Table 2 Study and patient characteristics

Min Lulin et al. (2017) [22]

China

RCT

low-dose prednisone plus leflunomide

full-dose prednisone

40

45

LEF group:

LEF, 40 (3d) -- 20 (20 m);

CS, 0.8 mg/kg/day (4-6w, max 40 mg/d).

CS group:

CS, 1 mg/kg/day (8-12w, max 60 mg/d).

12

ACEI/ARB

All patients had biopsy-proven primary IgAN with renal biopsy samples examined independently by two pathologists. Patients aged 18–65 years were included if they had proteinuria ≥ 1.0 g/24 h and an estimated glomerular filtration rate (eGFR) ≥ 30 ml/ min/1.73m² (calculated by CKD-EPI equation).

Li Yebei et al. (2021) [24]

China

retrospective cohort study

low-dose corticosteroid plus leflunomide

full-dose corticosteroid

65

84

LEF group:

LEF, 50 (3d) -- 20 (6 m);

CS, 0.4 ~ 0.6 mg/kg/day (2 m) -- 0.32 ~ 0.48 mg/kg/day (4 m).

CS group:

CS, 0.8 ~ 1 mg/kg/day (2 m) -- 0.64 ~ 0.8 mg/kg/day (4 m).

18

ARB

Patients met the following criteria: (1) IgAN diagnosed by renal biopsy; (2) an age range of 16–65 years; (3) 24-h urinary total protein (24 h UTP) level > 0.75 g, (4) estimated glomerular filtration rate (eGFR) ≥ 50 ml/min per 1.73 m², and (5) a follow-up time was up to 18 months.

Ni Zhaohui et al. (2021) [23]

China

RCT

low-dose prednisone plus leflunomide

conventionally dose prednisone

59

49

LEF group:

LEF, 40 (3d) − 20 (12 m);

CS, 0.5 ~ 0.8 mg/kg/day (8-12w, max 40 mg/d).

CS group:

CS, 1 mg/kg/day (8-12w, max 60 mg/d).

12

ACEI/ARB

Patients were aged 18–65 with biopsy-confirmed primary IgAN in recent 3 months, and with any one of the following indications for progression in IgAN: 24-h UPE > 1.0 g/day; eGFR < 60 mL/min per 1.73 m² (calculated by CKD-EPI equation); and renal histological lesions defined as Lee’s IV, or glomerulus and/or segmental sclerosis ≥ 40%.