Efficacy of abatacept for arthritis in patients with an overlap syndrome between rheumatoid arthritis and systemic lupus erythematosus

Abstract

Introduction: This study aimed to investigate the efficacy of abatacept for arthritis in patients with rhupus, an overlap syndrome between rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE).

Methods: Patients who fulfilled both the 2010 ACR/EULAR criteria for RA classification and the 1997 ACR revised criteria for classification of SLE and received abatacept treatment for arthritis were retrospectively studied.

Results: Six rhupus patients who fulfilled the inclusion criteria above were identified. All patients had active arthritis despite receiving antirheumatic drugs including methotrexate when abatacept was initiated. Clinical Disease Activity Index (CDAI) significantly decreased between baseline and 12 weeks (P = 0.028) and remained low through 24 weeks. All patients achieved either a good or moderate response according to the EULAR response criteria at 24 weeks. Health Assessment Questionnaire-Disability Index (HAQ-DI) also significantly decreased between baseline and 24 weeks (P = 0.043). In addition, the levels of immunoglobulin G and anti-DNA antibody significantly decreased between baseline and 24 weeks (P = 0.028 and P = 0.043, resp.).

Conclusions: Treatment with abatacept is likely to be efficacious in patients with rhupus whose arthritis is refractory to methotrexate. In addition, abatacept may have a moderate effect on abnormal antibody production in rhupus patients.

Figure 1

Changes in clinical indices and laboratory tests reflecting disease activity of RA and/or SLE in each case during 24 weeks after abatacept treatment. *P < 0.05, Wilcoxon's signed-rank test. Comparisons were made against baseline values. RA: rheumatoid arthritis; SLE: systemic lupus erythematosus; CDAI: Clinical Disease Activity Index; HAQ-DI: Health Assessment Questionnaire-Disability Index; SLEDAI: systemic lupus erythematosus disease activity index; CRP: C-reactive protein; ESR: erythrocyte sedimentation rate; RF, rheumatoid factor; IgG: immunoglobulin G; Anti-DNA Ab: anti-DNA antibody.

Figure 2

Joint swelling of hands in Case 3 before and after treatment. Dorsal aspects (a, c) and palmer aspects (b, d) of the hand are shown. Swelling in fingers and wrists before treatment (a, b) markedly improved after 24 weeks of abatacept treatment (c, d), leaving swan-neck deformity.

Figure 3

Plain radiographs of hands in Case 3. Plain radiographs of hands before treatment in the anterior-posterior view (a) and the oblique view (b). Arrows indicate small erosions in the heads of left 2nd and 3rd metacarpal bones and right proximal phalanx. Markedly thickened soft tissues are demonstrated (asterisks).

Figure 4

Ultrasound images of hands in Case 3 before and after treatment. Shown are the representative ultrasound images of the left hand before treatment (a–d) and after 24 weeks of abatacept treatment (e–h). Ultrasound images before treatment reveal moderate synovial hypertrophy with moderate Doppler signals in the 3rd proximal interphalangeal joint (a) and severe synovial hypertrophy with moderate Doppler signals in the flexor tendon of the 3rd finger (b) and extensor carpi ulnaris longitudinal view (c) (see also webvideo 1) and transverse view (d) (see also webvideo 2). Corresponding ultrasound images after abatacept treatment demonstrate marked improvement (e–h). PP: proximal phalanx; MP: middle phalanx; FD: flexor digitorum; ECU: extensor carpi ulnaris.

Figure 5

Treatment summary and clinical course of Case 3. MTX: methotrexate; CDAI: Clinical Disease Activity Index; CRP: C-reactive protein; WBC: white blood cell count; IgG: immunoglobulin G; RF: rheumatoid factor; Anti-DNA Ab: anti-DNA antibody; C3: complement component 3; CH50: 50% hemolytic complement activity of serum.1. Panush et al. [1].