SP184
CLINICAL IMPLICATIONS AND PATHOLOGICAL CLASSIFICATION OF TUBULOINTERSTITIAL INJURY FOR THE PREDICTION OF RENAL OUTCOME IN LUPUS NEPHRITIS

INTRODUCTION AND AIMS: Tubulointerstitial lesions are a common finding in Lupus Nephritis (LN) and impacts in renal outcome independently of glomerular lesions,however the current classification does not include a mandatory score of this kind of injury and there is scarce information about his role in the assessment of treatment response.

METHODS:We sought to determine predictors and influence of tubulointerstitial inflammation and fibrosis in renal outcomes and treatment response in a cohort of 82 patients with 100 biopsy proven LN flares, treated in the Hospital Clinic of Barcelona between 2000-2016.

RESULTS: Tubulointerstitial chronic damage and inflammation, were present in 74% of the biopsies. Patients with inflammation grade 1 o more ( >25%) had worse renal function and proteinuria than patients with no inflammation.The more fibrosis, the worst renal function, especially when it was more than 50%. Fibrosis >25% was an independent predictor of renal survival, augmented the possibility of reaching stage 4 KDOQI-CKD and having a progressive GFR decline. Acute inflammation correlates with the presence of AKI and hematuria with casts at presentation. Around 40% of patients with clinical remission still had significant inflammation on repeat biopsy

CONCLUSIONS: Tubulointerstitial chronic damage and inflammation had an important impact in renal outcomes and is essential in treatment response assessment. A proper evaluation of urine sediment is an important tool to detect early lesions in patients with Lupus nephritis.