HLA-B52 allele in giant cell arteritis may indicate diffuse large-vessel vasculitis formation: a retrospective study.

BACKGROUND: This study aimed to identify new characteristics of elderly onset large-vessel vasculitis (EOLVV) by focusing on human leucocyte antigen (HLA) genotype, polymyalgia rheumatica (PMR), and affected vascular lesions observed on positron emission tomography/computed tomography (PET/CT) imaging. METHODS: We retrospectively studied 65 consecutive Japanese patients with large-vessel vasculitis (LVV) who had extracranial vasculitis lesions and underwent PET/CT imaging. PET/CT images were assessed using the semi-quantitative PET visual score of each affected vessel, and the PET vascular activity score (PETVAS) and number of affected vessels were calculated. Subjects were subsequently grouped based on age at onset, superficial temporal artery (STA) involvement, and presence of PMR and compared each group according to HLA genotype. Unsupervised hierarchical cluster analysis was used to identify the patients with similar characteristics in terms of affected vascular lesions detected through PET/CT imaging. The clinical characteristics and PET/CT findings of the population newly identified in this study were examined. RESULTS: Twenty-seven patients with EOLVV did not meet the American College of Rheumatology 1990 criteria for giant cell arteritis (GCA) and Takayasu arteritis and were considered as unclassified EOLVV (UEOLVV). The unsupervised hierarchical cluster analysis revealed that UEOLVV with PMR and large-vessel GCA (LV-GCA) formed a cluster of LVV with GCA features (i.e., PMR and/or STA involvement) when restricted to patients who were HLA-B52-positive. Patients who were HLA-B52-positive with LVV and GCA features had similar clinical characteristics and patterns of affected vessels and presented with diffuse LVV lesions. HLA-B52-positive patients who had LVV with GCA features also presented with higher PETVAS, more affected vessels, and lower rates of biologics usage and relapse compared to HLA-B52-positive patients with TAK. CONCLUSIONS: Patients who had UEOLVV with PMR had similar characteristics to patients with LV-GCA. Patients who were HLA-B52-positive and had LVV with GCA features presented with diffuse vascular lesions and may comprise a core population of Japanese patients with EOLVV. The findings of HLA-B52 positivity and diffusely affected vessels in patients with EOLVV can be considered as suspicious findings of LV-GCA.

Increased Proportion of CD226+ B Cells Is Associated With the Disease Activity and Prognosis of Systemic Lupus Erythematosus.

Background: CD226, an activating receptor expressed on the surface of natural killer (NK) cells and T cells, is also seen on B cells and CD226 polymorphism is associated with systemic lupus erythematosus (SLE). Because the specific roles of CD226+ B cells in SLE are still unknown, we investigated the association of CD226+ B cells with SLE. Methods: We measured CD226 expression on B cells and its subsets using flow cytometry in 48 SLE patients and 24 healthy controls (HCs). We assessed the relationships between CD226+ B cells and SLE Disease Activity Index 2000 (SLEDAI-2K), clinical manifestations, laboratory data, and prognosis after 12 months. Results: The proportions of CD226+ cells in whole B cells and all its subsets were significantly higher in SLE patients than HCs. In SLE patients, the proportions of CD226+ B cells and CD226+ switched-memory (SM) B cells were significantly correlated with SLEDAI-2K scores and anti-dsDNA antibody titers, and negatively correlated with serum complement levels. Moreover, basal percentages of CD226+ B cells and CD226+ SM B cells were low in patients who were in Lupus Low Disease Activity State after 12 months. In patients with renal involvement, the proportion of CD226+ B cells increased. Additionally, the proportion of CD226+ B cells was higher in patients who were not in complete renal remission after 12 months. Conclusions: Increased proportion of CD226+ B cells was associated with disease activity and prognosis of SLE. CD226+ B cells may be a useful biomarker for the management of SLE.

Association of elevated serum soluble CD226 levels with the disease activity and flares of systemic lupus erythematosus.

CD226 is an activating receptor expressed on the cell surface of natural killer cells and T cells. Although CD226 polymorphism is known to be involved in systemic lupus erythematosus (SLE), the involvement of soluble CD226 (sCD226) in SLE is still unknown. In the present study, we measured serum sCD226 levels using an enzyme-linked immunosorbent assay in 58 SLE patients and 33 healthy controls (HCs) and evaluated their associations with SLE Disease Activity Index 2000 (SLEDAI-2K), clinical manifestations, laboratory data, and the cumulative probability of flare. Serum sCD226 levels showed no significant differences between SLE patients and HCs. However, sCD226 levels were significantly elevated in active SLE patients with a SLEDAI-2K score of ≥ 20 compared with HCs. In SLE patients, sCD226 levels were significantly correlated with SLEDAI-2K scores and anti-dsDNA antibody titers. Moreover, the cumulative probability of flare was markedly higher in patients with high sCD226 than in those with low sCD226. In patients with neuropsychiatric involvement, sCD226 levels were elevated and reflected neuropsychiatric disease activity. These findings indicate that serum sCD226 levels are associated with disease activity and flares of SLE. Thus, it may be a useful biomarker for SLE, and its monitoring allows for more precise SLE management.

Infected Thoracic Aortic Aneurysm Caused by Helicobacter cinaedi.

The causative organism is not identified in some cases of infected aneurysms, a life-threatening condition. A 68-year-old man presented with chest/back pain and a 1-year history of intermittent fever and fatigue. Computed tomography revealed a thoracic aortic aneurysm. After several negative blood cultures, he was eventually diagnosed with an infected aneurysm caused by Helicobacter cinaedi via gene analysis of an aortic tissue specimen. As H. cinaedi is a low-virulence bacterium, infection with this pathogen should be suspected in cases of aortic aneurysms with unidentified causative organism and a long history of subjective symptoms. Detailed examinations, including polymerase chain reaction, should be conducted in such cases.