GPA
Granulomatosis with polyangiitis (GPA), formerly known as Wegener’s granulomatosis, is a rare autoimmune condition in which the immune system mistakenly attacks small blood vessels throughout the body. In children, GPA can affect the sinuses, lungs, and kidneys, and requires coordinated care between nephrology and rheumatology. Early diagnosis and treatment are essential to preventing serious organ damage.
What Is GPA?
GPA is a type of vasculitis — inflammation of the blood vessels — caused by abnormal antibodies called anti-neutrophil cytoplasmic antibodies (ANCA). These antibodies trigger inflammation that damages small blood vessels, limiting blood flow to organs including the kidneys. GPA is rare in children, but when it does occur, it can be severe and requires prompt treatment.
How GPA Affects the Kidneys
Kidney involvement occurs in approximately 26–56% of children with GPA and is one of the most serious aspects of the disease. When the kidneys are affected, the small filtering units (glomeruli) become inflamed — a condition called glomerulonephritis. This can cause blood and protein to leak into the urine and, in severe cases, lead to rapid loss of kidney function (rapidly progressive glomerulonephritis). Long-term kidney damage or chronic kidney disease can occur if GPA is not diagnosed and treated promptly.
Signs and Symptoms
GPA can present gradually, and early symptoms are often mistaken for a common cold or infection. Symptoms may include:
- Ear, nose, and throat: persistent runny nose, nosebleeds, sinus pain, ear pain or hearing changes, hoarseness
- Lungs: shortness of breath, chronic cough, coughing up blood
- Kidneys: blood or protein in the urine, swelling, high blood pressure, decreased urination
- General: fever, fatigue, unexplained weight loss, joint pain, skin rashes
Because GPA affects multiple organ systems, it is important that all symptoms — even seemingly unrelated ones — are evaluated together.
Diagnosis
Diagnosing GPA requires a combination of findings, including:
- Blood tests – to detect ANCA antibodies (most commonly PR3-ANCA in GPA) and assess kidney function
- Urine tests – to identify blood, protein, or cellular casts that suggest kidney inflammation
- Imaging – chest X-ray or CT scan to look for lung nodules or other changes
- Kidney or tissue biopsy – to confirm the diagnosis and guide treatment
Treatment
Treatment for GPA focuses on inducing remission and preventing relapse. Most children require a combination of:
- Induction therapy: high-dose corticosteroids combined with cyclophosphamide or rituximab to bring the disease under control
- Maintenance therapy: lower-dose medications (such as rituximab, azathioprine, methotrexate, or mycophenolate mofetil) continued for a minimum of 24 months to prevent relapse
- Calcium and vitamin D supplementation to protect bone health during steroid treatment
- Close monitoring of kidney function throughout treatment
Relapses can occur, and ongoing follow-up is an important part of GPA management. Most children achieve remission with treatment, though some go on to develop chronic kidney disease.
Care at Rady Children’s
Children with GPA are cared for by our joint Lupus Clinic — a multidisciplinary clinic staffed by both nephrology and rheumatology specialists. This collaborative approach ensures that all aspects of the disease, including kidney involvement and systemic inflammation, are managed together in a single, coordinated visit.