[Renal involvement in monoclonal gammopathies]. / Compromiso renal en gammapatías monoclonales.

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.

Compromiso renal en gammapatías monoclonales / Renal involvement in monoclonal gammopathies

Introducción: El riñón es uno de los órganos más comprometidos en enfermedades con producción de inmunoglobulinas monoclonales, por lo que es de gran importancia caracterizar muy bien las alteraciones morfológicas e inmunopatológicas en dicho compromiso. Objetivo: Describir las características del compromiso renal en gammapatías monoclonales desde una perspectiva anatomopatológica. Material y métodos: Se realizó un estudio descriptivo, retrospectivo y transversal, recolectándose biopsias renales estudiadas en un único centro durante un período de 14 años. Resultados: Se incluyeron 102 casos provenientes de 102 pacientes, el 53% de sexo masculino, la mediana de la edad fue 62,5 años (rango 34-79). El diagnóstico histopatológico más frecuente fue riñón de mieloma (31,4% de los casos), siendo kappa la cadena ligera más frecuentemente depositada (65,6% de casos), seguido de amiloidosis AL (29,4%), donde predominó la cadena lambda en un 86,6% y la enfermedad por depósitos de cadenas ligeras (20,6%) con predominio de la cadena kappa: 66,6%. El 97% de las biopsias fueron de riñón nativo. Conclusiones: El compromiso renal por gammapatías monoclonales más frecuente fue el riñón de mieloma con depósito de cadenas ligeras kappa, seguida de la amiloidosis AL lambda; estas enfermedades se encontraron con mayor frecuencia en pacientes mayores de 50 años de edad.(AU)

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.(AU)