AB0299 QUANTITATIVE EVALUATION OF PROTEINURIA WITH URINALYSIS TEST AND COMPARING ITS CORRELATION WITH RANDOM SPOT URINE PROTEIN-CREATININE RATIO AND 24 HOUR URINE PROTEIN IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS –A SINGLE CENTRE EXPERIENCE IN MALAYSIA

Background:Lupus nephritis is an important concern among Systemic Lupus Erythematosus (SLE) patients in Asia and its mortality rate was reported to be 6 times higher compared to the general population [1]. Without prompt treatment it can lead to end stage renal failure and affect quality of life. 24 hour urine protein collection has long been used as the gold standard test to assess proteinuria. However due to its cumbersome process random spot urine protein-creatinine ratio is used as an alternative to replace the former in some centres before subjecting patients to renal biopsy. In a study done by Matar HE et al in 2012, he showed that there was a significant correlation between 24 hour urine protein and urine protein creatinine ratio in his 95 subjects [2].Urinalysis is a semi-quantitative screening tool for early detection of potential kidney disorders. A survey done by Siedner MJ et al on practice preferences among American Rheumatologists in 2005 reported that 64.6% of them preferred to use urinalysis as the primary tool to screen for proteinuria [3].Objectives:To assess the correlation of urinalysis test with random spot urine protein-creatinine ratio PCR) compared with 24 hour urine protein.Methods:This was a retrospective study. The electronic medical records of all SLE patients seen in the rheumatology clinic of Hospital Sultan Ismail from 1/1/2017 to 31/12/2020 were reviewed. Patients who had urinalysis, urine protein creatinine ratio and 24 hour urine protein tests done were identified. Data on demography, urinalysis, random spot urine protein creatinine ratio and 24 hour urine protein were obtained and analysed.Results:There were a total of 131 patients and 124 were females. The majority were Malays (75/131) followed by the Chinese (45/131),Indians (9/141) and others (2/131). The mean age group for the studied subjects was 34 (13-67). The urinalysis test showed that 34 of them had negative results, 37 of them had urine protein of 1 +, 18 of them had urine protein of 2+ followed by 23 patients with urine protein of 3 + and the rest had urine protein of 4+. The correlation between urinalysis and 24 hour urine protein was strong (r = 0.702), whereas the correlation between urinalysis and urine PCR ratio was stronger (r = 0.797).Conclusion:We conclude that urinalysis correlates well with both random spot urine protein creatinine ratio and 24 hour urine protein and the correlation is stronger with urine PCR.References:[1]Yap DY, Tang CS, Ma MK, Lam MF, Chan TM. Survival analysis and causes of mortality in patients with lupus nephritis. Nephrol Dial Transplant. 2012;27:3248–3254. [PubMed][2]Matar HE, Peterson P, Sangle S, D’Cruz DP. Correlation of 24-hour urinary protein quantification with spot urine protein: creatinine ratio in lupus nephritis. Lupus 2012 Jul;21(8): 836-9. doi:10.1177/0961203312437438. Epub 2012 Feb 13.[3]Siedner MJ, Christopher-Stine L, Astor BC, Gelber AC, Fine DM. Screening for proteinuria in patients with lupus: a survey of practice preferences among American rheumatologists. J Rheumatol. 2007;34:973–977. [PubMed].Disclosure of Interests:None declared

AB0286 EFFICACY OF MYCOPHENOLATE MOFETIL PLUS RITUXIMAB COMPARED WITH INTRAVENOUS CYCLOPHOSPHAMIDE PLUS RITUXIMAB IN PATIENTS WITH RELAPSING LUPUS NEPHRITIS

Background:Lupus nephritis (LN) remaining as one of the most devastating manifestations of systemic lupus erythematosus (SLE). Only 60% of patients with LN achieve a complete (CR) or partial remission (PR) with mycophenolate mofetil (MMF) or intravenous (iv) cyclophosphamide (CY) plus corticosteroids. Of those nearly one-half will have a relapse following maintenance therapy [1]. Rituximab (RTX) is considered a treatment of relapsing LN [2]. Although potential benefits have been revealed in descriptive studies, efficacy has not been established in randomized trials [3,4].Objectives:This study compares the efficacy achieving a CR or PR with MMF+RTX versus iv CY+RTX in patients with relapsing LN.Methods:Mexican SLE patients classified by SLICC 2012 criteria were recruited from 2013 to 2019 with LN diagnosed by renal biopsy who previously having achieved a CR with MMF or iv CY followed by the maintenance therapy with azathioprine (AZA) or MMF and subsequently present relapsing LN consisting of a new active urinary sediment (US), worsening proteinuria and renal function. Demographic, renal clinical and paraclinical variables were examined. All patients received oral prednisone (1 mg/kg/d) accompanying MMF 3 g/d or CY 0.5–1 g/m2 monthly plus RTX 1 g at 0 and 14 days. The data were evaluated at 0, 6, 12 and 24 month(s) after the start both treatments. CR was defined as normal serum creatinine (SCr), inactive US, plus 24-Hour Urine Protein (24hUP) <500 mg/d and PC was established as 50 percent improvement in renal parameters. Fisher’s exact and Student´s-t tests were performed by univariate analysis.Results:Of nine SLE patients with relapsing LN, seven were women. The mean age [standard deviation (SD)] was 25.1 (6.4) years. The mean time at the onset of SLE (SD) was 3.44 (1.12) years ago. Four and five patients had class IV and IV/V LN respectively. Time of relapsing LN after of CR (SD) was 21.2 (7.17) months. Seven patients used CY followed by AZA and two employed MMF previously of relapsing LN. The mean of basal SLEDAI and SLICC (SD) were 19.11(3.2) and 1.22 (0.44) respectively. The mean of basal 24hUP (SD) was 4.67 (2.6) g/d and sCr (SD) was 2.0 (0.84) mg/dl. Five patients used MMF+RTX and four patients utilized CY+RTX. No statistically significant differences were found for CR, PR, 24hUP, sCr, US, anti-dsDNA and complement between both groups. At 6 months one patient achieved a CR and six reached a PR. At 12 months four patients fulfilled a CR and seven had a PR. Finally, at 24 months seven patients showed a CR and a CP. Only two patients did not achieve a CR or PR at 24 months.Conclusion:This study suggests that the most of SLE patients with relapsing LN treated with CY or MMF plus RTX achieved CR or PR at 24 months, although were no found differences between both treatments. However, these observations must be confirmed in larger and prospective studies.References:[1]Ann Rheum Dis 2020;79(6):713;[2]Nephrol Dial Transplant 2019;34(1):22;[3]Clin J Am Soc Nephrol 2009;4(3):579;[4]Arthritis Rheum 2012;64(4):1215Disclosure of Interests:None declared

Análise do perfil clínico e sociodemográfico dos pacientes pediátricos diagnosticados com glomerulonefrite difusa aguda em hospital no Sertão de Pernambuco, Brasil

Introdução: A glomerulonefrite difusa aguda é uma glomerulopatia decorrente do dano inflamatório dos componentes glomerulares, comumente encontrada em pacientes pediátricos, com padrão e prevalência variáveis de acordo com idade, sexo, fatores socioeconômicos e geográficos (principalmente nas glomerulonefrites infecciosas ou pós-infecciosas), sendo a causa mais comum de acometimento renal após os seis anos de idade. Porém, faltam dados mundiais precisos sobre a prevalência da síndrome. Objetivo: Traçar o perfil sociodemográfico e clínico dos pacientes pediátricos diagnosticados com esta glomerulonefrite no Hospital Regional Professor Agamenon Magalhães, localizado no município de Serra Talhada, Pernambuco. Material e método: Trata-se de um estudo retrospectivo e descritivo de corte transversal. A coleta de dados foi realizada entre agosto de 2018 a junho de 2019, através da análise dos prontuários dos pacientes pediátricos que foram diagnosticados com glomerulonefrite difusa aguda. Resultados: 29 prontuários foram analisados, correspondendo aos anos 2015 a 2018, sendo 51,72% do sexo masculino, residente em Serra Talhada e em zona rural, com idade média 7,7 anos, todos de etnia parda. Em admissão para atendimento hospitalar 75,86% da amostra apresentou estado geral regular, e apenas 3,45% grave. 34,48% da população estudada apresentou oligúria, 89,66% edema generalizado, 58,62% hipertensão arterial durante admissão, 27,59% cefaleia e 55,17% febre. Conclusão: Os resultados obtidos através da pesquisa destacam a importância de traçar o perfil para guiar os profissionais do serviço na assistência aos pacientes pediátricos acometidos pela patologia abordada. Descritores: Glomerulonefrite; Glomérulos Renais; Pediatria. Referências Costa DMN, Valente LM, Gouveia PAC, Sarinho FW, Fernandes GV, Cavalcante MAGM, et al. Análise comparativa de glomerulopatias primária e secundária no nordeste do Brasil: dados do Registro Pernambucano de Glomerulopatias - REPEG. J. Bras. Nefrol. 2017; 39(1): 29-35. Sim JJ, Batech M, Hever A, Harrison TN, Avelar T, Kanter MH, et al. Distribution of biopsy-proven presumed primary glomerulonephropathies in 2000-2011 among a racially and ethnically diverse US population. Am J Kidney Dis. 2016; 68(4): 533-544. Crensiglova C, Rehme BB, Kinasz LRS, Chula DC, Do Nascimento MM, Soares MFS. Frequência e avaliação clínico-histológica das doenças glomerulares em um hospital terciário da região Sul do Brasil. J Bras Nefrol. 2016; 38(1): 42-48. Kasper DL, Fauci AS, Hauser SL, Longo DL, Jameson JL, Loscalzo J. Manual de Medicina de Harisson. 19. ed. Porto Alegre: Mc Graw Hill/ Artmed; 2017. Couser WG. Patogênese e tratamento da glomerulonefrite, uma atualização. J Bras Nefrol. 2016; 38(1): 107-122. Figueira F, Alves JGB, Ferreira OS, Maggi RRS, Correia JB. Pediatria. 4ª edição. Rio de Janeiro: MedBook; 2011. Moorani KN, Sherali AR. Histopathological pattern in childhood glomerulonephritis. J Pak Med Assoc. 2010; 60(12): 1006. Rocha LP, Carminati CR, Machado JR, Laterza VL, Reis MA, Corrêa RRM. Prevalence of nephropathies in children and adolescents and alterations in renal biopsies in Minas Gerais, Brazil, from 1996 to 2010. Ann Diagn Pathol. 2017; 17(1): 22-27. Silva VS, Hagemann R, Viero RM. Glomerulonefrites primárias. In: Riella MC. Princípios de Nefrologia e Distúrbios Hidroeletrolíticos. Rio de Janeiro: Guanabara Koogan; 2018. Bertola EA, Simonetti GD, Del Giorno R, Giannini O, Fossali EF, Meoli M, et al. Extrarenal Immune-mediated disorders linked with acute poststreptococcal glomerulonephritis: a systematic review. Clinic Rev Allerg Immunol. 2019;57(2): 294-302. Sethi S, Fervenza FC. Standardized classification and reporting of glomerulonephritis. Nephrol Dial Transplant. 2018;34(2):193-99. Kılıc BD, Akbalık MK, Buyukcelik M, Balat A. Pediatric post-streptococcal glomerulonephritis: Clinical and laboratory data. Pediatr Int. 2018; 60(7):645‐50. Ali el-TM, Babikir AM, El-Assad S, Abdelrahim MB. Prognosis of acute post-streptococcal glomerulonephritis in Sudanese children. Arab J Nephrol Transplant. 2014;7(2):103‐7. Gunasekaran K, Krishnamurthy S, Mahadevan S, Harish BN, Kumar AP. Clinical characteristics and outcome of post-infectious glomerulonephritis in children in Southern India: a prospective study. Indian J Pediatr. 2015;82(10):896‐903. Maia MLA, Vale MLD, Hatanaka E. Recomendações: Atualização de Condutas em Pediatria. Departamento de Nefrologia. Síndrome nefrítica. Departamentos Científicos SPSP, n. 88, p.10-14, 2019.

THU0430 RENAL URATE DEPOSITION: SUMMARY OF PUBLISHED EVIDENCE

Background:Gout is the most common inflammatory arthropathy in U.S. adults. Although the severity of this debilitating disease is often defined by the presence of tophi in the joints, systemic deposition of urate in major organ systems including the renal parenchyma is not as well established. Urate is primarily cleared through the kidneys and patients with gout often have concomitant renal disease along with other comorbidities such diabetes, coronary artery disease, and hypertension; however, a causal role between these entities has not yet been carefully established. We hypothesize that urate deposits serve as a trigger in the inflammatory nidus to propogate subclinical tissue damage that results in the chronicity of the disease. This could potentially explain its independent role in the development and progression of chronic kidney disease in gout patients.Objectives:To review the published literature for evidence of urate deposition in the renal parenchyma in patients with gout and summarize the histopathology and imaging findings.Methods:PubMed (from 1940 to 2020) was used to identify reports of autopsy, pathology and radiology imaging demonstrating urate deposition within the native renal parenchyma in patients with gout. Key words included: gout nephropathy, chronic urate nephropathy, renal tophi, gouty kidney, autopsy findings in gout, and renal imaging in gout. The reference lists from these publications were also used to identify additional articles. Literature referencing urate nephrolithiasis and renal transplants were excluded from the study.Results:There were 25 articles documenting renal parenchymal urate deposition in gout patients confirmed by autopsy, biopsy and/or radiology imaging in native kidneys. Among the 19 articles examining urate deposition by autopsy and/or biopsy, 100% found urate deposition in the collecting ducts and adjacent medullary interstitium. Based on these findings, the most commonly proposed mechanism for urate deposition is urate crystal precipitation in the collecting ducts with eventual desquamation of the collecting duct walls from inflammation and/or tubular obstruction with subsequent extrusion of crystals into the medullary interstitium. 89% of reports documented inflammatory cells and/or tubulointerstitial fibrosis adjacent to the renal urate deposits. 68% reported cortical thinning or scarring. In addition, 74% of included publications reported renal vascular pathology including arteriosclerosis, glomerosclerosis and nephrosclerosis. There were 6 imaging articles that all reported abnormal renal ultrasound findings with hyperechogenic renal medullas that were attributed to urate deposition.Conclusion:There is a growing body of literature documenting urate deposition in the renal parenchyma in gout patients based on autopsy, pathology and imaging findings. Inflammation and fibrosis adjacent to regions of urate deposition and vascular changes were common. Given the strong association of gout with renal disease, there is a critical need to elucidate the mechanism by which urate impairs the renal tissue. Thus dedicated investigation is key to determine the prevalence and clinical significance of urate deposition in the kidneys of gout patients.References:[1]Nickeleit, V, et al.Nephrol Dial Transplant.(1997) 12:1832-1838.[2]Tchacarski, V, et al.Intl Urol Nephrol.1992; 24(6): 649-655.[3]Modern, FW.Med Clin North Am.1952;21: 941-51.[4]Linnane, JW, et al.Nephron.1981; 29: 216-22[5]Greenbaum, D, et al. Br Med J. 1961 May 27; 1(5238): 1502–1504[6]Bluestone, R, et al.Seminars in Arthr and Rheum.1977;7(2).[7]Brown, J, et al.NEJM.1950; 243: 325-329.[8]Braga, T., et al.Sci Rep.2017; 7: 39884.Disclosure of Interests: :Puja Khanna Grant/research support from: Dyve, Selecta, Sobi, Consultant of: Sobi, Horizon, Brad Marder Employee of: Horizon Therapeutics, Brian LaMoreaux Shareholder of: Horizon Therapeutics, Employee of: Horizon Therapeutics, Ada Kumar Shareholder of: Horizon Therapeutics, Employee of: Horizon Therapeutics

AB0539 URINARY INFLAMMATORY CELL ANALYSIS REFLECTS THE RENAL HISTOPATHOLOGY IN ANTI-NEUTROPHIL CYTOPLASMIC ANTIBODY-ASSOCIATED VASCULITIS

Background:The anti-neutrophil cytoplasmic autoantibody (ANCA)- associated vasculitides (AAVs) include microscopic polyangiitis (MPA), granulomatosis with polyangitis (GPA), and eosinophilic granulomatosis with polyangitis (EGPA). These small-vessel vasculitides are characterized by necrotizing inflammation of the vessel wall, particularly affecting small arteries, arterioles, and capillaries in systemic organs, and the kidney is one of the most frequently involved organs. Although kidney biopsy is necessary for deciding the therapeutic protocol, it is invasive and is sometimes hard to perform biopsy because of patient’s severe general condition. We have already reported that T cells and macrophages appear in the urine of patients with glomerulonephritis, accompanied by active cellular infiltration such as cellular crescent formation and diffuse interstitial cell infiltration, but not in the urine of patients with glomerulonephritis without the active inflammatory lesions.Objectives:In this study, we examined the utility of urinary inflammatory cell analysis for accessing kidney histopathological findings in AAVs.Methods:This was a cross-sectional, retrospective chart study. Thirty-six AAV patients who had been referred to Niigata University Hospital between 2002 and 2018, and performed percutaneous kidney biopsy and urinary inflammatory cell analysis, were participated in this study. Thirty-two patients had MPA, and 4 had GPA. The kidney biopsy findings were classified into Berden’s classification (a method to categorize glomerular lesions into four classes) and Neumann’s classification (a method to evaluate glomerular, tubulo-interstitial, and vascular lesions by using activity indexes and chronicity indexes). Flow-cytometric analysis of urinary inflammatory cells was performed for each subject. Numbers of urinary T cells or macrophages were determined by multiplying the number of viable cells in the gated mononuclear cell region in each sample by the percentage of urinary CD3-positive or CD14-positive cells in the population, respectively. The correlations between the results of both methods and the numbers of urinary inflammatory cells were examined using Kruskal-Wallis test and Spearmann’s rank correlation coefficient. A p-value of <0.05 was taken to denote statistical significance.Results:The numbers of urinary inflammatory cells showed a trend of increase in crescentic category without statistical significance in Berden’s classification. Meanwhile, activity indexes had significant positive correlations with the number of urinary CD3-positive cells (r = 0.541, p = <0.001), CD14-positive cells (r = 0.354, p = 0.034), and total inflammatory cells (r = 0.449, p = 0.006) in Neumann’s classification.Conclusion:The numbers of urinary inflammatory cells reflect the active lesions of kidney histopathological findings, and these results indicate the usefulness of urinary inflammatory cell analysis for assessment of kidney biopsy findings in patients with AAVs.References:[1]Berden AE, et al. J Am Soc Nephrol. 2010 Oct;21(10):1628-36. 2) Neumann I, et al. Nephrol Dial Transplant. 2005 Jan;20(1):96-104.Disclosure of Interests:None declared

AB0540 CLINICAL ANALYSIS OF AORTA INVOLVEMENT IN PATIENTS OF ANCA-ASSOCIATED VASCULITIS

Background:ANCA-associated vasculitis (AAV) is an autoimmune disease that involves abnormal death of neutrophils and leads to necrotic inflammatory reactions in blood vessels, including microscopic polyangiitis (MPA), Granulomatous polyangiitis (GPA) and Eosinophilic granulomatous polyangiitis (EGPA). AAV is mainly involved in small blood vessels, and intermediate arterial lesions can also occur, but the large arteries and their primary branches are rarely involved.Objectives:To summarize the clinical characteristics of aortic involvement in patients with ANCA-associated vasculitis (AAV).Methods:The clinical manifestations, systemic involvement, laboratory examination, imaging characteristics and treatment of aortic involvement in AAV patients admitted to Peking Union Medical College Hospital from January 2013 to December 2018 were retrospectively analyzed.Results:Nine patients were enrolled in our study. The ratio of male to female was 2:1 and the median age was 47 years old. Of the 9 patients, 4 were GPA (44%), 4 were MPA (44%) and 1 was EGPA (11%). The aorta is involved in an average of 3 locations per case, mainly in 7 locations: 3 ascending aorta and aortic arch, 4 in the head and arm trunk (including carotid and subclavian artery), 2 in the abdominal aorta, and 1 in the abdominal cavity. There were 2 cases of renal artery, 1 case involving brachial radial artery, 2 cases of iliac artery and lower limb artery, and 1 case involving left main coronary artery, anterior descending branch, circumflex branch, and right coronary artery. Aortic lesions: 3 cases had aneurysms, arterial dilatation and / or dissection, 6 cases had arterial stenosis or occlusion and 3 cases had periarteritis.When major arterial involvement was found, the AAV of the patients were mostly active, with an average of 19 points for BVAS vasculitis activity and 1 for FFS score. 6 cases had lung involvement (67%), 6 cases had kidney involvement (67%), 4 cases had ENT involvement (44%), 3 cases had nervous system involvement (33%), and 1 case had gastrointestinal involvement (11%). All patients were treated by steroid and immunosuppressant, while 1 case received the operation of ascending aorta and aortic arch replacement.Conclusion:Mainly involved in small blood vessel inflammation, AAV may also have aorta involvement, which was more common in patients who had active disease and need more positive treatment. The affected aorta areas of these patients were mainly ascending aorta, aortic arch, and head and arm trunk, which can be manifested as aneurysms, dissections, and arterial stenosis Periarteritis, etc. If necessary, surgically treatment of the affected aorta could be considered when the situation of AAV was stable enough.References:[1]Jennette J C, Falk R J, Bacon P A, et al. 2012 revised International Chapel Hill Consensus Conference Nomenclature of Vasculitides[J]. Arthritis Rheum, 2013,65(1):1-11.DOI:10.1002/art.37715.[2]Eisenberger U, Fakhouri F, Vanhille P, et al. ANCA-negative pauci-immune renal vasculitis: histology and outcome[J]. Nephrol Dial Transplant, 2005,20(7):1392-1399.DOI:10.1093/ndt/gfh830.[3]Guillevin L, Pagnoux C, Seror R, et al. The Five-Factor Score revisited: assessment of prognoses of systemic necrotizing vasculitides based on the French Vasculitis Study Group (FVSG) cohort[J]. Medicine (Baltimore), 2011,90(1):19-27.DOI:10.1097/MD.0b013e318205a4c6.[4]Chirinos J A, Tamariz L J, Lopes G, et al. Large vessel involvement in ANCA-associated vasculitides: report of a case and review of the literature[J]. Clin Rheumatol, 2004,23(2):152-159.DOI:10.1007/s10067-003-0816-0.[5]Minnee R C, van den Berk G E, Groeneveld J O, et al. Aortic aneurysm and orchitis due to Wegener’s granulomatosis[J]. Ann Vasc Surg, 2009,23(6):715-786.DOI:10.1016/j.avsg.2009.06.011.Disclosure of Interests:None declared

SAT0259 ANCA-ASSOCIATED VASCULITIS WITH RENAL INVOLVEMENT: THE ROLE OF A COMBINED HISTOPATHOLOGICAL ASSESSMENT AS PREDICTOR OF PATIENTS’ PROGNOSIS

Background:Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis often affect the kidney and renal involvement has a considerable clinical impact on patient’s prognosis. Currently used histopathological classifications are basically focused on the glomerular damage and assessing chronic damage progression, but their prognostic role presented some limitations.Objectives:To combine the Berden Classification, the ANCA Renal Risk Score (ARRS) and the Mayo Clinic-Renal Chronicity Score (RCS) with the inflammatory interstitial infiltrate and to evaluate the prognostic value of the combined assessment in patients with AAVMethods:We included 19 AAV patients with renal involvement (mean age 63±13.2 years; disease duration 4.9±5.2 months) who underwent renal biopsy. Patients were classified according to age, sex, disease duration, ANCA positivity. The histopathological evaluation was performed assessing the Berden category, Risk group (low, medium, high) according to the ARRS and Chronicity class according to the RCS; we also assessed the % of inflammatory interstitial infiltrate. Each patient was followed-up for 12 months; we considered the stage IV (eGFR < 30 ml/min/m2) of theKDIGO CKDClassification as renal outcome.Results:8 (42.1%) AAV patients were p-ANCA and 11 (57.9%) c-ANCA. 12 months after renal biopsy, 8 patients (42.1%) had a GFR <30 ml/min. According to the ARRS, 10 (52.6%) patients were in low, 7 (36.8%) in medium and 2 (10.5%) in high risk group. According to the RCS, 2 (10.5%) biopsies had minimal, 10 (52.6%) mild and 7 (36.8%) moderate chronic changes, no one presented severe chronic changes. According to the Berden classification, 6 (31.6%) samples represented the focal, 2 (10.5%) the crescentic and 11 (57.9%) the mixed category, no one represented the sclerotic class. The mean % of inflammatory infiltrate was 37.4±25.2. The interstitial inflammatory infiltrate showed a direct correlation with the severity of the Berden category (R=0.51; p=0.025), the % of sclerotic glomeruli (R=0.6; p=0.007) and the number of fibrocellular crescents (0.46; p=0.05) and an inverse correlation with the GFR at 12 months (R=-0.48; p=0.045). A ROC curve study identified a 22.5% cut-off of inflammatory infiltrate to predict the outcome of GFR at 12 months < 30 ml/min (sensitivity 88%, specificity 97.5%). Patients in focal class developed less frequently a GFR<30 (χ2=9.1; p=0.003), but there were no differences in the outcomes between the crescentic and mixed class. ARRS could differentiate risk group with regard to the renal outcome stage IV (χ2=9.0 e p=0.01) as well as the chronicity Score (χ2=8.1; p=0.017). Finally, we built a matrix combining the different histopathological scores and the % of inflammatory infiltrate to predict the outcome; we found that an inflammatory infiltrate wider than 22.5% characterizes most of patients developing stage IV chronic renal failure at the 12th month. In fact, more than 75% of patients with eGFR < 30 ml/min had inflammatory infiltrate wider than 22.5% at biopsy, despite they were in the low risk class (ARRS) and in minimal changes class (RCS).Conclusion:Our results underline the importance of the inflammatory infiltrate in renal outcome and histology. Despite the limited number of patients, our data suggest that a combined histological score assessing the chronicity and activity of renal disease from both glomerular and interstitial perspective could better predict patients’ global and renal prognosis.References:[1]Berden, J Am Soc Nephrol, 2010 Berti, Nephrol Dial Transplant 2018 Brix, Kidney Int. 2018Disclosure of Interests:Laura Gigante: None declared, Pier Giacomo Cerasuolo: None declared, Gisella Vischini: None declared, Francesco Federico: None declared, Dario Bruno: None declared, Alessia Musto: None declared, Stefano Costanzi: None declared, Silvia Laura Bosello Speakers bureau: Abbvie, Pfizer, Boehringer, Elisa Gremese Speakers bureau: Abbvie, BMS, Celgene, Jannsen, Lilly, MSD, Novartis, Pfizer, Sandoz, UCB

P0112BOWMAN'S CAPSULE RUPTURE ON RENAL BIOPSY IMPROVES THE OUTCOME PREDICTION OF ANCA-ASSOCIATED GLOMERULONEPHRITIS CLASSIFICATION

Background and Aims ANCA-associated vasculitis is the most common cause of rapidly progressive glomerulonephritis (GN) and can lead to ESRD or death, even after aggressive immunosuppressive therapies (Jones et al, N Engl J Med, 363(2010), 211-220). The histological assessment of renal tissue can help in predicting the outcome and a 4-tiered classification based on glomerular lesions has been proposed to stratify these cases (Berden et al, J Am Soc Nephrol, 21(2010), 1628-1636). Subsequent studies, however, failed to confirm its predictive value (Tanna et al, Nephrol Dial Transplant, 30(2015), 1185-1192), stressing the need of new prognostic markers of the disease. The present study investigates whether additional histological features can improve the performance of the current classification in predicting the outcome of these patients. Method A retrospective series of biopsy-proven paucimmune crescentic GN has been collected between January 2012 and June 2018 from two Italian centers (San Gerardo Hospital, Monza and Fondazione Policlinico Universitario A. Gemelli IRCCS, Roma). After the exclusion of patients with negative/unavailable serum ANCA testing, lacking clinical data, less than 12 months of follow-up, less than 5 glomeruli per biopsy and coexisting glomerular diseases, a final cohort of 52 cases was selected. Demographic and clinical data at the time of the diagnosis are reported in Figure, panel A. Renal biopsies have been reviewed by two experts in renal pathology and scored for multiple glomerular, tubulointerstitial and vascular lesions, as well as classified following the 4-tiered schema. The outcome of interest was time to need for RRT or death, whatever occurred first. Cox proportional hazards regression models were constructed with time to composite event, loss to follow-up or censoring (06/30/2019). Time at risk started at the date of renal biopsy. Histologic predictors were collapsed into binary variables (0-1 = low; 2-3 = high) and tested in univariate models, with the association expressed as hazard ratios (HRs) and 95% confidence intervals (CI); those showing a significant association with the outcome ( Figure, panel B) were included in a multivariable model together with a variable representing the Berden class. The prognostic performance of models including only the Berden class or the Berden class plus additional predictors was assessed using Harrell’s c-statistic. Results During a follow-up of 1,828 person-months, 13 composite events developed (8 deaths, 5 RRT), corresponding to an incidence rate of 7.1 (95% CI 4.2, 12.2) per 1,000 person-months. Of the tested predictors, Bowman’s capsule rupture (BCR, Figure, panel C) was significantly associated with the outcome (p = 0.023). Compared with a model including only Berden class (c = 0.67), the addition of this parameter significantly improved the prognostic performance (c = 0.76). In the multivariable model including Berden class, BCR remained significantly associated with the outcome (HR 3.61, 95% CI 1.15, 11.34; p = 0.028). Conclusion The present study demonstrated an improved performance of Berden classification in predicting patients’ outcome after the implementation of BCR. This can allow a better stratification of these cases, leading to tailored therapeutic approaches. Further investigations on a larger prospective cohort are required to confirm these results.

AB0519 PULMONARY INVOLVEMENT IN ANCA ASSOCIATED VASCULITIS (AAV) ACCORDING TO ANTIGENIC SPECIFICITY: A RETROSPECTIVE ARGENTINE COHORT

Background:The lung in ANCA associated vasculitis (AAV) is one of the most frequently compromised organs (20-80%). The clinical features of pulmonary involvement vary according to the type of vasculitis and some studies have shown its association with the ANCa subtype or antigenic specifity (MPO-ANCA), (PR3-ANCA).Objectives:A-Describe the clinical features and tomographic findings of pulmonary involvement in vasculitis associated with ANCA and its association according to the ANCA subtypes.B-Evaluate outcome, relapses and associated mortality.Methods:Observational, analytical, retrospective study. Data was collected from the medical records and tomographic image files of patient evaluated in rheumatology department in a tertiary level hospital (2007-2019).Patients diagnosed with AAV, who met criteria for ACR 1990 classification or according to nomenclature of Chapel Hill 2012, with thoracic CT performed and dosage PR3 an MPO antibodies by ELISA technique by a pulmonologist and radiologist.Demographic data, subtype of vasculitis, concomitant organic involvement, disease activity evaluated by Birmingham Vasculitis Activity Score v 3 (BVAS v3), time of evolution of pulmonary involvement, ERS – PCR, serum creatinine, ANCA determined by ELISA were collected. The following findings in parenchyma were evaluated by thorax CT: Consolidation, Ground glass opacities, Reticulation, Honeycomb, cavitated or not nodules, Central airway compromise (thickening or stenosis), Bronchiectasis,Peribronchial thickening, Pleural effusion and the following patterns of disease:NIU (Usual Interstitial Pneumonia), NINE (Unspecified Interstitial Pneumonia),HAD (Diffuse Alveolar Hemorrhage)Results:66/87 patients were included, 59% female, with a mean age of 51 (14 SD) years. GPA 46.9%, MPA 39.4%, EGPA13.6%, median follow-up time of 36 months (RIC 12-77).According to antigenic specificity: 40.9% PR3 positive, 47.6% MPO positive and ANCA negative 11.5%. 74% of the GPA were positive for PR3, and 58% PAM at MPO.BVAS basal: 17.8 + 7.5 DS.Frequency of organic involvement: 81.8% pulmonar, 77% systemic, 57.6% renal, 43% ENT.54% of patients with pulmonary involvement was present at the onset of their disease.Table 1.shows the main findings in lung parenchyma.Parenchymal Findings%Consolidations37Ground glass opacities72Reticulation15Honeycomb9No cavitated nodules41Cavitated nodules20.7Central airways comp (stenosis)9.4Peribronchial thickening11.3Bronchiectasis9.4Pleural effusion7.7According to the pattern of tomographic condition: 36.5 HAD %, 9.6% NIU, 7.8% NINE and, 1.5% Bronchiolitis obliterans.The presence of positive MPO was significantly associated with the presence of honeycomb (p 0.017) and NIU (p 0.018).There were no significant associations with the presence of PR3.Mortality was 17%.No association was found in relation to mortality or relapse frequency among PR3 or MPO positive patients.Conclusion:The frequency of pulmonary involvement in this cohort of patients was 82%, similar to that reported in the literature and was presented at the beginning of the disease in half of the cases. The presence of positive MPO was associated with a higher frequency of usual interstitial pneumonia.References:[1]Sophia Lionaki. Classification of ANCA vasculitides: The role of anti-neutrophil cytoplasmic autoantibody specificity for MPO or PR3 in disease recognition and prognosis. Arthritis Rheum. 2012 October; 64(10): 3452–3462. doi:10.1002/art.34562.[2]Kouichi Hirayama. Pulmonary involvements of anti-neutrophil cytoplasmic autoantibody-associated renal vasculitis in Japan Nephrol Dial Transplant (2015) 0: 1–11 doi: 10.1093/ndt/gfu385 .3-Beatrice Feragalli.The Lung in Systemic Vasculitis: Radiological Patterns and Differential Diagnosis. British Institute of RadiologyDisclosure of Interests:None declared

Clinical, Paraclinical Characteristics in Children with Renal Tubular Acidosis

This descriptive study describes the clinical, paraclinical characteristics in children with renal tubular acidosis. In this study, 36 children with renal tubular acidosis were hospitalized in the National Hospital of Pediatrics from June, 2012 to July, 2017. Among the patients, 64.0% were male; the male/female ratio was 1.8/1. The average age of the patients was 7.7 ± 4.6 years. There were 29 type 1 renal tubular acidosis patients (80.6%) and 7 type 2 renal tubular acidosis (19.6%). The most common clinical signs were slow weight gain (100%), polyuria and vomiting were 25.7%, excessive water drinking (16.7%), diarrhea (13.9%), weak lower limb (11.1%), and apnea (8.3%). The laboratory values on admission were: blood pH 7.23 ± 0.11; HCO3- 12.5 ± 5.07; serum sodium 136 ± 7mmol/l; potassium 2.9 ± 0.5 mmol/l; chloride 112 ± 9 mmol/l. The study concludes that 53.8% of the clinical, paraclinical characteristics in children with Renal Tubular Acidosis were inconspicuousness, which effected the children’s growth. The study recommends a long-term strategy for diagnosis and follow–up treatment of renal tubular acidosis. Keywords Renal tubular acidosis, Fanconi syndrome. References [1] Edyta Golembiewska and Kazimierz Ciechanowski, Renal tubular acidosis—underrated problem?, Acta biochimica polonica. 59(2) (2012) 213-215.[2] WHO (2011), Haemoglobin concentrations for the diagnosis of annaemia and assessment of severity, VMNIS, 1.[3] A.P. Sharma, R.K. Sharma, R. Kapoor, et al, Incomplete distal renal tubular acidosis affects growth in children, Nephrol Dial Transplant. 22 (10) (2007) 2879-2783.[4] WHO Child Growth Standards: Methods and development, tại trang web http://www.who.int/childgrowth/standards/technical_report/en/, truy cập ngày 30/10/2018.[5] A. Bagga Bajpai, P. Hari, A. Bardia, et al, Long-term outcome in children with primary distal renal tubular acidosis, Indian Pediatr. 42(4) 321 -328.[6] J.C. Chan, F. Santos, Renal tubular acidosis in children, Diagnosiseatment and prognosis., Am J Nephrol. 6(4) (2005) 289-294.[7] Symptoma Renal Tubular Acidosisuy, tại trang web https://www.symptoma.com/en/info/renal-tubular-acidosis, truy cập ngày 30/10/2018.[8] Julian Yaxley, Christine Pirrone, Review of the Diagnostic Evaluation of Renal Tubular Acidosis, Ochsner J. 16(4) (2016) 525-232.[9] Pramod Sood, Gunchan Paul, and Sandeep Puril, Interpretation of arterial blood gas, Indian J Crit Care Med. 14(2) (2010) 57-63.[10] J.L. Wilson, A.M. Butler, S. Farber, Dehydration and acidosis with calcification at renal tubules, The Journal of Pediatrics. 8 (2006) 489-494.