Severe Jaccoud's arthropathy in systemic lupus erythematosus.

Jaccoud's arthropathy (JA) is a clinical situation nowadays present mostly in systemic lupus erythematosus (SLE). It is characterized by the presence of joint deformities such as "swan neck," ulnar deviation and "Z-thumb" resembling rheumatoid arthritis (RA) but that are passively correctable and without bone erosion on plain radiographs. From our cohort of SLE patients with JA, we selected a subgroup with a more severe form of this arthropathy and looked at their clinical and laboratory profile as well as studied the magnetic resonance imaging (MRI) findings or ultrasound (US) obtained from the hand with most evident deformities. Seven SLE patients with a severe form of JA were identified. All seven patients have "swan neck," ulnar deviation and "Z-thumb" deformities. Two out of seven had "mutilans-type JA" and four had fixed deformities in the metacarpophalangeal (MCP) joints. The MRI of the hand with more evident deformity clinically performed in six cases and US performed in one case showed mild synovitis in five and moderate synovitis in two patients, mild flexor tenosynovitis in six and severe tenosynovitis in one. Only two small bone erosions were observed in the second and third MCP joints of one patient with moderate synovitis. Severe JA compromises the functional capacity of the joints and imposes the risk of misdiagnosis of RA. With the improvement of the survival rate of SLE and the lack of specific prophylactic or therapeutical measures for JA, it is reasonable to assume that more and more cases of severe JA are going to be identified.