Granulomatosis with Polyangiitis (GPA)

Granulomatosis with polyangiitis (GPA), formerly known as Wegener's granulomatosis, is a rare autoimmune disorder characterized by the inflammation of blood vessels (vasculitis) and the formation of granulomas in various organs.

Causes and Risk Factors

The exact cause of GPA is unknown, but it is believed to be related to an abnormal immune response. The condition is associated with the presence of anti-neutrophil cytoplasmic antibodies (ANCA), which are proteins that attack the body's own tissues.

Symptoms

The symptoms of GPA can vary depending on the organs affected, but common symptoms include:

• Respiratory problems, such as coughing, shortness of breath, and chest pain
• Nasal congestion, discharge, and bleeding
• Sinusitis and otitis media (middle ear infection)
• Kidney damage and renal failure
• Joint pain and swelling
• Fever and fatigue
• Weight loss and loss of appetite
• Eye problems, such as conjunctivitis and scleritis
• Skin lesions and rashes

Diagnosis

The diagnosis of GPA is based on a combination of clinical evaluation, laboratory tests, and imaging studies. Diagnostic criteria include:

• Presence of ANCA in the blood
• Biopsy of affected tissue showing granulomatous inflammation and vasculitis
• Imaging studies, such as chest X-rays and CT scans, showing lung and sinus involvement
• Urinalysis showing kidney damage

Treatment

The treatment of GPA typically involves a combination of medications to induce remission and maintain disease control. Common treatments include:

• Cyclophosphamide, an immunosuppressive medication
• Rituximab, a monoclonal antibody that targets B cells
• Glucocorticoids, such as prednisone, to reduce inflammation
• Methotrexate, an immunosuppressive medication
• Azathioprine, an immunosuppressive medication
• Plasmapheresis, a procedure that removes antibodies from the blood

Prognosis and Complications

The prognosis for GPA varies depending on the severity of the disease and the response to treatment. Complications can include:

• Kidney failure requiring dialysis or transplantation
• Respiratory failure requiring oxygen therapy or mechanical ventilation
• Infections, such as pneumonia and sepsis
• Osteoporosis and fractures due to glucocorticoid use
• Increased risk of cardiovascular disease

Epidemiology

GPA is a rare condition, affecting approximately 3-12 people per million per year. It can occur at any age, but it is most common in middle-aged adults. The condition affects men and women equally.