1802 Scientific Abstracts AB1018 TREATMENT RESPONSE OF HYDRONEPHROSIS ASSOCIATED WITH IDIOPATHIC RETROPERITONEAL FIBROSIS, FOCUSING ON RATIO OF IGG4/IGG3 SERUM CONCENTRATION S. J. Choi 1 , S. H. Nam 1 , J. S. Lee 1 , W. J. Seo 2 , J. S. Oh 3 , S. Hong 1 , C. K. Lee 1 , B. Yoo 1 , Y. G. Kim 1. 1 University of Ulsan College of Medicine, Asan Medical Center, Division of Rheumatology, Department of Internal Medicine, Seoul, Korea, Rep. of (South Korea); 2 Seoul Veterans Hospital, Division of Rheumatology, Department of Internal Medicine, Seoul, Korea, Rep. of (South Korea); 3 Asan Medical Center, Department of Biomedical Informatics, Seoul, Korea, Rep. of (South Korea) Background: Hydronephrosis, a common complication of idiopathic retroper- itoneal fbrosis (iRPF), may lead to poor renal outcomes unless it is resolved. Pathological confrmation can help to identify the aetiology of the disease and determine the treatment strategy. But, in most cases, it is difficult to obtain suffi- cient tissue due to the location of fbrosis. In a recent study, parts of iRPF are cor- related with IgG4-related disease characterised by elevated serum IgG4 levels (>135 mg/dL). Normal serum IgG3 level (21–176 mg/dL) has been known to be higher than normal serum IgG4 level (4–86 mg/dL). The reverse IgG4/IgG3 ratio has been suggested to be an IgG4-related disease component that distinguishes it from primary sclerosing cholangitis [1]. However, the ratio of IgG3 and IgG4 may be reversed in iRPF patients with hydronephrosis. Objectives: We aimed to investigate the ratio of IgG subclasses as a predictive factor associated with treatment response of hydronephrosis in patients with iRPF. Methods: We retrospectively recruited 19 iRPF patients with hydronephrosis who evaluated serum IgG subclasses in a tertiary hospital between 2004 and 2019. Hydronephrosis was evaluated on the basis of imaging fndings. Medications and clinical and laboratory fndings, including IgG subclasses, were reviewed following the diagnosis of hydronephrosis. Hydronephrosis improvement on sub- sequent images was evaluated to assess treatment response. Categorised data were compared using chi-square or Fisher’s exact test. Continuous variables were compared using Mann–Whitney U test. Results: At baseline, median serum IgG3 and IgG4 levels were 64 (IQR 37– 82) mg/dL and 71 (IQR 40–171) mg/dL. Five patients had serum IgG4 levels > 135 mg/dL and 11 patients had the reverse serum level of IgG4/IgG3. On sub- sequent images (median follow-up at 3.2 [IQR 1.7–4.0] months), 11 patients showed hydronephrosis improvement. The proportions of positive ratio of serum IgG4/IgG3 (81.8% vs. 25%, p = 0.024), periaortic involvement (81.8% vs. 25%, p = 0.024) and high-dose glucocorticoid treatment (45.5% vs. 0%, p = 0.045) were signifcantly higher in patients with improvement than in those without improvement (Table 1). Interestingly, even in cases with normal serum IgG4 lev- els, patients with improvement showed a higher serum IgG4/IgG3 ratio than in those without improvement (median 1.5 vs. 0.7, p = 0.038). Table 1. Clinical characteristics and treatment according to the short- term outcome of hydronephrosis Improvement (n = 11) No improvement (n = 8) p-value Time to subsequent imaging (months) a 2.2 (1.3–4.2) 3.2 (2.0–3.8) 0.778 Males (n, %) 8 (72.7%) 7 (87.5%) 0.603 Periaortic involvement (n, %) 9 (81.8%) 2 (25%) 0.024 Impaired renal function (n, %) b 5 (45.5%) 2 (25%) 0.633 Serum IgG4 (mg/dL) a 114 (59–172) 43 (35–109) 0.152 Elevated serum IgG4 (n, %) 4 (36.4%) 1 (12.5%) 0.338 Serum IgG4/IgG3 ratio a 2.1 (1.2–4.9) 0.8 (0.4–1.0) 0.041 Positive ratio of serum IgG4/IgG3 (n, %) 9 (81.8%) 2 (25%) 0.024 Medical treatment (n, %) 7 (63.6%) 1 (12.5%) 0.059 High-dose glucocorticoid treatment (n, %) 5 (45.5%) 0 (0%) 0.045 Surgical intervention (n, %) 8 (72.7%) 4 (50%) 0.377 a Values are median and interquartile range (25 th –75 th percentile) b Defned as serum creatinine level > 1.24 mg/dL Conclusion: The reverse ratio of serum IgG4/IgG3 was associated with hydro- nephrosis treatment response, thus suggesting favourable responses to high- dose corticosteroid. References: [1] Boonstra K, Culver EL, de Buy Wenniger LM, et al. Serum immunoglob- ulin G4 and immunoglobulin G1 for distinguishing immunoglobulin G4-as- sociated cholangitis from primary sclerosing cholangitis. Hepatology 2014;59:1954-63. Disclosure of Interests: None declared DOI: 10.1136/annrheumdis-2020-eular.4159 AB1019 THERAPEUTIC PROFILE OF PATIENTS WITH VOGT KOYANAGI HARADA DISEASE FOLLOWED AT THE HOSPITAL DE CLÍNICAS. SAN LORENZO PARAGUAY. N. Colman 1 , J. Losanto 1 , S. Riquelme 1 , M. Melo 1 on behalf of Autoimmune Eye Diseases Unit. Hospital de Clínicas. PY. 1 Hospital de Clínicas, San Lorenzo, Paraguay Background: Vogt-Koyanagi-Harada Disease (VKHD) is an autoimmune eye disease that causes chronic vision complications in young people. The treatment is based on corticosteroids and immunosuppressants, to which biological drugs are currently added. The visual prognosis depends on the stage in which it is diagnosed and the effective and timely treatment. 1,2 Objectives: Describe the evolution and the therapeutic profle of patients with VKHD who go to the Rheumatology Department of the Hospital de Clínicas. San Lorenzo Paraguay until November 2019 Methods: Descriptive cross-sectional study conducted at the Hospital de Clíni- cas, San Lorenzo Paraguay, where clinical histories of patients with this disease and who have regular follow-up were reviewed. Results: 21 patients were included, 17 (81%) women, average age of 35 years. The diagnosis and treatment were made 15 (71%) in acute phase, 4 (19%) con- valescent phase and 2 (10%) in chronic phase. Corticosteroids: All received corticosteroids at diagnosis. Methylprednisolone IV 1g /day for 3 consecutive days in 8 (44%) cases and for 5 days in 10 (55.5%) cases. The frst month everyone received prednisone orally at 1mg / kg / d on average (60-75 mg/d), at 3 months the average dose of prednisone was 37 mg / d, at 6 months of 23 mg/d and at 12 months 10 mg / d months. Immunosuppressive treatment: They received 20 (95%) patients. Induction with monthly intravenous cyclophosphamide was performed in 8 (40%) cases and with Azathioprine in 12 (60%) cases. Of the patients treated with Azathioprine initially, in 5 (23%) patients it was necessary to switch to Cyclophosphamide IV due to failure or intolerance. The maintenance treatment was azathioprine in 13 (62%) of the patients, MTX in 4 (19%) and the association of both drugs was indicated in 3 (14%) patients. One case was refractory and received infiximab and subsequently Rituximab, which resulted in remission. The best fnal Visual Acuity (AV) was recorded with the Snellen chart in 40 eyes (20 patients), 27 (67.5%) patients with good vision (20/20 to 20/50), 8 (20%) patients with decreased VA (20 / 50-20 / 200), and 5 (12.5%) with legal blindness (<20/200) and of these only 3 patients had unilateral involvement and one patient with bilateral blindness. Sequelae / complications: 6 (28.5%) patients presented cataracts and fnally 3 (14%) glaucoma, 5 (24%) anterior / posterior synechiae. Conclusion: The majority of patients in this series presented a good vision when the infammatory process was resolved (AV 20 / 20-20 / 50), this probably related to early diagnosis and initial aggressive treatment with intravenous corticosteroid pulses and its association with immunosuppressants of entry as mentioned in the literature. The worst vision, (visual acuity <20/200) occurred in 5 of 40 eyes, corresponding to 4 patients, two of them diagnosed and treated in the chronic stage. Timely treatment improves visual prognosis. References: [1] Lodhi SAK, Lokabhi Reddy JM, Peram V. Clinical spectrum and man- agement options in Vogt–Koyanagi–Harada disease. Clin Ophthalmol. 2017;11:1399–406. [2] Concha-del Río LE, Gómez L, Arellanes-García L. Corticotherapy vs. Corticotherapy Plus Immunosuppressive Therapy in Acute Vogt-Koyana- gi-Harada Disease. Arch Soc Esp Oftalmol [Internet]. 2018;93(5):225–30. Available from: https://doi.org/10.1016/j.oftal.2017.09.010 Acknowledgments: Department of Rheumatology Department of Ophthalmology Disclosure of Interests: None declared DOI: 10.1136/annrheumdis-2020-eular.792 AB1020 APPLICATION OF THE 2019 ACR/EULAR CLASSIFICATION CRITERIA CONTRIBUTES TO THE DIAGNOSIS OF IGG4-RELATED DISEASE L. F. Chen 1 , J. J. Liang 1 , Z. M. Ouyang 1 , J. D. MA 1 , D. H. Zheng 1 , L. Dai 1 . 1 Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Rheumatology, Guangzhou, China Background: IgG4-related disease (IgG4-RD) is a rare and systemic disease characterized by swelling or masses in the involved organs, elevated serum IgG4, marked IgG4+ plasma cells infltration and fbrosis. However, lacking of patholog- ical data limited the defnite diagnosis of IgG4-RD. As results of high-quality clin- ical and epidemiological investigations collected, new classifcation criteria for on February 19, 2022 by guest. Protected by copyright. http://ard.bmj.com/ Ann Rheum Dis: first published as 10.1136/annrheumdis-2020-eular.792 on 13 June 2020. Downloaded from