Trends in diagnosis of amyloid kidney disease in people who inject drugs (PWID)

BACKGROUND People who inject drugs (PWID) face elevated risk of proteinuria and chronic kidney disease (CKD). AA (inflammatory) amyloid kidney disease, though rare in the general population, represents an important cause of progressive CKD in PWID, particularly among those with recurrent skin and soft tissue infections. METHODS Using TriNetX data, we performed a retrospective cohort study examining trends in amyloid CKD stage ≥3 diagnoses among PWID from 2018-2025. We compared PWID with and without renal involvement, assessing outcomes including mortality, dialysis initiation, infections, major limb amputation, and thrombotic complications. Associations were assessed after propensity score matching. RESULTS Age-adjusted incidence of amyloid kidney disease among PWID increased from 146 to 238 per 100,000 person-years (PY) between 2018 and 2025 (annual percent change 6.8%). Dialysis incidence rose from 2.04 to 8.83 / 100 PY, alongside increases in mortality. After matching, renal involvement was associated with higher hazards of death (HR 1.80, 95% CI 1.44–2.25) and dialysis or death (HR 2.54, 95% CI 2.02–3.19). Secondary outcomes were largely similar between groups, although venous thromboembolism or catheter-associated bloodstream infections were modestly increased. CONCLUSIONS: Amyloid kidney disease among PWID is increasingly recognized and is associated with substantially higher risks of dialysis and death highlighting the importance of early recognition and intervention.