Clinical association of mixed connective tissue disease and granulomatosis with polyangiitis: a case report and systematic screening of anti-U1RNP and anti-PR3 auto-antibody double positivity in ten European hospitals

Prevalence of overlap of antineutrophil cytoplasmic antibody associated vasculitis with systemic autoimmune diseases: an unrecognized example of poliautoimmunity

We aimed to estimate the frequency of overlap of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) with systemic autoimmune diseases. Retrospective single-center study to identify patients with AAV diagnosis and concomitant autoimmune systemic diseases, simultaneously, before or after the diagnosis of AAV. Sociodemographic characteristics, such as comorbidities; follow-up time; type of AAV; disease duration; relapses; treatment and response; clinical, serological, and histological characteristics; disease activity and damage; prognosis; dialysis requirements, and death were assessed. Twenty-eight of two hundred and forty-seven patients (11.3%) with AAV had a concomitant diagnosis of autoimmune disease. The predominant AAV type was renal-limited vasculitis (39%), followed by granulomatosis with polyangiitis (29%), mycroscopic polyangiitis (25%), and eosinophilic granulomatosis with polyangiitis (7%). Mean age at AAV diagnosis was 50 ± 17 years and 24/28 were ANCA positive. The main clinical manifestations were renal (79%), otorhinolaryngologic (43%), and pulmonary and peripheral neuropathy (32%). Sixteen patients (57%) experienced partial or total remission at a median follow-up of 34 months, and four patients (14%) died. The most frequent autoimmune disease overlapped was rheumatoid arthritis (39%), followed by Sjögren's syndrome and systemic sclerosis (14%), mixed connective tissue disease (11%), systemic lupus erythematosus and juvenile idiopathic arthritis (7%), and ankylosing spondylitis and IgG4-related disease (4%). In nine patients (32%), both diagnoses were simultaneous; in the rest, median time elapsed between the autoimmune disease and AAV diagnosis was 173 months. The prevalence of overlap AAV with other autoimmune diseases was low. The most common AAV phenotype was renal-limited vasculitis, and the most frequent overlap disease was rheumatoid arthritis.

Pulmonary-Limited Granulomatosis with Polyangiitis Coexisting with Mixed Connective Tissue Disease

Granulomatosis with polyangiitis (GPA) is a systemic disease characterized by necrotizing, granulomatous vasculitis of the upper and lower respiratory tracts and glomerulonephritis, and is classified as a classical or limited form. The classical form of GPA demonstrates the involvement of the upper respiratory tract, sinuses, lungs and kidneys, whereas the limited form is characterized by the lack of the renal involvement with female predominance. On the other hand, mixed connective tissue disease (MCTD) shows the clinical and laboratorial features of systemic lupus erythematosus, systemic sclerosis and polymyositis, along with high titers of anti-ribonucleoprotein antibodies and is characterized by good response to corticosteroid therapy and favorable prognosis. We herein report a patient with a history of MCTD that developed into a limited form of GPA (pulmonary-limited GPA). A 39-year-old woman suffered from persistent cough, left back pain and appetite loss. At 21 years of age she was diagnosed with MCTD, but the persistent administration of prednisolone or immunosuppressants was not needed. On admission, high-resolution chest computed tomography showed bilateral, multiple, poorly circumscribed nodules and masses, some of which showed cavitation. A surgical lung biopsy demonstrated granulomas with vasculitis surrounding the necrotic lesions. She was diagnosed with pulmonary-limited GPA. In conclusion, we should recognize that GPA may develop during the disease course of MCTD even after prolonged disease remission. To prevent progression to an irreversible state, physicians should consider a surgical lung biopsy for the diagnosis in patients suspected of having pulmonary-limited GPA.

Analysis of Antineutrophil Cytoplasm Antibody from 118 730 Patients in Tertiary Hospitals in Jiangxi Province, China

BACKGROUND The discovery of antineutrophil cytoplasm antibody (ANCA) makes the early diagnosis of primary vasculitis possible, and also has important guiding significance for the diagnosis and treatment of secondary vasculitis. This study aimed to investigate the clinical significance of ANCA. MATERIAL AND METHODS ANCA was detected by indirect immunofluorescence assay (IIF), and anti-myeloperoxidase (MPO) antibody, and anti-proteinase 3 (PR3) antibody were detected by ELISA. The results were analyzed retrospectively. RESULTS Among 118 730 patients, a total of 5853 (4.93%) were positive for ANCA. In the positive cases, 3.98% were male and 6.33% were female, with significant differences (χ²=123.38, P<0.01). For ANCA, the department with the highest positive rate (15.06%) was the Department of Rheumatology, followed by 7.78% in the Department of Dermatology, 6.79% in the Department of Nephrology, and 5.72% in the Department of Traditional Chinese Medicine (TCM). Anti-PR3 and cANCA were highly specific in primary vasculitis (P<0.01). Anti-MPO and pANCA had high specificity for other autoimmune diseases (P<0.01). CONCLUSIONS ANCA has important guiding significance for vasculitis-related diseases. Therefore, it is important in the diagnosis and treatment of this disease and has value in clinical practice.