Over a 10-year period, amyloid A (AA) amyloidosis was the predominant cause of progressive renal disease in patients with current or prior intravenous drug use and chronic kidney disease who underwent renal biopsy in Frankfurt, Germany, being responsible for 50% of cases. 67% of the patients with AA amyloidosis were HIV positive compared with 17% of the patients without AA amyloidosis (P = 0.036). The researchers suggest that the increased frequency and duration of infections and the immunosuppression in intravenous drug users with HIV might promote the development of AA amyloidosis.