Participação do receptor TRPA1 como um componente imunomodulador na artrite reumatóide

Abstract

The transient receptor potential ankyrin 1 (TRPA1) is a non-selective Ca+2 channel expressed on neuronal and non-neuronal cells, and mediates pain and inflammation; being implicated in rheumatoid arthritis (RA). Here, we evaluated the expression of TRPA1 on peripheral blood leukocytes obtained from RA patients, as well as its correlation with pain and disability, in addtition to the immune alterations in RA patients treated or not with antirheumatic drugs: the disease-modifying angent leflunomide (LFN) and the anti-TNFα adalimumab (ADA); in comparison with healthy subjects. Peripheral blood samples were taken from 15 healthy subjects (controls), 10 RA patients not undertaking anti-rheumatic therapy (NST), 15 patients treated with LFN and 15 patients treated with ADA. C reactive protein (CRP), rheumatoid factor (FR), hydrogen peroxide (H2O2), 4-hydroxynonenal (4- HNE) and tumour necrose factor α (TNFα) levels were quantified. Also, leukocyte subpopulations, the number of red blood cells, the levels of haemoglobin and the expression of TRPA1 on peripheral blood leukocytes, were evaluated. TRPA1 expression was increased on NST leukocytes and this was correlated with pain and disability and was associated with the number of polymorphonuclear cells and the activation of CD14+ cells. It was also demonstrated that treatment with either LFN or ADA attenuates anaemia in AR, with those treatments being effective in treating both the intra- and extra-articular disease. Overall, our data showns that TRPA1 influences pain and disability in RA and that its expression is reduced in patients treated with LFN or ADA. These evidences, together with the promissing data on the anti-rheumatic therapy in reducing anaemia in RA patients suggest that these drugs are effective in treating both the intra- and extra-articular alterations of RA.