Coexistence of β2 microglobulin and λ light chain in amyloid fibrils of dialysis-unrelated plasma cell dyscrasia-associated systemic amyloidosis

Background Systemic amyloidosis occurs as a result of amyloid deposition in various tissues. The amyloid fibrils in systemic amyloidosis have been reported to originate from immunoglobulin light chains. Objectives We studied the composition of amyloid fibrils from two patients with plasma cell-assoc...
Ausführliche Beschreibung

Background Systemic amyloidosis occurs as a result of amyloid deposition in various tissues. The amyloid fibrils in systemic amyloidosis have been reported to originate from immunoglobulin light chains. Objectives We studied the composition of amyloid fibrils from two patients with plasma cell-associated systemic amyloidosis (PASA). Methods A double immunofluorescence study of the lesional skin of PASA was undertaken. Amyloid proteins were extracted with distilled water from one case of PASA. Results The double immunofluorescence study showed that anti-λ light chain and anti-β2 microglobulin antibodies mostly reacted with the same area of amyloid deposit. Amyloid deposits from two patients with PASA who had never undergone haemodialysis showed a positive reaction with the antibodies for β2 microglobulin as well as immunoglobulin λ light chain. By the use of immunoblot assay of amyloid fibril proteins, polypeptides immunoreactive with antiγ light chain antibody (29 kDa) and with anti-β2 microglobulin antibody (12 kDa) were detected. Conclusions These results indicate that β2 microglobulin is a component of amyloid fibrils in PASA. Ausführliche Beschreibung