SP166
PAUCI IMMUNE RAPIDLY PROGRESSIVE GLOMERULONEPHRITIS, CLINICAL AND HISTOPATHOLOGICAL DATA. EXPERIENCE FROM CROATIAN UNIVERSITY HOSPITAL Free

Introduction and Aims: Retrospective cohort presents clinical and histopathological data of patients with pauci immune rapidly progressive glomerulonephritis (RPGN), diagnosed and treated in our hospital over 15 year period. (2000-2015.)

Methods: 75 of 1517 patients, enrolled in our renal biopsy registry, with pauci immune RPGN were analysed. Based on patohistological and clinical data they were diagnosed with one of the small-vessel ANCA associated vasculitis: microscopic polyangiitis (MPA) 45,3%, granulomatosis with polyangiitis (GPA) 22,7%, eosinophilic granulomatosis with polyangiitis (EGPA) 4% or renal limited vasculitis (RLV) 28%. We analysed epidemiological data, blood pressure, extrarenal disease manifestations (respiratory, skin, general simptoms), serum creatinine (Sc), creatinine clearance (CrCl), 24h proteinuria, C-reactive protein (CRP), antineutrophilic cytoplasmic antibiodies (PR3 and MPO - ANCA), treatment, plasmapheresis (PF) and need for renal replacement therapy (RRT). Birmingham vasculitis activity score was calculated. Median value and interquartile(IQ) range of continuing variables were compared using Kruskal-Wallis and Mann-Whitney U test. Category variables were compared using χ2-test and Fisher Exact test. Analysis was performed using SPSS statistical software version 17.0. (p<0,05)

Results: 75 patients (52% female) median age 61 (IQ range 48-68). MPA patients were older than those with EGPA (p=0,037) and RLV (p=0,019), as to GPA there was no difference. Prevalence of general simptoms (88% of all patients) and arterial hypertension (52% of all patients) was not statistically different between entities. Most of the patients (48%) presented with rapidoprogressive nephritic syndrome (MPA 55,99%; GPA 82,4%) while patients with RLV mostly presented with nephrotic syndrome (42,9%). Respiratory symptoms were more associated with GPA (p=0,004) and skin with nonGPA (p=0,028) and nonRLV (p=0,002). Majority of the patients had some degree of renal impairment with reduced CrCl (CKD-EPI formula) except for EGPA patients. MPA and GPA patients had significantley higher Sc and lower CrCl than those with EGPA (p=0,026 for Sc; 0,017 for CrCl) and RLV (p=0,003; 0,001). There was no significant difference for 24h proteinuria. RLV patients had lower CRP compared to MPA (p=0,01) and GPA (p=0,021) patients. GPA patients had significantley higher BVAS compared to MPA (p=0,019) and RLV (p=0,006) patients. 17,4% patients had PR3-ANCA, 36% MPO-ANCA, 5,3% both ANCA subtipes and 41,3% of the patients were ANCA negative. Analysing pathohistological types, MPA (47,1%) and RLV(76,2%) had significantly greater proportion of mixed type compared to others ( (p=0,022), GPA presented predominantly as crescentic and EGPA as focal type. In majority of the patients (93,4%) induction therapy included glucocorticoids and cyclophosphamide, 1,3% glucocorticoid monotherapy and 5,3% symptomatic treatment. 33,3% of all patients were treated with PF and 32% of all patients required RRT. PF treatment was more associated with GPA (p=0,011) and nonRLV (p=0,001) and RRT with MPA (p=0,04) and nonRLV (p=0,009).

Conclusions: Clinical and histological data on pauci-immune glomerulonephritis are basis for better understanding of these diseases and for determening prognostic factors. We also emphesize larger percentage of ANCA negative patients compared to other reports.