[Renal involvement in monoclonal gammopathies]

Abstract

Introduction: The kidney is one of the organs most frequently affected by disease processes which produce monoclonal immunoglobins, therefore renal morphological and immunopathological alterations should be clearly recognized.

Objective: To describe the pathological features of renal involvement in monoclonal gammopathies.

Material and methods: A descriptive, retrospective and cross-sectional study of renal biopsies studied in a single center during a period of 14 years was carried out.

Results: 102 cases were included, of which 53% were male patients and the median age was 62.5 years (range 34 - 79). 97% of the biopsies were from native kidneys. The most frequent histopathological diagnosis (31.4%) was myeloma kidney, with kappa being the light chain most frequently deposited (65.6% of cases). AL amyloidosis was the second most common (29.4%) where the lambda chain predominated in 86.6%, followed by light chain deposition disease (20.6%) with the predominance of the kappa chain in 66.6%.

Conclusions: The most frequent renal involvement due to monoclonal gammopathies was myeloma kidney with deposition of kappa light chains, followed by AL lambda amyloidosis; these diseases were found more frequently in patients over 50 years of age.

Keywords: AL amyloidosis; Amiloidosis AL; Cast nephropathy; Enfermedad por depósito de cadenas ligeras; Gammapatía monoclonal; Light chain deposition disease; Light chain proximal tubulopathy; Mieloma múltiple; Monoclonal gammopathy; Multiple myeloma; Riñón de mieloma; Tubulopatía proximal por cadenas ligeras.