CST3 and acute kidney injury: Similarly, when positive cystatin C was used as the diagnostic marker for AKI, there was an association with increased risk of mortality among children with malaria (RR 2.97 (95% CI 1.29 to 6.87), p = 0.01) but not among children with NMFI (RR 1.83 (95% CI 0.77 to 4.30), p = 0.17) after adjusting for age and sex and severity of illness.