Extrarenal monoclonal immunoglobulin deposition disease: mechanisms, clinical presentation, diagnostics and treatment approaches (review)

In monoclonal gammopathies the aberrant B-cell clone produces the monoclonal immunoglobulin (MIG) which could present as only one light chain or only one heavy chain or the whole immunoglobulin. Due to somatic mutations in B-cell clone genetic the MIG obtains abnormal features and different types of tissue toxicity. The condition of non-organized granular MIG deposition leading to organ damage and dysfunction is known as monoclonal immunoglobulin deposition disease (MIDD). Most commonly MIDD involves the kidney parenchyma. However, extrarenal MIDD may affect other tissues and present as local or systemic condition. This review summarizes the current knowledge concerning the mechanisms, clinical manifestation, diagnostics and treatment approaches in extrarenal MIDD.