Early Application of Budesonide Enteric-coated Capsules in the Treatment of Primary IgA Nephropathy.

Inclusion Criteria: * (1) Age ≥ 18 years (2) Primary IgA nephropathy confirmed by renal-biopsy pathology within the past 2 weeks (3) eGFR ≥ 20 mL/min/1.73 m² (4) 24-hour urinary protein 0.5-3.5 g/day (5) Patient has been fully informed, agrees to receive supportive care plus budesonide enteric-coated capsules, and has signed the informed-consent form Exclusion Criteria: * (1) Secondary IgAN attributable to, but not limited to, Henoch-Schönlein purpura, systemic lupus erythematosus, liver cirrhosis, rheumatoid arthritis, or ankylosing spondylitis (2) Previous renal transplantation or current dialysis (3) Co-existing glomerular disease on biopsy (e.g., C3 glomerulopathy, diabetic nephropathy) or nephrotic syndrome (4) Acute, chronic, or latent infection, including hepatitis, tuberculosis, HIV, or chronic urinary-tract infection (5) Type 1 or type 2 diabetes with poor control (HbA1c \> 9 %) (6) History of unstable angina, NYHA class III/IV congestive heart failure, or clinically significant arrhythmia (7) Uncontrolled hypertension (systolic ≥ 160 mmHg or diastolic ≥ 90 mmHg) (8) Malignancy diagnosed within the past 5 years (9) Known glaucoma, cataract, or history of cataract surgery (10) Gastro-intestinal disorders that may interfere with drug release or efficacy (peptic-ulcer disease, inflammatory bowel disease, chronic diarrhea) (11) Previous severe adverse reaction to corticosteroids, including psychotic symptoms (12) Concomitant use of potent cytochrome P450 3A4 (CYP3A4) inhibitors (13) Pregnancy, lactation, or unwillingness to use highly effective contraception during treatment and the 3-month follow-up (applies to women of child-bearing potential) (14) Patients whom the investigator deems unsuitable for budesonide enteric-coated-capsule therapy