Urine Complement Factor Ba Identifies Persistent Acute Kidney Injury and Organ Failures in Critically Ill Adults

Area of Science:

• Nephrology
• Critical Care Medicine
• Immunology

Background:

• Critically ill adults with acute kidney injury (AKI) face high mortality and limited treatment options.
• Complement activation is implicated in AKI pathogenesis, but its clinical utility is unclear.

Purpose of the Study:

• To assess the association between complement activation, measured by urine Ba fragment levels, and the development and severity of AKI.
• To determine if urine Ba levels correlate with organ failure outcomes in critically ill patients.

Main Methods:

• Utilized a biorepository of critically ill adults, staging AKI using Kidney Disease Improving Global Outcomes (KDIGO) serum creatinine criteria.
• Measured urine Ba levels via ELISA at ICU admission and 12/24 hours post-admission; analyzed associations with AKI stage, recovery, and organ failure using regression, adjusting for age and APACHE-II score.

Main Results:

• Higher urine Ba levels correlated with increased AKI severity.
• Urine Ba was significantly higher in patients with persistent AKI compared to those with AKI recovery or no AKI.
• Increased urine Ba was associated with worse organ failure outcomes, including fewer ventilator-free, ICU-free, and inotrope-free days.

Conclusions:

• Urine Ba fragment levels are elevated in severe AKI and can differentiate between AKI recovery and persistent AKI.
• A doubling of urine Ba was associated with a 6.6-fold increased odds of persistent AKI.
• Further research is warranted to validate these findings and explore complement inhibition therapies for AKI.