10.2: Proteinuria-lowering and blood pressure-lowering therapy 10.2.1 For proteinuria >1g/d, long-term oral ACEI or ARB is recommended, and the drug dose should be adjusted according to blood pressure. 10.2.2 For proteinuria between 0.5 and 1g/d [between 0.5 and 1g/(d-1.73m2) in children], ACEI or ARB therapy is recommended. 10.2.3 A gradual increase in ACEI or ARB dose to a tolerable dose is recommended to achieve urinary protein <1g/d. 10.2.4 Blood pressure control goal for IgAN patients with proteinuria <1g/d is <130>1g/d with blood pressure control goal <125/75 mmHg. Principle A large number of clinical trials on the use of ACEI/ARB drugs enrolled IgA nephropathy patients with proteinuria ≥1 g/d, whereas only some studies enrolled proteinuria ≥0.5 g/d. In the registry data, the rate of renal function decline accelerated with increasing proteinuria, with patients with proteinuria ≥3 g/d declining 25 times faster than patients with proteinuria <1 g/d. Patients with proteinuria ≥3 g/d at onset who were controlled to <1 g/d had a similar course to those who always had proteinuria <1 g/d and were far better off than those whose proteinuria was not controlled to that level. However, there is no evidence to suggest whether there is an additional benefit of continuing to reduce proteinuria in patients with proteinuria below 1 g/d. Several RCTs have shown that ACEI and ARB can reduce proteinuria and improve renal function (as assessed by the rate of decline in GFR). However, there is no clear evidence that ACEI or ARB reduces the risk of ESRD. There are no data suggesting that ACEI is superior to ARB or vice versa, but ARB has somewhat less adverse drug effects than ACEI. One study showed that combining ACEI and ARB reduced proteinuria by 73% compared with monotherapy (38% for ACEI and 30% for ARB). A small study with only 7 pediatric patients also showed that the combination of ACEI and ARB was superior, however more studies are needed to clarify whether the combination is effective and better at reducing renal endpoint events.