Granulomatosis with polyangiitis, a form of ANCA-associated small vessel vasculitis

Abstract

Granulomatosis with polyangiitis (GPA), formerly known as Wegener’s granulomatosis, is a rare systemic vasculitis that affects small- and medium-sized vessels, with a predilection for the respiratory tract and kidneys.

We present the case of a 52-year-old woman with no relevant personal or family medical history, who initially developed disabling polyarthralgia and was treated for presumed rheumatoid arthritis. She later experienced ocular pain, conjunctival injection, and sudden vision loss in the right eye, followed by hemoptysis and progressive dyspnea. She went to the General Hospital where she underwent a computed tomography scan of the chest, which revealed cavitated pulmonary nodules. Laboratory findings included anemia, elevated acute-phase reactants, strongly positive C-ANCA with anti-PR3 >100, and proteinuria on urinalysis. Infectious and other autoimmune causes were ruled out. Based on multisystem involvement and serological markers, GPA was diagnosed. The patient underwent induction therapy with monthly pulses of cyclophosphamide and oral prednisone, leading to resolution of pulmonary cavitations, clinical stabilization, and partial visual recovery. This case illustrates an atypical and progressive form of GPA, initially misdiagnosed, in which severe ocular involvement preceded the definitive diagnosis. The clinical evolution underscores the importance of maintaining high clinical suspicion when facing systemic, nonspecific symptoms accompanied by cavitary pulmonary lesions and extrapulmonary manifestations. It also highlights the critical role of early diagnosis and timely initiation of immunosuppressive therapy to prevent irreversible damage. GPA remains a diagnostic challenge requiring multidisciplinary management and close clinical monitoring to optimize patient outcomes.