TNFRSF11B and acute kidney injury: However, in a backward stepwise logistic regression model controlling for age and parasitaemia, both OPG and angiopoietin-2 (but not CFHb) remained as independent risk factors for severe malaria (with hyperparasitaemia removed as a severity criterion), and for AKI (Table 3; alternative logistic regression models shown in Supplementary Tables 2 and 3).