

Microscopic Polyangiitis (MPA) is a rare and serious autoimmune disease that affects small blood vessels and capillaries, leading to inflammation that can impact the kidneys, lungs, and skin.Although uncommon, delayed diagnosis or treatment can result in life-threatening complications.At Daleely Medical, we shed light on the causes of microscopic vasculitis, its most common symptoms, accurate diagnostic methods, and both medical and natural treatment options. We also offer practical tips for prevention and patient support.If you're looking for a clear and comprehensive guide to this complex condition, this article is for you.
1. Is Microscopic Polyangiitis a serious disease?
Yes, it can be serious if not diagnosed and treated early. It may lead to complications such as kidney failure, lung hemorrhage, or inflammation of the nerves or heart. However, with early detection and proper treatment, it can be effectively controlled.
2. Can Microscopic Polyangiitis be completely cured?
There is no definitive cure yet, but many patients achieve what is called complete remission and live normal lives with regular follow-up and adherence to treatment.
3. Is Microscopic Polyangiitis contagious?
No, it is not contagious. It is an autoimmune condition caused by a dysfunction in the immune system, not by a bacterial or viral infection.
4. How does the disease affect the kidneys?
It often causes inflammation of the glomeruli (glomerulonephritis), leading to protein or blood in the urine. In advanced cases, it may cause kidney failure if not treated promptly.
5. Can women with MPA get pregnant?
Yes, but pregnancy should be planned during the remission phase and under strict medical supervision. Some medications used for MPA may affect fertility or pregnancy, so treatment plans may need adjustment.
6. What’s the difference between MPA, lupus, and rheumatoid arthritis?
Disease | Most Affected Areas |
---|---|
Lupus (SLE) | Skin, joints, kidneys, nervous system |
Rheumatoid arthritis | Primarily the joints |
Microscopic Polyangiitis (MPA) | Small vessels, especially in the kidneys and lungs |
7. Are there any beneficial herbs for MPA patients?
Some herbs like turmeric, ginger, and chamomile may help reduce inflammation. However, they are not a replacement for medical treatment. Always consult a doctor before using herbal remedies to avoid drug interactions.
8. Does psychological stress affect the disease?
Yes, stress can trigger immune activity and increase disease flares. Stress-relieving techniques like meditation, relaxation, and yoga are recommended to support both physical and mental well-being.
9. How long does treatment for MPA last?
It depends on the disease phase:
Active phase: around 3 to 6 months
Maintenance (relapse prevention) phase: 18 to 24 months or longer
Microscopic Polyangiitis is a type of ANCA-associated vasculitis that affects small vessels such as capillaries, small arteries, and venules. It primarily involves the kidneys, lungs, and other organs, and can be classified in different ways:
1. Classic Microscopic Polyangiitis (MPA)
The most common type typically referred to when discussing MPA.
Organs affected: kidneys, lungs, skin, peripheral nerves
Common ANCA: p-ANCA (especially anti-MPO)
2. ANCA-associated Pauci-immune Glomerulonephritis
A kidney-specific form without significant immune deposits.
Seen in kidney biopsy results
May occur independently or as part of MPA
Type | Affected Vessels | Main Organs Involved | Common ANCA Type |
---|---|---|---|
MPA | Small vessels only | Kidneys, lungs, skin | p-ANCA (MPO) |
GPA (Granulomatosis with Polyangiitis / Wegener’s) | Small + medium vessels | Nose, sinuses, lungs, kidneys | c-ANCA (PR3) |
EGPA (Eosinophilic Granulomatosis with Polyangiitis) | Small vessels | Lungs, heart, nerves, skin | p-ANCA (MPO) |
⚠️ Note: MPA does not cause granulomas or elevated eosinophils, unlike GPA and EGPA.
Microscopic Polyangiitis (MPA) is a rare and serious autoimmune disease that targets small blood vessels, including capillaries, venules, and arterioles. It often affects vital organs such as the kidneys, lungs, skin, and nervous system. Although uncommon, MPA can be life-threatening if not diagnosed and treated early. In this comprehensive guide by Daleeli Medical, we explore the causes, symptoms, diagnostic methods, treatment options—both medical and natural—and essential tips for prevention and patient care.
MPA symptoms vary depending on the affected organ and may range from mild to life-threatening. Here’s a breakdown:
These appear in the early stages and are often nonspecific:
Persistent fatigue
Unexplained weight loss
Loss of appetite
Night sweats
Low-grade fever
Muscle or joint pain
⚠️ These symptoms are often misdiagnosed as flu, rheumatoid arthritis, or viral infections.
The kidneys are most frequently affected. Symptoms may include:
Dark or bloody urine
Swelling in legs or face
High blood pressure
Fatigue due to toxin buildup
Gradual kidney function decline
In advanced cases: renal failure requiring dialysis or transplant
MPA can cause immune-related lung inflammation or alveolar hemorrhage:
Chronic cough
Shortness of breath
Coughing up blood (pulmonary hemorrhage)
Chest pain
Anemia due to blood loss
Skin involvement often presents as:
Purple rash (Purpura), especially on legs
Subcutaneous bleeding spots
Painful or slow-healing ulcers
Finger or toe sores
⚠️ These signs may be the first visible indicators of the disease.
Due to inflamed vessels feeding the nerves:
Tingling or numbness in limbs
Sudden muscle weakness
Burning or stabbing nerve pain
Balance issues or coordination problems
Nausea or vomiting
Abdominal discomfort
Rare: gastrointestinal bleeding
Seek urgent medical care if you notice:
Sudden blood in urine
Coughing up blood
Severe unexplained fatigue
Dramatic reduction in urine output
Nerve symptoms like paralysis or loss of sensation
Immune system produces harmful p-ANCA antibodies targeting small vessels
No visible symptoms, but abnormal lab results may appear
Nonspecific signs like fever, fatigue, muscle aches
Often misdiagnosed as infections or other autoimmune diseases
Kidneys: protein or blood in urine, hypertension, renal damage
Lungs: chronic cough, bleeding
Skin/Nerves: rashes, numbness
Biopsy and ANCA tests confirm diagnosis in this stage
Rapid decline in kidney or lung function
Internal bleeding or respiratory failure
Life-threatening infections due to immune suppression
With proper treatment, many patients enter remission
Others may have partial control and require continuous care
Long-term monitoring is essential
Classic MPA: Affects kidneys, lungs, skin, nerves – often positive for MPO-ANCA
ANCA-Associated Glomerulonephritis: Isolated kidney involvement
Identified via kidney biopsy
Type | Vessels Affected | Main Organs | Common ANCA |
---|---|---|---|
MPA | Small vessels only | Kidneys, lungs, skin | p-ANCA (MPO) |
GPA (Wegener’s) | Small & medium | Nose, lungs, kidneys | c-ANCA (PR3) |
EGPA | Small | Lungs, heart, nerves, skin | p-ANCA (MPO) |
MPA does not cause granulomas or high eosinophils like GPA or EGPA
Type | Description |
---|---|
Renal-only | Rapidly progressive glomerulonephritis with no external signs |
Pulmonary-renal syndrome | Combines bleeding in lungs with kidney failure |
Cutaneous MPA | Rash, purpura, skin ulcers |
Peripheral nerve involvement | Neuropathy due to small vessel inflammation |
Clinical evaluation
ANCA antibody testing (especially MPO-ANCA)
Tissue biopsy (kidney, skin, or lung)
Accurate diagnosis is essential for choosing the right treatment, especially biological therapies
If left untreated, MPA can cause serious damage:
Rapidly Progressive Glomerulonephritis (RPGN)
Leads to chronic renal failure
Symptoms: blood/protein in urine, swelling, hypertension
Pulmonary Alveolar Hemorrhage
Life-threatening: coughing up blood, anemia, breathlessness
Fibrosis or secondary infections
Purple rashes, painful ulcers, slow-healing wounds
Peripheral neuropathy: tingling, weakness, numbness
Rarely: central nervous system involvement (stroke-like episodes)
Myocarditis
Pericarditis
Irregular heartbeat
Severe cases: heart failure
Severe anemia
Increased risk of infection due to immunosuppressants
Possible osteoporosis (from prolonged steroid use)
Complication | Potential Outcome |
---|---|
End-stage kidney failure | Lifetime dialysis |
Respiratory failure | ICU admission |
Life-threatening infections | Due to suppressed immunity |
Internal bleeding | In lungs, kidneys, or GI tract |
Bone loss | Due to steroids |
Yes, by:
Early diagnosis using ANCA tests & biopsies
Timely treatment with immunosuppressants & corticosteroids
Ongoing monitoring of kidney and lung function
Consulting a rheumatologist or nephrologist
Diagnosing MPA can be challenging because it mimics other autoimmune diseases. Accurate diagnosis relies on a combination of clinical symptoms, laboratory tests, imaging studies, and biopsies.
Monitor for concerning symptoms such as:
Unexplained fever
Hemoptysis (coughing up blood)
Skin rash
Hematuria (blood in urine)
Swelling in limbs
Physical exam should assess joints, skin, respiratory and nervous systems to identify affected organs.
Test | Purpose |
---|---|
ESR & CRP | Detect elevated inflammatory markers |
CBC | Detect anemia, thrombocytopenia, or leukocytosis |
Kidney function tests (Urea, Creatinine) | Assess renal involvement |
Liver function tests | Check liver health and readiness for treatment |
ANCA (essential test) | Positive in 90% of cases, especially p-ANCA/MPO |
⚠️ Important Note: ANCA positivity alone is not enough for diagnosis, but it's a key indicator when correlated with symptoms.
Hematuria (blood in urine)
Proteinuria (protein in urine)
Presence of cellular casts
These findings suggest ANCA-associated glomerulonephritis.
Imaging | Purpose |
---|---|
Chest X-ray | Detect inflammation or bleeding in the lungs |
CT scan (chest/abdomen) | More detailed view of organ involvement |
Renal ultrasound | Evaluate kidney size and structure |
Biopsy is the gold standard for confirming diagnosis.
Kidney biopsy: Shows pauci-immune glomerulonephritis (without immune deposits)
Skin or nerve biopsy: If skin or nervous symptoms are present
It’s essential to exclude other diseases such as:
Systemic lupus erythematosus (SLE)
Granulomatosis with polyangiitis (GPA / Wegener’s)
Hepatitis B and C
Chronic infections or malignancies
Suppress autoimmune inflammation
Relieve symptoms
Protect kidney and lung function
Achieve long-term remission
Used during the acute phase to gain rapid control, especially in severe cases.
Medication | Notes |
---|---|
Prednisone (Corticosteroid) | High doses initially, tapered gradually |
Cyclophosphamide | Powerful immunosuppressant, oral or IV |
Rituximab | Effective alternative to cyclophosphamide, less toxic; suitable for elderly or women planning pregnancy |
⏳ Duration: 3 to 6 months depending on response.
After achieving remission, milder drugs are used to prevent relapse.
Medication | Use |
---|---|
Methotrexate | First-line for mild cases |
Azathioprine | Safe, long-term option |
Mycophenolate mofetil | Alternative in certain cases |
⏳ Duration: 18 to 24 months or longer.
Regular tests are needed to evaluate:
Kidney function: Creatinine, urea
Inflammatory markers: ESR, CRP
ANCA levels
Complete blood count (CBC)
Chest imaging (if lungs are involved)
Liver tests and drug safety profiles
Medication | Purpose |
---|---|
Trimethoprim-sulfamethoxazole (Cotrimoxazole) | Prevent PCP infection during immunosuppressive therapy |
Proton pump inhibitors (PPI) | Protect stomach from steroid-induced ulcers |
Vitamin D + Calcium | Prevent steroid-related osteoporosis |
Rest during flare-ups
Resume light physical activity after stabilization
Follow a kidney-friendly diet (low salt, low protein)
Seek emotional and family support to reduce anxiety or depression often associated with chronic illness