The Third Department of Pneumonology, National Tuberculosis and Lung Diseases Research Institute, Plocka St 26, 01-138, Warsaw, Poland.
Department of Microbiology, National Tuberculosis and Lung Diseases Research Institute, Warsaw, Poland.
Clin Rheumatol. 2019 Nov;38(11):3297-3305. doi: 10.1007/s10067-019-04693-0. Epub 2019 Jul 23.
Antineutrophil cytoplasmic antibodies (ANCAs) are considered a risk factor for granulomatosis with polyangiitis (GPA) exacerbation, especially when staphylococcal superantigens (SAgs) are present in nasal swabs. Their role in monitoring disease activity remains controversial. This study determined the relationship of ANCAs with disease activity and presence of SAgs in GPA patients.
Among a total of 115 GPA patients hospitalized in the period 2009-2016, we investigated the presence of SAgs and ANCA concentration. Blood samples and nasal swabs were taken at each visit (referred further to as episodes). Disease activity was assessed using the Birmingham Vasculitis Activity Score (BVAS).
We analyzed 362 episodes. ANCAs were detected in 215 (59.4%), while SAgs were detected in 126 (34.8%) episodes. We found a significant correlation between the presence of ANCAs and disease activity (p = 0.0032), as well as between their level and GPA severity (r = 0.25363, p = 0.000001). We also determined that an ANCA values ≥ 138 Ru/ml were an indicator of active disease with high specificity and low sensitivity (84.4% and 37.3%, respectively). The relationship between ANCA presence and the presence of SAgs was not confirmed; however, when SAgs were analyzed based on the different types, ANCA levels were found to be significantly higher in the group with SAg type B (p = 0.031).
There was no detectable evidence for the association between ANCA level and the presence of SAgs. Although monitoring ANCA levels as a marker of disease activity may be clinically relevant, GPA management cannot proceed on the basis of ANCA levels alone. Key Points • ANCA concentration usually correlates with GPA activity, although in half of patients, ANCAs persist despite effective treatment and clinical remission. • ANCA values of 138 Ru/ml seem to be an indicator of active disease with high specificity, but low sensitivity. • Although there is a relevance for ANCA monitoring as a marker of disease activity, GPA management cannot be based on ANCA levels alone. • The suspected clinical correlation between ANCA formation and SAg presence in nasal swabs is not obvious and requires further investigations.
抗中性粒细胞胞浆抗体（ANCA）被认为是肉芽肿性多血管炎（GPA）恶化的危险因素，尤其是当鼻拭子中存在葡萄球菌超抗原（SAg）时。其在监测疾病活动中的作用仍存在争议。本研究旨在确定 GPA 患者的 ANCAs 与疾病活动和 SAg 之间的关系。
在 2009 年至 2016 年期间住院的 115 名 GPA 患者中，我们调查了 SAg 和 ANCA 浓度的存在情况。在每次就诊时（进一步称为发作）采集血液样本和鼻拭子。使用伯明翰血管炎活动评分（BVAS）评估疾病活动度。
我们分析了 362 个发作。在 215 个发作（59.4%）中检测到 ANCAs，在 126 个发作（34.8%）中检测到 SAg。我们发现 ANCAs 的存在与疾病活动之间存在显著相关性（p=0.0032），以及它们的水平与 GPA 严重程度之间存在相关性（r=0.25363，p=0.000001）。我们还确定，ANCA 值≥138 Ru/ml 是疾病活动的指标，具有高特异性和低敏感性（分别为 84.4%和 37.3%）。ANCAs 存在与 SAg 存在之间的关系未得到证实；然而，当根据不同类型分析 SAg 时，发现 SAg 类型 B 组的 ANCA 水平显著更高（p=0.031）。
没有证据表明 ANCAs 水平与 SAg 的存在之间存在关联。虽然监测 ANCAs 水平作为疾病活动的标志物可能具有临床相关性，但 GPA 的管理不能仅基于 ANCAs 水平。
ANCAs 浓度通常与 GPA 活性相关，尽管在一半的患者中，尽管进行了有效治疗和临床缓解，但 ANCAs 仍持续存在。
138 Ru/ml 的 ANCA 值似乎是疾病活动的指标，具有高特异性，但敏感性低。
尽管 ANCAs 监测作为疾病活动的标志物具有相关性，但 GPA 的管理不能仅基于 ANCAs 水平。
鼻拭子中 ANCAs 形成与 SAg 存在之间的可疑临床相关性并不明显，需要进一步研究。
