Hyperfiltration predicts long-term renal outcomes in humanized sickle cell mice

Area of Science:

• Nephrology
• Hematology
• Genetics

Background:

• Sickle cell disease (SCD) is a major cause of morbidity and mortality, often involving kidney disease (nephropathy).
• Sex-dependent differences in SCD progression suggest underlying protective mechanisms that warrant investigation.

Purpose of the Study:

• To investigate sex-based differences in the development and progression of nephropathy in humanized sickle cell (HbSS) mice.
• To identify potential predictors and contributors to kidney injury severity in SCD.

Main Methods:

• Comparison of renal function and kidney damage markers in male and female HbSS mice over 20 weeks.
• Assessment of glomerular filtration rate, tubular injury (KIM-1 excretion, brush border loss), and interstitial fibrosis.

Main Results:

• Male HbSS mice exhibited rapid hyperfiltration followed by progressive renal function decline.
• Early tubular injury, including increased KIM-1, preceded glomerular damage in males, suggesting a tubuloglomerular mechanism.
• Female HbSS mice did not show significant renal function loss or severe kidney damage within the study period.

Conclusions:

• Hyperfiltration magnitude predicts chronic kidney damage in male HbSS mice.
• Protective mechanisms in female mice appear to delay the onset of SCD nephropathy.