[Shrunken Pore Syndrome - a new syndrome]

Area of Science:

• Nephrology
• Renal Physiology
• Biomarker Research

Background:

• Shrunken Pore Syndrome (SPS) was defined in 2015.
• It is characterized by selective reduction in glomerular filtration of 5-40 kDa molecules compared to smaller molecules (<0.2 kDa).
• Diagnosis relies on a decreased estimated Glomerular Filtration Rate (eGFR) cystatin C/eGFR creatinine ratio, typically below 0.6 or 0.7.

Purpose of the Study:

• To summarize the characteristics, diagnosis, prevalence, and implications of Shrunken Pore Syndrome.
• To highlight the association between SPS and increased mortality.
• To explore the potential pathophysiology and clinical utility of eGFRcystatin C in identifying at-risk kidney patients.

Main Methods:

• Review and synthesis of existing literature defining and investigating Shrunken Pore Syndrome.
• Analysis of diagnostic criteria based on the eGFRcystatin C/eGFRcreatinine ratio.
• Examination of prevalence data and mortality associations across different populations.

Main Results:

• A decreased eGFRcystatin C/eGFRcreatinine ratio is the diagnostic hallmark of SPS.
• Mortality is significantly elevated in individuals with SPS, increasing as the ratio decreases.
• Prevalence varies with diagnostic ratio thresholds, ranging from 2-8% when using a ratio of 0.6.

Conclusions:

• Shrunken Pore Syndrome is associated with substantial mortality risk.
• The accumulation of atherosclerosis-promoting proteins is a potential underlying pathophysiology.
• eGFRcystatin C may be superior to eGFR creatinine in identifying patients with kidney disease at high risk.