Multiple myeloma presenting as acute tubulointerstitial nephritis

Abstract

Background: Acute tubulointerstitial nephritis (ATIN) is a very rare paraneoplastic manifestation in patients with multiple myeloma (MM). It is an uncommon pattern of renal disease in such patients. Case presentation: We report a case of an 82-year-old male who was admitted with acute kidney injury. Renal biopsy showed typical findings of light chainassociated ATIN with scattered inflammatory cells in the interstitium and associated active tubulitis. No other common manifestations of MM were present at the time of presentation, including hypercalcemia, hyperuricemia, proteinuria, bone pain or lytic bone lesions. Subsequent immunoassays revealed significant serum lambda light chain burden and Bence Jones protein in urine. Immunofluorescence demonstrated linear tubular basement membranes with positive staining for lambda light chain (3+). Electron microscopy (EM) further showed interstitial edema and inflammation. All the aforementioned findings are consistent with ATIN and supported the diagnosis of MM. Conclusions: In conclusion, light chain-associated ATIN should be considered in the differential diagnosis of acute interstitial nephritis. Henceforth, serum free light chains as well as serum and urine protein electrophoresis should be included in the workup of such patients.

Impact of Initial Renal Involvement and Bence Jones Proteins in the Urine on Overall Survival of Patients With Multiple Myeloma

“…Despite this, it is well-known that more than 60% of patients with classical myeloma have BJP in their urine [27].…”

“…They are considered cornerstones with specific diagnostic importance in the context of target organ manifestations such as kidney failure, lytic bone lesions, anemia, or large numbers of plasma cells in the bone marrow of patients [10,11].…”

A massive acute tubulointerstitial nephritis as an expression of a kappa light chain multiple myeloma: a case study

“…The International Kidney and Myeloma group does not categorize LCTIN as an entity expression of a plasma cell dyscrasia [7,8]; despite the growing interest and ongoing debate on the prognostic and therapeutic implications, literature is lacking [2,3,9,10]. From the literature review, we found that data on the prevalence of LCTIN are limited to only two series [9,10].…”

“…However, the interstitial in ammation is an aspeci c nding since it is frequently reported in kidney biopsies as an expression of direct (e.g., nitric oxide production in the interstitium) or indirect (e.g., cytopathic damage against the tubular cells) insult of the kidney structures by the monoclonal light chains, according to their chemical and physical properties. However, in some patients, kidney biopsies show an inappropriately orid interstitial in ltration of in ammatory cells that may resemble allergic tubulointerstitial nephritis [2,3].…”

Implications of Chromosomal Abnormalities and Bence-Jones Proteins in Multiple Myeloma

“…In target organ manifestations of multiple myeloma like kidney failure, lytic bone lesions, anemia, or high numbers of plasma cells in the bone marrow of patients, Bence Jones proteins are critical diagnostic markers. In two thirds of cases of multiple myeloma, Bence Jones proteins are present [9,10].…”