Vnitr Lek 2025, 71(1):E14-E24 | DOI: 10.36290/vnl.2025.011

Treatment of monoclonal gammopathy of renal significance with manifestations of Light Chain Deposition Disease (LCDD) in the transplanted kidney

Tomáš Roháľ¹, Martin Kment², Luděk Voska³, Zdeněk Adam³, Marek Borský⁴, Lenka Zdražilová-Dubská⁵, Marta Krejčí¹, Zdeněk Král¹, Luděk Pour¹

¹ Klinika nefrologie, Institut klinické a experimentální medicíny, Praha

² Pracoviště klinické a transplantační patologie, Institut klinické a experimentální mdicíny, Praha

³ Interní hematologická a onkologická klinika LF MU a FN Brno

⁴ Centrum molekulární biologie a genetiky, Interní hematologická a onkologická klinika LF MU a FN Brno

⁵ Ústav laboratorní medicíny FN Brno a Katedra laboratorních metod LF MU Brno

Light Chain Deposition Disease (LCDD) is a very rarely diagnosed condition affecting the kidneys. We describe a case where this diagnosis was morphologically confirmed in a biopsy of a transplanted kidney, and retrospectively identified in a previous kidney biopsy where the changes were not correctly classified. The biopsy of the transplanted kidney was performed due to worsening graft function. Subsequent testing focused on monoclonal gammopathy, revealing elevated serum concentrations of free kappa light chains (FLC) with a maximum FLC kappa value of 226 mg/l and FLC lambda at only 6 mg/l. The FLC kappa / FLC lambda ratio was clearly pathological at 37 (normal range 0.26-1.65). Serum and urine immunofixation electrophoresis were repeatedly negative. Bone marrow cytology described 8% pathological plasma cells, and flow cytometry demonstrated 0.7% plasma cells among all nuclear bone marrow cells. These plasma cells were 100% clonal, of the abnormal kappa + phenotype. The diagnosis was thus concluded as a non-malignant gammopathy of the type „monoclonal gammopathy of clinical significance“ with renal damage in a morphological form corresponding to LCDD. A combination of daratumumab, bortezomib, cyclophosphamide and dexamethasone was chosen for treatment LCDD. Free light kappa chains decreased below the lower limit of the norm during the first two months of anti-CD38 therapy.

LCDD is one of the many forms of kidney damage that can occur in non-malignant gammopathies. Therefore, FLC testing should always be performed as part of the differential diagnosis of renal failure. For kidney damage by monoclonal immunoglobulin, a classification created by The International Kidney and Monoclonal Gammopathy Research Group was accepted. It is advisable to inform the evaluating morphologists of the possible presence of pathological concentrations of FLC and/or M-Ig so that they can focus the diagnosis in this direction, otherwise these rare forms of kidney injury may remain unrecognized.

Keywords: Light Chain Deposition Diesease – LCDD, free light chains, renal failure, daratumumab, kidney transplantation

Accepted: February 6, 2025; Published: February 18, 2025  Show citation