Originally, Wegener granulomatosis was classified as a subset of polyarteritis nodosa. In 1936, it was reclassified as a distinct disease. It is a disease that affects the upper and lower respiratory tracts. It also causes a necrotizing vasculitis of small— and medium—sized vessels. This makes it a disease that is truly multi-systemic. Histologically, lesions are necrotizing granulomas.
Potential etiology of Wegener's granulomatosis
As yet, no definitive mechanism for the disease has been defined. Present research implicates an effect of inflammatory mediators and immune effector cells on the lining of blood vessels. It is proposed that neutrophils and endothelial cells are involved as both targets and promoters of inflammation. Initially, c-ANCA activates neutrophils. The neutrophils target endothelium, which when damaged release activators. These recruit monocytes and T cells, and the inflammatory cycle begins.
Clinical presentation of Wegener's granulomatosis
Pulmonary manifestations of Wegener's granulomatosis begin with alveolitis. Granulomas are both intravascular and extravascular. Renal lesions are typically a necrotizing glomerulonephritis although many types of nephritis are possible. Neurologic involvement is common. The most frequent neurologic problem is a peripheral neuropathy although central lesions may be profoundly debilitating.
Wegener's granulomatosis should be suspected when patients present with chronic sinusitis that is highly resistant to treatment or there are signs of nasal ulceration. Lower respiratory symptoms include hemoptysis, dyspnea, or cough. Proteinuria, hematuria, and renal insufficiency are symptoms of renal involvement. Patients may also have more general complaints of fever, weight loss and anorexia. Since the disease is multi-systemic, a diverse array of other symptoms are possible including seizures, altered cognition from a cerebritis, focal motor or sensory complaints, headaches, and visual problems.
Wegener's granulomatosis rarely occurs in blacks. Its mortality rate is 18% on an annual basis with most deaths coming from renal compromise. (http://www.emedicine.com/DERM/topic460.htm)
Physical findings vary with nature of the lesions
C-antineutrophil cytoplasmic antibody (ANCA) has become a standard for diagnosing WG. In classic Wegener's granulomatosis , i.e. patients whose involvement is both upper and lower respiratory system and kidneys, ANCA has a sensitivity of 90%. In limited WG, i.e. only kidneys or the respiratory system are involved, its sensitivity falls to 40%. Anemia, thrombocytosis, and if muscle is involved, elevations of creatine kinase, are specific indicators of altered physiology.
Imaging studies, including neuro-imaging, are rarely specific
If there is significant lower airway involvement, transtracheal biopsy or open lung biopsy have a high yield of positive disease confirmation. Nasal biopsy carries much less morbidity, and is equally diagnostic. This is not true for renal biopsy, which is often non-specific. (http://www.emedicine.com/neuro/topic396.htm)
Treatment options for Wegener's granulomatosis
The goal of therapy in treatment of Wegener's granulomatosis is early diagnosis in an attempt to limit its damage. Treatment is divided into two phases—induction of remission and maintenance of remission. Induction uses short courses of cyclophosphamides in combination with glucocorticoids. The induction phase occurs during and after a tapering of glucocorticoids. Methotrexate and azathioprine are the typical agents used in the maintenance phase. (http://www.medscape.com/viewarticle/529310_1)