Clinical and radiological amelioration of refractory peripheral spondyloarthritis by pulse intravenous pamidronate therapy

Objective. To examine the potential therapeutic properties of an aminobisph osphonate, pamidronate, using clinical and laboratory outcome variables tog ether with dynamic magnetic resonance imaging (MRI) and gadolinium augmenta tion in patients with spondyloarthropathy (SpA) refractory to nonsteroidal antiinflammatory drugs (NSAID). Methods. We studied 9 patients (7 male, 2 female) of mean age 27.9 years (r ange 19-38) and mean disease duration of 5.5 years (range 0.5-20). Five had ankylosing spondylitis (AS), 3 had undifferentiated SpA, and one had react ive arthritis. Seven were HLA-B27 positive. Two had inflammatory bowel dise ase. Pamidronate (60 mg) was given intravenously on Days 1, 2, 14, 28, and 56, over 4 h in 500 mi of 5% dextrose. Clinical outcome assessments include d the BASDAI (disease activity), BASFI (function), BASGI (global well being ) composite visual analog instruments, and swollen and tender joint count. Laboratory variables included the erthrocyte sedimentation rate (ESR) and C -reactive protein (CRP). Dynamic MRI with gadolinium augmentation of synovi um and bone was performed at baseline and at Day 84 in the first 6 patients enrolled in the study. Results. All patients completed the study and there was a significant impro vement in all clinical and laboratory variables assessed. Mean swollen and tender joint count decreased by 93.8% (p = 0.017) and 98.2% (p = 0.012), re spectively, and complete clinical resolution of synovitis was noted in 5 pa tients. BASDAI decreased by 44.2% (p = 0.028), BASFI by 47.3% (p = 0.015), and BASGI by 42.2% (p = 0.011). ESR and CRP declined by 49.4% (p = 0.012) a nd 66.9% (p = 0.008), respectively. Acute lymphopenia accompanied by elevat ed CRP levels was noted in 8 patients in the 48 h after first pamidronate i nfusion. Maximal rate and magnitude of enhanced MRI signal after gadolinium augmentation decreased after pamidronate therapy, especially in the bone m arrow. Conclusion. preliminary data from uncontrolled studies support the efficacy of pamidronate therapy for NSAID refractory SpA and warrant further evalua tion in controlled trials.