Organ systems affected in Granulomatosis with polyangiitis
Besides the upper and lower respiratory tracts and kidney what other organ systems may be affected?
All organ systems may be affected to variable degrees by GPA. Furthermore, constitutional symptoms such as anorexia, weight loss, fatigue, malaise, and fever are common.
• Eye: commonly involved, affecting 30% to 60% of patients. Proptosis due to orbital inflammatory disease (OID) affects 15% of patients. This process may result in loss of visual acuity as a result of impingement upon the optic nerve and loss of conjugate gaze due to infiltration of the extraocular muscles. Other less specific ocular abnormalities include episcleritis/scleritis, peripheral ulcerative keratitis (with risk for corneal melt), uveitis, conjunctivitis, optic neuritis, lacrimal duct obstruction, and retinal artery thrombosis. Eye involvement may be the initial presentation of GPA before other manifestations occur.
• Ear: inner ear involvement can produce vertigo or hearing loss. Conductive hearing loss and mixed hearing loss (conductive and sensorineural) have been commonly described. Otitis media can be sufficiently severe to require tympanostomy tubes, which in an adult is a strong clue to the diagnosis of GPA. Mastoiditis can also occur.
• Skin: eventually involved in 40% to 50% of patients. Lesions include palpable purpura, ulcers, subcutaneous nodules, vesicles, and livedo reticularis. Pathologic examination may reveal necrotizing vasculitis with or without granulomatous infiltration of the vessel walls, in addition to extravascular granulomatous infiltration and necrosis. Children with GPA may present with palpable purpura and be misdiagnosed as having IgA vasculitis (Henoch–Schönlein purpura).
• Musculoskeletal system: commonly manifests as arthralgia and myalgia, eventually affecting 67% of patients. Synovitis is less common and, when present, does not result in erosive disease, articular destruction, or joint deformity.
• Peripheral and CNS: occurs in 15% and 8% to 10% of patients, respectively. The most common peripheral neuropathy is mononeuritis multiplex and less commonly a symmetric polyneuropathy. Sural nerve biopsy may show vasculitis. CNS syndromes include chronic pachymeningitis, cranial neuropathies, ocular palsies, cerebrovascular events, seizures, pituitary involvement, brain stem and spinal cord lesions, and brain hemorrhage (cerebral, subarachnoid, subdural).
• Cardiac: up to 5% of patients develop pericarditis, which rarely results in interference with ventricular filling. Involvement of the myocardium, endocardium, and coronary vasculature is unusual, but may result in significant morbidity and, rarely, mortality.
Involvement of other organ systems, including the gastrointestinal (intestinal perforations), genitourinary tracts (bladder/urethral vasculitis, orchitis, epididymitis, prostatitis, other), salivary gland (mass), pancreas (mass), and granulomatous infiltration of liver occurs less frequently but may occasionally result in life-threatening complications.
