RESUMEN
OBJECTIVE: Impaired clearance of apoptotic cells is a potential trigger of systemic lupus erythematosus (SLE). Milk fat globule epidermal growth factor 8 (MFG-E8) plays an important role in the clearance of dying cells. Previously, we reported serum MFG-E8 was elevated in some SLE patients. Here we further investigated the prevalence of MFG-E8 in active SLE and other autoimmune diseases and also tried to clarify the characteristics of MFG-E8-positive and -negative SLE. METHODS: Serum MFG-E8 was measured in 40 active non-treated SLE patients, 104 disease controls and 104 healthy controls by ELISA. Clinical characteristics and serum cytokine profiles were compared between MFG-E8-positive and MFG-E8-negative SLE patients. RESULTS: Prevalence of MFG-E8 was significantly higher in SLE patients (40%) than in various controls (p < 0.05). MFG-E8 level became negative after treatment, and increased again upon relapse. When compared, MFG-E8-positive SLE patients showed higher immune complex (p = 0.021) and lower complement (p = 0.004 for CH50). In contrast, MFG-E8-negative SLE patients tended to show higher CRP (p = 0.094). There was a positive correlation between MFG-E8 level and immune complex level (r s = 0.49, p = 0.049). TNF-α (p = 0.019), IFN-γ (p = 0.031) and IL-10 (p = 0.013) were significantly higher in MFG-E8-positive SLE. CONCLUSION: MFG-E8-positive SLE and -negative SLE may have different clinical features, the one with stronger immunological response and the other with stronger inflammatory response, and those two groups may be two distinct subtypes of SLE driven by different mechanisms. Further, MFG-E8 could be used as a biomarker for diagnosis and monitoring of disease activity in certain SLE patients.
Asunto(s)
Antígenos de Superficie/sangre , Interferón gamma/sangre , Interleucina-10/sangre , Lupus Eritematoso Sistémico/fisiopatología , Proteínas de la Leche/sangre , Factor de Necrosis Tumoral alfa/sangre , Adolescente , Adulto , Anciano , Biomarcadores/sangre , Estudios de Casos y Controles , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Lupus Eritematoso Sistémico/sangre , Lupus Eritematoso Sistémico/inmunología , Masculino , Persona de Mediana Edad , Recurrencia , Estudios Retrospectivos , Adulto JovenRESUMEN
Our aim was to analyze the performance of an interferon-gamma release assay, QuantiFERON-TB Gold (QFT-2G), for diagnosing Mycobacterium tuberculosis (MTB) infection in patients with systemic lupus erythematosus (SLE). We performed the QFT-2G and tuberculin skin test (TST) in 71 SLE patients. The QFT-2G results of 279 patients with other connective tissue diseases (CTD) and 35 healthy controls were analyzed. Of the 71 SLE patients, two (2.8%) were positive and 46 (64.8%) were negative by QFT-2G. All SLE patients had no evidence of active MTB infection, apart from one. QFT-2G produced a significantly higher number of indeterminate results in patients with SLE (23/71, 32.4%) compared with those with other CTD (5.7%) or healthy controls (0%) (p < 0.0001 and p < 0.0001). Decreased lymphocyte counts and high SLEDAI scores in SLE patients were shown to be risk factors for indeterminate results by multivariate analysis (p = 0.02 and p = 0.04). Among all patients with CTD, SLE itself and lymphocytopenia were found to be independent risks for indeterminate results (p = 0.00000625 and p = 0.000107). In conclusion, QFT-2G may have more potential to assist in the diagnosis of active and latent MTB infection than TST in SLE patients. However, because of the high frequency of indeterminate results, caution must be used when interpreting the results of QFT-2G among SLE patients, especially those who have parallel or subsequent flares.
Asunto(s)
Interferón gamma/inmunología , Interferón gamma/metabolismo , Lupus Eritematoso Sistémico/inmunología , Lupus Eritematoso Sistémico/microbiología , Mycobacterium tuberculosis/inmunología , Prueba de Tuberculina/métodos , Tuberculosis/diagnóstico , Adolescente , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo , Tuberculosis/inmunología , Adulto JovenRESUMEN
The prevalence of systemic lupus erythematosus (SLE) is far higher in females than in males and numerous investigations to understand this gender bias have been performed, which propose as casual actors genetic predispositions and sex hormones effects. We will describe in this review how the sex hormones estrogen and prolactin influence B cell maturation and selection, permitting B cells to mature to immunocompetence in a mouse model of lupus. Finally, we will discuss the relevance and implications of these results for human disease.
Asunto(s)
Andrógenos/metabolismo , Linfocitos B/inmunología , Estrógenos/metabolismo , Lupus Eritematoso Sistémico/inmunología , Animales , Linfocitos B/fisiología , Humanos , Tolerancia Inmunológica/inmunología , Lupus Eritematoso Sistémico/fisiopatología , Linfopoyesis/fisiología , Factores de RiesgoRESUMEN
Anti-neutrophil cytoplasmic antibodies (ANCA) have been widely studied and recognized to be clinically very important for some human diseases including systemic rheumatic diseases. We analyzed ANCA response and their target antigens in MRL/Mp-lpr/lpr (MRL-lpr) mice, an animal model of systemic rheumatic disease. P-ANCA was detected in 57% of the mice. Antibodies to the known P-ANCA target antigens at the same age were examined. Among these, antibodies to high mobility group (HMG) proteins HMG1 and HMG2 were detected in 57% of the mice, 75% of which were also positive for P-ANCA. These anti-HMG1/HMG2 activities were absorbed by preincubation with a mixture of HMG1 and HMG2. In contrast, antibodies to myeloperoxidase and cathepsin G were detected in 14% and 7%, respectively, but these activities were not inhibited by preincubation with corresponding antigens. In addition, the titers of P-ANCA and anti-HMG1/HMG2 antibodies in MRL-lpr mice were significantly correlated with each other. Thus, HMG1 and HMG2 were considered to be significant target antigens of P-ANCA in MRL-lpr mice.