Effect of Tonsillectomy on Longterm Renal Outcome of IgA Nephropathy

Inclusion Criteria: * Willingness to sign an informed consent * Age:18\~45 years, regardless of gender * Clinical evaluation and renal biopsy diagnostic for immunoglobulin A nephropathy (IgAN), excluded secondary IgAN. Renal histological criteria should be defined by Lee's glomerular grading system. * Any one of three Tonsilar conditions defined by Otorhinolaryngologist : 1,recurrent acute tonsillitis accompanied with gross hematuria or urinary findings abnormality；2,recurrent acute tonsillitis without gross hematuria，but tonsil provocation test was positive；3, No history of acute tonsillitis,body examination found hypertrophy or atrophy tonsils ,crypt pus of tonsils ,or scars on the tonsil surface ,and positive tonsil provocation test. * Estimated glomerular filtration rate (eGFR) ≥ 30 mL/min/1.73 m2 Exclusion Criteria: * Inability or unwillingness to sign the informed consent * Inability or unwillingness to meet the scheme demands raised by the investigators * Rapidly progressive nephritic syndrome and acute renal failure, 24-hour urine protein≥3.5g,including rapidly progressive IgAN (IgAN with rapid decline in renal function characterized histologically by necrotizing vasculitis and crescent formation≥30%) necessitating the use of other immunosuppressive agents. * Secondary IgAN such as systemic lupus erythematosus, Henoch-Schonlein purpuric nephritis and hepatitis B -associated nephritis * est GFR \< 30 mL/min/1.73m2 * Malignant hypertension that is difficult to be controlled by oral drugs * Cirrhosis, chronic active liver disease. * History of significant gastrointestinal disorders (e.g. severe chronic diarrhea or active peptic ulcer disease.) * Any Active systemic infection or history of serious infection within one month of entry or known infection with HIV, hepatitis B, or hepatitis C. * 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) * Malignant tumors (except fully cured basal cell carcinoma) * Current or recent (within 30 days) exposure to any other investigation * Current exposure to mycophenolic mofetil (MMF),azathioprine or corticosteroids. In case of current treatment with oral steroid ,entry is permitted after corticosteroids dosage below 0.4mg/kg per day. * Pregnancy or breast feeding at the time of entry or unwillingness to comply with measures for contraception * Tonsillectomy had been done when IgAN diagnosis or known contraindication to tonsillectomy(such as neutropenia，bleeding tendency，or anatomic abnormalities）