P0470IS GLYCOSURIA A MARKER OF TUBULO-INTERSTITITAL FIBROSIS AND PROGNOSIS IN PRIMARY GLOMERULOPATHIES?

Abstract

Abstract Background and Aims Multiple studies have shown that tubular damage is common in glomerular diseases and that it correlates better with chronic kidney disease (CKD) progression than glomerular lesion itself. The link between glomerular and tubular damage is not entirely established. Glycosuria can be found in (proximal) tubular dysfunction and may be used as a marker of tubular lesion and CKD progression. The aim of this study was to evaluate the association between glycosuria (at the diagnosis) and known histological prognostic markers (glomerular sclerosis (%GS) and interstitial fibrosis/tubular atrophy (IFTA)) and CKD progression, in patients with primary glomerulopathies (GP). Method We conducted a 36-month retrospective cohort study with 110 patients with primary GP confirmed by renal biopsy in the last 10 years in our centre – 39 (35.5%) IgA Nephropathy, 27 (24.5%) Membranous Nephropathy, 26 (23.6%) Focal Segmental Glomerulosclerosis and 18 (16.4%) Minimal Change Disease. Patients were divided in two groups according to their glycosuric status at the time of the diagnosis. Data was collected from patients’ charts. Exclusion criteria: patients with diabetes or glucose intolerance, use of SGLT2 inhibitors, secondary GP and transplant kidney patients. Results The global prevalence of glycosuria was 9.1% (n=10). Glycosuric patients had, at baseline, higher serum creatinine (3.9±5.1 vs 1.7±1.3mg/dL, p=0.001), higher baseline albuminuria (7.1±6.3 vs 3.2±3.4 g/g, p=0.002) and lower serum albumin (2.3±0.7 vs 3.2±1.1 g/dL, p=0.022). Both groups had similar proportion of patients that underwent immunosuppressive therapy. At the end of the follow-up, in glycosuric patients, only albuminuria was higher (3.3±0.6 vs 0.7±0.8 g/g, p<0.0001); the eGFR decline rate (ml/min/year), 3-year eGFR and 3-year CKD stage 5D incidence were not statistically different. Glomerular sclerosis (%GS) and interstitial fibrosis and tubular atrophy (IFTA) were not different between groups. These results were confirmed by multivariate analysis. Conclusion Patients with primary GP with glycosuria at diagnosis had higher baseline creatinine and albuminuria. Even though a worse clinical presentation, glycosuria was not associated with well-known prognostic factors (%GS and IFTA) or CKD progression. We can hypothesize that patients with primary GP with glycosuria have severe diseases at diagnosis, but the lesions may have greater reversibility. Prospective and longer studies are needed to confirm these results.