AB1011\u2005APPLICATION OF AUTOINFLAMMATORY DISEASE DAMAGE INDEX (ADDI) TO AUTOINFLAMMATORY DISEASES IN A TERTIARY REFERRAL HOSPITAL

Abstract

Background Autoinflammatory diseases (AIDs) cause chronic systemic inflammation that can damage multiple organs. Recently, the autoinflammatory disease damage index (ADDI) has been developed and validated in the four most common monogenic AIDs, Cryopyrin-associated Periodic Syndrome (CAPS), Familial Mediterranean Fever (FMF), Mevalonate Kinase Deficiency (MKD) and Tumor Necrosis Factor Receptor-associated Periodic Fever Syndrome (TRAPS). The use of ADDI index could also be of great value in other AIDs. Objectives The aim of this study is to assess the application of ADDI in patients with the four most common monogenic diseases and other AIDs. To accomplish this objective a detailed cohort of patients with different AIDs is presented. Methods All patients with AIDs followed in the Pediatric Rheumatology Unit comprising the Transitional Care and specialized AIDs outpatient clinics from Hospital Universitari Vall d’Hebron were identified. A cross- sectional, descriptive study was performed applying ADDI by two pediatric rheumatologists (EM, ML). Laboratory test including C-reactive protein (CRP) mg/dl, amyloid protein (AP) mg/L, erythrocyte sedimentation rate (ESR) mm/h and protein/creatinine rate (mg/g Cr) were performed at the moment ADDI was applied. Variables related with disease duration, current treatment and accumulated corticosteroids treatment were assessed. The continuous variables are presented as mean and standard deviation (mean ± SD) and categorical variables are presented by percentages. Results A total of 41 patients with AIDs were included, 61% were female, with a median age of 20 ± 11.9 years at inclusion. Disease duration was 11 ± 8.2 years. AIDs included were 11 patients with FMF (26.8%), TRAPS n=4 (9.8%), MKD n=3 (7.3%), CAPS n= 2 (4,9%), Blau syndrome n= 7 (17.1%), SAVI syndrome n=3 (7.3%), CRMO n=4 (9.8%), PFAPA n=2 (4.9%), APLAID n=1 (2.4%), Stickler syndrome n=1 (2.4%), and 3 unknown AIDs with genetic test negative n=3 (7.3%). Current treatment is variable among patients, 6 (15.8%) are taking disease-modifying antirheumatic drugs (DMARDs), 9 (23.7%) Colchicine, 8 (21.1%) Anakinra, 13 anti-TNF therapy (34.2%), 1 (2.6%) Ruxolitinib and 1 (2.6%) Abatacept. Only 6 patients were receiving corticoids with mean prednisone dose of 7.5 mg/day. The global ADDI mean score was 2.3 ± 2.2. Regarding the eight different items included in the item, musculoskeletal domain shown the highest score with 1.02, followed by the ocular domain with 0.42. The patient with APLAID syndrome had the highest score of 6 followed by BLAU syndrome with 4.71. FMF has the lowest score with 0.83. Laboratory test results were mean ESR 27.2 ± 26.7mm/h, CRP 0.7 ± 1.3 mg/dl, AP 13.9 ± 18.6mg/L. Proteinuria was present in 2 patients with mean 286.5 ± 246.1mg/g. EM and ML applied ADDI in 5-10 minutes average. Conclusion ADDI is a feasible index suitable to measure damage in a single patient. Despite it was performed to the four most common AIDs it could be applied to other diseases. In our cohort the mean ADDI index was low and musculoskeletal item has the highest score. This result could be explained by the tight control of the disease and successful targeted therapy. Laboratory tests also support this finding. Nevertheless, some organ systems are not assessed like respiratory, cardiovascular or cutaneous damage, important in some syndromes. Knowing the difficulties of applying an unified index for all diseases, ADDI may be supportive in other AIDs and longitudinal cohorts. References [1] Ter Haar NM, van Delft ALJ, et al. In silico validation of the Autoinflammatory Disease Damage Index. Ann Rheum Dis. 2018 Nov;77(11):1599-1605. [2] Ter Haar NM, Annink KV, et al. Development of the autoinflammatory disease damage index (ADDI). Ann Rheum Dis. 2017 May;76(5):821-830. Disclosure of Interests None declared