HTLV-I/II seropositivity among eligible blood donors from Minas Gerais State, Brasil

Contribution of Galvanic Vestibular Stimulation for the Diagnosis of HTLV-1-Associated Myelopathy/Tropical Spastic Paraparesis

BACKGROUND AND PURPOSE

Galvanic vestibular stimulation (GVS) is a low-cost and safe examination for testing the vestibulospinal pathway. Human T-lymphotropic virus 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a slowly progressive disease that affects the vestibulospinal tract early in its course. This study compared the electromyographic (EMG) responses triggered by GVS of asymptomatic HTLV-1-infected subjects and subjects with HAM/TSP.

METHODS

Bipolar galvanic stimuli (400 ms and 2 mA) were applied to the mastoid processes of 39 subjects (n=120 stimulations per subject, with 60 from each lower limb). Both the short latency (SL) and medium latency (ML) components of the EMG response were recorded from the soleus muscles of 13 healthy, HTLV-1-negative adults (56±5 years, mean±SD), and 26 individuals infected with HTLV-1, of whom 13 were asymptomatic (56±8 years) and 13 had HAM/TSP (60±6 years).

RESULTS

The SL and ML EMG components were 55±4 and 112±10 ms, respectively, in the group of healthy subjects, 61±6 and 112±10 ms and in the HTLV-1-asymptomatic group, and 67±8 and 130±3 ms in the HAM/TSP group (p=0.001). The SL component was delayed in 4/13 (31%) of the examinations in the HTLV-1-asymptomatic group, while the ML component was normal in all of them. In the HAM/TSP group, the most common alteration was the absence of waves.

CONCLUSIONS

A pattern of abnormal vestibular-evoked EMG responses was found in HTLV-1-neurological disease, ranging from delayed latency among asymptomatic carriers to the absence of a response in HAM/TSP. GVS may contribute to the early diagnosis and monitoring of nontraumatic myelopathies.

Long-term serological follow-up of blood donors with an HTLV-indeterminate western blot: antibody profile of seroconverters and individuals with false reactions

The high proportion of indeterminate results of the screening test for human T-lymphotropic virus (HTLV) infection has been a challenge worldwide. In this study, 60 persons with seroindeterminate results for HTLV were followed until their serological status was defined. At least two independent serological tests (EIA and WB) from sequential samples were performed at an average interval of 4.4 years, totaling 141 serum samples tested. Seroconversion occurred in 12 individuals (reactive by EIA, positive by WB and PCR), and 48 were classified as false reactions (non-reactive EIA and negative PCR, but indeterminate WB). The seroconverter group had epidemiological features similar to those seen in HTLV-1 carriers, and the average time of follow-up for seroconversion was 4 years. In the group with false reactions, the most frequent indeterminate WB pattern in the samples was the presence of p24 alone. This pattern was absent in the seroconverter group, suggesting that p24 alone is an indicator of false reactivity. In contrast, the presence of p19 and p24 seems to be an indicator of true reactivity, since this pattern was frequent (66.7%) among the seroconverters and much less common (10.4% of the first samples) among the individuals with false reactions (P = 0.0001). Thus, HTLV infection may be suspected when reactivity to p19 and p24 is observed. Individuals with an indeterminate WB pattern should be followed-up and retested. The improvement of the HTLV algorithm screening of blood donors has been necessary to reduce inconclusive results and to avoid unnecessary follow-up to define the status of infection.

Vestibular-evoked myogenic potential (VEMP) to evaluate cervical myelopathy in human T-cell lymphotropic virus type I infection

STUDY DESIGN

Cross-seccional analysis.

OBJECTIVE

To define the clinical usefulness of vestibular-evoked myogenic potential (VEMP) in detecting cervical medullar involvement related to human T-cell lymphotropic virus type 1 (HTLV-1) associated myelopathy/tropical spastic paraparesis (HAM/TSP).

SUMMARY OF BACKGROUND DATA

VEMP is generated by acoustic or galvanic stimuli, passing through the vestibulo-spinal motor tract, the spinal nerves and recorded by means of surface electrodes on the sternocleidomastoid muscle. HAM/TSP is a progressive inflammatory myelopathy with predominant lesions at the thoracic spinal cord level, although the cervical spine can be affected. VEMP may be of value to investigate cervical myelopathy.

METHODS

Seventy-two individuals were evaluated of whom 30 HTLV-1 were seronegative and 42 HTLV-1 seropositive (22 asymptomatic, 10 with complaints of walking difficulty without definite HAM/TSP and 10 with definite HAM/TSP). VEMP was recorded using monaural delivered short tone burst (linear rise-fall 1 millisecond, plateau 2 milliseconds, 1 KHz) 118 dB NA, stimulation rate of 5 Hz, analysis time of 60 milliseconds, 200 stimuli, band pass filtered between 10 and 1.500 Hz.

RESULTS

VEMP was normal in the seronegative group (30 controls). In the seropositive, abnormal VEMP was seen in 11 of 22 (50%) of the HTLV-1 asymptomatic carriers, in 7 of 10 (70%) of those with complaints of walking difficulty and in 8 of 10 (80%) of the HAM/TSP patients. In this last group, the pattern of response was different. No VEMP response was more frequent when compared with the HTLV-1 asymptomatic group (2-tailed P-value = 0.001).

CONCLUSION

VEMP may possibly be useful to identify patients with cervical myelopathy and to distinguish variable degrees of functional damage. Minor injury would be related to latency prolongation and major injury to no potential-evoked response.

Serological patterns and temporal trends of HTLV-1/2 infection in high-risk populations attending Public Health Units in São Paulo, Brazil

BACKGROUND

HTLV-1/2 diagnosis in high-risk populations from São Paulo, Brazil has been problematic due a high proportion of seroindeterminate results.

OBJECTIVES

To confirm and extend previous findings regarding HTLV-1/2 diagnosis in this geographic area.

STUDY DESIGN

Sera from 2312 patients were tested for HTLV-1/2 antibodies using enzyme immunoassay (EIA) and Western blot (WB) analysis. Patients were from AIDS Reference Centers (Group I; 1393 patients) and HTLV out-patient clinics (Group II; 919 patients). Results were analyzed according to patients' age, gender, and clinic type.

RESULTS

HTLV-1 and HTLV-2 were detected in both groups. Among seropositive females, HTLV-2 was slightly more common in Group I (54.5%), while HTLV-1 prevailed in Group II (73.9%). Males from Group II had a higher percentage of HTLV-seroindeterminate results. No correlation between HTLV serological results and age was detected. Temporal analyses disclosed a high number of HTLV-seroindeterminate samples, and a large spectrum of indeterminate WB profiles. GD21 and/or rgp46-II bands were detected in 34.6% of sera from Group I, and a p24 or p19 band was detected in 35.3% of sera from Group II.

CONCLUSIONS

High rates of HTLV-indeterminate serological patterns during temporal analyses were confirmed in high-risk populations from São Paulo, Brazil.

Immunologic markers, uveitis, and keratoconjunctivitis sicca associated with human T-cell lymphotropic virus type 1

PURPOSE

To verify the occurrence of keratoconjunctivitis sicca (KCS) and human T-cell lymphotropic virus type 1 (HTLV-1) associated uveitis (HAU) and to evaluate the immunologic status related to HTLV-1.

DESIGN

Cross-sectional study.

METHODS

Ophthalmic examination (both eyes) and immunophenotyping of peripheral blood lymphocytes were performed in 207 infected asymptomatic blood donors (AS), 55 controls (NI), and 55 patients with HTLV-1 associated myelopathy (HAM/TSP). Examiner was masked to patient's serologic status.

RESULTS

KCS was more frequent in HAM/TSP (30/55, 54.5%) than in NI and AS (07/55, 12.7% and 42/207, 20.3%, respectively). Presence of lacrimal hyposecretion in KCS individuals was higher in the HAM/TSP group (P < .001) as compared with NI and AS. HAU was found in 1/55 (1.82%) of HAM/TSP patients and 4/207 (1.93%) of HTLV-1 seropositive donors. Higher levels of activated CD4(+) and CD8(+) T cells were observed in HAM/TSP. Patients with HAU displayed higher percentage of both CD4(+) HLA-DR(+) and CD8(+)HLA-DR(+) when compared with NI and AS without HAU.

CONCLUSIONS

Patients with HAM/TSP manifested more ophthalmologic symptoms than asymptomatic HTLV-1-infected individuals, with significantly higher KCS and immunologic alterations. Levels of activated CD8+ T cells could be used as a prognosis marker of inflammatory disease manifestation to follow-up AS individuals.

Identification of clonally rearranged T-cell receptor beta chain genes in HTLV-I carriers as a potential instrument for early detection of neoplasia

We analyzed the genetic recombination pattern of the T-cell receptor beta-chain gene (TCR-beta) in order to identify clonal expansion of T-lymphocytes in 17 human T-lymphotropic virus type I (HTLV-I)-positive healthy carriers, 7 of them with abnormal features in the peripheral blood lymphocytes. Monoclonal or oligoclonal expansion of T-cells was detected in 5 of 7 HTLV-I-positive patients with abnormal lymphocytes and unconfirmed diagnosis by using PCR amplification of segments of TCR-beta gene, in a set of reactions that target 102 different variable (V) segments, covering all members of the 24 V families available in the gene bank, including the more recently identified segments of the Vbeta-5 and Vbeta-8 family and the two diversity beta segments. Southern blots, the gold standard method to detect T-lymphocyte clonality, were negative for all of these 7 patients, what highlights the low sensitivity of this method that requires a large amount of very high quality DNA. To evaluate the performance of PCR in the detection of clonality we also analyzed 18 leukemia patients, all of whom tested positive. Clonal expansion was not detected in any of the negative controls or healthy carriers without abnormal lymphocytes. In conclusion, PCR amplification of segments of rearranged TCR-beta is reliable and highly suitable for the detection of small populations of clonal T-cells in asymptomatic HTLV-I carriers who present abnormal peripheral blood lymphocytes providing an additional instrument for following up these patients with potentially higher risk of leukemia.

Heterogeneous geographic distribution of human T-cell lymphotropic viruses I and II (HTLV-I/II): serological screening prevalence rates in blood donors from large urban areas in Brazil

Brazil may have the highest absolute number of HTLV-I/II seropositive individuals in the world. Screening potential blood donors for HTLV-I/II is mandatory in Brazil. The public blood center network accounts for about 80.0% of all blood collected. We conducted a cross-sectional study to assess the geographic distribution of HTLV-I/II serological screening prevalence rates in blood donors from 27 large urban areas in the various States of Brazil, from 1995 to 2000. Enzyme immunoassay (EIA) was used to test for HTLV-I/II. The mean prevalence rates ranged from 0.4/1,000 in Florianopolis, capital of Santa Catarina State, in the South, to 10.0/1,000 in São Luiz, Maranhão State, in the Northeast. EIA prevalence rates are lower in the South and higher in the North and Northeast. The reasons for such heterogeneity may be multiple and need further studies.

[Dermatologic lesions in patients infected with the human T-cell lymphotropic virus type 1 (HTLV-1)]

Human T-cell Lymphotropic virus type I (HTLV-1) was the first human retrovirus described. Some time after its discovery a group of diseases were related to this virus, such as, adult T-cell leukemia lymphoma (ATLL), HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP) and HTLV-1 associated uveitis (HAU). In the nineties, HTLV-1 was associated to a severe eczema of children, called infective dermatitis (ID). Since then, several other skin manifestations have been observed in HTLV-1-infected individuals, particularly in patients with ATLL or HAM/TSP. However, according to some reports, dermatologic lesions are also common in asymptomatic HTLV-1 carriers. Besides ID, all other skin lesions reported are nonspecific. The aim of this review is to outline the dermatologic manifestations reported in HTLV-1 infected patients, emphasizing the clinical and epidemiological value of these findings.

[Infection and disease caused by the human T cell lymphotropic viruses type I and II in Brazil]

HTLV-I/II infection is present in all regions of Brazil, but its prevalence varies according to the geographical area, being higher in Bahia, Pernambuco and Pará. It has been estimated that Brazil has the highest absolute number of infected individuals in the world. Blood donors screening and research conducted with special groups (indigenous population of Brazil, IV drug users and pregnant women) are the major sources of information about these viruses in our Country. HTLV-I causes adult T cell leukemia/lymphoma (ATLL), HTLV associated myelopathy/tropical spastic paraparesis (HAM/TSP), HTLV associated uveitis (HAU), dermatological and immunological abnormalities. HTLV-II is not consistently associated with any disease. Diagnosis is established using screening (enzymatic assays, agglutination) and confirmatory (Western blot, PCR) tests. The viruses are transmitted by blood and contaminated needles, by sexual relations and from mother to child, especially by breast feeding. Prevention efforts should focus on education of positive blood donors, infected mothers and IV drug users.

Counseling blood donors seropositive for human T-lymphotropic virus types I and II in a developing country

Human T-lymphotropic virus types I and II (HTLV-I/II) are blood-transmitted retroviruses associated with leukemia, myelopathy, and uveitis. From 51,135 eligible blood donors at the Fundação Hemominas tested in 1993, 689 (1.35%) were repeatedly reactive to HTLV-I/II antibodies by enzyme immunoassay and were notified accordingly. Routes of transmission and preventive measures were emphasized in the orientation. Supplementary laboratory tests should be available and free of cost. Health services should recommend the use of latex condoms and make them available. Avoiding shared use of needles or syringes is important for both the seropositive donor and public health in general. In a country with such widespread malnutrition, the benefits of breast-feeding usually outweigh the risks of virus transmission. Based on our experience, we recommend that: 1) identical orientation be given to donors by all health professionals involved in counseling; 2) level of schooling be considered and information provided accordingly; 3) donors be assisted in understanding and assessing available information; 4) psychological assistance be provided to anxious or depressed donors; and 5) joint counseling be offered to donors with stable partners.

Erectile insufficiency as first symptom of HTLV I/II associated myelopathy. Case report

A case of HTLV-I/II myelopathy in which the initial complaint was erectile insufficiency (EI) is reported. The only abnormalities found on the neurological exam were discrete weakness of the psoas and increased knee jerk reflexes. Diagnosis was made by demonstrating antibodies anti-HTLV I/II in the serum and cerebrospinal fluid (with the techniques of ELISA and Western blot), with confirmation by the polymerase chain reaction (PCR). EI can thus be the first symptom of HTLV-I/II infection and patients with EI of unknown etiology should be tested for HTLV-I/II in endemic areas.

Presence of human immunodeficiency virus (HIV) and T-lymphotropic virus type I and II (HTLV-I/II) in a haemophiliac population in Belo Horizonte, Brazil, and correlation with additional serological results

The aim of this study was to determine the prevalence of human immunodeficiency virus type 1 (HIV-1) and human T lymphotropic virus types I and II (HTLV-I/II) infections in 226 haemophiliac patients treated at Fundação Hemominas in Belo Horizonte, Minas Gerais State, Brazil, and to verify association with other serological results. Patients positive for HTLV-I/II had also a neurological, haematological and ophthalmological evaluation. Fundação Hemominas offers comprehensive care for all haemophiliac patients in Minas Gerais. Thirty-six (15.9%) of the 226 patients showed reactive results to HIV-1 [ELISA, Abbott, USA, confirmed by Western blot (WB), Cambridge Biotech, USA, and/or immunofluorescence, Fiocruz, Brazil] and 16 (7.1%) had reactive sera to HTLV-I/II (ELISA, Ortho). Eleven of these 16 (4.9%) were positive, 3/16 (1.3%) were indeterminate and 2/16 (0.9%) were negative in the HTLV WB (Cambridge Biotech). Neurological, haematological and ophthalmological examination of 9/16 patients revealed no abnormality suggestive of HTLV disease. Of the 16 patients reactive to HTLV-I/II ELISA test, six (37.5%) were also positive to HIV-1 (chi 2 = 5.92; P = 0.01). Seropositivity for HTLV-I/II and HIV-1 was associated with advancing age and positive results for hepatitis C virus (HCV), Chagas' disease (T. cruzi infection) and syphilis. No association between the presence of HTLV with type and severity of haemophilia and hepatitis B results was detected. The prevalence of antibodies against HIV-1 is approximately three times that of HTLV-I/II and a patient positive for HTLV-I/II had a significantly increased risk of being positive for HIV-1, HCV and T. cruzi.

HTLV-I and HTLV-II infections in hematologic disorder patients, cancer patients, and healthy individuals from Rio de Janeiro, Brazil

To clarify the seroprevalence of human T-cell lymphotropic virus type I (HTLV-I) among hematologic and cancer patients in the State of Rio de Janeiro, Brazil, we investigated sera from 2430 individuals from the following groups: 152 patients with T-cell diseases, 250 with B-cell disorders, 67 with myeloid leukemia, 41 with Hodgkin's disease, 351 with a history of multiple blood transfusions, 235 patients with solid tumors of different types, and 109 family members of HTLV-I-infected patients. Antibodies to HTLV-I were screened by enzyme-linked immunosorbent assay or particle agglutination assays (or both). Repeatedly reactive samples were tested by Western blot and polymerase chain reaction assay to differentiate HTLV-I from HTLV-II. We found an increased seroprevalence rate of HTLV-I among those with lymphoid malignancies, mainly in T-cell diseases (28.9%), and these results were important in characterizing 44 cases of adult T-cell leukemia/lymphoma. We confirmed the presence of HTLV-I and HTLV-II infections in blood donors (0.4% and 0.1%, respectively), in patients exposed to multiple blood transfusions (10.2% and 0.8%, respectively), and in 30 (27.5%) of 109 family members of HTLV-I- or HTLV-II-infected patients. We also confirmed the high rate occurrence of adult T-cell leukemia/lymphoma among lymphoproliferative disorders in Rio de Janeiro, Brazil.