Table 1 Search strategy according to populations, interventions, comparators, outcomes, and study designs (PICOS)

Inclusion Criteria

Patient was diagnosed as IgAN by renal biopsy

low-dose corticosteroid plus leflunomide

full-dose corticosteroid

eGFR (ml/min/1.73m²).

Serum creatinine.

Urine protein excretion.

Complete remission.

Overall remission.

Complications.

Clinical research

Exclusion Criteria

Patients with rapidly progressive IgA nephropathy.

Secondary IgA nephropathy due to the patient’s systemic illness.

Patients with severe infections.

Patients with Patients were on CS or other immunosuppressive therapy within 6 months before enrollment.

Patients with malignancy, HIV infection, or acute central nervous system diseases.

Not performed

Not performed

Blood pressure.

Hematuria.

End-stage renal disease (ESRD).

Acute kidney injury.

Edema.

Letters, comments, reviews, qualitative studies