Systemic AL amyloidosis mimicking rheumatoid arthritis

AL amyloidosis presenting as inflammatory polyarthritis: a case report

Amyloidosis is a condition characterised by extracellular tissue deposition of fibrils causing a wide range of clinical manifestations. This protein deposition can occur in any tissue, most commonly in the kidney, heart, skin, peripheral nervous system, and gastrointestinal tract. However, the deposition of amyloid fibrils in the synovium is seldom reported. Musculoskeletal manifestations are subtle, subclinical and rarely the patient presents with symptoms that resemble rheumatic diseases. Here, we describe a 55-year-old man with AL (amyloid light chain) amyloidosis who presented with inflammatory polyarthritis with significant morning stiffness, inflammatory low back pain, and painful thickened tongue. The patient had anaemia, macroglossia with lateral scalloping of the tongue, papules, and plaques in the periocular, perioral and perinasal area, bilateral carpal tunnel syndrome, localised soft tissue swelling over the joints, restricted movement in different joints with flexion contractures in some joints. Rheumatoid factor and ACPA were negative and the X-ray of the sacroiliac joints was normal. We confirmed amyloidosis by biopsy of an affected skin lesion. In the urine, no Bence Jones protein was found and bone marrow study and x-ray of the skull were normal. Plasma immuno-electrophoresis and serum free light chain (FLC) assay confirmed lambda light chain type monoclonal gammopathy. Take home message: Although AL amyloidosis is a rare condition, it should be considered while evaluating atypical symptoms in patients presenting with rheumatic complaints. A high index of suspicion is necessary for proper diagnosis as delay in diagnosis will yield a poorer treatment outcome.

Synovial Tissue Biopsy Collection by Rheumatologists: Ready for Clinical Implementation?

Synovial tissue from arthritis patients is increasingly used for both basic pathophysiological and clinical translational research. This development has been spurred by the development of biotechnological techniques for analysis of complex tissues and the validation of ultrasound guided biopsies for easier tissue sampling. This increasing use of synovial tissue raises questions on standardization of methodologies for tissue processing and cellular & molecular analyses. Furthermore, it raises the question if synovial tissue biopsy analysis may be more widely implemented in clinical practice, what are the methodological hurdles for implementation and what are the lessons that can be learned from previous experience. This will be the focus of this review.

Multimodality Imaging Including PET/CT in a Patient with Amyloid Arthropathy and Multiple Myeloma

We report a case of amyloid arthropathy in a patient with multiple myeloma. Amyloid arthropathy is a very rare condition that may be associated with multiple myeloma. It presented in our patient as soft tissue masses around joints and eroding into adjacent bones. We found it to be hypermetabolic on fused positron emission tomography and computed tomographic scanning.

Multiple myeloma masquerading as severe seropositive rheumatoid arthritis with subcutaneous nodules and mononeuritis multiplex

Multiple myeloma can rarely mimic seronegative rheumatoid arthritis (RA). We report a 55-year-old woman who presented with longstanding deforming polyarthritis with extensive subcutaneous nodules, tenosynovitis, anti-cyclic citrullinated peptide positivity and mononeuritis multiplex. Even though the clinical picture was consistent with seropositive RA, the absence of bone erosion or joint space narrowing on hand and knee radiographs led us to question the diagnosis of RA. Further investigation revealed a diagnosis of multiple myeloma with cutaneous amyloid deposits, based on serum immunofixation, bone marrow aspiration and biopsy of a subcutaneous nodule. The only clue to suspect myeloma from the basic investigations and clinical examination was mild hypercalcemia. This case serves to reiterate the need to maintain a heightened suspicion for other diagnoses even when RA appears most likely.

[A 48-year-old patient with oligoarthritis of the knees, having excluded spondyloarthritis and rheumathoid arthritis]

We report the case of a patient with amyloid light-chain (AL) amyloidosis, presenting for more than 1.5 years with oligoarthritis as the only clinical symptom of the underlying disease. Developing further organ symptoms (heart and gastrointestinal tract) led to the definitive diagnosis. Joint involvement due to AL amyloidosis is extremely rare and may mimic rheumatoid arthritis. Arthritis might be the first symptom of the AL amyloidosis. The combination of arthritis and other organ disorders (e.g., proteinuria, heart failure, or diarrhea) should initiate further diagnostic efforts considering AL amyloidosis as a differential diagnosis. The diagnosis will be confirmed by the typical histology of synovia or involved organs including immunohistochemistry for typing amyloid and performing immunoelectrophoresis.

Clinical manifestations at diagnosis in Japanese patients with systemic AL amyloidosis: a retrospective study of 202 cases with a special attention to uncommon symptoms

OBJECTIVE

To retrospectively investigate the clinical manifestations at diagnosis in Japanese patients with systemic AL amyloidosis.

METHODS

We reviewed the medical records of 230 Japanese patients who had visited our hospital and been diagnosed with AL amyloidosis, and abstracted those with the systemic type. The clinical data at diagnosis of systemic AL amyloidosis, including laboratory and imaging findings, were analyzed.

RESULTS

Two hundred and two patients (mean, 58.7±9.5 years) were enrolled in this study. Immunofixation or immunoelectrophoresis was performed in 173 patients, 144 of whom were positive for M-protein in the serum and/or urine (κ:λ=30:114). The primary clinical manifestations at diagnosis were proteinuria and/or renal dysfunction (54.0%), congestive heart failure (24.8%), peripheral neuropathy (10.4%), hepatomegaly (7.9%) and arrhythmia (5.0%). The remaining patients developed unusual manifestations, such as solitary tumor, lymphadenopathy, gastrointestinal bleeding, intestinal pseudoobstruction, hemorrhagic tendencies and polyarthralgia. Dilatation of the intestine with marked thickening of the gastrointestinal wall on computed tomography and multiple nodular lesions with associated mucosal friability on endoscopy are characteristic findings of systemic AL amyloidosis.

CONCLUSION

The clinical pictures of Japanese patients with systemic AL amyloidosis are similar to those previously reported from the US and European nations; however, some patients with this disease develop uncommon symptoms. Conducting laboratory and histological examinations for systemic AL amyloidosis is necessary when making a differential diagnosis of these symptoms.

Synovial deposition of wild-type transthyretin-derived amyloid in knee joint osteoarthritis patients

OBJECTIVE

To investigate histological features of deposited amyloid in the synovial tissue and its clinical significance in knee joint osteoarthritis (OA) patients.

METHODS

We prospectively enrolled 232 consecutive patients who underwent arthroplasty or total replacement of the knee joint for treatment of OA. Congo red staining and immunohistochemistry were performed in the synovial tissue obtained at surgery. When transthyretin (TTR)-derived amyloid was positive, we analyzed all 4 exons of the TTR gene using the direct DNA sequencing method in order to detect mutations.

RESULTS

We analyzed 322 specimens in this study. Twenty-six specimens (8.1%) obtained from 21 patients (5 men and 16 women; mean, 79.0 ± 4.6 years) showed deposition of amyloid, which was positively stained with the anti-TTR antibody. Eighteen patients showed inhomogeneous accumulations of amyloid in the loose connective tissue under the synovial epithelia sometimes with nodule formation, while in the remaining three, small vessels in the adipose tissue were involved. Medical records of these patients revealed nothing remarkable in the clinical course, laboratory data or macroscopic intraarticular findings at surgery. No mutations were detectable in the TTR gene analysis.

CONCLUSION

Wild-type TTR-derived amyloid may affect the synovial tissue as a result of long-term mechanical stress or as a part of senile systemic amyloidosis in approximately 8% of knee joint OA patients. No obvious clinical significance was found in synovial deposition of amyloid.

Gene expression profile of the synovium and cartilage in a chronic arthritis rat model

BACKGROUND

Primary osteoarthritis (OA) is a polygenic disease. To investigate the gene expression profile of cartilage and synovium from osteoarthritis and healthy rats using cDNA microarray is beneficial to recognize the pathogenesis of osteoarthritis and provide evidence for gene therapy of osteoarthritis.

OBJECTIVE

The present study aimed to investigate the gene expression profile of the cartilage and synovium of chronic arthritis and healthy rats through cDNA microarray assay, and identify the differentially expressed genes. This study may be helpful for understanding the role of differentially expressed genes in osteoarthritis and the gene polymorphism of osteoarthritis.

METHODS

A total of 24 male Wistar rats were randomly divided into control group and osteoarthritis group (n = 12 per group). The synovial and cartilage were obtained and total RNA was extracted. cDNA microarray assay was performed to identify the differentially expressed genes, and cluster analysis was conducted.

RESULTS AND CONCLUSION

A total of 82 differentially expressed genes were identified, among which 27 were up-regulated and 55 down-regulated. Gene microarray assay is effective to identify differentially expressed genes and may find out novel osteoarthritis associated genes. Multiple genes are involved in the pathogenesis of osteoarthritis. The differentially expressed genes provide important information for further studies on the pathogenesis of osteoarthritis and gene therapy of osteoarthritis.

Amyloid arthropathy mimicking seronegative rheumatoid arthritis in multiple myeloma: case reports and review of the literature

We report two patients who suffered from symmetrical polyarthritis simulating rheumatoid arthritis. Acute phase response was almost within normal limits, and autoantibodies including rheumatoid factor were negative. Both of them were diagnosed as having amyloid arthropathy (AmyA) secondary to kappa multiple myeloma based on deposition of kappa-light chain-immunoreactive amyloid in biopsied tissue and Bence Jones protein in urine. Systemic AL amyloidosis may be important in the differential diagnosis of chronic polyarthralgia.