Familial multiple sclerosis in a Brazilian sample: Is HLA-DR15 involved in susceptibility to the disease?

BACKGROUND: The HLA-DR15 extended haplotype HLA-DRB1*15:01-DQA1*01:02-DQB1*06:02 comprises the strongest genetic risk factor for multiple sclerosis (MS). The aim of this work was to investigate whether HLA-DR15 alleles were significantly associated with the susceptibility to MS familial forms (MSf) in an admixed Brazilian population. METHODS: Association analyses between DR15 and the clinical and demographic variables were made. RESULTS: We have genotyped 25 familial cases. The DR15 was detected in 11/25 (44%) of them and in none of controls (P < .00001). DR15 was significantly associated to a foreign ancestor background (P = .029) and later age of onset (P = .018).

Familial forms of multiple sclerosis and neuromyelitis optica at an MS center in Rio de Janeiro State, Brazil.

OBJECTIVE: To describe familial forms of demyelinating diseases from an MS referral center in Río de Janeiro State, Brazil. METHODS: A descriptive, cross-sectional study was done to identify familial IIDD cases in Hospital da Lagoa, a public hospital where 75% of patients with IIDD who live in Rio de Janeiro state, located in the Southeast region of Brazil, are referred. The diagnoses of all consecutive patients followed in 2011 were reviewed to apply new diagnostic criteria (Wingerchuk et al., 2008). The diagnosis of IIDD was confirmed based on clinical history, neurological examination, MRI of the skull and spinal cord, CSF analysis and investigation of IgG NMO antibodies. The cases that had at least one other relative with IIDD were selected for the study. RESULTS: Familial forms were found only in the multiple sclerosis (MS) and neuromyelitis optica syndrome (NMOSD) categories. 23 MS families were identified, 60.86% with first degree kinship. It has a Caucasian preponderance, 90% of whom were white. The frequency of early onset was 15% and 20% of the MSf cases have progressive primary course. CONCLUSION: The frequency of familial cases of IIDD was 6.12% among MS patients and 2.8% in NMO spectrum syndromes.

Differences in the progression of primary progressive multiple sclerosis in Brazilians of African descent versus white Brazilian patients.

Recent studies have suggested faster clinical progression and greater disability in multiple sclerosis patients of African descent. This study analysed the effect of ethnicity on progression and disability. Sixty-five patients with primary progressive multiple sclerosis were selected and classified as being of African descent or white. Time from onset of the disease until reaching Expanded Disability Status Scale grades 3, 6, and 8 was assessed, as well as irreversible disability (Expanded Disability Status Scale grade maintained for >or=6 months). In the African descent group, the median time to reach Expanded Disability Status Scale 3 was 1 year shorter (1 year vs 2 years, p= 0.02), and to reach Expanded Disability Status Scale 6 was 2 years shorter (3 years vs 5 years, p= 0.01) than in the group of white patients. According to the Kaplan-Meier survival curves, patients of African descent reached every disability stage faster than white patients (p= 0.03, p = 0.04, and p = 0.03, respectively, for Expanded Disability Status Scale grades 3, 6, and 8). As in United States and European patients of African descent, the more severe and faster progression of multiple sclerosis seen in Brazilian primary progressive multiple sclerosis patients of African descent suggests a possibly greater effect of ethnicity rather than environment on the progression of multiple sclerosis.

HLA class II alleles in patients with multiple sclerosis in the Biscay province (Basque Country, Spain).

Genetic susceptibility to multiple sclerosis (MS) is associated with genes of the major histocompatibility complex, particularly with the HLA DRB1*1501-DQA1*0102-DQB1*0602 haplotype in Caucasians. To investigate the association of DRB1, DQA1 and DQB1 alleles and haplotypes with MS in Biscay, Basque Country, northern Spain, we examined 197 patients and 200 regionally matched controls. High resolution HLA class II typing was performed by polymerase chain reaction followed by sequence-specific oligonucleotide probe hybridization. Several alleles were overrepresented in MS patients compared with those of controls: DRB1*0402, DRB1*1303, DRB1*1501, DQA1*0102, DQB1*0301, and DQB1*0602. DQB1*0602 was the only potentially predisposing allele for MS that withstood Bonferroni correction and maintained the association in a logistic regression model. On the other hand, several alleles showed lower frequencies in the MS group: DRB1*0101, DQA1*0101, DQB1*0303, and DQB1*0501, but only DRB1*0101 and DQB1*0303 maintained a negative association with the disease in the regression analysis. Three haplotypes were identified as potentially predisposing for MS in our population: DRB1*1501-DQA1*0102-DQB1*0602, DRB1*0402-DQA1*0301-DQB1*0302, and HLA-DRB1*013-DQA1*05-DQB1*0301. Additionally, three haplotypes associated with a lower risk for MS were identified, exhibiting DRB1*0101-DQA1*0101-DQB1*0501 the strongest negative association with MS [12% in controls vs. 3.8% in MS, Pc = 0.00047, OR = 0.290 (95% CI = 0.160­0.528)], and suggesting, therefore, a putative protective role for this haplotype in the population under study.

The reliability of specific primary progressive MS criteria in an ethnically diverse population.

UNLABELLED: Three different diagnostic criteria for primary progressive MS were recently proposed for Caucasian population of Western European region. OBJECTIVE: The objective of the study was to apply these criteria to a series of Brazilian patients with high ethnic diversity background to evaluate reproducibility and reliability. METHODS: 52 patients classified as form of the disease that is progressive from onset and followed between 2000 and 2006 were included. Thompson, McDonald and Polman criteria were applied based in clinical date and complementary exams. RESULTS: 72% fulfilled all three criteria with moderate agreement (p<0.001). Ten patients fulfilled at least one criterion and four failed to fulfill any of the three criteria. Strong agreement was found between Thompson and McDonald criteria (p<0.001), agreement was moderate between Thompson and Polman criteria (p<0.001) and weak agreement occurred between McDonald and Polman criteria (p=0.042). CONCLUSION: The main difference between these criteria is the change in the role of CSF, previously a prerequisite for diagnosis. Rigid diagnostic criteria as Thompson have higher specificity, should be used in clinical research protocols, while more flexible criteria as Polman facilitate the diagnosis of PPMS in neurological practice, particularly in initial stages of the disease, because of their potentially higher sensitivity.

Post-dengue neuromyelitis optica: case report of a Japanese-descendent Brazilian child.

Monophasic neuromyelitis optica (NMO) is a rare form of post-infection acute disseminated encephalomyelitis (ADEM). Cases occurring after dengue virus infection are rare, despite the high prevalence of this disease in tropical and subtropical countries. We report a female patient, 11 years old, of Japanese ancestry and living in North Brazil, who developed NMO 1 week after having had a benign form of dengue fever. The disease was confirmed by the detection of dengue IgM antibodies in serum and cerebrospinal fluid (CSF). Restricted distribution of the lesions in the optic nerve and spinal cord was confirmed by ophthalmological evaluation and magnetic resonance imaging of the brain and spinal cord. Therapeutic intervention with corticotherapy resulted in benign evolution. This is the second report of optic spinal syndrome following dengue virus infection in patients of Japanese ancestry, suggesting an influence of the genetic background in the susceptibility to post-dengue NMO.