Paulo Pinho e Costa

Oligomeric TTR V30M aggregates compromise cell viability, erythropoietin gene expression and promoter activity in the human hepatoma cell line Hep3B

Abstract Familial amyloidotic polyneuropathy, ATTRV30M (p. TTRV50M) amyloidosis, is a neurodegenerative disease characterized by systemic extracellular amyloid deposition of a mutant transthyretin, TTRu2009V30M. Anemia, with low erythropoietin (EPO) levels and spared kidney function, affects about 25% of symptomatic patients, suggesting a blockage of EPO-producing cells. Early non-fibrillar TTR aggregates are highly cytotoxic, inducing oxidative stress, the expression of apoptosis-related molecules and secretion of pro-inflammatory cytokines, factors capable of inhibiting EPO production. Low EPO levels in these patients are not related to renal amyloid deposition or the presence of circulating TTR V30M. However, the role of early non-fibrillar TTR aggregates remains unexplored. We used the EPO producing Hep3B human hepatoma cell line to study the effect of TTR oligomeric aggregates on EPO expression. Hep3B cells were incubated with soluble and oligomeric TTR V30M, and cell proliferation as well as caspase 3/7 activation was evaluated. Relative quantification of EPO mRNA transcripts was performed by real-time PCR. Significant reductions in cell viability (13u2009±u20097.3%) and activation of caspases 3/7 were seen after 24u2009h in the presence of oligomeric TTR V30M. Also, EPO expression was significantly reduced (50u2009±u20092.8%), in normoxic conditions. A reporter assay was constructed with a PCR fragment of the EPO promoter linked to the luciferase gene to evaluate the role of transcription factors targeting the promoter. A significant reduction of EPO promoter activity (53u2009±u20096.5%) was observed in transfected cells exposed to TTR oligomers. Our results show that oligomeric TTR V30M reduces EPO expression, at least in part through inhibition of promoter activity.

HLA and age of onset in myasthenia gravis

The aetiology of MG is unknown, but both genetic and environmental factors are important. Over the years association of MG with Human Leucocyte Antigens (HLA) has been described in different populations. We investigated a possible association between HLA-DRB1 alleles and age of onset in MG. One hundred and fourteen MG patients (82 females) and 282 control individuals (CP) were studied. Patients were classified according to the age of onset (early-onset <50, nu2009=u200974 and late-onsetu2009≥u200950, nu2009=u200920). Patients with thymoma (nu2009=u200920) were analyzed separately. HLA-DRB1 and HLA-B*08 genotyping was performed using PCR-SSP methodology. HLA-DRB1*03 allele was overrepresented in the global MG. When the early-onset subgroup was considered, this association became even stronger. Regarding the late-onset subgroup, the frequency of HLA-DRB1*01 allele was higher than in the CP. For the thymoma subgroup, the HLA-DRB1*10 allele frequency was significantly higher when compared to the CP. These results have shown a strong association of HLA-DRB1*03 with MG, especially for EOMG also in our population. HLA-DRB1*01 was associated to LOMG suggesting that is a susceptibility factor for this subgroup of the disease. This study confirms a different genetic background of MG subgroups regarding age of onset.

Characteristics of Neuro-Behçet's Disease in a Case-Series from a Single Centre in Northern Portugal

Introduction: Behçets disease (BD) is a multisystem inflammatory disease of unknown etiology that may affect the CNS - Neuro-Behçet (NB). Our aim was to evaluate the frequency of neurological involvement and characterize a cohort of our NB patients. Methods: We retrospectively revised the clinical, laboratory and imaging data of a cohort of BD patients, followed in our hospital outpatient clinic. Results: We identified 138 BD patients. Twenty-five out of 138 had NB (15 female). Four patients presented with neurological symptoms. We identified a total of 37 attacks. Twenty-one attacks were classified as parenchymatous, four non-parenchymatous and 12 as other syndromes. Seventeen patients had CSF analysis performed (20 samples). Five samples were normal, 15 showed CSF pleocytosis. The most frequent finding on MRI performed in the acute phase was extensive lesions involving the brainstem. Two patients died due to the neurological involvement of BD. Conclusion: We found 18.1% prevalence of NB and a higher female-to-male ratio in our group than in other series. Gastrointestinal and vascular involvement was more frequent in the NB group. The fact that neurological involvement may be the first manifestation of BD with therapeutic implications and associated morbidity points out the relevance of an early diagnosis.