ABSTRACT
Giant cell aortitis is a rare cause of acute aortic syndrome. We describe the cases of two patients who had presented with chest pain, hypertension, and computed tomography angiographic evidence of mural thickening typical of thoracic aortic intramural hematoma. Although the patients' symptoms improved with hypertension control, elevated inflammatory markers and persistent fever to 103°F raised concern for an inflammatory etiology. Empiric steroids were administered, resulting in prompt cessation of fever and decreasing inflammatory markers. The findings from temporal artery biopsies were positive in both patients. Follow-up axial imaging after 2 weeks of steroid therapy revealed improvement in aortitis with decreased wall thickening. Giant cell aortitis should be considered in patients presenting with acute aortic syndrome in the setting of elevated inflammatory markers and noninfectious fever.
ABSTRACT
OBJECTIVE: Protein tyrosine phosphatase nonreceptor type 22 (PTPN22) is associated with an increased risk of systemic lupus erythematosus (SLE). PTPN22 encodes Lyp, and a disease-associated coding variant bears an R620W substitution (LypW). LypW carriage is associated with impaired production of type I interferon (IFN) by myeloid cells following Toll-like receptor (TLR) engagement. The aim of this study was to investigate the effects of LypW carriage on TLR signaling in patients with SLE. METHODS: Plasma IFNα concentrations and whole-blood IFN gene scores were compared in SLE patients who were LypW carriers and those who were noncarriers. TLR-7 agonist R848-stimulated IFNα and tumor necrosis factor levels, IFN-dependent gene expression, and STAT-1 activation were determined in peripheral blood mononuclear cells (PBMCs) and/or plasmacytoid dendritic cells (PDCs) obtained from these patients. The effect of LypW expression on the systemic type I IFN response to R848 stimulation in vivo was assessed in transgenic mice. RESULTS: Plasma IFNα levels and whole-blood IFN gene signatures were comparable in SLE patients who were LypW carriers and those who were noncarriers. However, PBMCs from LypW carriers produced less IFNα and showed reduced IFN-dependent gene up-regulation and STAT-1 activation after R848 stimulation. The frequency of PDCs producing IFNα2 and the per-cell IFNα2 levels were significantly reduced in LypW carriers. LypW-transgenic mice displayed reduced TLR-7-induced circulating type I IFN responses. CONCLUSION: PDCs from SLE patients carrying the disease-associated PTPN22 variant LypW showed a reduced capacity for TLR-7 agonist-induced type I IFN production, even though LypW carriers displayed systemic type I IFN activation comparable with that observed in noncarriers. LypW carriage identifies SLE patients who may harbor defects in TLR- and PDC-dependent host defense or antiinflammatory functions.
Subject(s)
Interferon-alpha/immunology , Lupus Erythematosus, Systemic/genetics , Membrane Glycoproteins/immunology , Protein Tyrosine Phosphatase, Non-Receptor Type 22/genetics , Toll-Like Receptor 7/immunology , Adult , Animals , Case-Control Studies , Dendritic Cells/immunology , Female , Gene Expression Profiling , Gene Expression Regulation , Humans , Imidazoles/pharmacology , Interferon Type I/immunology , Leukocytes, Mononuclear/immunology , Lupus Erythematosus, Systemic/immunology , Membrane Glycoproteins/agonists , Mice, Transgenic , Middle Aged , Polymorphism, Single Nucleotide , STAT1 Transcription Factor/immunology , Toll-Like Receptor 7/agonists , Tumor Necrosis Factor-alphaABSTRACT
Accelerated atherosclerosis remains a major cause of death in late systemic lupus erythematosus (SLE). Omega-3 has been reported to have benefit for endothelial dysfunction, one of the earliest stages of atherosclerosis, and to reduce disease activity in SLE. We performed a randomized, double-blind placebo-controlled trial to examine the effect of Omega-3 on endothelial function, disease activity, inflammatory markers and lipids in SLE. SLE patients (n = 85, mean age 47, 55% Caucasian, 38% African-American, 94% female) were randomly assigned to 3 g of Omega-3 (Lovaza, GSK) versus placebo for 12 weeks. Endothelial function was measured at baseline and at 12 weeks using flow-mediated dilation, calculated using high-resolution B-mode ultrasound of the brachial artery diameter in response to vasoactive stimuli (hyperemia). Disease activity was measured using the physician global assessment and SELENA-SLEDAI score. Inflammatory markers (sICAM-1, sVCAM-1, IL-6) and fasting lipid profile were done at baseline and 12-week follow-up. There was no difference between the treatment groups with respect to changes in flow-mediated dilation parameters or disease activity. An average increase in LDL cholesterol of 3.11 mg/dL (±21.99) was found with Omega-3 versus a decrease of 1.87 mg/dL (±18.29) with placebo (p = 0.0266). In this trial, Omega-3 did not improve endothelial function, disease activity, nor reduce inflammatory markers in SLE. Longer trials might be required if there are delayed clinical effects. There was evidence that Omega-3 may increase LDL cholesterol, but not the LDL/HDL ratio.