Ana Claudia Celestino Bezerra Leite

Human T Lymphotropic Virus Type 1 (HTLV-1) Proviral Load in Asymptomatic Carriers, HTLV-1–Associated Myelopathy/Tropical Spastic Paraparesis, and Other Neurological Abnormalities Associated with HTLV-1 Infection

Recent reports have demonstrated that human T lymphotropic virus type 1 (HTLV-1) is associated with other neurological abnormalities in addition to HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). It has been well established that high HTLV-1 proviral loads are associated with the development of HAM/TSP. We now demonstrate, for the first time, to our knowledge, that HTLV-1 proviral loads in patients with other neurological abnormalities are also significantly higher than in asymptomatic HTLV-1 carriers.

Progression of neurological disability in HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP).

HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is apparently a disease with a chronic evolution without spontaneous remissions. The real profile of its natural history and of the progression of the neurological disability, however, awaits confirmation. We devised the present study to evaluate the progression profile of the neurological disability of HAM/TSP in a series of 43 patients who have never received any kind of previous immune therapy. Patients were divided into different groups according to the duration of their disease. Age, gender and the Kurtzkes disability status scale (DSS) at the time of the first examination were compared. There were no statistically significant differences among groups with different disease duration. The present study suggests that the evolution of the neurological disability in HAM/TSP occurs mainly during the first year of the disease and becomes relatively stable after that. Therefore we speculate that the variable therapeutic success rates observed in many series of the literature could be due to the timing in the beginning of the pharmacological immunosuppression. Probably the therapeutic window in HAM/TSP lies within the first year of the disease. Thus it might be of utmost importance that future therapeutical trials take into consideration the duration of the disease since this factor can play an important role in the results of the trial.

Dysautonomia in human T‐cell lymphotrophic virus type I‐associated myelopathy/tropical spastic paraparesis

The frequency and importance of dysautonomia in human T‐cell lymphotrophic virus type I–associated myelopathy/tropical spastic paraparesis (HAM/TSP) have not been fully investigated. We describe the characteristics of dysautonomia in such patients in a case‐control study. Our results indicate that autonomic disturbances are more frequent in HAM/TSP than has been previously suggested, with a predominance of sympathetic nervous system dysfunction. In some of these patients, the symptoms may be severe enough to warrant specific treatment.

Genetic polymorphisms and cerebrovascular disease in children with sickle cell anemia from Rio de Janeiro, Brazil

The aim of the present work was to examine possible genetic risk factors related to the occurrence of cerebrovascular disease (CVD) in Brazilian population, the frequency of β(S)-globin gene haplotypes and co-inheritance with α-thalassemia (-α(3.7kb)) and single nucleotide polymorphism of methylenetetrahydrofolate reductase (MTHFR-C677T), Factor V Leiden (FV-G1691A) and prothrombin (PT-G20210A) genes in children from Rio de Janeiro. Ninety four children with sickle cell anemia (SCA) were included, 24 patients with cerebrovascular involvement and 70 patients without CVD as control group. The mean age of children at the time of the cerebrovascular event was similar to the control group. The frequency of -α(3.7kb) thalassemia was similar in both groups (p=0.751). Children with Bantu/Atypical β(S)-globin gene haplotype presented 15 times more chance (OR=15.4 CI 95% 2.9-81.6) of CVD than the other β(S)-globin gene haplotypes. The C677T polymorphism of MTHFR gene was similar in both groups (p=0.085). No mutation in the FV Leiden or PT genes was found. A large study seems necessary to establish the role of these genetic polymorphisms in Brazilian miscegenated population.

Intravenous methylprednisolone in HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP)

HTLV-I (Human T-lymphotropic virus type I) associated myelopathy/tropical spastic paraparesis (HAM/TSP) is an immunomediated myelopathy induced by the HTLV-I. Some patients, specially those from Japan, seem to have a good response to steroid treatment. However, this has not been found in other regions of the world. High dose intravenous methylprednisolone has been used with success in patients with relapses of multiple sclerosis (MS), another autoimmune disease of the central nervous system. To test the effectiveness of methylprednisolone in patients with HAM/TSP, we devised an open trial in 23 patients. We found a very limited benefit of this form of treatment in these patients. Only one patient, who had the shortest disease duration (five months) in the whole group, showed a sustained benefit. We speculate that those patients with a shorter history, with presumably less demyelination and more inflammatory lesions, would show a better response to immunosuppressive treatments.

Brazilian Guidelines for transcranial doppler in children and adolescents with sickle cell disease

Background Sickle cell disease is the most common monogenic hereditary disease in Brazil. Although strokes are one of the main causes of morbidity and mortality in these patients, the use of transcranial Doppler to identify children at risk is not universally used. Objective To develop Brazilian guidelines for the use of transcranial Doppler in sickle cell disease children and adolescents, so that related health policies can be expanded, and thus contribute to reduce morbidity and mortality. Methods The guidelines were formulated in a consensus meeting of experts in transcranial Doppler and sickle cell disease. The issues discussed were previously formulated and scientific articles in databases (MEDLINE, SciELO and Cochrane) were carefully analyzed. The consensus for each question was obtained by a vote of experts on the specific theme. Results Recommendations were made, including indications for the use of transcranial Doppler according to the sickle cell disease genotype and patients age; the necessary conditions to perform the exam and its periodicity depending on exam results; the criteria for the indication of blood transfusions and iron chelation therapy; the indication of hydroxyurea; and the therapeutic approach in cases of conditional transcranial Doppler. Conclusion The Brazilian guidelines on the use of transcranial doppler in sickle cell disease patients may reduce the risk of strokes, and thus reduce the morbidity and mortality and improve the quality of life of sickle cell disease patients.

Abnormal transcranial Döppler ultrasonography in children with sickle cell disease

Background Stroke is a potentially fatal complication of sickle cell disease in children between 2-16 years and transcranial Döppler has been recommended as a screening method in these cases. Objective The main goal of this study was to correlate transcranial Döppler results to complications related to stroke in sickle cell disease and baseline characteristics of the population. Methods This was an observational study of children and adolescents with ages between 2-16 years with sickle cell disease who were followed in three centers. Results From January 2008 to July 2009, 902 patients were enrolled in this study. The median age was 6.5 years (range: 1.8-15.8), 52.3% were male, 74.4% had hemoglobin SS; 221 (28.6%) had at least one complication associated with sickle cell disease. A total of 773 patients performed transcranial Döppler; in 91.2% this was a method of screening. Conditional or abnormal transcranial Döppler results were more common in patients with sickle cell disease complications versus those without complications (ODDS ratio = 3.18; 95% Confidence interval = 1.92-5.27). There was a significant difference in the frequency of conditional or abnormal transcranial Döppler results in patients with abnormal laboratory results compared to those without abnormalities (OR=4.03); 95% confidence interval = 2.30-7.06. Conclusions Conditional or abnormal transcranial Döppler results were significantly more frequent in patients with complications of sickle cell disease confirming the increased risk of stroke in this subgroup of patients. This observation reinforces the recommendation of transcranial Döppler as a screening test for all patients with sickle cell disease with ages between 2 and 16 years.

High Frequencies of Functionally Competent Circulating Tax-Specific CD8+ T Cells in Human T Lymphotropic Virus Type 2 Infection

Human T lymphotropic virus type 2 (HTLV-2) is characterized by a clinically asymptomatic persistent infection in the vast majority of infected individuals. In this study, we have characterized for the first time ex vivo specific CTL responses against the HTLV-2 Tax protein. We could detect CTL responses only against a single HLA-A*0201-restricted Tax2 epitope, comprising residues 11–19 (LLYGYPVYV), among three alleles screened. Virus-specific CTLs could be detected in most evaluated subjects, with frequencies as high as 24% of circulating CD8+ T cells. The frequency of specific CTLs had a statistically significant positive correlation with proviral load levels. The majority of virus-specific CD8+ T cells exhibited an effector memory/terminally differentiated phenotype, expressed high levels of cytotoxicity mediators, including perforin and granzyme B, and lysed in vitro target cells pulsed with Tax2(11–19) synthetic peptide in a dose-dependent manner. Our findings suggest that a strong, effective CTL response may control HTLV-2 viral burden and that this may be a significant factor in maintaining persistent infection and in the prevention of disease in infected individuals.

Neuroimaging in Parkinsonism: a study with magnetic resonance and spectroscopy as tools in the differential diagnosis

The differential diagnosis of Parkinsonism based on clinical features, sometimes may be difficult. Diagnostic tests in these cases might be useful, especially magnetic resonance imaging, a noninvasive exam, not as expensive as positron emission tomography, and provides a good basis for anatomical analysis. The magnetic resonance spectroscopy analyzes cerebral metabolism, yielding inconsistent results in parkinsonian disorders. We selected 40 individuals for magnetic resonance imaging and spectroscopy analysis, 12 with Parkinsons disease, 11 with progressive supranuclear palsy, 7 with multiple system atrophy (parkinsonian type), and 10 individuals without any psychiatric or neurological disorders (controls). Clinical scales included Hoenh and Yahr, unified Parkinsons disease rating scale and mini mental status examination. The results showed that patients with Parkinsons disease and controls presented the same aspects on neuroimaging, with few or absence of abnormalities, and supranuclear progressive palsy and multiple system atrophy showed abnormalities, some of which statistically significant. Thus, magnetic resonance imaging and spectroscopy could be useful as a tool in differential diagnosis of Parkinsonism.

High IFN-γ/IL-10 Expression Ratio and Increased Frequency of Persistent Human T-Cell Lymphotropic Virus Type 1-Infected Clones Are Associated with Human T-Cell Lymphotropic Virus Type 1-Associated Myelopathy/Tropical Spastic Paraparesis Development

Background/Aims: Human T-cell lymphotropic virus type 1 (HTLV-1) is a retrovirus that causes a persistent infection, and only 0.5-5% of infected individuals will develop HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Therefore, we investigated parameters to discriminate HTLV-1 asymptomatic carriers (ACs) with an increased chance to develop HAM/TSP. Methods: We evaluated integration patterns of HTLV-1 provirus, the relative expression of HTLV-1 tax and HBZ mRNAs and of IFN-γ and IL-10 mRNAs, in addition to proviral load (PVL) levels. Results: HAM/TSP patients presented a higher number of large persistent HTLV-1-carrying clones compared to ACs, and the expression of the HTLV-1 tax and HBZ genes by infected cells was detected at low levels and correlated positively with PVL. In addition, HAM/TSP patients and ACs with high PVL expressed higher levels of IFN-γ mRNA in comparison to IL-10, while ACs with low PVL presented an equilibrate IFN-γ/IL-10 ratio. Conclusions: The presence of large persistent HTLV-1-infected clones in association with viral gene expression, even at small levels, could stimulate the intense inflammatory response in HTLV-1-infected individuals. This was supported by a high ratio of IFN-γ/IL-10 relative expression in HAM/TSP patients and ACs with high PVL, indicating that these parameters could aid the identification of ACs with a high risk to develop HAM/TSP.