Background: In IgAN with cellular crescents (CIgAN) urinary excretion of α2-macroglobulin (α2m/C, MW 720 kDa) may be a marker of podocytes damage induced by crescents. The purpose of the study was the evaluation of the clinical significance of α2m/C excretion in 177 patients with glomerulonephritis (GN), nephrotic syndrome (NS) and functional outcome. Methods: In all 177 patients α2m/C excretion was measured; the patients were divided in 2 groups: α2mC=0 (n. 72) and α2m/C >0 (n. 105); for each group were assessed the outcomes considered in combination: Remission & persistent nephrotic syndrome (PNS) with long lasting NRF designed “Remission & NRF”; ESRD & eGFR < 50% & PNS with CRF designed “Progression and progression risk”. Results: In 72 patients with α2m/C=0 “Remission & NRF” was 78% and “Progression & progression risk” was 22%; in 105 patients with α2m/C>0 “remission & NRF” was 52% and “Progression & progression risk” was 48%. “Remission & NRF” in each GN type with α2m/C=0 was: 100% in MCD and LN; 82%, 79%, 67% in FSGS, IMN, MPGN; in α2m/C>0 “Progression and progression risk” was 0%, 38%, 46%, 54%, 56%, 85% in MCD, LN, IMN, MPGN, FSGS, CIgAN with cellular crescents, respectively. Conclusion: Urinary excretion of α2m is a very simple marker available in all clinical practice laboratories, marker of damage of podocytes at least in CIgAN and LN with crescents and marker of GFB damage in different GN types and useful to predict outcome and treatment responsiveness.
May be Urinary Excretion of α2-macroglobulin (MW 720 kDa) a Proteinuric Marker of Podocytopathy? Insight from Analysis of 204 Patients with Glomerulonephritis (GN) and Nephrotic Syndrome, 177 with Functional Outcome