Summary about Disease
Pauci-immune glomerulonephritis (PIGN) is a type of glomerulonephritis (inflammation of the kidney's filtering units, the glomeruli) characterized by minimal or no immune deposits (antibodies or complement) seen on kidney biopsy using immunofluorescence microscopy. It is often associated with circulating anti-neutrophil cytoplasmic antibodies (ANCAs) and is therefore frequently classified as ANCA-associated glomerulonephritis. PIGN leads to rapidly progressive kidney damage and can result in kidney failure if untreated.
Symptoms
Symptoms can develop rapidly over days or weeks. Common symptoms include:
Hematuria (blood in urine)
Proteinuria (protein in urine)
Edema (swelling, especially in legs, ankles, and around the eyes)
Hypertension (high blood pressure)
Fatigue
Weakness
Weight loss
Fever
Night sweats
Arthralgia (joint pain)
Myalgia (muscle pain)
Symptoms related to underlying systemic vasculitis if present, such as lung involvement (cough, shortness of breath), skin rashes, or nerve damage.
Causes
The exact cause of PIGN is not fully understood. It is often associated with:
ANCA-associated vasculitis: This is the most common association. ANCAs are antibodies that target neutrophils (a type of white blood cell). In PIGN, ANCAs activate neutrophils, leading to inflammation and damage of the glomeruli. The two main types of ANCA involved are myeloperoxidase (MPO)-ANCA and proteinase 3 (PR3)-ANCA.
Systemic Vasculitis: Conditions such as Granulomatosis with Polyangiitis (GPA), Microscopic Polyangiitis (MPA), and Eosinophilic Granulomatosis with Polyangiitis (EGPA).
Drug-induced: Certain drugs, such as hydralazine, have been linked to ANCA-associated vasculitis and PIGN.
Idiopathic: In some cases, no specific cause can be identified.
Medicine Used
Treatment typically involves a combination of immunosuppressive medications to reduce inflammation and prevent kidney damage. Common medications include:
Corticosteroids: Such as prednisone, to rapidly reduce inflammation.
Cyclophosphamide: A potent immunosuppressant used to suppress the immune system.
Rituximab: A monoclonal antibody that targets B cells (a type of immune cell). It is often used as an alternative to cyclophosphamide.
Plasma exchange (plasmapheresis): To remove ANCA antibodies from the blood, especially in severe cases or those with lung involvement.
Maintenance therapy: After the initial induction phase, medications like azathioprine, mycophenolate mofetil, or low-dose corticosteroids are used to maintain remission and prevent relapses.
ACE inhibitors or ARBs: Used to control blood pressure and reduce proteinuria.
Is Communicable
Pauci-immune glomerulonephritis is not communicable. It is not caused by an infection and cannot be spread from person to person.
Precautions
Precautions are related to managing the condition and minimizing complications:
Adherence to medication regimen: Strict adherence to the prescribed medications is crucial for controlling the disease and preventing kidney damage.
Regular monitoring: Regular blood and urine tests are necessary to monitor kidney function and detect relapses.
Blood pressure control: Maintaining healthy blood pressure is important for protecting the kidneys.
Infection prevention: Immunosuppressive medications increase the risk of infections. Taking precautions such as frequent handwashing, avoiding sick contacts, and receiving recommended vaccinations (after discussing with your doctor) are essential.
Dietary modifications: A low-sodium diet may be recommended to help control blood pressure and edema. Consulting a registered dietitian is recommended.
Lifestyle modifications: Maintaining a healthy lifestyle, including regular exercise and avoiding smoking, can improve overall health and support kidney function.
How long does an outbreak last?
Pauci-immune glomerulonephritis is not an "outbreak" in the infectious disease sense. It is a chronic condition with periods of active disease (flares) and remission. Without treatment, the active phase can lead to rapid kidney damage. Treatment aims to induce remission, which can last for variable periods. Relapses (recurrence of active disease) are possible, even with treatment, and require prompt intervention. The duration of flares and remissions can vary greatly from person to person.
How is it diagnosed?
Diagnosis typically involves:
Medical history and physical examination: Assessing symptoms and potential risk factors.
Urine tests: To detect hematuria and proteinuria.
Blood tests: To assess kidney function (creatinine, BUN), electrolytes, and to detect ANCAs.
Kidney biopsy: This is the most important diagnostic test. The biopsy sample is examined under a microscope to assess the extent of glomerular damage and to look for immune deposits (though these are typically absent or minimal in PIGN). Immunofluorescence staining will show little or no immunoglobulin or complement deposition.
Imaging studies: Chest X-ray or CT scan may be performed to assess for lung involvement, especially if ANCA-associated vasculitis is suspected.
Timeline of Symptoms
The timeline of symptoms can vary, but typically follows a rapid progression:
Initial phase: Vague symptoms such as fatigue, weight loss, and joint or muscle pain may be present for weeks or months.
Rapidly progressive phase: More specific kidney symptoms, such as hematuria, proteinuria, and edema, develop rapidly over days or weeks. Kidney function deteriorates quickly, potentially leading to kidney failure.
Treatment phase: With prompt and aggressive treatment, symptoms can improve, and kidney function may stabilize or recover.
Maintenance phase: After remission is achieved, maintenance therapy aims to prevent relapses.
Important Considerations
Early diagnosis and treatment: Early diagnosis and prompt treatment are crucial to prevent irreversible kidney damage and improve outcomes.
Risk of relapse: Relapses are possible, even with treatment. Regular monitoring and prompt intervention are necessary.
Side effects of medications: Immunosuppressive medications can have significant side effects. Close monitoring and management of side effects are essential.
Impact on quality of life: PIGN and its treatment can significantly impact quality of life. Support groups and counseling can be helpful.
Long-term kidney health: Even with successful treatment, some patients may develop chronic kidney disease and require ongoing monitoring and management. Kidney transplant may be needed if end-stage renal disease develops.