TỔN THƯƠNG THẬN Ở BỆNH NHÂN ĐA U TỦY XƯƠNG THỂ CHUỖI NHẸ: BÁO CÁO CA LÂM SÀNG

Abstract

Light-chain myeloma (LCM) is a distinct subtype of multiple myeloma, accounting for approximately 15 - 20% of cases. It is characterized by the monoclonal overproduction of free light chains (FLC) without a corresponding increase in intact immunoglobulins. Approximately 20 - 50% of patients with LCM initially present with kidney injury, most commonly due to light chain cast nephropathy. The diagnosis of LCM is often delayed, especially in patients with concurrent risk factors for kidney injury. We present two cases of acute kidney injury (AKI) caused by multiple contributing factors, with clinical features suspicion of LCM such as discrepancy between total and ionized calcium levels, hypoproteinemia with normal serum albumin, and a negative M-spike. In which serum-free light chain quantification and urine 24h Bence Jones protein detection serve as non-invasive, highly sensitive diagnostic tools. Renal biopsy and bone marrow biopsy remain the gold standards for confirming myeloma-related kidney injury. Early recognition of LCM is of prognostic significance and allows clinicians to “open the therapeutic window”, particularly when initiating bortezomib-based regimens or other rapid FLC-lowering strategies at an early stage.