Treatment of renal amyloidosis with etanercept in tumour necrosis factor receptor-associated periodic syndrome

Objective. To describe the effect of Etanercept treatment in systemic AA amyloidosis in tumour necrosis factor receptor-associated periodic syndrome (TRAPS). Methods. Etanercept therapy was given to a 27 year old woman, with systemic amyloidosis and nephrotic syndrome, and to her 51 year old father, also affected by TRAPS, who had previously undergone renal transplant for amyloidosis. Serum SAA levels, plasma cytokines, glomerular filtration rate and serum amyloid P scanning were monitored. Results. Etanercept treatment resulted in initial clinical resolution of nephrotic syndrome in the 27 year old female. Both subjects demonstrated improvements in GFR and initial reduction or stabilisation of amyloid deposits on SAP scanning. Conclusion. Etanercept may reverse or slow the progression of systemic AA amyloidosis in subjects with C33Y TNFRSF1A mutation. Treatment may however need to be continuous and life-long to prevent progression to end stage disease.