[Light and heavy chain deposition disease with cutaneous and renal manifestations]

Monoclonal light and heavy chain deposition disease is a rare syndrome distinct from light chain amyloid, which is defined by the presence of monoclonal deposits of immunoglobulins in various tissues.

A 65-year-old man presented with renal symptoms due to membranoproliferative glomerulonephritis, associated with urticarial papules located on the arms and back. Histological examination of a skin biopsy specimen showed lymphocytic vasculitis. Direct immunofluorescence examination of kidney and skin lesions using anti-gamma 2 and anti-Kappa monoclonal antibodies, showed a similar staining on the basement membrane zone and vessel walls.

As far as we know, this is the first documentation of monoclonal light and heavy chain deposition disease associated with a lymphocytic skin vasculitis and renal involvement caused by similar monoclonal deposits of immunoglobulins in the kidney and skin.