Fatigued PR3-ANCA patients had higher rates of cognitive failure (p = 0.001) and arthralgia (p = 0.03), more females (<0.001), and higher levels of CRP (p = 0.03), with a trend also evident for fibromyalgia symptoms (p = 0.05) (Supplementary Table S2). Here, CRP is linked to fibromyalgia.