Chronic lymphocytic leukemia infiltration of a transplanted kidney successfully treated with venetoclax and obinutuzumab: a case report

Background: Chronic lymphocytic leukemia (CLL) is a chronic lymphoproliferative disorder characterized by gradual accumulation of monoclonal lymphocytes. End-stage renal disease (ESRD) patients with CLL can be candidates for kidney transplant but despite potential benefits, significant challenges exist. Due to risk of CLL progression and organ infiltration, many of these patients are excluded from the transplant list. CLL infiltration of the transplanted kidneys is not reported to be common but when present signifies poor prognosis and poses a challenge for treatment. Case Description: A 71-year-old male with CLL and chronic kidney disease (CKD) progressed to ESRD due to factors unrelated to CLL and received kidney transplantation. His CLL was stable prior to transplantation without requiring any treatment. After transplantation, despite stability of his blood counts and adenopathy, he developed acute kidney injury. Biopsy of the transplanted kidneys revealed CLL infiltration without any signs of graft rejection. He was then treated with venetoclax and obinutuzumab following which the renal function improved and there was no residual CLL in subsequent kidney biopsies. He continues to do well 4 years post-transplant with normal renal function and no evidence of CLL recurrence. Conclusions: Our case highlights the possibility of CLL progression after kidney transplantation. Newer targeted therapies can be effective in treating CLL progression and additional research is required to better characterize the frequency of kidney infiltration and to identify optimal treatment strategies.