A Crystal Clear Case of Seropositive Rheumatoid Arthritis
Dr C. Donaghy, Dr A. Cairns
The presentation of inflammatory arthritis can be diverse and can provide diagnostic challenges for the clinician.
We present a case of an elderly lady diagnosed with late onset rheumatoid arthritis who had poor response to treatment with standard DMARDs and biologic agents.
A 69 year old lady was diagnosed with rheumatoid arthritis in 2008 following a hospital admission with lobar pneumonia, during which she developed wrist synovitis. Rheumatoid factor (RF) and anti-CCP were weakly positive. She had persistent wrist synovitis after the acute illness was treated. She was treated with standard DMARD therapy, including methotrexate, hydroxychloroquine, sulfasalazine, leflunomide and gold, with poor response and multiple intolerable side effects. She had recurrent synovitis of her wrist, knees and shoulders. She met criteria for biologic agents and in 2011 was commenced on etanercept, with initial benefit. She developed secondary failure in 2016, and had trials of adalimumab and rituximab with little benefit. She had multiple hospital admissions with acute arthritis associated with joint effusions and severe pain. Repeated aspirations of knee and shoulder effusions demonstrated the presence of calcium pyrophosphate crystals. Review of radiographs of affected joints demonstrated minor degenerative changes, but no erosions or progressive changes over a nine year period. A diagnosis of pseudo-rheumatoid presentation of calcium pyrophosphate deposition (CPPD) was considered, and a trial of Anakinra commenced.
The patient responded well to Anakinra and continues on this with no further acute flares of synovitis, and has not required any further hospital admissions.
A pseudo-rheumatoid presentation of CPPD is well recognized, affecting <5% of patients with CPPD. Weakly positive RF, along with symmetrical polyarthritis, morning stiffness and elevated inflammatory markers can lead to diagnostic confusion. There is usually absence of anti-CCP and radiographic joint erosions.
To date Anakinra has been shown to be relatively well tolerated and has potential for long term benefit in patients with recurrent CPPD arthritis, including those presenting with a pseudo-rheumatoid pattern.