Antibodies to human adult T cell leukaemia virus type I associated antigens in Swedish leukaemia patients and blood donors

HTLV-I and -II in intravenous drug users from Sweden and Denmark

693 IVDU (intravenous drug user) sera from Copenhagen, Malmö and Stockholm were tested, 247 retro- and 446 prospectively, for antibodies to human T-lymphotropic virus (HTLV), types I and II, by means of a commercial whole-virus EIA and/or an HTLV-I/-II peptide-based EIA. Positive EIA reactions were checked and typed by electrophoretic immunoblotting, a differential peptide-based EIA and nucleic acid amplification/hybridization with HTLV-I and -II specific primers and probes. 3 (0.7%) of the prospectively tested IVDUs from Malmö, none of 100 from Stockholm and none of 45 from Copenhagen were HTLV-seropositive. The 3 Malmö IVDU cases were a female immigrant from South America, her male native Swedish spouse (both HTLV-I), and a male immigrant Italian heroinist (HTLV-II). We conclude that HTLV was uncommon among intravenous drug users, a sentinel population, in Sweden and Denmark during 1986 and 1989. However, the occurrence of 3 HTLV-positive cases in Malmö 1993 indicates that the situation can change rapidly.

HTLV-II among injecting drug users in Stockholm

134 injecting drug users (IDUs) treated at the Department of Infectious Diseases of Roslagstull Hospital, Stockholm, were tested for antibodies to human T-lymphotropic virus, types I and II, by means of 2 HTLV-I/-II peptide-based enzyme immunoassays (EIAs), followed by a whole-virus EIA. Positive EIA reactions were checked and typed by electrophoretic immunoblotting with native HTLV-I and recombinant HTLV-I and -II proteins. 10 IDUs were diagnosed as HTLV-II seropositive. All 10 were of Scandinavian descent. Thus, like HIV-1, HTLV-II infection has entered the injecting drug user population in Stockholm.

Increased antiretroviral antibody reactivity in sera from a defined population of patients with systemic lupus erythematosus. Correlation with autoantibodies and clinical manifestations

OBJECTIVE

The implied role of retroviruses in the pathogenesis of murine systemic lupus erythematosus (SLE) led us to study antiretroviral antibodies in a population-based SLE cohort.

METHODS

Immunoassays using whole virus and synthetic peptides were performed on sera from 72 patients with SLE and 88 control subjects.

RESULTS

Reactions with whole baboon endogenous virus occurred more frequently in patients with SLE, and correlated with the presence of anti-RNP and anti-Sm. Some retroviral env and gag peptides, several of which were similar to U1 small nuclear RNP, reacted more strongly in patients with SLE, and their presence was correlated with discoid rash, hematologic disorder, and other symptoms.

CONCLUSION

These results provide circumstantial evidence for involvement of retroviruses in the pathogenesis of human SLE; further studies should be carried out using other techniques for measurement of retroviral expression.

Antibodies against retroviral core proteins in relation to disease outcome in patients with mycosis fungoides

We have studied the relationship of antibodies reacting with human retroviral core proteins to the disease outcome in Finnish mycosis fungoides (MF) patients in a prospective manner. Antibodies recognizing human T-cell leukaemia/lymphoma virus I (HTLV-I) or human immunodeficiency virus type 1 (HIV-1) core proteins were found in 12 of 14 MF patients as shown by the Western blot method. The antibody reactivities showed three patterns: three patients had antibodies cross-reacting with the gag-encoded core proteins of both HTLV-I and HIV-1; seven patients showed antibodies reacting with HTLV-I core proteins only; and the sera of two patients reacted with HIV p24 core protein only. When following the clinical course of these patients, we found that the three patients with antibodies cross-reacting with both viruses had the most fulminant clinical course, and the overall duration of MF was, on average, 4 years less than in the rest of the patients. None of the patients, however, became leukaemic, or showed any other features suggestive of acute T-cell leukaemia/lymphoma (ATL). Two patients, who did not show anti-retroviral antibodies during the follow-up, had a stable disease with plaque-type skin lesions. Histological or immunohistological typing of the skin infiltrates did not correlate with the disease outcome or the above antibody patterns. Our results thus raise the possibility that an unknown retrovirus, immunologically related to the known human retroviruses, may be aetiologically linked to MF.

Seroepidemiology of human retroviruses in Ogun State of Nigeria

We analyzed sera collected during 1987 and 1988 from 385 healthy business employees of both sexes, of Ogun state in Nigeria, for antibodies to the 3 human retroviruses HIV-1, HIV-2 and HTLV-I. No serum was HIV-1 positive, 1 was HIV-2 positive and 2 were HTLV-I positive. A few sera were false-positive in the antibody screening tests which preceded the confirmatory antibody tests. In the confirmatory tests, we found that in the HIV-1 Western blot test 1 serum reacted only with the HIV-1 gag protein p17, and 2 sera reacted only with the HIV-1 pol proteins p64, p53 and p31. None of these reactivities fulfill internationally accepted criteria for HIV-1 seropositivity. We conclude that HIV-1 was rare in the study population and that HIV-2 and HTLV-I are present at a low frequency. The false positive serological reactions observed are similar to those described previously from Africa and elsewhere. The findings emphasize the importance of routinely testing blood donations for antibodies to these retroviruses in Nigeria.

No evidence for true HTLV-I or HIV-1 antibodies in Finnish Lapps

Previous seroepidemiologic studies have suggested that in addition to certain subtropical and tropical parts of the world, human T cell leukemia virus type I (HTLV-I) may be endemic in the arctic regions, too. We studied 111 sera collected from original inhabitants of Finnish Lapland with ELISA and Western blot analysis for antibodies to HTLV-I and human immunodeficiency virus type 1 (HIV-1). No true positive sera for either virus were found in the confirmatory Western blot assays, albeit 6 and 2%, respectively, were positive in the screening ELISA assays. Despite the small sample size this survey does not support the hypothesis that HTLV-I would be endemic in the Arctic.

Lack of evidence of HTLV-I antibodies in the Finnish population

5,287 serum samples from 2 different sources in Finland, people possibly at risk and healthy blood donors, were tested for the presence of HTLV-I antibodies. No positive cases were found. The result suggests that this virus is not endemic in Finland. 10 cases gave repeatedly a low positive value in the enzyme immune assay (EIA) test but were confirmed negative with other tests that included western blot, passive agglutination and immunofluorescence. Four of these samples originated from healthy blood donors, 6 from other categories. Several of them showed restricted reactivity in western blots. Five HIV-positive sera, discovered during the study from people with possible risk factors, were also tested for HTLV-I but showed no reactivity.

Immunologic assessment of a cluster of asymptomatic HTLV-I-infected individuals in New Orleans

PURPOSE

Although clusters of individuals infected with the human T-cell lymphotrophic virus type I (HTLV-I) have been identified in the United States, no systematic evaluation of the immunologic status of these persons has been reported. We therefore studied a group of 11 HTLV-I-infected former intravenous drug abusers who were long-term participants in a methadone maintenance program in New Orleans, Louisiana, to determine the effects of HTLV-I and chronic opiate use on immunity.

PATIENTS AND METHODS

Mitogenic responses and results of serologic studies, cell phenotype analysis, and cytotoxicity assays were compared to those in two other HTLV-I seronegative groups: a similar group of 17 methadone users and 15 healthy age-, sex-, and race-matched control subjects. All study participants were seronegative for human immunodeficiency virus type 1.

RESULTS

Percentages and numbers of total T lymphocytes (CD2+,CD3+), T-suppressor/cytotoxic lymphocytes (CD8+), cytotoxic lymphocytes (Leu7+, Leu11+, NKH-1+) and B lymphocytes (B4+) were similar among the study groups. Although percentages and numbers of total T-helper lymphocytes (CD4+) were also similar among the groups, HTLV-I-infected subjects had higher percentages and proportions of helper/inducer cells (CD4:4B4+) than did HTLV-I seronegative methadone users. Both methadone using groups had decreased percentages and numbers of suppressor/inducer T lymphocytes (CD4:2H4+). Major histocompatibility complex unrestricted T-cell cytotoxicity (lectin-dependent cellular cytotoxicity), natural killer cell function, and mitogenic responses to the T-cell mitogen phytohemagglutin were similar among the three study groups. Pokeweed mitogen responses were severely depressed in the HTLV-I-infected population.

CONCLUSIONS

We conclude that HTLV-I infection is associated with abnormalities in T-cell-dependent B-cell proliferative responses. Furthermore, both long-term methadone use and HTLV-I infection are associated with abnormalities in the distribution of CD4+ cell subpopulations. The increase in the helper/inducer and T-cell cell populations and decrease in the pokeweed mitogenic response noted in HTLV-I-infected subjects appear to be markers for infection with this retrovirus.

Infection with human T-cell leukemia virus type I in patients with leukemia

Among 211 adults with leukemia who received multiple transfusions, 6 were found to be seropositive for human T-cell leukemia virus Type I (HTLV-I). Before the positive serum specimens were obtained, these patients received a mean of 14 units of red cells and 78 units of platelets. Seroconversion could be documented in three patients. None of the 6 patients seropositive for HTLV-I had a T-cell leukemia, other illnesses attributable to HTLV-I infection, or risk factors for HTLV-I infection other than transfusion: none were seropositive for human immunodeficiency virus. Patients with leukemia who receive multiple transfusions appear to be at risk for HTLV-I infection.

Tropical spastic paraparesis associated with human T lymphotropic virus type I in an east African naturalised in Sweden

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Demonstration of antibodies binding to autologous and allogeneic leukemic cells in childhood ALL. Evidence for a common ALL antigen(s)

The humoral immune response to autologous leukemic cells was investigated in childhood ALL using a 125I protein A binding assay. In 5/7 patients antibodies were demonstrated at diagnosis and in 3/7 cases also after chemotherapy. Sera from 2/3 patients, which bound significantly to autologous leukemic cells, did not bind significantly to autologous remission cells. In allogeneic experiments sera bound significantly to ALL leukemic cells (6/7 positive combinations), but not to AML leukemic cells (8/8 negative combinations). We propose that ALL sera contain antibodies binding to autologous leukemic cells and that they are directed against a common ALL antigen(s).

Immunoglobulin G antibodies binding to a synthetic peptide deduced from the nucleotide sequence of the env gene of HTLV I in patients with leukemia and rheumatoid arthritis, HLA sensitized persons and blood donors

A synthetic pentadecapeptide preparation, env 406-420, with an amino acid sequence deduced from the envelope glycoprotein gene of human T cell leukemia virus type I (HTLV I), was used as the antigen in an enzyme immunoassay for immunoglobulin G antibodies, exploring its usefulness for seroepidemiological purposes. The frequency of reactivity in the test groups, presented in decreasing order was: patients with rheumatoid arthritis; multitransfused nonleukemic patients; Japanese cases of adult T cell leukemia (ATL); HLA sensitized persons; Swedish cases of adult acute leukemia; and Swedish blood donors. Three American cases of ATL and 12 HTLV I seropositive monkeys did not react. In RF positive sera from patients with rheumatoid arthritis, no quantitative correlation between RF activity and anti-env 406-420 activity was seen. Anti-env 406-420 positive sera did not react or reacted only weakly with four control peptide preparations with different amino acid sequences. The experience with oligopeptide serology still is limited. Our results illustrate that unexpected cross-reactions which are hard to interpret can occur. Although absorption experiments indicated an HTLV I specific component of the reactivity, antibodies against epitopes of allo- and auto-immune specificity may also have participated.