Shrunken Pore Syndrome Is Associated with Renal Function Decline in Female Patients with Kidney Diseases

Abstract

Background. Shrunken pore syndrome (SPS) represents selective impairment of kidney filtration of low-molecular-weight molecules between 1 and 30 kDa and has been related to outcomes including morbidity, mortality, and cardiovascular events. However, the prevalence and kidney outcomes of SPS have not been investigated in patients with IgA nephropathy (IgAN) and membranous nephropathy (MN). Methods. We retrospectively collected information of 536 patients including 414 with IgAN and 122 with MN. SPS was mainly defined by cystatin C-based eGFR < 70 % of creatinine-based eGFR using the CAPA-LM equation pairs, while CKD-EPI equations were also employed in sensitivity analyses. Prevalence rate of SPS and its association with end-stage renal disease (ESRD) or severe eGFR decline (≥50% eGFR reduction or doubling of baseline creatinine) were investigated. Results. 44% (8%) patients were identified as possessing SPS using the CAPA-LM definition. ESRD happened in 24 patients during the average follow-up period of 27.7 months. Despite dramatic increase of incidence rate of ESRD for SPS, significant hazard ratio (HR) only existed in IgAN patients after multivariable adjustment (HR: 8.35, 95% CI: 2.10~33.26), but lost significance in sensitivity analyses. 36 patients were determined as having experienced severe eGFR decline after excluding transient creatinine fluctuation. SPS was associated with severe eGFR decline by Kaplan-Meier survival analyses in the overall population as well as the IgAN, MN, male, and female subpopulations, which remained significant in multivariable adjustments in all groups except IgAN. However, only in female patients the association between SPS and eGFR decline remained significant in all the sensitivity analyses. Conclusions. SPS was independently associated with eGFR decline in female patients with IgAN and MN.

Shrunken Pore Syndrome Is Frequently Occurring in Severe COVID-19

“…In patients with IgA nephropathy and membranous nephropathy, women were not overrepresented in patients with SPS. However, there was a significant association between SPS and end-stage renal disease in females, but not in males [ 38 ]. In healthy volunteers aged 60 years or older, the eGFR CYSTATIN /eGFR CKD-EPI ratio was significantly higher in women and increased progressively with age in both genders [ 6 ].…”

The Association of Intraindividual Difference Between Cystatin- and Creatinine-Based Estimated GFR and Contrast-Associated Acute Kidney Injury

“…Previous studies have shown that a significantly lower eGFRcys than eGFRcr may also be a manifestation of kidney disease, [27][28][29] which is mainly manifested in glomerular filtration dysfunction of medium-sized molecules, 27,30 such as cystatin C. And, eGFRdiff is negatively correlated with the severity of this novel kidney disease. 31 Moreover, this disease may cause the decline of the resistance and defense of the kidneys 32 and lead to a tendency of CA-AKI when hit by the contrast agent. Besides, patients with either CKDcys or CKDcr were found to be associated with CA-AKI development in this study.…”