Hypothesis
Low-dose IL2 raises regulatory T cells, which reverse protein loss in the urine in animal models of nephrotic syndrome, so it would lower protein loss in children whose nephrotic syndrome resists all other drugs.
What failed
In 5 boys given six monthly cycles, IL2 raised regulatory T cells in some, but protein in the urine and kidney function did not change at any point. One child had an asthma attack after the first dose.
Broken assumption
Raising regulatory T cells reduces protein loss in human nephrotic syndrome, as it does in rodent models.
Why
The effect of regulatory T cells seen in rats and mice did not carry over to people. The authors say this reduces interest in IL2 for this disease.
From the published paper: Bonanni et al. PLoS ONE, 2015. ↗CC BY