Amyloid arthropathy

Persistent fever and destructive arthritis caused by dialysis-related amyloidosis: A case report

RATIONALE

Dialysis-related amyloidosis (DRA) can present rheumatic manifestations in patients on long-term hemodialysis. Typical articular symptoms with DRA involve carpal-tunnel syndrome, effusion in large joints, spondyloarthropathy, or cystic bone lesions, which are usually with non-inflammatory processes.

PATIENT CONCERNS

A 64-year-old man on hemodialysis for >30 years was admitted because of intermittent fever, polyarthritis, and elevated serum C-reactive protein (CRP) level, which was continuous for 2 years. Several antibiotics were ineffective for 3 months before his admission. On physical examination, joint swelling was observed at bilateral wrists, knees, ankles, and hip joints. Laboratory tests revealed elevation of serum inflammatory markers and β2-microglobulin (β2-MG). Synovial fluid showed predominant infiltration of polymorphonuclear leukocytes and the increase of β2-MG level.

DIAGNOSIS

Significant deposition of β2-MG with inflammatory cell infiltration was found in biopsied samples from synovium, skin, and ileum.

INTERVENTIONS

We decided to switch to the hemodialysis column with membrane that can effectively absorb β2-MG in circulation.

OUTCOMES

The relief of symptoms and a decrease of CRP level by changing the membrane lead to the final diagnosis of DRA.

LESSONS

Our case demonstrates that DRA arthropathy can be inflammatory and destructive, and also develop systemic inflammatory signs and symptoms. In such cases, aggressive absorption of β2-MG in circulation might help the amelioration of symptoms.

Systemic amyloidosis of beta 2 microglobulin type

A patient receiving haemodialysis for 15 years developed systemic amyloidosis of beta 2 microglobulin type. Noticeable deposits of amyloid were present in the myocardium, intervertebral discs, joint cartilages and tendons. Less conspicuous amounts were present in blood vessel walls in the lungs, liver, adrenal glands and brain, and within the stroma of the prostate, testis and kidney, often with foci of calcification.

Localized deposition of amyloid in articular cartilage

The frequency, nature and tissue distribution of localized amyloid deposits in articular cartilage of young and elderly patients, with and without evidence of arthritic disease, was determined. Localized amyloid deposits in articular cartilage were not found in young patients with osteoarthritis of the hip or chondromalacia/osteoarthritis of the patella. However, in elderly patients with osteoarthritis of the hip, amyloid deposits were commonly found, although at no greater frequency than in elderly patients with no evidence of arthritis. Amyloid deposits were commonly present (in 95% of cases) in osteoarthritis of the knee joint and in the articular cartilage of all joints containing pyrophosphate deposits. Similar deposits of amyloid were also found in the articular cartilage of 40-45% of rheumatoid joints. These findings indicate that localized amyloid deposits in the articular cartilage are largely age-related and not due to specific pathological alterations affecting articular cartilage.

B2-microglobulin and associated amyloidosis presenting as bilateral popliteal tumors

Chronic hemodialysis has led to the prolongation of life in many patients with end-stage renal disease, but has also allowed for the development of new diseases that are a consequence of this clinical setting. B2-microglobulin accumulation leading to systemic amyloidosis may be the most recent disease in this category. This case report documents the development of bilateral popliteal tumors in a patient undergoing chronic hemodialysis for 9 years. Removal of one of the tumors and pathological examination demonstrated amyloid that was positive for B2-microglobulin by specific antibody testing. This case adds further support to the suggestion that B2-microglobulin amyloidosis in chronic hemodialysis patients is truly a systemic disorder. The development of popliteal tumors, particularly in proximity to joints, in a chronic hemodialysis patient, must include amyloidosis in the differential diagnosis.

Beta 2-microglobulin: a new form of amyloid protein associated with chronic hemodialysis

Carpal tunnel syndrome (CTS) has been associated with amyloid deposits and is now regarded as a major complication in chronic hemodialysis patients. While this new syndrome has been receiving increasing attention, its etiology has not been clarified. We have isolated amyloid fibrils from amyloid laden tissues inside the carpal tunnel in four different hemodialysis patients with CTS. After solubilization in guanidine HCl, a significant amount of the protein was located in a homogeneous, low molecular weight fraction. Each protein was found to be identical to beta 2-microglobulin with regard to its molecular weight of 11,000 on SDS-PAGE, amino acid composition and N-terminal amino acids: Ile-Gln-Arg-Thr-Pro-Lys-Ile-Gln-Val-Tyr-Ser-Arg-His-Pro-Ala-Glu. In direct immunofluorescent study, anti-beta 2-microglobulin did react positively with amyloid deposits. These results demonstrate that the amyloid associated with chronic hemodialysis contains as major component a new form of amyloid fibril protein that is homologous to beta 2-microglobulin. It is postulated that beta 2-microglobulin cannot be removed from the blood by conventional hemodialysis, and accumulates in tissues causing the formation of amyloid fibrils, which, having a relatively high affinity to the carpal tunnel area, thus causes CTS.