Abstract: Objective To investigate the risk factors of systemic lupus erythematosus(SLE) combined with pulmonary arterial hypertension (PAH) and the clinical value of perinuclear-ANCA(p-ANCA) test. 
Methods In total, 64 patients with SLE combined with PAH treated in the Second Hospital of Hebei Medical University were screened as the SLE-PAH group, of which 44 patients were positive for p-ANCA and 20 patients were negative for p-ANCA. Then according to the ratio of 1∶3 we matched 192 SLE patients without PAH hospitalized during the same period as SLE-nonPAH group. The patients′ basic information, clinical data related to SLE activities, laboratory test results and transthoracic echocardiography (TTE) results were recorded. Clinical characteristics of SLE-PAH patients as well as clinical and laboratory features of p-ANCA-positive and p-ANCA-negative patients with PAH were analyzed to explore the risk factors of SLE-PAH. 
Results Compared with the SLE-nonPAH group, patients in the SLE-PAH group had olderer age and a higher percentage of moderate-to-severe disease activity, showing significant difference between the two groups (P＜0.05). More patients showed Raynaud′s phenomenon, increased white blood cell count and absolute neutrophil count, elevated standardized SCT ratio of lupus anticoagulant, positive anticardiolipin antibodies, and abnormalities of pulmonary artery diameter, right atrial diameter, and interventricular septal thickness. There was a significant difference in the severity of PAH between the p-ANCA positive group and the p-ANCA negative group in SLE-PAH patients (P＜0.05). Multivariate Logistic regression analysis suggested that Raynaud′s phenomenon，anticardiolipin antibodies，and increased neutrophil count (OR=0.802) were independent risk factors for combined PAH in patients with SLE (P＜0.05). 
Conclusion SLE patients presenting with moderate to severe disease activity, elevated peripheral blood leukocytes, neutrophils, standardized SCT ratios, and positive anticardiolipin antibodies are alerted to the development of PAH. p-ANCA positivity may be associated with the severity of pulmonary hypertension and requires close follow up. 

Key words: lupus erythematosus, systemic, pulmonary arterial hypertension, transthoracic echocardiography