PB1866: RESPONSE TO NOVEL ANTI CD20 ANTIBODY AND BCL2 INHIBITOR IN A PATIENT WITH CLL AND MEMBRANOPROLIFERATIVE GLOMERULONEPHRITIS ASSOCIATED WITH LEUKEMIC KIDNEY INFILTRATION AND REVIEW OF LITERATURE

Background: Chronic lymphocytic leukemia (CLL) is a chronic lymphoproliferative disorder with mature B cell, characterized by a progressive accumulation of monoclonal B lymphocytes in the peripheral blood, bone marrow, lymphatic tissue and rarely in other organs. Although renal impairment occurs in approximately 80-90% of patients with CLL, nephrotic syndrome is rare and occurs in less than 2% of patients. In the literature this condition is reported in a maximum of 16 patients with CLL, and no cases described with Membranoproliferative glomerulonephritis (MPGN) treated with Obinutuzumab and Venetoclax. Renal failure due to leukemic infiltration in chronic lymphocytic leukemia is extremely rare condition. Aims: To evaluate the response of renal impairment due to leukemic infiltration and due to MPGN as well as disease response, after specific treatment, compared with literature data. Methods: We present a 58-year-old male diagnosed with B-CLL stage A (0) in November 2020, under hematologic regular monitoring with no specific therapy since November 2021. This year he presented with important lower and upper extremities edema, oliguria (1100ml / 24h), minor increase of lymph nodes and spleen; laboratory test showed: haemoglobin: 11.4 g / dl, white blood cells: 186.020 / mm3, platelet count 207.000 / mm3, urea: 126 mg / dl, creatinine: 1.94 mg / dl; urinary protein excretion: 10 g / 24 h, serum proteins: 4.7 g / dl, serum albumin: 1.9 g / dl. We contacted the Nephrology Department, where renal biopsy was performed with histopathological and immunohistochemical examination. Findings were consistent with MPGN secondary type and moderate involvement with leukemic cells CD20 +, CD5 +, CD23 +. Treatment with novel anti CD20 (cluster of differentiation) antibody Obinutuzumab and Venetoclax has been initiated with tumor lysis syndrome prophylaxis. Results: After first cycle of Obinutuzumab and Venetoclax (OV) regimen, renal function was normal, proteinuria has been improved decreasing to 1g / 24h, the edema was remitted and the blood count returned to normal, white blood cell count was 4.200 / mm3. Until today the patient followed 4 cycles of OV with complete remission of CLL and complete response of his underlying MPGN and leukemic renal infiltration. Summary/Conclusion: Of all the cases in the literature, our approach to this condition was different, choosing Obinutuzumab and Venetoclax therapy, obtaining the complete response after the first cycle.