Antibodies to HTLV-I p24 in sera of blood donors, elderly people and patients with hemopoietic diseases in France and in French West Indies

Retinal Nerve Fiber Layer Thickness in Human T-cell Lymphotropic Virus Type 1 Patients

PURPOSE

To determine whether there is an optic neuropathy (ON) in patients with human T-cell lymphotropic virus type 1 (HTLV-1) infection.

METHODS

We included HTLV-1 asymptomatic carriers (a.c.HTLV-1) and tropical spastic paraparesis/HTLV-1 associated myelopathy (TSP/HAM) patients between January 1st, 2014 and March 31st, 2015. All patients had complete eye examination. The visual acuity (VA) and retinal nerve fiber layer (RNFL) thickness were measured and compared to age- and sex-matched control groups including patients seen in our refraction clinic with no previous medical or surgical history.

RESULTS

Thirty-one a.c.HTLV-1 (group 1) and 29 TSP/HAM patients (group 2) were included. The average RNFL thickness was 99.9 ± 14.3 µm in group 1 and 87.8 ± 19.2 µm in group 2. The average RFNL thicknesses were lower in both groups, when compared to controls. The difference was significant in patients with TSP/HAM (87.8 ± 19.2 µm vs. 97 ± 7.8 µm; p = 0.003) who also had significantly decreased VA.

CONCLUSIONS

We report here the first study about the RNFL thickness in patients with TSP/HAM. In these patients, there is decrease of the RNFL thickness with subtle but definite decrease of VA. This suggests that subclinical ON occurs in the natural history of the disease. The diagnosis of TSP/HAM must be evoked as a differential of primary progressive multiple sclerosis in a population at risk. Moreover, RNFL thinning with no evidence of glaucoma should raise suspicion for HTLV-1 infection and TSP/HAM in a population at risk.

HTLV-I infection in the South West Indian Ocean islands, particularly in La Réunion and the Seychelles

Data on HTLV-I are scarce in several Southwest Indian Ocean islands except for La Réunion and The Seychelles. The two cases of HTLV-I have been confirmed by Western-Blot in La Réunion, among blood donors. In Seychelles (87 400 inhabitants in 2012), where blood donors and some other cases are screened, HTLV-I was confirmed with a line immune assay in 43 persons and at least 10-20 patients are known to have tropical spastic paraparesia or adult T-cell lymphoma associated with HTLV-I. In the south-west Indian Ocean, a possibly important other issue may be co-infection of HTLV-1 with the Strongyloides stercoralis roundworm, which is endemic in all countries of the region and which can sometimes lead to severe symptomatic infestation.

Increased proviral load in HTLV-1-infected patients with rheumatoid arthritis or connective tissue disease

BACKGROUND

Human T-lymphotropic virus type 1 (HTLV-1) proviral load is related to the development of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and has also been shown to be elevated in the peripheral blood in HTLV-1-infected patients with uveitis or alveolitis. Increased proliferation of HTLV-1-infected cells in, or migration of such cells into, the central nervous system is also seen in HAM/TSP. In the present study, we evaluated the proviral load in a cohort of HTLV-1-infected patients with arthritic conditions.

RESULTS

HTLV-1 proviral load in the peripheral blood from 12 patients with RA and 6 patients with connective tissue disease was significantly higher than that in matched asymptomatic HTLV-1 carriers, but similar to that in matched HAM/TSP controls. HAM/TSP was seen in one-third of the HTLV-1-infected patients with RA or connective tissue disease, but did not account for the higher proviral load compared to the asymptomatic carrier group. The proviral load was increased in the synovial fluid and tissue from an HTLV-1-infected patient with RA, the values suggesting that the majority of infiltrated cells were HTLV-1-infected. In the peripheral blood from HTLV-1-infected patients with RA or connective tissue disease, HTLV-1 proviral load correlated with the percentages of memory CD4+ T cells and activated T cells, and these percentages were shown to be markedly higher in the synovial fluid than in the peripheral blood in an HTLV-1-infected patient with RA.

CONCLUSIONS

These biological findings are consistent with a role of the retrovirus in the development of arthritis in HTLV-1-infected patients. A high level of HTLV-1-infected lymphocytes in the peripheral blood and their accumulation in situ might play a central role in the pathogenesis of HTLV-1-associated inflammatory disorders. Alternatively, the autoimmune arthritis, its etiological factors or treatments might secondarily enhance HTLV-1 proviral load.

Human T-lymphotropic virus type 1 infection

Human T-cell lymphotropic virus type-1 (HTLV-1) is aetiologically associated with adult T-cell leukaemia/lymphoma (ATL). HTLV-1 infection can also lead to various non-malignant diseases, for example, HTLV-1 associated myelopathy/tropical spastic paraparesis and HTLV-1 uveitis. HTLV-1 is endemic in southern Japan and the Caribbean. HTLV-1 infection is mainly transmitted by either breast-feeding, sexual intercourse or blood transfusions. Primary prevention of HTLV-1 in endemic areas by screening of blood and by refraining from breast-feeding have been successful. The incidence of ATL is rather low among HTLV-1 carriers (<5%). The precise mechanism of development of ATL remains unknown. It is a multiple-step process which does not require viral expression in the later stages of leukaemogenesis. Many samples have mutations of the tumour suppressor genes, p53 and/or p16(INK4A). Four subtypes of ATL have been identified, each having distinctive clinical features. Monoclonal integration of HTLV-1 proviral DNA into tumour cells is found in each of the subtypes. At present, no effective therapy for ATL exists.

Seroindeterminate patterns and seroconversions to human T-lymphotropic virus type I positivity in blood donors from Martinique, French West Indies

BACKGROUND

Screening for human T-lymphotropic virus type I (HTLV-I) antibodies in volunteer blood donors has been systematic in the French West Indies since 1989. Western blot-indeterminate results are commonly obtained. The significance of these indeterminate serologic patterns in HTLV-I-endemic areas is still unclear.

STUDY DESIGN AND METHODS

During a 2-year period, 9759 blood donors were tested for HTLV-I antibodies. The epidemiologic features of HTLV-I-seropositive, -seroindeterminate, and -seronegative donors were compared. A lookback investigation was performed for the HTLV-I-seropositive donors, and the HTLV-I-seroindeterminate individuals were followed up.

RESULTS

Thirty-nine donors (0.4%) were HTLV-I seropositive and 49 (0.5%) were seroindeterminate. The age and sex ratio characteristics of the seroindeterminate donors are divergent from those of the HTLV-I-seropositive group and are more like those of the seronegative population. However, during the study period, three cases of seroconversion after an initial seroindeterminate profile were reported. Two cases were detected through follow-up of 38 HTLV-I-seroindeterminate donors over a mean of 8 months (2-24 months). The third seroconverter belonged to the HTLV-I-seropositive group and was identified through lookback investigation. This case is atypical, with p19 reactivity for several months before HTLV-I seropositivity.

CONCLUSION

These findings indicate that, although HTLV-I-seroindeterminate donors mainly are HTLV-I-noninfected, the rate of seroconversion in a repeat blood donor population from an endemic region must be taken into consideration. Moreover, the case of delayed seroconversion observed in this study suggests the difficulty of counseling seroindeterminate blood donors in endemic regions.

The epidemiology of HTLV-I in Europe

Although human T-lymphotropic virus type I (HTLV-I) infection in Europe is thought to be unusual except amongst people who have immigrated from countries where HTLV-I is endemic, the screening of blood donors has revealed a low seroprevalence across Europe, not only in donors originating from endemic areas but also in the indigenous population. Data from blood donors should not be extrapolated to other groups because blood donors are selected to be at low risk of parenterally transmissible infections. Unfortunately only small studies have been conducted in other population groups, including women attending antenatal clinics, despite the importance of breast-feeding in vertical transmission. Data from metropolitan areas of the United Kingdom and France suggest that the seroprevalence of HTLV-I in pregnant women is up to 100 times higher than in blood donors. HTLV-I infection is also more common in patients attending sexually transmitted disease clinics, whilst HTLV-II is endemic in many cities amongst intravenous drug users. There are few incidence data for diseases associated with HTLV-I, even though cases of adult T-cell leukemia/lymphoma and HTLV-I-associated myelopathy have been described in many European countries. Data on the seroprevalence of HTLV-I in central and eastern Europe are scanty but the few published studies suggest a higher rate than has been documented in western Europe.

Prevalence of antibodies to HTLV-1 in South American Indians (Mapuches) from Chile

The seroprevalence of HTLV-1 antibodies was investigated in 405 serum samples from healthy South American Indians (Mapuches) from Chile, using enzyme linked immunoassay (ELISA), Western immunoblot (WB) and radioimmuno precipitation assay (RIPA). Six samples were positive by ELISA; 3 of them were confirmed by WB/RIPA. Thus, we observed a seroprevalence of 0.7% for HTLV-1 antibodies in healthy Mapuches.

[Epidemiologic study of anti-HTLV-I/II antibodies in blood donors in metropolitan France. The Retrovirus Working Group of the National Blood Transfusion Society]

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-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.

HTLV-I-associated leukemia: a model for chronic retroviral diseases

Human T-lymphotropic virus type I (HTLV-I) has been associated with adult T-cell leukemia/lymphoma (ATL), a malignancy of mature CD4-positive lymphocytes, and with tropical spastic paraparesis (TSP), a demyelinating neurological syndrome. This article describes the clinical and pathological features of ATL and reviews the epidemiology of this disease and of its putative etiological agent, HTLV-I. From what is known about the molecular biology and epidemiology of HTLV-I, hypotheses on the etiology of TSP are proposed, and strategies for studying the neurological syndrome are suggested.

HTLV-I antibody and cell-mediated immunity status in sickle cell anemia

Patients with sickle cell anemia (SCA) had an abnormal susceptibility to infections. In Martinique (French West Indies), a human T-cell leukemia/lymphoma virus type I (HTLV-I) endemic area, we found that 17 (10%) of 173 SCA patients had antibodies to HTLV-I. The possible relationship between HTLV-I seropositivity and altered immunity was studied in 13 SCA patients with HTLV-I antibodies compared with 13 matched SCA patients without HTLV-I antibodies. The immunological results, as evaluated by the T-cell subsets analysis, the lymphocyte proliferation responses analyzed after activation with concanavalin A, phytohemagglutinin, or pokeweed mitogen, and the natural killer activity were not statistically different in these two groups of patients (SCA HTLV-I positive vs SCA HTLV-I negative). These data suggest that HTLV-I infection did not result in a major alteration of cellular immunity in this population.

Endemic tropical spastic paraparesis associated with human T-lymphotropic virus type I: a clinical and seroepidemiological study of 25 cases

Tropical spastic paraparesis (TSP) is a common myeloneuropathy with primary and predominant involvement of the pyramidal tract and minimal sensory loss. The epidemic form of TSP is related to toxic nutritional factors, but the endemic form occurs in clusters in tropical areas, especially in India, Africa, the Seychelles, Colombia, and areas of the Caribbean. We describe the clinical and epidemiological features of 25 TSP patients from Martinique (French West Indies) with serum antibodies to human T-lymphotropic virus type I (HTLV-I). Furthermore, all 11 patients who were seropositive for HTLV-I had specific HTLV-I antibodies in their CSF. All were women. The age of onset varied from 25 to 60 years (mean, 45 years). The main clinical features are spastic paraparesis or paraplegia with spasticity of the upper limbs, minimal sensory loss, and bladder dysfunction. Minimal estimated incidence and prevalence are 1 per 100,000 inhabitants per year and 8 per 100,000, respectively. Seventeen percent of the relatives of patients with HTLV-I-associated TSP have HTLV-I antibodies (1 husband and 7 children). In Martinique, the prevalence of HTLV-I antibodies in the general population is about 2% and reaches 10% for neurological disorders other than TSP. Since our initial report, the association between spastic paraparesis and HTLV-I has been confirmed in Jamaica, Colombia, and Japan, suggesting the neurotropism of this lymphotropic human retrovirus.

Antibodies to human T-lymphotropic virus type-I in patients with tropical spastic paraparesis

10 out of 17 (59%) patients with tropical spastic paraparesis (TSP) had antibodies to human T-lymphotropic virus-I (HTLV-I), as did 5 out of 5 TSP patients with systemic symptoms. Only 13 out of 303 (4%) controls, made up of blood donors, medical personnel, and other neurological patients, had such antibodies. These findings suggest either that HTLV-I is neurotropic or that the virus or a related one contributes to the pathogenesis of TSP.

Seroepidemiologic studies of human T-cell leukemia/lymphoma virus type I in Jamaica

The prevalence of HTLV-I antibodies was evaluated in Jamaica among persons with various malignant, infectious, autoimmune and hematologic disorders and in clinically normal persons. Results document that: (1) the prevalence of HTLV-I antibodies in this population increases with age; (2) overall, there is no significant difference in the antibody prevalence between males and females; (3) antibody-positive individuals are born in all major regions of the island and geographical variance in antibody prevalence by place of birth was not prominent; (4) there is further confirmation of the high prevalence of HTLV-I antibody-positive lymphomas in Jamaica; and (5) the prevalence of HTLV-I antibodies in hemophiliacs, patients with chronic lymphocytic leukemia (CLL), myelogenous leukemias, and patients with breast cancer is higher than in the age-matched population without malignancies, although none of these differences were statistically significant. The increased prevalence in hemophiliacs is most likely related to their frequent transfusion with blood products, but it has not yet been determined whether the prevalence in patients with other diseases is related to their diseases or other as yet undefined factors in common.