OVERVIEW

What is ANCA-associated vasculitis?

ANCA (Antineutrophil Cytoplasmic Antibody) is an abbreviation for anti-neutrophil cytoplasmic antibody. Its presence indicates an abnormality in the autoimmune system, where the body mistakenly identifies its own immune cells (such as neutrophils) as invading pathogens and attacks them as it would viruses or bacteria.

ANCA-associated vasculitis is caused by the immune system attacking blood vessels. Since blood vessels are distributed throughout the body, ANCA-associated vasculitis can damage multiple organ systems, with kidney and lung involvement being particularly common.

This disease is relatively rare and primarily affects elderly individuals. It can lead to chronic organ dysfunction and, in severe cases, death due to organ failure.

Treatment depends on the severity of the condition and may include glucocorticoids and/or immunosuppressants such as cyclophosphamide.

Is ANCA-associated vasculitis common?

No, it is uncommon, with a low incidence rate (20 to 100 cases per million people).

SYMPTOMS

What are the manifestations of antineutrophil cytoplasmic antibody-associated vasculitis?

• Fever, migratory arthralgia, malaise, anorexia, and weight loss;
• Ear, nose, and throat: May present as sinusitis, otitis media, oral and/or nasal ulcers, polychondritis, etc. Patients may also report ear pain, hearing loss, otorrhea (also known as ear discharge), etc.;
• Lungs: Cough, hemoptysis, dyspnea, with notable abnormalities (e.g., infiltrates, nodules) on chest CT;
• Abdomen: Abdominal pain, diarrhea, anorexia, nausea, vomiting, and possible gastrointestinal bleeding;
• Kidneys: A commonly affected organ, presenting as microscopic hematuria, red blood cell casts, proteinuria, and impaired renal function;
• Hypertension;
• Neurological dysfunction: Such as limb numbness, tingling, or even stroke and seizures;
• Red or purple skin spots, most commonly on the lower legs;
• Eyes: Orbital masses, scleritis, corneal ulcers, conjunctivitis, episcleritis, etc.;
• Severe vasculitis may involve the coronary arteries, leading to myocardial infarction.

Generally, a combination of the above symptoms occurs. A significant proportion of patients exhibit most of these symptoms.

What other diseases can antineutrophil cytoplasmic antibody-associated vasculitis cause?

• Renal failure;
• Pulmonary hemorrhage;
• Respiratory infections, systemic sepsis, etc.

CAUSES

What causes anti-neutrophil cytoplasmic antibody-associated vasculitis?

The exact cause is unknown, but it is currently believed to result from a combination of genetic predisposition and environmental factors (such as bacterial or viral infections, or medications like propylthiouracil).

Is anti-neutrophil cytoplasmic antibody-associated vasculitis hereditary?

ANCA-associated vasculitis has some genetic component. However, only close relatives have a slightly increased risk, though the overall risk remains very low. After all, this is a relatively rare disease.

Who is most commonly affected by anti-neutrophil cytoplasmic antibody-associated vasculitis?

It can occur at any age, but most cases are concentrated between 65–74 years old. Childhood onset is rare.

DIAGNOSIS

What tests are needed for ANCA-associated vasculitis?

Blood and urine tests, ANCA, MPO, PR3, liver and kidney function tests are required, and a kidney biopsy may be necessary if needed.

Which diseases have similar manifestations to ANCA-associated vasculitis?

Many systemic autoimmune diseases (such as systemic lupus erythematosus) may present similarly to ANCA-associated vasculitis and require differentiation.

Additionally, ANCA-associated vasculitis must be distinguished from thrombotic diseases, Goodpasture syndrome, and tumors (such as leukemia, lymphoma, lung cancer, etc.).

TREATMENT

Which department should patients with anti-neutrophil cytoplasmic antibody-associated vasculitis generally visit?

Typically, they should visit the rheumatology and immunology department.

Is it necessary for patients with anti-neutrophil cytoplasmic antibody-associated vasculitis to seek medical treatment and hospitalization?

All patients suspected of having ANCA-associated vasculitis require medical treatment and hospitalization.

With standardized treatment, most patients can survive for more than 5 years. However, as the incidence of uremia increases, long-term survival rates become less optimistic. Without treatment, nearly all patients will die within 1–2 years.

After treatment and discharge, patients must follow medical advice for regular medication and check-ups. If symptoms such as fever, musculoskeletal pain, or rashes occur, they should seek immediate medical attention for evaluation on whether rehospitalization is necessary.

How is anti-neutrophil cytoplasmic antibody-associated vasculitis treated?

The goal of treatment is to reduce the disease's impact on the body, such as eliminating symptoms like fever, musculoskeletal pain, and normalizing urine protein and kidney function.

Medication plans are tailored based on disease severity. Glucocorticoids and cyclophosphamide are the most common drugs for inducing remission, while hormones combined with methotrexate or azathioprine are commonly used for maintenance therapy.

If financially feasible, combining with rituximab is also a good option. Most patients require long-term medication, and lifelong treatment is not uncommon.

What medications are needed for anti-neutrophil cytoplasmic antibody-associated vasculitis?

Glucocorticoids and cyclophosphamide are the most common drugs for inducing remission, while hormones combined with methotrexate or azathioprine are commonly used for maintenance therapy. If financially feasible, rituximab may also be considered.

The most significant side effect is an increased risk of bacterial, viral, or fungal infections, which can be life-threatening in severe cases.

Can anti-neutrophil cytoplasmic antibody-associated vasculitis be completely cured?

It cannot be completely cured.

Treatment aims to reduce disease activity, such as resolving symptoms like fever and musculoskeletal pain, and normalizing urine protein and kidney function. Most patients require long-term medication, and lifelong treatment is not uncommon.

Can anti-neutrophil cytoplasmic antibody-associated vasculitis cause death?

Yes, it can lead to death.

The most common causes of death are bacterial, viral, or fungal infections, followed by uremia and intracranial vasculitis. Studies in China show that 85% of patients survive for 5 years after diagnosis, but nearly half develop uremia after 5 years.

How often should patients with anti-neutrophil cytoplasmic antibody-associated vasculitis undergo follow-up examinations?

Initially, follow-ups are typically monthly, later extending to every 3 or 6 months. Generally, if the condition remains stable for over 2 years, discontinuation of medication may be considered.

DIET & LIFESTYLE

What should patients with anti-neutrophil cytoplasmic antibody-associated vasculitis pay attention to in their diet?

Generally, due to kidney damage and significant proteinuria in ANCA vasculitis patients, it is recommended to control total protein intake. Daily protein intake should not exceed 0.8 g per kilogram of body weight. Additionally, strict salt restriction is necessary.

Will daily work and study be affected for young patients with anti-neutrophil cytoplasmic antibody-associated vasculitis?

Young patients often coexist with lupus, which tends to be more severe with a less optimistic prognosis, significantly impacting both work and study.

PREVENTION

Can ANCA-associated vasculitis be prevented?

The exact cause of this disease is unknown, possibly related to genetic and environmental factors (such as bacterial or viral infections, medications like propylthiouracil), but there are no clear and feasible preventive measures.