IgA Nephropathy in Children Under 18 — When RAS Blockade Has Not Achieved Proteinuria Targets

This protocol addresses children under 18 years of age with confirmed IgA nephropathy (IgAN) whose proteinuria has not reached the treatment target despite an adequate trial of first-line RAS blockade.

Previous treatment — target not reached

First-line management in children with IgAN and elevated proteinuria consists of RAS blockade (an ACE inhibitor or an angiotensin receptor blocker), advice on moderating dietary salt intake, and optimisation of blood pressure with a target systolic pressure below the 90th percentile for age, sex, and height.

Escalation to this protocol is indicated when that approach has not achieved proteinuria ≤200 mg/d or PCR ≤200 mg/g and/or blood pressure remains above the 90th percentile.

Next step — partial overview

In children with persistent proteinuria above target despite RAS blockade, a systemic oral glucocorticoid regimen may be added to therapy. The specific choice of agent, dosing approach, and tapering schedule are set out in the full protocol.

Full regimen, dosing schedule, duration, and tapering details are available in the structured protocol below.

Treatment goal

Achieve proteinuria ≤200 mg/d or PCR ≤200 mg/g.

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References

In this guideline, we define children as those aged <18 years, but it is acknowledged that postpubertal children may in some respects have a similar course and response to treatment as adults with IgAN.

Systemic oral glucocorticoids are used in selected settings in children with clinical risk of progression, as evidenced by one of the following: (i) PCR 500–1000 mg/g (50–100 mg/mmol) despite 3–6 months of RASi, (ii) PCR >1000 mg/g (>100 mg/mmol) despite 4 weeks of RASi, or (iii) active MEST-C scores (≥1 of the following scores: M1, E1, S1 with podocyte lesions, and/or C1) and/or PCR consistently (≥2 measurements 1–2 weeks apart over 2–3 weeks) >1000 mg/g (100 mg/mmol) in addition to RAS blockade.

Duration of treatment is not established, but usually 2 mg/kg/d (maximum 60 mg/m²/d) of oral prednisone/prednisolone (or equivalent) for a maximum of 4 weeks followed by alternate-day dosing tapered over 5–6 months is given.

Lower doses, such as those emerging from the adult Therapeutic Effects of Steroids in IgA Nephropathy Global (TESTING) trial (0.4 mg/kg/d of prednisone/prednisolone [or equivalent] for 2 months, tapering over 6 months) should be considered.

Aim for proteinuria ≤200 mg/d (≤400 mg/1.73 m² per day) or PCR ≤200 mg/g (≤20 mg/mmol).