher than other assays. DUOII was equivalent to or superior in detecting results earlier than other assays in an evaluation using 10 commercial HIV-1 seroconversion panels of primary infection. DUOII detects anti-HIV IgM antibody, so no negative sample was found in the second window between p24 antigen disappearance and raised anti-HIV IgG antibody. DUOII has sufficient specificity and sensitivity for HIV screening, and detects primary infection sooner than other assays. These results indicate that DUOII is useful and reliable in HIV screening.

Human T-cell lymphotropic virus type I (HTLV-I) is associated with certain hematologic and neurologic disorders. Seroprevalence studies demonstrated that the distribution of HTLV-I is heterogeneous worldwide and not specific to 1 region. Because blood is one of the major routes of transmission of the virus, blood banks of several countries routinely screen all blood donations for HTLV-I. The aim of the present study was to assess the seroprevalence rate of HTLV-I/II antibodies among Lebanese blood donors. Between August 2001 and March 2002, consecutive blood samples of 3529 blood donors were collected at blood banks of 4 major hospitals in Lebanon. Initial enzyme-linked immunosorbent assay (ELISA) screening resulted in 23 (0.7%) positive samples, of which 12 (0.3%) were reconfirmed positive by ELISA. Further analysis by Western blot resulted in 2 (0.06%) positive samples, of which 1 tested positive for HTLV-I by PCR (0.028%). Although its very low prevalence among Lebanese blood donors does not support routine screening of Lebanese blood donors for HTLV-I, screening of blood donors from other nationalities may be exercised, especially those from HTLV-I endemic areas.

The relationship between acute myeloid leukemia (AML), acute lymphocytic leukemia, chronic myeloid leukemia (CML), and refractory anemia with excess of blasts (RAEB) and antibodies to human T-cell lymphotropic virus types I and II (HTLV-I and HTLV-II), and hepatitis B virus and hepatitis C virus (HCV) was investigated in a multicenter case-control study. There were 431 cases enrolled in the study at the time of diagnosis of hematological malignancies, and 862 controls ages 15 years or older were recruited in three hospitals. Antibodies to HTLV-I and HTLV-II, antibody to HCV, hepatitis B surface antigen, and antibody to hepatitis B core antigen were assayed. All cases and controls were negative for HTLV-1 antibodies; one case (1 of 431; 0.2%), and one control (1 of 862; 0.1%) were found positive for HTLV-II antibodies. A nonsignificant excess of risk for hepatitis B surface antigen was present among RAEB cases (odds ratio, 2.40; 95% confidence interval, 0.46--12) CML, (odds ratio, 2.70; 95% CI, 0.86--8.43), and between antibody of hepatitis B core antigen and AML (odds ratio, 1.40; 95% CI, 0.93-2.10). A weak, nonsignificant association was present between AML, acute lymphocytic leukemia, RAEB, and antibody to HCV. These preliminary results suggest a possible association (elevated odds ratios) between hepatitis B virus, AML, RAEB, and CML. However, because all confidence intervals overlapped the null value, these findings need to be confirmed in larger case-control studies.

The prevalence of HIV infection was assessed among 15,611 consecutive patients attending a Parisian anonymous testing center from April 1988 to June 1993. Sera (17,910) were tested for the presence of anti-HIV antibodies using two different enzyme-linked immunosorbent assays. Seropositivity was verified by Western blotting. The sera were also assayed for HIV antigenemia detection in 2,493 cases. Six hundred and seventy-seven patients were found to be anti-HIV antibody positive: among them 666 were infected by HIV-1 and only 11 by HIV-2. Antigenemia was detected in 108 samples (4.3%). In all cases but 5, antigenemia was associated with the presence of specific antibodies. Risk factors for HIV infection could be determined for 5,735 patients. The HIV prevalence rates were 5.2% in 1988-89, 4.9% in 1990, 3.4% in 1991, 2.8% in 1992 and 1.8% for the 6 first months of 1993 (p < 0.01). Only one patient was coinfected with HTLV-1. This study shows a trend of decreasing seropositivity rates among the patients attending the anonymous testing center since 1990. By contrast, the percentage of seropositive patients with antigenemia was stable between 1988 and 1993.

Objectives: To determine the prevalence of antibodies to the human T cell leukaemia/lymphoma viruses (HTLV-I and HTLV-II) in blood donors in north London in order to assess the economic impact and the logistic effects that routine screening would have on the blood supply., Design: All donations collected by the north London blood transfusion centre between January 1991 and June 1991 were screened for antibodies to HTLV-I and HTLV-II by modified, improved Fujirebio gel particle agglutination test. Positive samples were titrated and retested as necessary., Subjects: 96,720 unpaid volunteers, who gave 105,730 consecutive donations of blood and plasma., Setting: North London blood transfusion centre., Main Outcome Measure: Observed numbers of donors confirmed to be seropositive for HTLV by reference laboratories., Results: Of 2622 (2.5%) initially reactive samples, 414 (0.4% of all samples) gave a titre of > or = 1 in 16 on the modified agglutination test. Thirty five of the 414 serum samples yielded positive results on one of two enzyme linked immunosorbent assays (ELISA (Cambridge Biotech and Abbot)), and none of these results were confirmed by either reference laboratory. Five samples yielded positive results on both ELISAs and all five of these were confirmed to contain antibodies to HTLV. One of the five contained antibodies to HTLV-II and the others antibodies to HTLV-I. Four seropositive donors were white women whose only risk factor for infection was sexual contact. The fifth (positive for antibodies to HTLV-II) was an Anglo-Caribbean man who admitted to previous misuse of intravenous drugs., Conclusion: The prevalence of antibodies to HTLV in blood donors in north London was one in 19,344 (0.005%). Up to 100 donors a year might be identified in the United Kingdom as being infected with HTLV, although prevalence in different regions may vary considerably.

Two recombinant fusion proteins representing the C-terminus of the envelope glycoprotein of HTLV-I (rEnv-93(201-440)) and the C-terminus of the external glycoprotein (RE-3(165-306)) were tested in a Western blot (WB) assay for their ability to detect the presence of env antibodies in serum specimens from HTLV-I (n = 27) and HTLV-II (n = 22) infected individuals. The rEnv-93 reacted with 27 (100%) of 27 HTLV-I-infected specimens and 19 (86%) of 22 of HTLV-II-infected specimens. In contrast, RE-3 reacted with 25 (93%) of 27 HTLV-I-infected specimens, and only six (27%) of 22 HTLV-II-infected specimens, thus demonstrating predominant reactivity with HTLV-I compared with HTLV-II. Because of the high sensitivity of rEnv-93 reactivity in both HTLV-I and HTLV-II, the specificity of this env protein was evaluated in specimens with isolated gag reactivity (HTLVind). Of the 44 HTLVind specimens, four (9%) demonstrated reactivity to rEnv-93 in WB assay. We, therefore, conclude that although rEnv-93 is highly sensitive for detection of env protein, it has the potential to yield some false-positive reactions presumably due to the conserved nature of retroviral transmembrane epitopes.

DNA sequences distantly related to the proviral DNA of HTLV-I were found in the leukemic cells of a Hungarian patient suffering from Sézary syndrome. Serum samples from the patient contained antibodies reactive with the internal core polypeptides of HTLV-I and HTLV-II, but not with the env gene encoded type-specific HTLV antigens. The husband and daughter of the patient also had antibodies of the same specificity. These findings suggest the presence of a virus distantly related to HTLV-I and HTLV-II.

Of the 267,650 blood donations from members of the US armed forces, 72 (0.027%) were serologically confirmed to be positive for human T-lymphotropic virus type I/II (HTLVpos) and 379 (0.14%) were Western blot (WB)-indeterminate with banding pattern restricted to the proteins encoded by the gag gene only (HTLVind). To determine whether these apparently healthy HTLVind blood donors are infected with HTLV-I or HTLV-II, coded specimens from randomly selected military blood donors (n = 73) were tested for antibodies to HTLV by WB and radioimmunoprecipitation assay (RIPA) using HTLV-I (MT-2) antigens, by enzyme immunoassay using synthetic peptides representing the immunodominant epitopes of HTLV, and for sequences of proviral HTLV DNA by the polymerase chain reaction (PCR). Of the 73 HTLVind donors, none showed presence of env reactivity by HTLV WB and RIPA. Minimal reactivity was observed with synthetic immunodominant motifs derived from the env protein of HTLV-I (Env-1(191-214) and Env-5(242-257)) or HTLV-II (Env-2(187-209) and Env-20(85-102)) and gag protein (Gag-1a(102-117) and Gag-10(364-385)). A peptide corresponding to the endogenous retroviral sequence with structural homologies to the gag protein of HTLVs (RTVLgag) reacted with antibodies not only in HTLVpos (88%) and HTLVind (42% to 66%) specimens, but also reacted with normal control subjects (60%). Furthermore, none of the 73 HTLVind specimens demonstrated presence of the HTLV genome when amplified with primers for the pol and tax/rex region. Six to 23 months from the initial test, 27 subjects still gave indeterminate WB patterns, and 13 of these repeat specimens were still negative for the presence of HTLV genome. We conclude that individuals at low risk for HTLV infection who have HTLVind WB reactivity are rarely, if ever, infected with HTLV-I or HTLV-II.

Unlabelled: Background. The human T-cell lymphotropic virus Type I (HTLV-I) is associated with adult T-cell leukemia and myelopathy, whereas HTLV-II infection has uncertain clinical consequences. We assessed the seroprevalence of these retroviruses among intravenous drug users and among patients seen at clinics for sexually transmitted diseases (STD clinics)., Methods: We used serum samples that were collected in eight cities in 1988 and 1989 during surveys of human immunodeficiency virus infection among intravenous drug users entering treatment and persons seen in STD clinics. The serum samples were tested for antibodies to HTLV, and positive specimens were tested further by a synthetic peptide-based enzyme-linked immunosorbent assay to differentiate between HTLV-I and HTLV-II., Results: Among 3217 intravenous drug users in 29-drug-treatment centers, the median seroprevalence rates of HTLV varied widely according to city (range, 0.4 percent in Atlanta to 17.6 percent in Los Angeles). Seroprevalence increased sharply with age, to 32 percent in persons over 44 years of age. HTLV infection was more common among blacks (15.5 percent) and Hispanics (10.7 percent) than among whites (4.1 percent), and it was strongly associated with a history of heroin injection (P less than or equal to 0.001). Among 5264 patients in 24 STD clinics, the median rates of HTLV infection were much lower (range, 0.1 percent in Atlanta and Newark to 2.0 percent in Los Angeles). Again, this infection was more common among intravenous drug users (7.6 percent) than among non-drug users (0.7 percent). Eighty-four percent of the seropositive samples from drug-treatment centers and 69 percent of those from STD clinics were due to HTLV-II infection (P = 0.03)., Conclusions: HTLV infections are common among intravenous drug users and are primarily caused by HTLV-II. Among patients seen at STD clinics, HTLV is strongly associated with intravenous drug use, but the retrovirus is also prevalent among non-drug users.

In order to discriminate HTLV-II from HTLV-I, HTLV-II-specific polyclonal antibodies against a synthetic peptide of HTLV-II envelope sequence were raised in rabbits. We immunized two adult rabbits with a KLH-conjugated synthetic peptide corresponding to the amino acid sequence 171-196 of the HTLV-II envelope sequence, which is a specific region for HTLV-II as evaluated with an ELISA method. The resulting rabbit antisera to the synthetic peptide reacted with gp46 of HTLV-II lysates in Western blot analysis but not with that of HTLV-I. Flow cytometric analysis and immunohistochemical study revealed that these affinity purified antisera recognized some HTLV-II-producing cell lines examined, but not HTLV-I-producing cell lines or other cell lines uninfected by HTLV. These findings indicate that these antisera specifically recognized the envelope glycoprotein (gp46) of HTLV-II and suggest the specificity of this region in the immune response to HTLV-II. Such antisera are useful in distinguishing between HTLV-I and HTLV-II infection and in determining the presence of individual HTLV-II-infected cells both in vivo and in vitro, including non-lymphoid cells. They may also assist in the elucidation of the pathogenesis of HTLV-II.

Using the peptides from amino acids 100-130 of the HTLV-I gag protein, 175-199 of the HTLV-I env protein and the corresponding peptides of HTLV-II (amino acids 106 to 135 of the gag protein and 171 to 196 of the env protein), we tested for reactivity against antibodies by enzyme immunoassay in sera from HTLV-I and HTLV-II carriers. The peptides derived from the env proteins have high specificity for antibody binding. The peptide based on amino acids 175-199 of HTLV-I reacted with antibodies in sera from all HTLV-I carriers, and the peptide composed of amino acids 171-196 of HTLV-II reacted with antibodies in sera from all HTLV-II carriers. For the peptides derived from the gag proteins, we observed some cross-reactivity in sera from persons with anti-HTLV-I and anti-HTLV-II, due to antibody binding to the peptide corresponding to 12 amino acids from the C-terminal end of the gag protein. Separate enzyme immunoassays that used the four synthetic peptides as antigens clearly distinguished between serum with antibodies to HTLV-I or HTLV-II in various individuals and excluded false positive results using the particle agglutination assay that used a whole-virus lysate of HTLV-I as antigen.

The human T-cell lymphotropic viruses (HTLV) type I and type II are capable of inducing a variety of cellular genes, including many of the cytokines that regulate cell proliferation. To determine if the spontaneous proliferation of peripheral blood mononuclear cells from patients infected with HTLV-I and HTLV-II was related to coordinate expression of cytokines, we analyzed the levels of interleukin-1 beta (IL-1 beta), IL-2, IL-3, IL-4, IL-6, tumor necrosis factor-alpha (TNF-alpha) and interferon-tau (IFN-tau) in culture supernatants derived from spontaneously proliferating cells. Significantly elevated levels of IL-6 and TNF-alpha were present in culture supernatants from HTLV-I/II-infected individuals when compared with normal controls (P less than .01). Kinetic experiments showed that both IL-6 and TNF-alpha were elevated by day 5. None of the other cytokines (IL-1 beta, IL-2, IL-3, IL-4, and IFN-tau) were detectable in any of the culture. These data suggest that release of IL-6 and TNF-alpha may regulate lymphocyte proliferation in HTLV-I/II-infected individuals.

To define further the magnitude, epidemiology, and clinical features of human T-cell lymphotropic/leukemia virus type I/II (HTLV-I/II) infection in 454 intravenous drug users in New York City, we evaluated previously frozen aliquots of sera for HTLV-I/II antibodies using enzyme-linked immunoassay, Western blot, and radioimmunoprecipitation techniques. We found HTLV-I/II infection in 18.9% of the subjects. Age (p = 0.001), race (p = 0.001), having a same gender sexual relationship (p = 0.01), and HIV-1 infection (p = 0.041) were clear correlates of HTLV-I/II infection. HTLV-I/II seropositive subjects, in contrast to seronegative subjects, had lower leukocyte counts (p = 0.05) and higher globulin (p = 0.005) and gamma globulin (p = 0.009) levels even when HIV-1 serostatus was controlled. The considerable prevalence of HTLV-I/II infection and the morbidity of HTLV-I/II-associated disorders strongly suggest a continued need to define the dimensions of HTLV-I/II infection.

To evaluate the sensitivity and specificity of HTLV-I/II assays, serum from 1100 pregnant Haitian women was tested with seven commercially available HTLV I/II assays. Serum that was found to be reactive in any assay was analysed by western blot and all indeterminate samples were further characterised by radioimmunoprecipitation assays (RIPA). 59 (5.4%) samples were HTLV I/II antibody positive by western blot and/or RIPA. The sensitivity of these seven assays ranged from 93.2% to 100%. with the 'Recombinant HTLV-I' (Cambridge Bioscience) and 'Serodia HTLV-I' (Fujirebio) assays having the highest sensitivity (100%). The specificity of these assays ranged from 98.4% to 100%, with the Abbott assay having the highest specificity (99.5%, 100%) according to two different methods of evaluation. Whether the antigens used in any assay were whole disrupted virus or recombinant gene products made no difference. The low positive predictive values of some of these assays (71.8-91.7%), even in a high prevalence population, and the need for RIPA to test indeterminate sera, indicate that for routine screening of blood donors there is still room for improvement both in screening and confirmatory assays for HTLV-I/II.

Between march and april 1989, the prevalence of HTLV-I/II antibodies was studied in a non selected population of 45,033 blood donors of Continental France. Serum samples were collected and screened by 12 Blood Banks located in different parts of the country. Screening was performed by 4 ELISAs (Abbott-Du Pont de Nemours-Organon-Pharmacia) and by gelatin particle agglutination (Fujirebio); the sensitivity of these tests was previously evaluated with an HTLV-I/II panel of the French National Society of Transfusion. The reproducibly reactive sera were confirmed by Western-Blot (Du Pont) and radioimmunoprecipitation assay. Five donors were confirmed positive: the global prevalence is 0.011%. This prevalence is one of the highest in Europe. Three of the five positive donors (0.007%) are white subjects. The other two are natives from the French West Indies (0.81%). Since may 1989 the Ministry of Health recommends for Continental France to test donors originating from endemic zones or to use their plasma for fractionation. The results obtained in this study show that the efficacy of these measures are incomplete since 0.007% donors (1 out of 15,000 blood donations) are not tracked down.

Infection with human T lymphotropic virus type I (HTLV-I) is associated with specific forms of tumours and neurological disorders, but the pathogenic activity of HTLV-II is not yet established. Moreover, due to high crossreactivity between the two viruses, differential diagnosis is not readily achieved. To discriminate between HTLV-I and HTLV-II infections, we employed synthetic peptides specific for HTLV-I and HTLV-II env regions, and the polymerase chain reaction (PCR). In a series of 962 intravenous drug addicts (IVDAs) and 50 patients with haematological malignancies, 51 and 2 samples, respectively, were reactive against HTLV-I proteins; among these, HTLV-I infection was confirmed only in 1 patient with adult T-cell lymphoma, while HTLV-II infections were identified in 6 out of 14 PCR-tested IVDAs. These findings provide evidence of HTLV-II infection among Italian IVDAs. The differentiation between HTLV-I and HTLV-II infections may contribute to a better understanding of HTLV-II pathogenicity in man.

Synthetic peptides corresponding with unique regions of the envelope glycoproteins (gp46) of human T cell lymphotropic viruses (HTLVs) were used in an enzyme immunoassay to determine if HTLV-I and -II infections could be discriminated. Two synthetic HTLV-I sequence-derived peptides, Env-1 (amino acids 191-215) and Env-5 (amino acids 242-257), reacted with 92% and 100% of the serum specimens (n = 52) from HTLV-I-infected persons, respectively. Although a small percentage (8.6%) of serum specimens from persons infected with HTLV-II cross-reacted with Env-1, none of these specimens reacted with Env-5. Peptide Env-2 encoded by the envelope region of HTLV-II (amino acids 187-210) reacted with serum specimens from both HTLV-I (94%)- and HTLV-II (74%)-infected patients, whereas Env-6, another HTLV-II peptide (amino acids 238-254), reacted with less than 6% of the specimens. Therefore, the Env-5 peptide with amino acid sequence SerProAsnValSerValProSerSerSerSerThrProLeuLeuTyr represents an immunodominant domain of HTLV-I that is recognized by serum antibodies from all HTLV-I-infected persons. Moreover, the Env-5-based ELISA allows a categorical distinction between the closely related HTLV-I and -II infections.

Objective: To determine the seroprevalence and epidemiologic features of human T-lymphotropic virus (HTLV I-II) among an emergency department patient population with a high rate of human immunodeficiency virus (HIV-1) infection., Design: Prospective survey using identity-unlinked consecutive sampling during a 6-week period in 1988., Setting: Inner-city teaching hospital., Patients: Sequential sample of 2544 adult patients with sufficient excess sera for analysis., Measurements and Main Results: Twenty-eight (1.1%) (95% CI, 0.7% to 1.5%) serum samples were seropositive for HTLV I-II whereas 152 (6.0%) (CI, 5.1% to 6.9%) were seropositive for HIV-1. The age distribution of HTLV I-II was similar to the study population while HIV-1 was concentrated among younger (25 to 44 years) age groups (P less than 0.05). Only 16 (57.1%) HTLV I-II infected patients had identified risk factors; 11 were intravenous drug users, 4 received transfusions, and 1 had heterosexual exposure to a high-risk partner. None of 39 identified homosexual men had HTLV I-II antibodies although 29 (74.3%) were HIV-1 seropositive., Conclusion: HTLV I-II infection may be more prevalent among certain segments of the U.S. population than previously realized and appears to have a different demographic distribution than HIV-1 infection. Although HTLV I-II may represent a nosocomial risk to health care providers, the risk of occupational transmission is probably less than for hepatitis B virus and even HIV-1. Adherence to universal precautions should minimize the risk.

Serum specimens from patients attending sexually transmitted disease (STD) clinics in Denver and several southeastern US cities were tested for antibody to human T-lymphotropic virus type I or II (HTLV-I/II). In Denver, 8 (2.1%) of 384 patients with a history of intravenous (IV) drug use, versus none of 201 non-IV-drug users, were HTLV-I/II seropositive. Only 2 (0.18%) of 1095 STD clinic patients from the southeastern USA had antibodies to HTLV-I/II. These data document a low prevalence of HTLV-I/II in STD clinic patients from the southeastern USA and confirm that IV drug use is an important risk factor for HTLV-I/II in the USA.

In a prospective study of street-recruited intravenous drug users (IVDUs) in Miami, Florida, USA, 107 (46.5%) of 230 IVDUs were infected with HIV-1. Of these HIV-1 seropositive individuals, 23 were also infected with human T-lymphotropic virus type I or II (HTLV-I/II). To test the hypothesis that HTLV-I/II infection has an effect on the survival of HIV-1 seropositive IVDUs, various baseline clinical and laboratory HIV-1 related indices in HTLV-I/II positive and negative groups were compared. Life table analysis and Cox's proportional hazards model were used to estimate the potential effect of HTLV-I/II infection on the survival patterns of people infected with HIV-1. IVDUs infected with both viruses were three times more likely to die from AIDS during follow-up than were those infected with HIV-1 only. This finding suggests that HTLV-I/II seropositivity may adversely affect the clinical outcome of HIV-1 seropositive patients.

We have characterized the immunoreactivity to human T-cell lymphotropic virus type I (HTLV-I) among 26,983 persons of various seroprevalence groups by using enzyme immunoassay, immunoblot (IB), and radioimmunoprecipitation assays (RIPA) in accordance with Public Health Service recommended guidelines for the interpretation of serologic test results for HTLV-I infection. IB-indeterminate serum specimens (n = 178) were reactive to HTLV-I gag proteins, and no serum contained only env reactivity. Overall, RIPA resolved 40% of IB-indeterminate serum samples; however, the probability that RIPA would confirm IB-indeterminate samples depended on the seroprevalence of the population tested. HTLV-I gag p19-only reactivity on IB was not a reliable marker of HTLV-I infection, while gag p24 reactivity on IB was clearly associated with positive seroreactive specimens. IB and RIPA tests did not clearly distinguish between HTLV-I and HTLV-II seroreactivities. These data emphasize that patterns of immunoreactivity to HTLV-I antigens are dependent upon the seroprevalence of the risk groups tested. In addition, RIPA detected antibodies to env proteins present in low titer in a substantial number of IB gag-only reactive sera and resolved the HTLV-I antibody status of these sera.

Serum specimens that had been obtained for routine operational procedures from consecutive entering male inmates during Spring 1987 and the same calendar period in 1988 were tested to identify prevalence and risk groups for antibody to HTLV-I/II. Specimens were assayed for antibody to HTLV-I/II using ELISA, RIPA, and Western blot techniques. Demographics were compared by serostatus using chi 2 and Fisher's exact tests. Of the 1,932 inmates entering prison, 49.3% were 25 years of age or older, 70.1% were black, 62.4% were committed from the Baltimore metropolitan area, 34.1% were intravenous drug users, and 7.0% demonstrated antibody to HIV-1. Among 1,932 inmates, 18 (0.9%) were HTLV-I/II seropositive. All seropositives were black; age greater than 25 years old was significantly (p less than 0.01) associated with seropositivity. Reactivity to HTLV-I/II did not vary significantly by year of entry, HIV-1 serostatus, jurisdiction, offense category, or sentence. Prevalence of HTLV-I/II among incoming male inmates was elevated compared to available local population comparisons. Additional blinded epidemiological serosurveys of antibody to HTLV-I/II are indicated for prison populations in order to monitor the extent and scope of infection in this population.

We wished to develop criteria for serological confirmation of human T-lymphotropic virus type I (HTLV-I) infection in healthy donors. Selected serum or plasma samples reactive by HTLV-I enzyme immunosorbent assay or gel-agglutination assays with at least one viral-specific band on Western immunoblot (WIB) were tested in six laboratories by four WIBs and four radioimmunoprecipitation assays (RIPAs) for antibodies to HTLV-I proteins encoded by gag (p19 and p24), env (gp46 and/or gp61), and tax (p40x) genes. One hundred forty-two donor sera were obtained from 38 Japanese, 69 American, and 35 Caribbean blood or plasma donors. Among these samples, WIB assays appeared more sensitive to p24 antibodies, whereas RIPAs were significantly more sensitive to gp61 antibodies. All sera (137) with gp61 antibodies had p24 antibodies. Of the 137 sera positive for p24 and gp61 antibodies, p19 antibodies were detected in 129 sera, and p40x antibodies were detected in 108. In sera with p19 antibodies and antibodies to env- or tax-encoded proteins, p24 antibodies were always present. Antibodies to p40x were not found in the absence of gp61 antibodies. Virological evidence of infection was found in seven American donors by lymphocyte coculture (one HTLV-I, one HTLV-II) or by polymerase chain reaction (three HTLV-I, two HTLV-II). Sera from all seven donors showed p24 and gp46 and/or gp61 antibodies. We suggest that seroreactivity to both p24 and gp46 and/or gp61 by WIB or RIPA or both are suitable criteria to confirm but not to distinguish HTLV-I and HTLV-II infections.

Previously we demonstrated the prevalence of human T lymphotropic virus type I (HTVL-I) infection among cancer patients in Japan. This study was carried out to examine antigenic properties of retroviruses prevalent among Japanese cancer patients. Sera of 126 Japanese patients with cancer of different organs and with no history of blood transfusion, 94 in adult T cell leukemia (ATL)-endemic area and 32 in ATL-nonendemic area, were surveyed for antibodies to HTLV-I and HTLV-II by enzyme-linked immunosorbent assay (ELISA), Western blot analysis, and indirect immunogold electron microscopy. Among patients who were seropositive to HTLV-I, 39 of 56 (69.6%) in ATL-endemic area and 9 of 9 (100%) in ATL-nonendemic area were seropositive also to HTLV-II. Of 48 sera positive to both HTLV-I and HTLV-II, 34 (70.8%) showed stronger reactivities to HTLV-I than to HTLV-II. Among patients who were seronegative to HTLV-I, 3 of 38 (7.9%) in ATL-endemic area and 5 of 23 (21.7%) in ATL-nonendemic area were seropositive to HTLV-II. Antibodies appearing and disappearing in sera of patients examined during the clinical course reacted with peptide species of HTLV-I and/or HTLV-II not always consistent with peptide species cross-reactive between HTLV-I and HTLV-II. These results indicate the antigenic diversity of retroviruses prevalent among Japanese cancer patients.

Confirmed infection with HTLV-II (human T cell leukemia virus type II) has been described only in rare cases. The major limitation to serological diagnosis of HTLV-II has been the difficulty of distinguishing HTLV-II from HTLV-I (human T cell leukemia virus type I) infection, because of substantial cross-reactivity between the viruses. A sensitive modification of the polymerase chain reaction method was used to provide unambiguous molecular evidence that a significant proportion of intravenous drug abusers are infected with HTLV, and the majority of these individuals are infected with HTLV-II rather than HTLV-I. Of 23 individuals confirmed by polymerase chain reaction analysis to be infected with HTLV, 21 were identified to be infected with HTLV-II, and 2 were infected with HTLV-I. Molecular identification of an HTLV-II--infected population provides an opportunity to investigate the pathogenicity of HTLV-II in humans.