A case of diagnosis of light chain proximal tubulopathy in a kidney transplant patient
Light chain proximal tubulopathy (LCPT) is a disease characterised by accumulation of monoclonal immunoglobulins produced by tumour clones of plasma cells or B-lymphocytes in the epithelium of proximal renal tubules. One of LCPT forms is the crystal one, against the background of which epithelium of proximal renal tubules accumulates crystal structures of different sizes and shapes. This work presents an observation of a kidney transplant patient with crystal LCPT. The patient was admitted with azotaemia and underwent renal biopsy in order to establish the diagnosis. Morphological analysis drew attention to necrosis of epithelium of proximal renal tubules. Electron microscopy visualised crystal structures, immunohistochemical analysis of which revealed their monotypy in relation to lambda light chains of immunoglobulins. LCPT was diagnosed based on the comparison of the morphological picture and clinical data.