Perinuclear anti neutrophil cytoplasmic antibody vasculitis with nonspecific muscle pain

This is a case report describing p-ANCA vasculitis presenting with nonspecific muscle pain. It is a very uncommon finding seen in p-ANCA vasculitis patients which they usually present with palpable purpura alone. In this case, along with nonspecific muscle pain, renal involvement of the disease has been explained and there are no upper and lower respiratory tract complaints which favours more towards microscopic polyangitis.

The association of airway comorbidities with the clinical phenotypes and outcomes of ANCA-associated vasculitis patients.

Objective We investigated the association of airway comorbidities with the clinical phenotypes and outcomes of myeloperoxidase (MPO)-anti-neutrophil cytoplasmic antibodies (ANCA)-positive ANCA-associated vasculitis (AAV). Methods An AAV patient multi-center cohort trial was established in 13 hospitals in western Japan between 2012 and 2018. We examined 143 of the new-onset MPO-ANCA-positive AAV patients. Their clinical characteristics and comorbidities at disease onset were compared based on clinical phenotypes. Multivariate analysis was performed to identify factors predictive for remission and death. Results Ten cases with eosinophilic granulomatosis with polyangitis (EGPA), 27 with granulomatosis with polyangitis (GPA), 81 with microscopic polyangitis (MPA) and 25 with unclassified AAV were identified. The average age was 71.4 years old. Comorbidity (87.4%) and airway comorbidity (70.6%) were frequently observed in these patients. Examination of the clinical phenotypes revealed that the cases of GPA were frequently accompanied by infectious airway comorbidity (upper airway disease, bronchiectasis, pulmonary infections), and most of the cases of MPA and unclassified AAV were accompanied by fibrotic interstitial lung disease (fILD) or emphysema. Among MPO-ANCA-positive patients, infectious airway comorbidity was predictive of both remission (HR 1.58, p=0.027) and mortality (HR 2.64, p=0.040), and fILD was predictive of mortality (HR 7.55, p=0.0078). The combination of infectious airway comorbidities and fILD caused the worst survival outcomes in those patients. Conclusion MPO-ANCA-positive AAV was frequently accompanied by airway comorbidities. In addition to fILD, infectious airway comorbidities were closely associated with those clinical phenotypes and outcomes.