A recent study published in Open Rheumatology has shown that the serum biomarkers CXCL3, IL6, IL8, IL5, IL8BP, matrix metalloproteinase-3, and ESR are associated with active disease in antineutrophil cytoplasmic antibody-associated vasculitis (AAV), and IL15, IL8BP, and IL8 are found to be good at predicting flare.
The former set of markers has shown a weaker association with mild flare. Certain markers like CXCL3 and MMP3 are found to be elevated in patients on glucocorticoids and marker levels may not be indicative of future flare. Hence, it may not be considered a biomarker on disease relapse.
AAV comprises of two diseases namely granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA). It is a chronic disease requiring long-term immunosuppressive therapy. The mortality due to the disease is very high and is further exacerbated by cardiovascular disease, infection (secondary to treatment), and malignancy.
Due to the variable course of the disease, it is highly challenging to determine whether it is a disease flare or abnormalities in diagnostic tests are due to prior damage, medication toxicities, infection, or other causes. Although ESR and CRP have been suggested to be useful for predicting relapse, they may not be adequate to determine the management strategies of individual patients.
The present study, which measured 22 proteins using 347 serum samples obtained from 74 patients, corroborated the role of several serum markers in determining active AAV. The study has also highlighted the need for hypothesis-based studies for validating the role of more generic markers of inflammation or ANCA titers that indicate disease activity or predict future flare.
Reference: Monach PA, Warner RL, Lew R, et al. Serum Biomarkers of Disease Activity in Longitudinal Assessment of Patients with ANCA-Associated Vasculitis [published online ahead of print, 2021 Nov 18]. ACR Open Rheumatol. 2021;10.1002/acr2.11366.