Amyloid arthropathy with joint flexion contracture as the initial manifestation:a report of 5 cases and literature review / 解放军医学杂志

ABSTRACT

Objective To report 5 cases of amyloid arthropathy with joint flexion contracture as the first manifestation,and perform a literature review to improve the understanding of the disease.Methods Retrospective analysis of the clinical manifestations,laboratory and imaging results clinical data of patients with immunoglobulin light chain(AL)amyloidosis related amyloid arthropathy with joints flexion contracture as the first manifestation at the Department of Rheumatology and Immunology,the First Medical Center of People's Liberation Army General Hospital from January 2012 to February 2022.Meanwhile searching the database(CNKI,Wanfang Data,PubMed),excluding myeloma-associated amyloid arthropathy,and analyzing the literature results comprehensively.Results There were a total of 5 patients with amyloid arthropathy with joint flexion contracture as the initial manifestation in this center,including 4 males and 1 female.By February 2022(searching CNKI,Wanfang Data and PubMed),two eligible patients were selected,all males.A total of 7 patients were included with male-to-female ratio of 6:1.The median age was 30-year-old(range from 19 to 73).Spine and limb joints were involved,especially finger joints(7 cases,100%).Soft tissue was involved in 5 patients(71.4%),carpal tunnel syndrome in 4 patients(57.1%),giant tongue in 3 patients(42.9%),shoulder pad sign in 2 patients(28.6%),muscle swelling in 2 patients(28.6%).Five patients were misdiagnosed as rheumatoid arthritis(RA)and 1 patient was misdiagnosed as spondyloarthritis(SpA).The median time of delayed diagnosis was 24 months(2-204 months).The laboratory results showed that 3 patients(42.9%)were positive for immunoelectrophoresis,all of which were λ light chain.Only 1 patient was positive for HLA-B27,while the other patients were negative for autoantibodies and rheumatoid factors.Only 1 patient had elevated C reactive protein(CRP)and erythrocyte sedimentation rate(ESR).Ultrasound examination of the lesion site of 5 patients(71.4%)showed hypoechoic area around the joint,thickening of ligaments or periarticular tenosynovitis.Five patients(71.4%)underwent X-ray examination,of which 4 patients had no bone destruction,1 patient had soft tissue swelling with bone erosion and subchondral cyst.MRI was performed in 5 patients(71.4%),in which low signal on T1 weighted image,medium signal on T2 weighted image and edema signal on peripheral tendon sheath were seen in 1 patient.One patient(14.3%)underwent emission computed tomography(ECT)without abnormal uptake.Conclusion Joint flexion contracture may be the first sign of amyloid arthropathy.Vigilance for amyloid arthropathy is warranted when there is associated soft tissue involvement,negative autoantibodies,and imaging showing no joint destruction but surrounding soft tissue abnormalities.