Reduction in glomerular pore size is not restricted to pregnant women. Evidence for a new syndrome: 'Shrunken pore syndrome'.
The plasma levels of cystatin C, β2-microglobulin, beta-trace protein, retinol binding protein (RBP) and creatinine were determined in plasma samples from 111 randomly selected patients with eGFRcystatin C ≤ 60% of eGFRcreatinine and from 55 control patients with 0.9eGFRcreatinine ≤ eGFRcystatin C ≤ 1.1eGFRcreatinine (eGFRcystatin C ≈ eGFRcreatinine). The concentration ratios of cystatin C/creatinine, β2-microglobulin/creatinine, beta-trace protein/creatinine and RBP/creatinine were significantly higher in patients with eGFRcystatin C ≤ 60% of eGFRcreatinine than in patients with eGFRcystatin C ≈ eGFRcreatinine. When the patients were divided into three groups with different estimated GFR intervals (≤ 40, 40-60 and ≥ 60 mL/min/1.73m(2)) the concentration ratios of cystatin C/creatinine, β2-microglobulin/creatinine, and beta-trace protein/creatinine were significantly higher in patients with eGFRcystatin C ≤ 60% of eGFRcreatinine than in patients with eGFRcystatin C ≈ eGFRcreatinine for all GFR intervals. Similar results were obtained when the population without pregnant women was studied as well as the subpopulations of men or of non-pregnant women. Populations of pre-eclamptic women and pregnant women in the third trimester display similar results. Since the production of these four proteins with sizes similar to that of cystatin C is not co-regulated, the most likely explanation for the simultaneous increase of their creatinine-ratios in patients with eGFRcystatin C ≤ 60% of eGFRcreatinine is that their elimination by glomerular filtration is decreased. We suggest that this is due to a reduction in pore diameter of the glomerular membrane and propose the designation 'Shrunken pore syndrome' for this pathophysiological state.
Department of Clinical Chemistry, Skåne University Hospital , Lund.
Anders
A
Grubb
Veronica
V
Lindström
Magnus
M
Jonsson
Sten-Erik
SE
Bäck
Tomas
T
Åhlund
Bengt
B
Rippe
Anders
A
Christensson
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003404:Creatinine / Q000097:blood; D055316:Cystatin C / Q000097:blood; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D019746:Intramolecular Oxidoreductases / Q000097:blood; D007674:Kidney Diseases / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology; D007678:Kidney Glomerulus / Q000473:pathology / Q000503:physiopathology*; D054834:Lipocalins / Q000097:blood; D008297:Male; D008875:Middle Aged; D054839:Retinol-Binding Proteins, Plasma / Q000378:metabolism; D013577:Syndrome; D001613:beta 2-Microglobulin / Q000097:blood
D055316:Cystatin C; D054834:Lipocalins; D054839:Retinol-Binding Proteins, Plasma; D001613:beta 2-Microglobulin; D003404:Creatinine; D019746:Intramolecular Oxidoreductases; C022466:prostaglandin R2 D-isomerase
Beta-trace protein; beta 2-microglobulin; creatinine; cystatin C; glomerular filtration rate; kidney diseases; retinol-binding proteins