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Wegener's Granulomatosis

Pathology

In Wegener's granulomatosis, the entire respiratory tract from nasal septum to pleura can be involved with necrotizing inflammation. The typical pathologic features seen on open lung biopsy are (1) parenchymal necrosis, (2) vasculitis, and (3) granulomatous inflammation. Necrosis may involve collagen of any structure of the lung, including walls of blood vessels, conducting airways, alveolar walls, and pleura. Foci of micronecrosis (less than 1 mm in diameter) of collagen are the earliest lesions of Wegener's granulomatosis. Micronecrosis consists of a microabscess with punctate collections of neutrophils.

Vascular changes are identified in up to 90% of open lung biopsy specimens from patients with Wegener's granulomatosis. The blood vessels affected are most commonly within the nodular inflammatory lesions. A recent report describing 87 open lung biopsies from 67 patients with Wegener's granulomatosis emphasized the variation in vascular pathology. Chronic inflammation of vessels was seen in 87% of the specimens, acute inflammation in 37%, necrotizing granulomatous.

Clinical Features

The mean age at diagnosis is 41 years (range, 9 to 78 years), and 15% of the patients are less than 19 years of age. The median and mean periods from the onset of symptoms to a diagnosis of Wegener's granulomatosis are 4.7 and 15 months, respectively. The diagnosis of Wegener's granulomatosis was made within 3 months of symptom onset in 42% of the patients, in 30% of the patients the diagnosis was made more than 1 year after they initially sought medical attention, and in 8% of the patients, the diagnosis was not made until 5 to 16 years later.

Ninety-percent of patients with Wegener's granulomatosis initially seek medical care because of upper or lower airway symptoms. Nasal, sinus, tracheal, or ear abnormalities were initially responsible for symptoms in 73% of the patients and occurred in 92% of the patients overall. Pulmonary symptoms included cough, hemoptysis, and pleuritis. Lung disease related to Wegener's granulomatosis eventually developed in 85%

Ocular involvement will ultimately occur in 25% to 50% of the patients. Conjunctivitis, uveitis, episcleritis, optic neuritis, and occlusion of the central retinal artery may each occur. Unilateral or rarely bilateral proptosis may be caused by granulomatous pseudotumors of the orbit. Proptosis, the most specific finding,

Before initiation of therapy, patients with active Wegener's granulomatosis often have leukocytosis. Anemia occurs in the majority of patients and is usually normocytic or normochromic. Thrombocytosis is also

Antineutrophil Cytoplasmic Antibodies

Antineutrophil cytoplasmic antibodies have been described as sensitive and specific markers for active

Diagnosis

The diagnosis of Wegener's granulomatosis is established when a characteristic clinical syndrome is accompanied by typical pathologic features on a biopsy specimen. The American College of Rheumatology criteria for Wegener's granulomatosis is vasculitis (tissue or angiographically demonstrated).

Therapy

Before the development of therapy, the mean survival of patients with untreated Wegener's granulomatosis was 5 months. The use of corticosteroids only improved the average survival to 12.5 months.

The best treatment for Wegener's granulomatosis currently is oral cyclophosphamide (2 mg/kg/day) and prednisone (initially at 1 mg/kg/day). Among patients who achieve remission after receiving standard therapy, conversion from daily to alternate-day prednisone usually occurs at approximately 3 months. Cyclophosphamide should be continued for at least 1 full year after the patient is in complete remission. This