| disease | Primary Small Vessel Vasculitis-related Renal Damage |
A disease characterized by segmental necrotizing glomerulonephritis caused by primary small vessel vasculitis (mainly seen in microscopic polyangiitis and Wegener's granulomatosis), often accompanied by renal insufficiency, with most patients testing positive for serum anti-neutrophil cytoplasmic autoantibodies (ANCA).
bubble_chart Diagnosis
1. Medical History and Symptoms
More common in middle-aged and elderly individuals, with a higher incidence in autumn and winter. Most patients have prodromal manifestations resembling a common cold or drug allergies. Symptoms often include irregular fever, rash, arthralgia, muscle pain, weight loss, abdominal pain, and gastrointestinal symptoms. The extent of lung and kidney involvement is consistent, presenting as allergic asthma, hemoptysis, or refractory pulmonary infections. Some patients may have sinusitis, otitis media, or ocular manifestations (such as conjunctivitis, granulomatous keratitis, episcleritis, iridocyclitis, and choroiditis). Early kidney involvement typically presents with hematuria, with about one-third showing gross hematuria. Most cases are accompanied by proteinuria or nephrotic syndrome, while hypertension is uncommon or mild. Half of the patients exhibit rapidly progressive glomerulonephritis. With timely and effective treatment, some patients may achieve complete renal function recovery.
2. Physical Examination Findings
Fever is common during the active phase, and grade I anemia, eyelid or lower limb edema may be observed. Some patients present with rashes or ocular manifestations.
3. Auxiliary Examinations
(1) Urinalysis reveals varying degrees of proteinuria, hematuria, and cylindruria.
(2) Most patients exhibit anemia and leukocytosis, with occasional eosinophilia.(3) During the acute phase, erythrocyte sedimentation rate (ESR) is elevated, and C-reactive protein (CRP) levels exceed normal. γ-Globulin levels are often increased.
(4) Most patients test positive for ANCA (anti-neutrophil cytoplasmic antibodies), which is a key diagnostic marker for primary small-vessel vasculitis. ANCA positivity may reflect disease activity or relapse, appearing approximately 4 weeks before recurrence.
(5) Creatinine clearance rate (Ccr) is often reduced to varying degrees, while blood urea nitrogen (BUN) and creatinine levels are elevated.
(6) Chest X-ray typically shows alveolar hemorrhage, lobular pneumonia, or localized cavitary necrotizing pneumonia. CT scans may reveal sinus or orbital lesions. Renal ultrasound usually indicates normal or enlarged kidneys.
(7) Early renal biopsy can aid in diagnosis.
4. Differential Diagnosis
Conditions to exclude include Goodpasture syndrome, rapidly progressive glomerulonephritis, systemic lupus erythematosus, allergic purpura, rheumatoid arthritis with vasculitis, and cryoglobulinemia.
bubble_chart Treatment Measures
1. Early diagnosis and early treatment of this disease are key to improving prognosis. The principle of combined use of glucocorticoids and cytotoxic drugs should be routinely adopted. Standard hormone therapy plus CTX can be administered, with the treatment course lasting more than 2 years.
2. For patients with acute progressive renal function deterioration, standard hormone therapy plus CTX pulse therapy, or methylprednisolone pulse therapy plus CTX pulse therapy should be administered as early as possible under dialysis conditions. Plasma exchange therapy also has certain efficacy, particularly for pulmonary hemorrhage, with definite and rapid effects. In cases of severe hypervolemia or refractory heart failure, emergency dialysis should be performed to help the patient survive the critical period, creating conditions and buying time for drug treatment.
4. Intravenous high-dose immunoglobulin, common bletilla tuber, or monoclonal anti-T-cell antibodies may have some therapeutic effects.
5. Patients with end-stage renal failure should be managed according to chronic kidney failure protocols.
