Rituximab and RASi in Patients with IgAN

Inclusion Criteria: * 1\. 18 to 75 of age, male or female; * 2\. primary IgA nephropathy confirmed by renal biopsy * 3\. eGFR\>30ml/min/1.73m2(calculated according to the CKD-EPI formula); * 4\. After using maximum tolerated doses of ACEI and/or ARB for 3 months, the following two points should be met: 1. 24h proteinuria ≥1g; 2. Bp\<130/80 mmHg； * 5\. Serum albumin \> 25g/L; * 6\. Sign the informed consent. Note : It is suggested that active IgAN patients should be selected. Active IgAN is specifically defined as conforming to any of the following : 1. ) intradermal augmentation ( E1 ), 2. ) crescentic body 0 - 50 % ( C1 / C2 ), 3. ) fibrinoid necrosis, 4. ) more interstitial inflammatory cell infiltration. At the same time, the proportion of sclerosis was low ( spherical or segmental sclerosis ball \< 50 % ), and interstitial fibrosis was low ( below T2 ). Exclusion Criteria: * 1\. Evidence of the use of glucocorticoids for immunosuppressive therapy, such as: nephrotic syndrome, pathology for small lesions with IgA nephropathy. or the proportion of crescents confirmed by renal biopsy within 12 months was more than 50 %. * 2\. Clinical confirmation of cirrhosis, chronic active liver disease, or hepatitis B, C, or HIV which can detect viral replication; * 3\. Clinically confirmed IgA nephropathy secondary to systemic diseases such as systemic lupus erythematosus, allergic purpura. * 4\. Patients with non-simple IgA nephropathy, such as diabetic nephropathy or obesity-related nephropathy. * 5\. A history of active systemic infection or severe infection occurred one month before enrollment. * 6\. Those who are pregnant or lactating or unwilling to take contraceptive measures. * 7\. Current or recent ( within 30 days ) exposure to any research drug. * 8\. Patients with allergic reactions to rituximab and / or known allergic reactions. * 9\. Laboratory tests meeting the following criteria should be excluded: (1) Hemoglobin \<80g/L; (2) Platelet \<80×10\^9/L; (3) Neutrophils \< 1.0×10\^9/L; (4) Aspartic acid aminotransferase (AST) or alanine aminotransferase (ALT) \>2.5× normal upper limit, except for the correlation with the primary disease; * 10\. Continuous use of hormones or other immunosuppressive therapy in the past 6 months; * 11\. Accompanying or past malignant tumors, except for fully treated skin basal or squamous cell carcinoma or cervical carcinoma in situ; * 12\. History of psychosis may interfere with normal participation in this study; * 13\. Patients with major heart or lung diseases (including obstructive pulmonary disease); * 14\. In acute and chronic tuberculosis infection period (tuberculin test positive, chest X-ray suspected tuberculosis patients); * 15\. Patients with history of immunodeficiency, including other acquired or congenital immunodeficiency diseases, or a history of organ transplantation; * 16\. Weight less than 50kg should be excluded; * 17\. Other researchers judge the patients unsuitable for inclusion in the study