To Evaluate the Effect and Safety of Telitacicept and Standard Treatment for 6months in IgA Nephropathy

Inclusion Criteria: * Age 18\~75 years, regardless of gender. * Clinical evaluation and renal biopsy diagnostic for IgA nephropathy. * Average urinary protein excretion of 0.3\~3.5g/24h on two successive examinations. * Urine Protein to Creatinine Ratio (UPCR) \>= 0.75 and \<= 6 milligram per milligram (mg/mg) during screening. * Stable and optimal dose of Angiotensin converting enzyme (ACE) inhibitor and/or angiotensin II receptor blockers (ARB) at least 8 weeks prior to screening. * eGFR≥30 ml/min/1.73m2. * Willingness to sign an informed consent. Exclusion Criteria: * • Secondary IgA nephropathy such as systemic lupus erythematosus, Henoch-Schonlein purpuric nephritis and hepatitis B-associated nephritis, etc. * IgA nephropathy with significant glomerulosclerosis or cortical scarring. * Failure to meet estimated glomerular filtration rate (eGFR) and biopsy requirement criteria. * Rapidly progressive nephritic syndrome. * Acute renal failure, including rapidly progressive IgA nephropathy. * Current or recent (within 30 days) exposure to high-dose of steroids or immunosuppressive therapy (CTX、MMF、CsA、FK506). * Cirrhosis, chronic active liver disease, and serious liver function damage. * 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. * 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). * Active tuberculosis or untreated latent TB infection. * Malignant hypertension that is difficult to be controlled by oral drugs. * Known allergy, contraindication, or intolerance to the steroids. * Pregnancy or breast feeding at the time of entry or unwillingness to comply with measures for contraception. * Malignant tumors. * Excessive drinking or drug abuse. * Mental aberrations. * Any condition, including any uncontrolled disease state other than IgA nephropathy.