Characteristics and clustering analysis of peripheral blood lymphocyte subsets in patients with ANCA-associated vasculitis

Objective This study aimed to investigate the clusters of lymphocyte subset in patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) and their correlation with clinical characteristics. Methods A total of 247 active AAV patients, 70 AAV patients with induced remission, and 252 healthy controls (HCs) were enrolled. Based on lymphocyte subsets, results were visualised by principal component analysis, and subgroups of patients were identified by cluster analysis. Results The absolute number of total lymphocytes and lymphocyte subsets were lower in patients with AAV than in HCs. All lymphocyte subsets were negatively correlated with BVAS (p<0.01) in patients with AAV, except for B cells. A decrease in lymphocyte subset count was associated with renal damage in patients with AAV. T lymphocyte subset features recovered during remission compared with the active disease state. However, the percentage and absolute number of B cells markedly decreased in the induced remission group (p<0.0001). Cluster analysis classified patients into three distinctive subgroups: Patients in cluster 2 had the highest white blood cell count, serum albumin level, monocyte count, and eGFR, whereas they had the lowest serum creatinine level and ESR (p<0.05). Patients with decreased lymphocyte subsets showed poor disease outcome. The count of CD3(+)T lymphocytes had the best predictive power for identifying disease outcome in AAV patients. Conclusion The counts of lymphocyte are lower in patients with active AAV than HCs. Decreased lymphocyte subsets may serve as a biomarker for assessing disease severity and predict poor outcome in AAV patients.