Avaliação do volume plaquetário médio em pacientes com lúpus eritematoso sistêmico

Abstract

Introdução: O Lúpus eritematoso sistêmico (LES) é uma doença inflamatória autoimune crônica de etiologia ainda pouco conhecida, e de natureza pleomórfica, que intercala períodos de atividade e remissão. O desenvolvimento da autoimunidade no LES está associado à perda da tolerância imunológica e do controle imunorregulatório, tendo seus achados clínicos e laboratoriais variados. A atividade do LES pode ser medida pelo SLEDAI (systemic lupus erythematosus disease activity index) que é uma ferramenta complexa e que exige treinamento e conhecimento para sua aplicação. O volume plaquetário médio (VPM) é um marcador de ativação de plaquetas associado à inflamação, o que o torna um potencial candidato para a avaliação de atividade de doença no LES. Objetivos: Avaliar o VPM em pacientes com LES e comparar com indivíduos hígidos. Estudar a correlação entre o VPM e o índice de atividade de doença (SLEDAI) nos pacientes com LES. Analisar a correlação entre o VPM e a velocidade de sedimentação globular (VSG), a proteína C reativa (PCR), e os componentes do complemento C3 e C4. Métodos: Estudo transversal no qual foram incluídos 81 pacientes com LES segundo critérios de classificação diagnóstica do American College of Rheumatology (ACR), e 58 controles hígidos. Os pacientes foram selecionados consecutivamente por conveniência, de acordo com exames laboratoriais e SLEDAI devidamente calculados. As coletas foram realizadas entre outubro de 2015 e julho de 2016. LES ativo foi definido como SLEDAI>0 no momento da coleta. O VPM foi analisado no equipamento de automação Sysmex XE 5000. Resultados: O VPM estava reduzido nos pacientes com LES em atividade, quando comparado ao grupo de pacientes com LES inativo (10,0±0,7fL vs. 10,7±1,0fL, p=0,005). Existe uma fraca correlação inversa entre o valor do SLEDAI e o VPM (r=-0,29, p=0,009). Houve uma diferença significativa no VPM entre o grupo dos controles e os pacientes com LES ativo

Background Systemic Lupus Erythematosus (SLE) is an inflammatory autoimmune chronic disease etiology still unknown, and pleomorphic nature, which intersperses periods of activity and remission. The development of autoimmunity in SLE is related to loss of immunological tolerance and immunoregulatory control and clinical symptoms can be varied. The SLE activity can be measured by SLEDAI (systemic lupus erythematosus disease activity) which is a complex tool and it requires time and knowledge for your application. The MPV (mean platelet volume) is a marker of platelet activation and has been shown to be associated with inflammation, which makes it a potential candidate for use in the assessment of disease activity in SLE. In this study, we evaluated the MPV (Mean platelet volume) in healthy individuals and compared with SLE patients and correlate with SLEDAI VPM. Objectives: -To evaluate the MPV in SLE patients and compared with healthy individuals; to study the correlation between MPV and the SLEDAI patients with SLE and assess a possible correlation between MPV with erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), complement 3 (C3), and complement 4 (C4). Methods: This is a cross-sectional study in which 81 patients with SLE according to the American College of Rheumatology (ACR) diagnostic classification criteria and 58 healthy controls were included. Patients were selected for convenience, according to laboratory tests and SLEDAI duly calculated. The collections were carried out between October 2015 and July 2016. Active LES was defined as SLEDAI>0 at the time of collection. The VPM was analyzed in the Sysmex XE 5000 automation equipment. Results: In this study in patients with active SLE, the MPV is reduced when compared to the group of patients with inactive SLE [10.0±0.7fL vs. 10.7±1.0fL, p=0.005]. There is a weak inverse correlation between the SLEDAI value and the MPV (r=-0.29, p=0.009). There was a significant difference between the control group and the patients with active SLE (10.9 ±1.0fL vs. 10.0±0.7fL, p <0.001). In contrast, the MPV was similar between the control group and the group of patients with inactive SLE (10.9±1.0fLvs10.7±1.0fL, p=0.40). There was no correlation between MVP and CRP, ESR, C3 and C4. Conclusion: MPV is decreased in patients with active SLE and inversely correlated with SLEDAI. Despite the difference between MVP values, between active and inactive SLE patients, the results may not be clinically relevant. Prospective longitudinal studies are needed to better characterize the fluctuation of MPV in different states of disease activity to more clearly define the role of MPV in SLE.