Aquaporin-4 antibodies are not related to HTLV-1 associated myelopathy.

INTRODUCTION: The seroprevalence of human T-cell leukemia virus type 1 (HTLV-1) is very high among Brazilians (1:200). HTLV-1 associated myelopathy or tropical spastic paraparesis (HAM/TSP) is the most common neurological complication of HTLV-1 infection. HAM/TSP can present with an acute/subacute form of longitudinally extensive myelitis, which can be confused with lesions seen in aquaporin-4 antibody (AQP4-Ab) positive neuromyelitis optica spectrum disorders (NMOSD) on MRI. Moreover, clinical attacks in patients with NMOSD have been shown to be preceded by viral infections in around 30% of cases. OBJECTIVE: To evaluate the frequency of AQP4-Ab in patients with HAM/TSP. To evaluate the frequency of HTLV-1 infection in patients with NMOSD. PATIENTS AND METHODS: 23 Brazilian patients with HAM/TSP, 20 asymptomatic HTLV-1+ serostatus patients, and 34 with NMOSD were tested for AQP4-Ab using a standardized recombinant cell based assay. In addition, all patients were tested for HTLV-1 by ELISA and Western blotting. RESULTS: 20/34 NMOSD patients were positive for AQP4-Ab but none of the HAM/TSP patients and none of the asymptomatic HTLV-1 infected individuals. Conversely, all AQP4-Ab-positive NMOSD patients were negative for HTLV-1 antibodies. One patient with HAM/TSP developed optic neuritis in addition to subacute LETM; this patient was AQP4-Ab negative as well. Patients were found to be predominantly female and of African descent both in the NMOSD and in the HAM/TSP group; Osame scale and expanded disability status scale scores did not differ significantly between the two groups. CONCLUSIONS: Our results argue both against a role of antibodies to AQP4 in the pathogenesis of HAM/TSP and against an association between HTLV-1 infection and the development of AQP4-Ab. Moreover, the absence of HTLV-1 in all patients with NMOSD suggests that HTLV-1 is not a common trigger of acute attacks in patients with AQP4-Ab positive NMOSD in populations with high HTLV-1 seroprevalence.

In contrast to HIV, KIR3DS1 does not influence outcome in HTLV-1 retroviral infection.

While most carriers of human T-cell leukemia virus type 1 (HTLV-1) remain asymptomatic throughout their lifetime, infection is associated with the development of adult T-cell leukemia (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The exact parameters that determine these outcomes are unknown but are believed to include host genetic factors that control the immune response to infection. Host response to fellow retroviridae member HIV is influenced by the expression of members of the Killer Immunoglobulin Receptor (KIR) family including KIR3DS1. In this study we examined the association of KIR3DS1 with the outcome of HTLV-1 infection in three geographically distinct cohorts (Jamaican, Japanese and Brazilian). Despite increased prevalence of KIR3DS1 in the HAM/TSP patients of the Jamaican cohort, we found no evidence for a role of KIR3DS1 in influencing control of proviral load or disease outcome. This suggests that unlike HIV, KIR3DS1-mediated regulation of HTLV-1 infection does not occur, or is ineffective.

Absence of consistent association between human leukocyte antigen-I and -II alleles and human T-lymphotropic virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis risk in an HTLV-1 French Afro-Caribbean population.

OBJECTIVES: Human T-cell lymphotropic virus type 1 (HTLV-1) infection leads to the risk of developing HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) in less than 5% of cases. The mechanism of disease progression in HAM/TSP remains unknown. A significant role of certain human leukocyte antigen (HLA) genotypes in determining the risk of HAM/TSP has been reported in Japan, where the HLA-A*02 gene has been found to be associated with a lower HTLV-1 provirus load and with protection from HAM/TSP, whereas HLA-DRB1*0101 has been found to be associated with an increased susceptibility to HAM/TSP. The aim of the present case-control study was to investigate the HLA class I and class II allele distribution in HTLV-seropositive French Afro-Caribbean individuals, originating from the French West Indies. METHODS: Associations with HLA class I (A and B) and class II (DRB1 and DQB1) alleles were tested in 123 HAM/TSP patients and 85 asymptomatic HTLV-1 carriers. HLA typing was undertaken on genomic DNA extracted from peripheral blood leukocytes. RESULTS: In our cohort, no significant effect on either the risk of developing HAM/TSP or HTLV-1 provirus load was found for HLA class I or class II, including HLA-A*02 (p=0.43). CONCLUSIONS: Our findings are in contrast to those in the Japanese population, however the literature on HLA associations in HTLV-1 infections across different populations over the past decade have reported conflicting results and this suggests strong ethnic disparities.

Frequent HTLV-1 infection in the offspring of Peruvian women with HTLV-1-associated myelopathy/tropical spastic paraparesis or strongyloidiasis.

OBJECTIVES: To describe the frequency of HTLV-1 infection among offspring of mothers who had presented with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), strongyloidiasis, or asymptomatic HTLV-1 infection, and to identify factors associated with HTLV-1 infection. METHODS: In a descriptive study, records were reviewed of HTLV-1-positive women and their offspring who had been tested for HTLV infection at a public hospital in Lima, Peru, from 1989 to 2003. Sons and daughters of women who had presented with strongyloidiasis, HAM/TSP, or asymptomatic infection were eligible for this study. RESULTS: Three hundred seventy subjects were included: 279 were the offspring of 104 mothers presenting with HAM/TSP, 58 were the offspring of 22 mothers with strongyloidiasis, and 33 were the offspring of 26 asymptomatic mothers. Mean age of the offspring at the time of testing was 26 years (standard deviation 12). Nineteen percent of the offspring tested positive for HTLV-1: 6% (2/33) of those with asymptomatic mothers, 19% (52/279) among the offspring of mothers with HAM/TSP, and 31% (18/58) among the offspring of mothers presenting with strongyloidiasis On multiple logistic regression analysis, three factors were significantly associated with HTLV-1: (a) duration of breast-feeding (odds ratio [OR] = 15.1; [4.2-54.1] for 12 to 24 months versus less than 6 months breast-feeding); (b) clinical condition of the mother (OR = 8.3 [1.0-65.3] for HAM/TSP and OR = 11.5 [1.4-98.4] for strongyloidiasis in comparison with offspring of asymptomatic mothers); and (c) transfusion history (OR = 5.5 [2.0-15.2]). CONCLUSIONS: In addition to known risk factors for HTLV-1 transmission (duration of breast-feeding and history of blood transfusion), maternal HAM/TSP and strongyloidiasis were associated with seropositivity among offspring of HTLV-1-infected mothers.

Frequent HTLV-1 infection in the offspring of Peruvian women with HTLV-1-associated myelopathy/tropical spastic paraparesis or strongyloidiasis

OBJECTIVES: To describe the frequency of HTLV-1 infection among offspring of mothers who had presented with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), strongyloidiasis, or asymptomatic HTLV-1 infection, and to identify factors associated with HTLV-1 infection. METHODS: In a descriptive study, records were reviewed of HTLV-1-positive women and their offspring who had been tested for HTLV infection at a public hospital in Lima, Peru, from 1989 to 2003. Sons and daughters of women who had presented with strongyloidiasis, HAM/TSP, or asymptomatic infection were eligible for this study. RESULTS: Three hundred seventy subjects were included: 279 were the offspring of 104 mothers presenting with HAM/TSP, 58 were the offspring of 22 mothers with strongyloidiasis, and 33 were the offspring of 26 asymptomatic mothers. Mean age of the offspring at the time of testing was 26 years (standard deviation 12). Nineteen percent of the offspring tested positive for HTLV-1: 6 percent (2/33) of those with asymptomatic mothers, 19 percent (52/279) among the offspring of mothers with HAM/TSP, and 31 percent (18/58) among the offspring of mothers presenting with strongyloidiasis On multiple logistic regression analysis, three factors were significantly associated with HTLV-1: (a) duration of breast-feeding (odds ratio [OR] = 15.1; [4.2-54.1] for 12 to 24 months versus less than 6 months breast-feeding); (b) clinical condition of the mother (OR = 8.3 [1.0-65.3] for HAM/TSP and OR = 11.5 [1.4-98.4] for strongyloidiasis in comparison with offspring of asymptomatic mothers); and (c) transfusion history (OR = 5.5 [2.0-15.2]). CONCLUSIONS: In addition to known risk factors for HTLV-1 transmission (duration of breast-feeding and history of blood transfusion), maternal HAM/TSP and strongyloidiasis were associated with seropositivity among offspring of HTLV-1-infected mothers.

OBJETIVOS: Describir la frecuencia de la infección por HTLV-1 en los hijos e hijas de madres diagnosticadas con mielopatía/paraparesia espástica tropical asociada con el HTLV-1 (M/PET-HTLV-1), estrongiloidiasis o infección asintomática por HTLV-1, e identificar los factores asociados con la infección por HTLV-1. MÉTODOS: Para este estudio descriptivo se revisaron los registros de mujeres positivas a HTLV-1 y de sus hijos evaluados con pruebas para la infección por HTLV en un hospital público de Lima, Perú, entre 1989 y 2003. Eran elegibles para este estudio los hijos y las hijas de las mujeres que se presentaron con estrongiloidiasis, M/PET-HTLV-1 o infección asintomática. RESULTADOS: En el estudio participaron 370 personas: 279 hijos de 104 madres con M/PET-HTLV-1, 58 hijos de 22 madres con estrongiloidiasis y 33 hijos de 26 madres asintomáticas. La edad promedio de los participantes en el momento de su prueba para HTLV era de 26 años (desviación estándar: 12 años). De las personas estudiadas, 19 por ciento resultaron positivas a la infección por HTLV-1: 6 por ciento (2/33) de los hijos de madres asintomáticas, 19 por ciento (52/279) de los hijos de madres con M/PET-HTLV-1 y 31 por ciento (18/58) de los hijos de madres con estrongiloidiasis. Según el análisis de regresión logística múltiple, tres factores se asociaron significativamente con la infección por HTLV-1: a) duración de la lactancia materna por 12_24 meses (razón de posibilidades [odds ratio, OR] = 15,1; intervalo de confianza de 95 por ciento [IC95 por ciento]: 4,2 a 54,1, frente a la lactancia materna por menos de 6 meses); b) que la madre presentara M/PET-HTLV-1 o estrongiloidiasis (OR = 8,3; IC95 por ciento: 1,0 a 65,3 y OR = 11,5; IC95 por ciento: 1,4 a 98,4, respectivamente, en comparación con los hijos de madres asintomáticas); y c) los antecedentes de haber recibido una transfusión sanguínea (OR = 5,5; IC95 por ciento: 2,0 a 15,2). CONCLUSIONES: Además de los factores...

Tc1/Tc2 and Th1/Th2 balance in Asian and Western types of multiple sclerosis, HTLV-I-associated myelopathy/tropical spastic paraparesis and hyperIgEaemic myelitis.

CD8+ T cells, like CD4+ T cells, can differentiate into at least two subsets with distinct cytokine patterns: Tc1 cells produce Th1-like cytokines and Tc2 cells produce Th2-like cytokines. To clarify the immunopathological roles of Tc1 and Tc2 cells in central nervous system (CNS) inflammation, we examined intracellular cytokines in CD8+ and CD4+ T cells by flow cytometry and analyzed the Tc1/Tc2 balance as well as the Th1/Th2 balance in 80 patients with various CNS inflammatory diseases, including 20 with optico-spinal multiple sclerosis (OS-MS), 21 with conventional MS (C-MS), 22 with human T-lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and 17 with hyperIgEaemic myelitis. Twenty-two healthy subjects were also examined as controls. Patients with OS-MS showed a significantly higher percentage of INF-gamma+IL-4- CD8+ T cells as well as CD4+ T cells and a significantly higher intracellular interferon-gamma (IFN-gamma)/interleukin-4 (IL-4) ratio both in CD8+ and CD4+ T cells throughout the relapse and remission phases than the healthy controls. Furthermore, the patients with OS-MS showed a significantly lower percentage of INF-gamma-IL-4+ CD4+ T cells as well as CD8+ T cells during the relapse phase than the healthy controls. On the other hand, the patients with C-MS showed a significantly higher percentage of IFN-gamma-IL-4+ CD8+ T cells in addition to more IFN-gamma+IL-4- CD4+ T cells during the relapse phase than the healthy controls. The HAM/TSP patients showed a significantly higher percentage of INF-gamma+IL-4- CD8+ T cells and a significantly higher intracellular IFN-gamma/IL-4 ratio in CD8+ T cells than the healthy controls. In contrast, in hyperIgEaemic myelitis, in addition to a significantly lower intracellular IFN-gamma/IL-4 ratio in CD4+ T cells, a tendency toward a lower intracellular IFN-gamma/IL-4 ratio in CD8+ T cells in comparison to the healthy controls was observed. These results clarified for the first time the distinct Tc1/Tc2 balance in each disease condition as follows: Tc1 cell response is predominant in OS-MS and HAM/TSP, while Tc2 cell response is predominant in hyperIgEaemic myelitis and at relapse phase of C-MS. Furthermore, our results suggest that CD8+ T cells play an adjunctive role in disease induction and the clinical course of MS.

New corneal findings in human T-cell lymphotrophic virus type 1 infection.

PURPOSE: Human T-cell lymphotrophic virus type 1 is a RNA retrovirus that primarily affects CD4+ T-cells. Human T-cell lymphotrophic virus type 1 infection is the established cause of adult T-cell leukemia/lymphoma, an aggressive malignancy of CD4+ T-cells, and two nonneoplastic conditions: human T-cell lymphotrophic virus type 1-associated myelopathy/tropical spastic paraparesis and human T-cell lymphotrophic virus type 1 uveitis. Other reported ophthalmic manifestations of human T-cell lymphotrophic virus type 1 infection include lymphomatous and leukemic infiltrates in the eye and ocular adnexa in patients with adult T-cell leukemia/lymphoma, retinal pigmentary degeneration, and neuro-ophthalmic disorders in patients with human T-cell lymphotrophic virus type 1-associated myelopathy/tropical spastic paraparesis and keratoconjunctivitis sicca, episcleritis, and sclerouveitis in asymptomatic human T-cell lymphotrophic virus type 1 carriers. This report describes the ocular findings in three Jamaican patients with human T-cell lymphotrophic virus type 1 infection and adult T-cell leukemia/lymphoma. METHODS: The clinical records of three patients with human T-cell lymphotrophic virus type 1 infection and adult T-cell leukemia/lymphoma examined at the National Eye Institute were reviewed. Each patient had one or more complete ophthalmic evaluations. RESULTS: All three patients had corneal abnormalities, including corneal haze and central opacities with thinning; bilateral immunoprotein keratopathy; and peripheral corneal thinning, scarring, and neovascularization. All three patients had elevated serum immunoglobulin levels. CONCLUSIONS: We believe that the novel corneal findings in these patients are most likely a consequence of the hypergammaglobulinemia induced by the human T-cell lymphotrophic virus type 1 infection or the T-cell malignancy.

Optic-spinal form of multiple sclerosis and immune-mediated myelopathy in Japan.

Optic-spinal form of multiple sclerosis (OS-MS) and HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP) are two immune-mediated myelopathy relatively common in Japan. (1) Transverse myelitis, once seen in 60% of MS, mostly OS-MS, 30 years ago, drastically decreased (5%) recently in Japan. In contrast, frequency of conventional form of MS (C-MS) increased during this period of time. But unlike C-MS in white patients, cerebellar hemispheric lesions are uncommon in Japanese C-MS. These findings emphasize influence of changes in exogenous factors on manifestations of MS and distinct genetic factors related to MS in Japanese and white patients. (2) To clarify the reason of high HTLV-I proviral load in HAM/TSP, we studied cellular immune surveillance against HTLV-I and found that significant cytotoxic T lymphocyte activity, and suppressed natural killer activity and antibody-dependent cell-mediated cytotoxicity in the patients. These altered immune surveillance may be associated with the spread of HTLV-I infection and the pathogenesis of HAM/TSP.

Flow cytometric differentiation of Asian and Western types of multiple sclerosis, HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and hyperIgEaemic myelitis by analyses of memory CD4 positive T cell subsets and NK cell subsets.

We examined the alterations of memory CD4(+) T cell subsets bearing surface receptors linked to either Th1 or Th2 cytokine production as well as natural killer (NK) cell subsets by three color flow cytometry in the peripheral blood from 36 patients with clinically definite multiple sclerosis (MS), 27 patients with HAM/TSP, 13 patients with hyperIgEaemic myelitis who had mite antigen-specific IgE and 25 healthy controls (HC). The patients with MS were clinically classified into an optico-spinal form of MS (Asian type, MS-A) and the conventional form of MS (Western type, MS-W). MS-A showed a significant increase of CD4(+)CD45RA(-)CCR5(+) cells (Th1 cells) through the relapse and remission phases in comparison to HC, while MS-W showed a significant increase of CD4(+)CD45RO(+)CD62L(-) cells (Th1 cells) only at the relapse phase. HAM/TSP showed a significant increase of CCR5(+) and CD62L(-) memory CD4(+) T cells as well as CD30(+) memory CD4(+) T cells (Th2 cells) in comparison to HC. On the other hand, a selective increase of CD4(+)CD45RO(+)CD30(+) cells was found in hyperIgEaemic myelitis. The percentage of mature NK cells (CD3(-)CD16(+)CD56(+) cells) as well as double negative T cells (CD3(+)CD4(-)CD8(-) cells) decreased significantly in HAM/TSP in comparison to HC. Our findings therefore suggest a flow cytometric analysis of Th1/Th2-associated markers on memory CD4(+) T cells as well as NK cell subsets to be useful for differentiating various inflammatory neurologic conditions.

Hyperprolactinemia in optico-spinal multiple sclerosis.

OBJECTIVE: To clarify the clinical features of MS patients with hyperprolactinemia. SUBJECTS AND METHODS: The serum prolactin level was measured in 67 Japanese patients (19 men and 48 women) with multiple sclerosis (MS) and in 16 patients (4 men and 12 women) with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) using a two-site immunoradiometric assay. RESULTS: In the MS patients, 32 were classified as having Asian type MS showing a selective involvement of the optic nerves and spinal cord, while the other 35 were classified as having Western type MS which displayed disseminated central nervous system involvement. In women, the serum prolactin level was found to be significantly higher only in Asian type MS (mean=23.1 ng/ml, n=25) than in HAM/TSP (mean=6.9 ng/ml, n=12) (p=0.0297), while it did not differ significantly in men among the three groups. Hyperprolactinemia was significantly associated with acute relapse involving the optic nerves. All MS patients with hyperprolactinemia (7 women with Asian type MS and 2 women with Western type MS) showed recurrent opticomyelitis either throughout or in the early course of the disease, and also had a higher age of onset, a higher Expanded Disability Status Scale score, a greater visual impairment, and higher cell counts and protein contents in the cerebrospinal fluid than did the normoprolactinemic patients. CONCLUSION: Hyperprolactinemia may be one of the characteristic features of Asian patients with MS who preferentially show the optic nerve involvement.

[Progressive myelopathy caused by human T-cell lymphotropic virus type I (HTLV-I) in 3 patients in The Netherlands]. / Progressieve myelopathie veroorzaakt door humaan T-cellymfotroop virus type I (HTLV-I) bij 3 patiënten in Nederland.

One man and two women (aged 30, 44 and 46, respectively) were seen between 1987 and 1992 with a myelopathy caused by the human T-cell lymphotropic virus type I (HTLV-I). The first symptoms were impaired gait in the man and micturition disorders in the women. Diagnosing took 2 to 4 years, possibly due to the fact that many Dutch physicians are unfamiliar with the disease. The diagnosis was based on originating from an endemic area (i.e. Surinam and the Caribbean basin), the clinical picture and the presence of antibodies against HTLV-I in blood and CSF. The disease in a number of years leads to spastic paraparesis, incontinence for urine and dependence on a wheelchair.

Immunogenetics of HTLV-I/II and associated diseases.

The ethnic background of human T-lymphotropic virus types I and II (HTLV-I/II) infections and associated diseases was investigated in association with human leukocyte antigens (HLA) (alleles) and haplotypes. Japanese HTLV-I carriers were characterized by two categories of HLA class I antigens (A24, A26, B7, B61, Cw1, and Cw7) and class II alleles (DRB1 *0101, 0803, 1403, 1501, and 1502 and DQB1 *0303, 0501, and 0601); one category was associated with adult T-cell leukemia (ATL) patients and the other with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) patients. The ATL-associated haplotypes had unique DRB1-DQB1 alleles (0901-0303, 1501-0602, 1401-0503), which were correlated with a low immune responsiveness to HTLV-I, while the HAM/TSP haplotypes had different DRB1-DQB1 alleles (0101-0501, 0803-0601, 1502-0601), which were correlated with a high immune responsiveness to HTLV-I. Both ATL- and HAM/TSP-associated haplotypes were found among HTLV-I carriers and the patients from other ethnic groups (Jamaican blacks, Andes natives, South American mestizos, and Mashhadi Jews). HLA haplotypes of HTLV-II carriers were different from those of HTLV-I carriers among South American natives. These results suggested that HTLV-I/II infections and the associated diseases might be determined by immunogenetic factors segregated with HLA alleles and haplotypes.

HTLV-negative and HTLV type I-positive tropical spastic paraparesis in northeastern Brazil.

A type-specific serological survey among 1042 random nonneurological outpatients in two cities in the state of Ceara (northeastern Brazil) shows a low prevalence of HTLV-I (0.34% in Fortaleza; 0.44% in Crato) and of HTLV-II (0.34% in Fortaleza; 0% in Crato). Among 62 chronic myelopathic patients seen in Fortaleza 27 patients were found with clinical features of tropical spastic paraparesis (TSP); 10 of 27 were found HTLV-I seropositive (37%; 95% confidence limits, 19-58%). Proviral genome detection by polymerase chain reaction in 5 seropositive and 12 seronegative patients confirmed the serological findings. This excludes HTLV-I or -II infection as a cause in the seronegative TSP patients. The HTLV-positive and -negative patients did not differ clinically and by history, except that seropositives had a longer mean disease duration, a female predominance, and a higher proportion of white Caucasians. In this population with low HTLV-I and HTLV-II prevalences, HTLV-negative TSP is at least as frequent as the HTLV-I-associated TSP.

Nucleotide sequence analysis of HTLV-I isolate from a Korean patient with HAM/TSP.

Limited nucleotide sequences of human T-cell lymphotropic virus type I (HTLV-1) provirus isolated from the first case of a Korean patient with HTLV-I associated myelopathy and tropical spastic paraparesis (HAM/TSP) were analysed and compared with other isolates from different regions of the world. The sequences of the env, LTR regions (536bp, 690bp respectively) showed 98.7%, 99.3% homologies with the prototype HTLV-I, ATK-1, isolated from a Japanese Adult T-cell leukemia (ATL) patient. A comparison between other isolates from different geographical origins revealed that the Korean HTLV-I isolate is more closely related to Japanese isolates than to those from other geographical origins.

Spastic paraparesis associated with human T-lymphotropic virus type I: a clinical, serological, and genomic study in Iranian-born Mashhadi Jews.

The Mashhadi-Jewish community originating in Iran is a closed and ethnically segregated population with a unique history and a high rate of intrafamilial marriage among its members. A high risk of infection by human T-lymphotropic virus type I (HTLV-I) and of adult T-cell leukemia associated with such infection was found in this population. HTLV-I is also associated with a syndrome of progressive spastic paraparesis. We therefore evaluated the occurrence of HTLV-I infection and spastic paraparesis in Mashhadi-born Iranian Jews who immigrated to Israel. We examined 83 Mashhadi-born subjects (52 women, 31 men; mean age, 61 +/- 15.5 years) and 73 age-matched non-Mashhadi Iranian-born Jews. Blood samples were tested for HTLV-I antibodies by particle agglutination test. The polymerase chain reaction (PCR) was used to detect HTLV-I proviral DNA sequences from peripheral blood mononuclear cells. Fifteen Mashhadi-born Jews (18%) were both seropositive and PCR-positive for HTLV-I. Four HTLV-I-seronegative subjects were found to be positive for HTLV-I proviral DNA by PCR. Of the 19 HTLV-I-infected subjects (11 women, 8 men; mean age, 59 +/- 16 years), 13 (68%) had spastic paraparesis of varying severity. There were no signs of myelopathy in the Mashhadi-born subjects who were negative for HTLV-I proviral DNA by PCR. None of the non-Mashhadi Iranian Jews was seropositive or PCR-positive for HTLV-I proviral DNA, or had clinical signs of spastic paraparesis.(ABSTRACT TRUNCATED AT 250 WORDS)

The risk of tropical spastic paraparesis differs according to ethnic group among HTLV-I carriers in Inongo, Zaire.

Following the finding in 1990 of six HTLV-I-positive cases of tropical spastic paraparesis (TSP/HAM) is a field survey carried out in the city of Inongo (Bandundu, Zaire), the prevalence of HTLV-I infection has been studied by detection of specific antibodies on a randomized sample of the general population. Among the 1,162 subjects surveyed, 36 (3.1%) were found to be HTLV-I seropositive, giving a seroprevalence of 3.2% (CI: 2.1, 4.3) estimated by direct standardization on age and sex distribution given by the census in the city. Among the five major ethnic groups, the Bolia showed the highest prevalence rate (6.5%) but with no detected TSP/HAM cases, while all six TSP/HAM cases were found among the Ntomba, who showed a prevalence rate of only 2.2%. This finding suggests that besides HTLV-I infection, critical environmental and/or genetic cofactors play a part in the development of TSP/HAM.

Tropical spastic paraparesis in an aborigine.

OBJECTIVE: To present the first documented case of human T-lymphotropic virus type I (HTLV-I) associated myelopathy/tropical spastic paraparesis in the Australian population. CLINICAL FEATURES: A 31-year-old Aboriginal man with an 18-month history of progressive weakness of the legs was found to have an upper motor neurone weakness of all limbs associated with sphincteric disturbance and impotence. HTLV-I antibodies were detected in his serum and no other cause for the patient's myelopathy could be found. INTERVENTION AND OUTCOME: He was counselled regarding HTLV-I associated myelopathy/tropical spastic paraparesis. CONCLUSION: This is the first description of HTLV-I associated myelopathy/tropical spastic paraparesis in an Australian. In cases of spinal cord disorder without evidence of compression we recommend serological testing for HTLV-I, especially in Aboriginal patients. Additionally, testing of blood donors for this retrovirus needs consideration.

HTLV-I associated myelopathy in a Seychellois immigrant.

OBJECTIVE: To describe the clinical and laboratory features of human T-lymphotropic virus type I (HTLV-I) associated myelopathy in an immigrant from the Seychelles. CLINICAL FEATURES: A slowly progressive myelopathy has been recently diagnosed in a 64-year-old woman who emigrated to Australia from the Seychelles in 1957. Sphincter disturbance and back pain were the first manifestations, followed by gait disturbance. Neurophysiological investigation supported the clinical diagnosis of a myelopathy and radiological investigations revealed no structural cause. Serum antibodies to HTLV-I were detected by enzyme-linked particle agglutination and the presence of antibodies to individual HTLV-I gene products in the serum was confirmed by western blot. The virus was detected in a culture of the patient's peripheral blood mononuclear cells by antigen capture assay and by sequencing a polymerase chain reaction product amplified from the env gene. INTERVENTION AND OUTCOME: The patient was advised of the nature and prognosis of her illness. Oral corticosteroids were tried without benefit. CONCLUSIONS: The prevalence of HTLV-I infection is low in Australia although it may be endemic in some Aboriginal communities. Most infections are asymptomatic but the chronic neurological disease associated with HTLV-I infection has now been shown to exist in this country. HTLV-I infection should be considered in the aetiology of myelopathy without another obvious cause.