Amyloid arthropathy associated with multiple myeloma: a systematic analysis of 101 reported cases.

OBJECTIVE: Amyloid deposition in multiple myeloma (MM) may lead to an arthropathy resembling rheumatoid arthritis (RA). Since a systematic description of its natural history is lacking, we have performed a systematic analysis of all published cases. METHODS: Literature review featuring backward and forward database searches and direct inspection of reference lists. Inclusion criteria were as follows: publication between 1931 and 2012, diagnosis of multiple myeloma, and demonstration of light chain amyloid (AL) in any organ or in synovial fluid, arthritis, or synovitis. RESULTS: Overall, 101 cases were identified. Median age was 59 years and the male-to-female ratio was 1:1. A systemic manifestation of MM was reported in 88 cases. In 53 of these, characteristic physical findings (carpal tunnel syndrome, macroglossia, shoulder pad, and soft tissue swelling/masses) were present. Arthritis manifested before the diagnosis of MM in 63 cases, with 33 cases initially misdiagnosed as RA. There were 72 cases of poly-, 17 of oligo-, and three of monoarthritis. The shoulder joint was most commonly affected, followed by knees and small hand joints. Median synovial fluid leukocyte count was 2460 cells/mm(3), and was normal in seven cases. Synovial histopathology often featured mild synovitis without plasma cell infiltration. Imaging revealed articular or periarticular inflammation in many cases and bone lesions near 22% of affected joints. Treatments varied but led to some improvement in the majority of cases. CONCLUSIONS: These results solidify previous experience that MM arthropathy tends to feature a symmetric RF-negative nonerosive polyarthritis. However, the results also highlight the diversity of its presentations and stress the importance of arthropathy as a potentially under-recognized presenting manifestation of MM.

Monoclonal gammopathies presenting as inflammatory arthritis: uncommon but important--a case series.

OBJECTIVE: To review the clinical profile of patients with plasma cell dyscrasias presenting with inflammatory arthritis. MATERIAL AND METHODS: Retrospective analysis was performed on clinical, laboratory and imaging data of patients who presented with inflammatory arthritis between May 2009 and April 2010 and were subsequently diagnosed as having plasma cell dyscrasias. Six out of 630 patients presenting with inflammatory arthritis were identified. The demographic, clinical and laboratory characteristics of these patients were analyzed. The diagnosis of monoclonal gammopathy was based on protein electrophoresis, immunoelectrophoresis and bone marrow biopsy. The outcomes of the treatments were analyzed. RESULTS: Four patients had monoclonal gammopathy of unknown significance and two patients had multiple myeloma. Mean age of the patients was 65 years (range 59-74). Three patients presented with oligoarticular arthritis, two with symmetrical polyarticular joint pains and one with fleeting periarticular pains. Wrist and shoulder were the most commonly involved joints. Three patients had carpal tunnel syndrome. Five patients were seronegative for both rheumatoid factor and anti-cyclic citrullinated peptide antibodies. Mean erythrocyte sedimentation rate (ESR) was high in all patients (range: 82-120 mm/h with a mean of 99.6 mm/h). Arthritis improved with chemotherapy in patients with multiple myeloma. CONCLUSION: Occurrence of inflammatory arthritis with plasma dyscrasias is more than a chance association. Plasma cell dyscrasias should be ruled out in any elderly patient presenting with atypical arthritis with disproportionately high ESR, high creatinine and hyperglobulinemia.