AB0346 RHUPUS SYNDROME: CLINICAL ANALYSIS OF 21 PATIENTS
Authors: M. Ben Brahim, S. Daada, M. Elghali, J. Mahbouba, N. Bergaoui, S. Hammami
Journal: Annals of the Rheumatic Diseases (2021)

Background: Rhupus syndrome is a clinical condition characterized by a combination of the clinical and immunologic features of rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) (1). However, this definition did not establish whether Rhupus syndrome is a distinct clinical entity or is an overlap between RA and SLE. To date, fewer than 200 cases of Rhupus have been reported (1). Objectives: Our purpose was to analyze the clinical and serological characteristics of patients with Rhupus and compare them with patients with SLE. Methods: We undertook a retrospective study covering 10 years (2009 to 2019) of experience in our University Hospital: Department of Internal Medicine and department of Rheumatology. 238 patients hospitalized were evaluated during this period. The clinical and laboratory parameters of 21 patients with Rhupus syndrome were compared with those of 217 SLE without RA patients Results: Twenty one patients were included (all fulfilled ACR criteria for SLE as well as for RA).They were 19 female and 2 male. The mean age of patients at the disease onset was 43.5 years. Among these, 9 patients (42.8%) were diagnosed with RA at the onset of disease and then developed SLE over an average period of 6.2 years. Six patients (28.5%) had a diagnosis of SLE prior to the RA diagnosis with an interval of 8.6 years between diagnoses. Six patients (28.5%) were diagnosed with RA and SLE concomitantly. Patients with Rhupus experienced more often arthritis, joint swelling, morning stiffness and joint erosions then patients with SLE alone (p&lt;0.001). Comparison of extra-articular manifestations showed that, renal involvement was less often in patients with Rhupus when compared to patients with SLE-alone. There were no significant differences in the prevalence of malar rash, serositis, neurological and hematological features between the Rhupus and SLE-alone groups. Rheumatoid factor and anticyclic citrullinated peptide (CCP) antibody were significantly more prevalent in the Rhupus group than in the control group. The incidences of increased erythrocyte sediment rate (ESR) and C-reactive protein (CRP) were also significantly higher in Rhupus patients. (Table 1) Table 1. Comparison of clinical and biological features between Rhupus Syndrome (Rhupus Group) and SLE-alone patients (Control Group). Rhupus Group N=21 (%) Control Group N=217 (%) p Malar rash 12 (57.1) 120 (55.3) 0.87 serositis 6 (28.5) 47 (21.7) 0.46 Lupus nephritis 4 (19) 56 (25.8) 0.49 Hemolytic anemia 1 (4.7) 8 (3.6) 1 Leucopenia 8 (38) 90 (41.4) 0.15 Thrombopenia 4 (19) 27 (12.4) 1 Polyarthritis 21 (100) 54 (24.8) &lt;0.001 Erosion of joint 21 (100) 0 &lt;0.001 Increased ESR 20 (95.2) 155 (71.4) 0.019 Increased CRP 18 (85.7) 88 (40.5) &lt;0.001 Anti-DNA antibodies 16 (76.1) 134 (61.7) 0.61 Anti-Sm antibodies 6 (28.5) 63 (29) 0.57 Rhumatoide Factor 12 (57.1) 52 (23.9) 0.04 Anti-CCP antibody 6 (28.5) 14 (6.5) 0.027 CRP: C-reactive protein, ESR: erythrocyte sediment rate, Anti-CCP: anticyclic citrullinated peptide antibody. Conclusion: Patients sharing features of both RA and SLE have been observed infrequently. In fact, the incidence of Rhupus syndrome in SLE patients is estimated at 1.3% (2 ). In our study, this incidence was 8.8%. The findings of our study are consistent with those of most studies with respect to the frequencies arthritis, lupus related features, and serological disorders (2,3 ). References: [1]Rubini E, Foddai SG, Radin M, Cecchi I, Rossi D, Sciascia S, et al. Ab1177 How to Define Rhupus Syndrome: Systematic Review of the Current Literature. Ann Rheum Dis. 2019 Jun 1;78(Suppl 2):2049–50. [2]Li J, Wu H, Huang X, Xu D, Zheng W, Zhao Y, et al. Clinical Analysis of 56 Patients with Rhupus Syndrome: Manifestations and Comparisons with Systemic Lupus Erythematosus. Medicine(Baltimore). 2014; 93(10): 958-63. [3]Liu T, Li G, Mu R, Ye H, Li W, Li Z. Clinical and laboratory profiles of rhupus syndrome in a Chinese population: a single-centre study of 51 patients. Lupus. 2014;23(9):958–63. Disclosure of Interests: None declared