What happens in the body
ANCA antibodies activate neutrophils directly inside small vessels. Activated cells damage the vascular wall, and it undergoes necrosis, and a granuloma, an accumulation of immune cells, forms around the lesion. In the mucous membrane of the nose and sinuses it looks like a non-healing inflammation with crusts and destruction of cartilage, in the lungs - like nodes and cavities, and in the kidneys - like rapidly progressing glomerulonephritis. It is the rate of kidney damage that determines the prognosis, so urine tests are repeated regularly.
- Inflammation and necrosis of the walls of small vessels
- Granulomas in the nose, sinuses and lungs
- Rapidly progressive glomerulonephritis
- Possible damage to eyes, skin and nerves
- Severity is determined by kidney and lung involvement
Causes and risk factors
The cause of the disease has not been established. We are talking about a breakdown of immune tolerance in a predisposed person, after which the body produces antibodies to its own neutrophil enzymes. The role of chronic carriage of staphylococcus in the nose, occupational contact with silica dust and certain medications is discussed. The disease is not directly inherited and is not contagious. Middle-aged and older people are more likely to get sick; men and women are approximately equally likely.
- Autoimmune production of ANCA antibodies
- Age 40–65 years
- Chronic carriage of staphylococcus in the nose
- Professional exposure to silica dust
- Certain medications as a trigger
Symptoms by organ
The disease usually begins gradually, with general complaints: weakness, low-grade fever, weight loss, pain in joints and muscles. At the same time, problems with the nose appear - congestion, crusts, nosebleeds, decreased sense of smell, pain in the sinuses. Then cough, shortness of breath, and sometimes hemoptysis occur. Kidney damage is asymptomatic for a long time and is detected only by urine analysis, so it is easy to miss. There may be redness and pain in the eye, a rash, and numbness or weakness in certain nerves.
- Prolonged rhinitis and sinusitis with crusts and blood
- Hearing loss, otitis media
- Cough, shortness of breath, hemoptysis
- Changes in urine analysis: protein and red blood cells
- Inflammation of the eye, protrusion of the eyeball
- Purpura and skin ulcers
- Numbness and weakness like foot drop
Diagnostics
The examination begins with a simple and accessible one: a general urine test reveals protein and red blood cells, and creatinine shows whether the kidneys are coping. Inflammatory markers are elevated, and there is often anemia in the blood. The key specific test is ANCA antibodies, often to proteinase-3. Visualization is carried out using CT of the paranasal sinuses and CT of the chest, where nodes, cavities and infiltrates are visible. Final confirmation is provided by a biopsy of the affected tissue: the mucous membrane of the nose, lung or kidney. It is important to exclude tuberculosis, fungal infection and tumors that give a similar picture.
- Urinalysis and urine sediment
- Creatinine and filtration rate calculation
- ANCA antibodies
- ESR, C-reactive protein, complete blood count
- CT scan of the paranasal sinuses and CT scan of the lungs
- Biopsy of the kidney, lung or nasal mucosa
Treatment and observation
Treatment is divided into two stages. First, remission is achieved: high doses of glucocorticoids are prescribed in combination with a cytostatic or anti-B-cell drug, and if life is threatened, treatment begins in the hospital. Then they move on to maintenance therapy, which continues for years and keeps the disease dormant. Due to immune suppression, infection prevention and vaccination are required according to a plan agreed with the doctor. Relapses are possible, so regular urine and blood tests are needed even if you feel excellent.
- Induction of remission: glucocorticoids plus a cytostatic or anti-B-cell drug
- Maintenance therapy for several years
- Plasma exchange and dialysis according to indications
- Prevention of infectious complications
- Monitoring urine and creatinine analysis
- Quitting smoking and treating nasal infections