This prospective, randomized, controlled, multi-center clinical trial will evaluate the effect and security of steroids therapy for patients of IgA nephropathy with crescents.

It has been reported that for urinary protein excretion that is persistently more than 1g/24h and eGFR>50ml/min/1.73m2 in IgA nephropathy(IgAN), the KDIGO guidelines suggest a 6-month course of glucocorticoids. The famous study by Pozzi C has proved that for patients of IgAN with proteinuria of 1.0-3.5g/24h and serum creatinine concentrations of 133 umol/L or less, a 6-month course of steroid treatment(1g/d methylprednisolone intravenously for 3 consecutive days, with the course repeated 2 months and 4 months later,then oral prednisone 0.5mg/kg/d on alternate days for 6 months) could significantly reduce proteinuria and protect against renal function deterioration in IgAN. However, according to Oxford classification, crescents in IgAN would effect the prognosis.This will be a prospective, randomized, controlled, multi-center study. Patients in treatment group will receive 0.5g/d methylprednisolone intravenously for 3 consecutive days in the 1st-2nd-3rd month ,then oral prednisone 0.5mg/kg/d on alternate days. Patients in control group will receive 0.5g/d methylprednisolone intravenously for 3 consecutive days in the 1st-3rd-5th month ,then oral prednisone 0.5mg/kg/d on alternate days. After followed-up for 6 months, the curative effect of steroid therapy on proteinuria and the progression of IgAN will be evaluated.

Inclusion Criteria:

1. Age 14~65 years, regardless of gender
2. Clinical evaluation and renal biopsy diagnostic for IgA nephropathy, presenting with crescents.
3. Average urinary protein excretion of 0.3~3.5g/24h on two successive examinations.
4. eGFR≥30 ml/min/1.73m2.
5. Willingness to sign an informed consent.

Exclusion Criteria:

1. Secondary IgAN such as systemic lupus erythematosus, Henoch-Schonlein purpuric nephritis and hepatitis B-associated nephritis, etc.
2. Rapidly progressive nephritic syndrome (crescent formation≥50%).
3. Acute renal failure, including rapidly progressive IgAN.
4. Current or recent (within 30 days) exposure to high-dose of steroids or immunosuppressive therapy (CTX、MMF、CsA、FK506).
5. Date of renal biopsy exceeds more than 30 days.
6. Cirrhosis, chronic active liver disease, and serious liver function damage.
7. History of significant gastrointestinal disorders (e.g. severe chronic diarrhea or active peptic ulcer disease).
8. Any Active systemic infection or history of serious infection within one month.
9. Other major organ system disease (e.g. serious cardiovascular diseases including congestive heart failure , chronic obstructive pulmonary disease, asthma requiring oral steroid treatment or central nervous system diseases).
10. Active tuberculosis
11. Malignant hypertension that is difficult to be controlled by oral drugs.
12. Known allergy, contraindication or intolerance to the steroids.
13. Pregnancy or breast feeding at the time of entry or unwillingness to comply with measures for contraception.
14. Malignant tumors.
15. Excessive drinking or drug abuse.
16. Mental aberrations.
17. Current or recent (within 30 days) exposure to any other investigational drugs.
18. Current use of RAS inhibitors needs to be eluted for at least 1 week before participating in the study.