Clinical correlation between incipient C-reactive protein and kidney injury of anti-neutrophil cytoplasmic antibody associated vasculitis

Objective To investigate the relationship between the incipient serum C-reactive protein (CRP) and clinicopathologic features in anti-neutrophil cytoplasmic antibody associated vasculitis (AAV). Methods Data of 138 consecutive AAV patients were collected. According to their serum CRP levels, patients were divided into group 1 with normal CRP, group 2 with slightly increased CRP and group 3 with severely increased CRP. Clinical features of AAV and histopathologic features of the kidney injury were compared among groups. Results CRP levels increased in 77.53% AAV patients on admission. Patients in the group of severely increased CRP had the highest levels of BVAS, serum C3, serum ANCA titer, leukocyte counts and the lowest levels of hemoglobin and albumin among the 3 groups (all P＜0.05). The mortality during the stage of therapy was highest in patients with severely increased CRP (P＜0.05). The focal kidney damage was more obvious in patients with severely increased CRP. There was no significant difference in renal prognosis among patients with different CRP levels. Conclusion The levels of incipient serum C-reactive protein of AAV vary in different patients and are positively correlated with patients' inflammation status as well as the disease activity, but are not correlated with the severity of kidney injury.