[More than 10 years of complete remission of monoclonal gammopathy of undetermined significance and cessation of light chain deposition disease-associated nephrotic syndrome following treatment with vincristine, adriamycin and high-dose dexamethasone (VAD)].

Light chain deposits in the form of amorphous material (light chain deposition disease) damage most frequently kidneys and, less frequently, they affect other organs. The incidence of light chain deposition disease is much lower than that of AL-amyloidosis. Symmetrical swelling of both legs, swelling of the eye lids, erythrocyturia and nephrotic proteinuria were the first signs of light chain deposition disease in our patient. The disease was diagnosed from kidney biopsy performed at the stage of advanced nephrotic syndrome with reduced filtration. The bone marrow aspirate contained 0.8% of plasma cells, serum contained monoclonal immunoglobulin IgG-kappa and urine contained free kappa chains. Blood count was normal and no osteolytic changes to the skeleton were identified. The patient was, therefore, diagnosed with monoclonal gammopathy of undetermined significance (MGUS) and was treated with 10 cycles ofchemotherapy consisting of vincristine, adriamycin and high/dose dexamethasone (VAD). Following the 10th cycle, the concentration of monoclonal IgG declined below the threshold for quantitative densitometric identification, while the more sensitive immunofixation electrophoresis remained positive. However, 2 months after the completion of chemotherapy, the immunofixation electrophoresis had become negative and thus complete haematological treatment response (remission) was achieved. Restoration of the kidney function was only gradual. Proteinuria declined below 1 g/l and no erythrocyturia was present 4 years post-treatment. Proteinuria declined to 0.19 g/I, i.e., normal values, 9 years post-treatment completion. Regular follow-ups in patients with MGUS should seek to identify not only whether MGUS is transforming into malignant disease but also whether monoclonal immunoglobulin is damaging the organism. Treatment of patients with monoclonal immunoglobulin-associated damage should be initiated early as the restoration of the affected organs function (organ treatment response) after complete haematological remission is only gradual. At present, treatment regimes with high-dose dexamethasone are recommended for patients with primary systemic AL-amyloidosis. We believe that the same approach is suitable for the treatment of light chain deposition disease in MGUS patients.