#2672 Real-life analysis of a monocentric cohort of IgA nephropathy patients

Abstract Background and Aims IgA nephropathy (IgAN) exhibits a great clinical variability in terms of onset, disease progression, and response to treatment. Data from clinical studies, due to the homogeneous characteristics of the patients analyzed, may provide literature values that differ from in clinical practice. To describe and analyse the main characteristics of IgAN, observe any factors influencing the annual decline of eGFR and the consequent progression toward chronic kidney disease (CKD), as well as analyse the factors contributing to the reduction of proteinuria. Method A monocentric study conducted at the Nephrology and Dialysis Department of San Raffaele Hospital in Milan, involving 34 patients with a histological diagnosis of IgAN. Patients were monitored through renal function analysis, proteinuria, and blood pressure measurements from the first nephrological visit (T0), at the time of renal biopsy (T1), and at the end of follow-up (T2). MEST-C score was calculated according to histological data. Results In our cohort, IgAN was more common in males, with a mean age of 34 years. A delay in nephrological diagnosis and renal biopsy was observed from symptom onset (35 month). This diagnostic delay can be attributed to an initial conservative approach in treating patients with proteinuria and/or microhematuria, reserving renal biopsy for patients showing renal function deterioration or persistent proteinuria despite maximal tolerated antiproteinuric therapy. Analysis of comorbidities in the 34 patients revealed hypertension as the most common (58.8% of patients). These data confirm a significant incidence of uncontrolled hypertension at disease onset, with notable improvement in blood pressure control during follow-up (Patients whit uncontrolled hypertension: 26.5% at T0 vs 9,5% at T2) due to a more targeted therapeutic approach using ACE inhibitors/ARBs, which may help slow the progression of IgAN and have positive effects on renal function. Most patients (91%) had persistent or intermittent microhematuria on standard urine testing during follow-up. Microhematuria is one of the most common clinical signs of IgA nephropathy, and its persistence over time is aspect of disease management and prognosis. In our cohort, the average eGFR value at T0 was 78.43 ml/min/1.73 m² (using the CKD-EPI formula). The average annual eGFR decline in our cohort was 5.08 ml/min/1.73 m², with 41% of patients showing an annual eGFR decline >3.16% of patients started hemodialysis, with 3% undergoing renal transplantation. The average proteinuria value in our cohort at T0 was 2.21 g/24 h. At the end of follow-up, the average proteinuria value was 0.74 g/24 h, which is particularly significant as proteinuria values <1 g/24 h are generally associated with a lower risk of disease progression. Proteinuria values significantly correlate (P < 0.05) with the annual eGFR decline, with a 2.8 ml/min/1.73 m² decline in patients with proteinuria <0.5 g/24 h, while in patients with higher proteinuria values (1–3.5 g/24 h), the annual eGFR decline was 8.276. Conclusion In our cohort IgAN proves to be a heterogeneous condition that can progress rapidly to end-stage kidney disease in a portion of patients. Therefore, it is essential to raise awareness for the referral of patients to nephrology for earlier histological diagnosis, enabling timely therapeutic intervention. Control of proteinuria and blood pressure is crucial for slowing disease progression, and consistent monitoring along with a targeted therapeutic approach are key to improving long-term prognosis.