Elevated serum levels of immunoglobulin A correlate with the possibility of readmission in patients with microscopic polyangiitis

Huijuan Wang, Chao Zhang, Zhaohui Tong, Xiaoning Bu


Background: The evidence for the short-term prognosis of patients with microscopic polyangiitis (MPA) is weak, and the objective of this study was to analyze the clinical features of the disease and evaluate the risk factors for readmission in patients with MPA.
Methods: Fifty-seven patients with MPA were recruited into this study. The clinical data of these MPA patients were collected. Clinical manifestations, laboratory results, and imaging results were analyzed. Patients who were readmitted to our hospital within 6 months after their first diagnosis and treatment of MPA were defined as the readmission group; the remaining patients were defined as the control group.
Results: Respiratory symptoms, including cough, dyspnea (87.72%), and hemoptysis (3.51%), seemed to be the initial symptoms in many patients with MPA. Systemic symptoms included fever (71.93%), hearing loss (12.28%), vision loss (3.51%), and joint involvement (5.27%). The D-dimer levels of 43 patients (75.44%) were >500 ng/dL, and only three of these patients had venous thrombosis. Age and immunoglobulin A (IgA) were the risk factors for readmission in patients with MPA, with odds ratios (ORs) of 1.162 [95% confidence interval (CI): 1.025–1.317, P=0.019] and 1.010 (95% CI: 1.001–1.018, P=0.028). The days of hospitalization and the a2-globulin level were protective factors with ORs of 0.849 (95% CI: 0.725–0.993 P=0.041) and 0.789 (95% CI: 0.64–0.971, P=0.025), respectively. IgA levels were positively correlated with the number of hospitalizations, with a correlation coefficient of 0.428 (P=0.002). Receiver operating characteristic curve analysis showed that the possibility of readmission increases when the serum levels of IgA were >217.5 mg/dL.
Conclusion: The level of serum IgA is a risk factor for the readmission of patients with MPA, and correlated with the number of hospitalizations in these patients.