Original Research Article
Year: 2017 | Month: January | Volume: 7 | Issue: 1 | Pages: 130-137
Levels of Circulating Reticulocytes-C4d: Is There Link to Disease Activity in Patients with SLE?
Karine Silvestre Ferreira1, Cristina de Mello Gomide Loures1, Fernanda Magalhães Freire Campos1, Walter Batista Cicarini1, Luan Carlos Vieira1, Vicente de Paulo Coelho Peixoto Toledo1, Cláudia Lopes Santoro Neiva2, Renato Vargas Consoli2, Paulo Madureira de Pádua2, Maria das Graças Carvalho1
1Departamento de Análises Clínicas e Toxicológicas, Faculdade de Farmácia, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
2Serviço de Reumatologia, Santa Casa/BH, Belo Horizonte, Minas Gerais, Brazil.
Corresponding Author: Karine Silvestre Ferreira
ABSTRACT
Objective: The determination of cell-bound complement activation products (CB-CAPs), such as C4d linked to reticulocyte (R-C4d), are potential biomarkers of disease activation state. Within this context, this cross-sectional study aimed to assess whether, in SLE, R-C4d levels can be predictors of the disease activity in a set of patients selected from Brazilian population.
Method: Forty patients with SLE confirmed by the American College of Rheumatology (ACR) classification criteria who were assessed at the time of the visit to the clinic using the SLEDAI-2K index (Systemic Lupus Erythematosus Disease Activity Index 2000) were recruited, besides to 20 adult healthy subjects (controls). Patients with SLEDAI≤ 4 were classified as having low disease activity (SLE-I, n = 20) and those with SLEDAI > 4 as carriers of active disease (SLE-A, n = 20). Peripheral blood samples were collected in EDTA with subsequent separation of reticulocytes population and analyze by flow cytometry to determine the levels of R-C4d.
Results: A positive correlation between R-C4d levels and SLEDAI 2K was observed. Significant differences between controls and LES-A (p <0.0001), and between LES-I and LES-A (p <0.0001) were observed.
Conclusion: Since reticulocytes are present in the peripheral blood for a period of only 24-48 hours and then turning into mature erythrocytes, higher levels of R-C4d may reflect early active disease. Thus, increased R-C4d expression may be a useful tool for screening disease severity at initial diagnosis and for monitoring disease status of patients.
Key words: Cell bound complement c4d, reticulocytes, systemic lupus erythematosus of disease activation state.