Clinical disease activity index applicability in lupus arthropathy: Unraveling underdiagnosed joint activity

Introduction Lupus arthropathy (LA) ranges from arthralgia and non-deforming arthritis to severe forms such as Jaccoud-type deformities and mutilating arthritis. Considering the evolving concept of LA, measuring arthritis activity in lupus patients may require a more practical and sensitive tool other than the classical composite scores. Methods In this cross-sectional study, we evaluated the articular pattern of a sample of SLE patients which were divided into those that scored in articular domain on Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) and those with activity arthritis using the Clinical Disease Activity Index (CDAI). After all, we analyzed the association between CDAI and arthritis by SLEDAI-2K as well as its association with the presence or not of Jaccoud-type arthropathy (JA). Results A total of 127 patients with SLE were evaluated. According to SLEDAI-2K, 17 (13.4%) patients have scored in its joint criteria and 32 patients (25.19%) were considered to have some articular activity by CDAI. A total of 16 patients (50%) who scored some activity on CDAI did not score in articular domain of SLEDAI-2K. Also, the presence of Jaccoud-type arthropathy was significantly associated with arthritis activity according to the CDAI score ( p = .014) but not with SLEDAI-2K joint criteria ( p = .524). Conclusion The CDAI was not directly associated with the presence of arthritis by the joint criteria of SLEDAI-2K and the presence of JA was significantly associated with the CDAI but not with arthritis at SLEDAI-2K.