AB1636 CLINICAL PHENOTYPES IN SARCOIDOSIS USING CLUSTER ANALYSIS IN A COHORT OF 342 PATIENTS

Abstract

BackgroundSarcoidosis is a multi-system disease with unknown etiology characterized by the formation of granulomas in various organs. It affects people of all ethnic backgrounds and occurs at any time of life. This disease can affect any organ with a frequency varying according to ethnicity, sex and age most of the time affecting the pulmonary system with symmetrical bilateral hilar adenopathy. Extrapulmonary manifestations in skin, eyes, liver or lymphatic system can take a great morbimortality in patients.ObjectivesToa) indicate the phenotypes with similar characteristics with a cluster analysis andb) describe the principal features of those phenotypes.MethodsA model-based clustering was performed in a cohort of 342 sarcoidosis patients, diagnosed and follow-up from 1999 to 2019 at northern Spain hospital. Four homogeneous phenotypes were proposed in our study (C1: parenchymal lung involvement with dyspnea; C2: erythema nodosum and articular involvement with asthenia; C3: isolated hilar adenopathy; C4: miscellaneous extrapulmonary sarcoidosis). Chi-square test and ANOVA were used to compare, respectively, categorical, and continuous variables among groups. Two-sample t-tests and the partition of Pearson’s chi-square statistic for were used in pairwise comparisons.ResultsCluster analysis identified four groups: C1 (n=128; 37.4%), C2 (n=75; 21.9%), C3 (n=82; 24.0%), and C4 (n=57; 16.7%)(Table 1).Lung involvement was predominant in all clusters, ranged from 93.3% (C2) to 100% (C3). Extrapulmonary involvement was significantly higher in C2 (97.3%) and C4 (98.2%). Systemic steroids were significantly more used in cluster 1 (75.8%) compared to the rest (C2: 57.3%; C3: 48.8%; C4: 47.4%)(Figure 1).ConclusionSarcoidosis has a heterogenous disease, and a cluster analysis can be a useful tool to identify the clinical patterns and can be useful for the management.Reference[1]Sève P, Pacheco et al. Cells 2021;10. PMDI: 1739240.Table 1.Demographic and clinical characteristics of the study population. Data presented: n (%) or mean±SDCharacteristicsWhole cohort n=342C1 n=128C2 n=75C3 n=82C4 n=57p-valueq-valueGender (female)177 (51,8)45 (35.2)A,B,C47 (62.7)A46 (56.1)B39 (68.4)C<0.001<0.001Age at diagnosis (years)47.7±15.146.4±14.0A43.4±13.1B, C51.7±16.8A, B50.5±15.5C0.002<0.004Ethnicity0.80.8Caucasian322 (94.2)121 (94.5)70 (93.0)76 (92.7)56 (98.2)Hispanic15 (4.4)5 (3.9)4 (5.3)5 (6.1)1 (1.8)Black4 (1.2)2 (1.6)1 (1.3)1 (1.2)0Pulmonary involvement302 (88.3)120 (93.8)A70 (93.3)B82 (100)A,B30 (52.6)A,B<0.001<0.001Extrapulmonary involvement234 (68.6)68 (53.1)A,B73 (97.3)A,C37 (45.1)C,D56 (98.2)B,D<0.001<0.001Skin117 (34.2)26 (20.3)A56 (74.7)A3 (3.7)A32 (56.1)A<0.001<0.001Eye61 (17.8)22 (17.2)A15 (20.0)B21 (25.6)C3 (5.3)A,B,C0.020.04Liver33 (9.6)12 (9.4)5 (6.7)10 (12.2)6 (10.5)0.70.8Spleen7 (2.0)5 (3.9)1 (1.3)1 (1.2)00.30.4Bone4 (1.2)1 (0.8)2 (2.7)01 (1.8)0.40.5Joint95 (27.8)23 (18.0)A49 (65.3)A0A25 (43.9)A<0.001<0.001Parotid4 (2.3)2 (1.6)3 (4.0)2 (2.4)1 (1.8)0.70.8Kidney13 (3.8)2 (1.6)A0B0C11 (19.3)A,B,C<0.001<0.001Nervous system29 (8.5)6 (4.7)A16 (21.3)A,B,C6 (7.3)B1 (1.8)C<0.001<0.001Heart5 (1.5)3 (2.3)002 (3.5)0.20.3CIS: conventional synthetic immunosuppressants; SD: standard deviation.Groups sharing the same letter (A, B, C, D) have statistically significative differences (q>0.005) in the pairwise comparison.Abbreviation in alphabetical order: n=number; SD: standard deviation.Figure 1.Dendrogram of the hierarchical clustering leading to four clusters.C1: parenchymal lung involvement with dyspnea;C2: erythema nodosum and articular involvement with asthenia;C3: isolated hilar adenopathy;C4: miscellaneous extrapulmonary sarcoidosis.Acknowledgements:NIL.Disclosure of InterestsFabricio Benavides-Villanueva: None declared, Raúl Fernández-Ramón: None declared, Jorge Javier Gaitán-Valdizán: None declared, Iñigo Gonzalez-Mazon: None declared, Lara Sanchez-Bilbao: None declared, José Luis Martín-Varillas: None declared, David Martínez-López: None declared, Rosalía Demetrio-Pablo: None declared, Ricardo Blanco Speakers bureau: Speakers bureau: Abbvie, Pfizer, Roche, lilly, Bristol-Myers, Janssen, Galapagos and MSD, Consultant of: Consultant of: Abbvie, Pfizer, Roche, lilly, Bristol-Myers, Janssen and MSD, Grant/research support from: Grant/research support from: Abbvie, MSD, novartis and Roche.