Polyarteritis nodosa diagnosed in a young male after COVID-19 vaccine: A case report.

In response to the coronavirus disease 2019 pandemic, the coronavirus disease 2019 vaccine was rapidly developed and the effectiveness of the vaccine has been established. However, various adverse effects have been reported, including the development of autoimmune diseases. We report a case of new-onset polyarteritis nodosa in a 32-year-old male following the coronavirus disease 2019 vaccination. The patient developed limb pain, fever, pulmonary embolism, multiple subcutaneous nodules, and haematomas. Skin biopsy revealed necrotising inflammation accompanied by fibrinoid necrosis and high inflammatory cell infiltration in the walls of medium to small arteries. The symptoms resolved following corticosteroid treatment. Although it is difficult to prove a relationship between the vaccine and polyarteritis nodosa, similar cases have been reported and further reports and analyses are therefore necessary.

Performance of classification and diagnostic criteria for IgG4-related disease and comparison of patients with and without IgG4-related disease.

IgG4-related disease (IgG4-RD) was recently described in Japan. It is characterised by extensive organ involvement with tissue fibrosis. We assessed the performance of the 2019 American College of Rheumatology and European League Against Rheumatism (ACR/EULAR) classification criteria and the 2020 revised comprehensive diagnostic (RCD) criteria as well as differences between patients with and without IgG4-RD. In this retrospective, single-centre study of 50 patients admitted with suspected IgG4-RD, we evaluated the sensitivity and specificity of both criteria. We also compared clinical characteristics and laboratory data of patients with IgG4-RD (n = 42) and patients without IgG4-RD (n = 8). The ACR/EULAR classification criteria had 88.1% sensitivity and 87.5% specificity for IgG4-RD diagnosis. The RCD criteria had 100% sensitivity and 50% specificity. Patients with IgG4-RD had significantly more affected organs (p = 0.002). Patients with a single affected organ and IgG4-RD had significantly higher serum IgG4/IgG ratios (p = 0.027), lower serum C-reactive protein levels (p = 0.020), and lower total haemolytic complement activity (p = 0.044) than those without IgG4-RD. The ACR/EULAR classification criteria have high specificity and the RCD criteria have high sensitivity for diagnosing IgG4-RD. The number of affected organs is important for diagnosing IgG4-RD.

Changes in anti-MDA5 antibody titres and serum cytokine levels before and after diagnosis of anti-MDA5 antibody-positive dermatomyositis.

OBJECTIVES: Anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive DM is characterized by rapidly progressive interstitial lung disease and has a poor prognosis. We aimed to investigate whether anti-MDA5 antibody titres and cytokine levels predict clinical course, and evaluate changes in both parameters before and after diagnosis. METHODS: This was a retrospective, single-centre study in 38 patients with anti-MDA5 antibody-positive DM. We compared clinical characteristics and laboratory data at diagnosis between patients in the treatment response (n = 23) and non-response (n = 15) groups, and between those in the relapse (n = 5) and non-relapse (n = 24) groups. We also measured serum anti-MDA5 antibody titres and cytokine levels before and after diagnosis. RESULTS: The non-response group was older, had a higher ground-glass opacity score, lower PaO2/FiO2, higher CRP level, and higher anti-MDA5 antibody titre than the response group. No cytokines significantly differed between groups at diagnosis. The relapse group had a significantly higher anti-MDA5 antibody titre than the non-relapse group. In the survivor group, the anti-MDA5 antibody titre and levels of IFN-α, IFN-γ, monocyte chemotactic protein-1 (MCP-1), IL-6, IL-33, CRP, and ferritin were significantly lower 6 months post-treatment than at diagnosis. Macrophage-associated cytokines such as IL-6, IL-8, IL-18 and MCP-1 increased after anti-MDA5 antibody positivity in three patients who were anti-MDA5 antibody-positive before diagnosis. CONCLUSION: The anti-MDA5 antibody titre at diagnosis may predict the clinical course. Levels of macrophage-associated cytokines significantly declined at 6 months post-treatment, and they may have increased after anti-MDA5 antibody titre positivity.

Bacteremia in systemic lupus erythematosus: Risk factors, clinical and microbiological characteristics, and outcomes in the largest single-center retrospective cohort in Japan.

BACKGROUND: In patients with systemic lupus erythematosus (SLE), infections, especially bacteremia, can occur throughout the course of the disease and are often fatal. We evaluated the characteristics of patients with bacteremia and SLE. METHODS: In this retrospective single-center observational study, we analyzed bacteremia in 65 patients with SLE. We compared the group that survived to the group that died. To compare demographic and clinical characteristics between groups, the Mann-Whitney U test was used for non-normally distributed variables. Categorical variables were compared using Fisher's exact test. RESULTS: The median observation period was 39 (interquartile range: 6-74) months. The median age was 54 (43-64) years. Patients consisted of six males and 59 females. In 49 cases, the patient survived. In 16 cases, the patient died. The dead group was older, with lower Glasgow Coma Scale scores, higher sequential organ failure assessment (SOFA) scores, and lower fibrinogen levels. CONCLUSION: When physicians encounter patients with suspected bacteremia, they should pay attention to the consciousness assessment and SOFA score, and be aware of infections caused by common microorganisms and opportunistic infections.