Acute renal failure after rituximab infusion in a patient with chronic lymphocytic leukemia

A 67-year-old woman presented with numbness in her feet and hands for more than 6 months, accompanied by Raynaud's phenomenon in both hands, no rash, and no fever. Laboratory tests revealed that she had decreased complements, thrombocytopenia, anemia, elevated vascular endothelial growth factor (VEGF) and rheumatoid factor (RF), and positive antinuclear antibody (ANA). Serologic tests for hepatitis viruses, syphilis spirochetes, and HIV were negative. Both serum and urine immunofixation electrophoresis were negative. Neurophysiology demonstrated peripheral neuropathy. Biopsy was performed on both the left axillary lymph node and bone marrow, and was suggestive of chronic lymphocytic leukemia (CLL). The patient was treated with methylprednisolone combined with rituximab. 23 days after rituximab 600 mg infusion, the patient developed severe acute kidney injury, hematuria, proteinuria, worsening thrombocytopenia and anemia, further decrease in complements. Renal biopsy showed fibrinoid necrosis of glomerular endothelial cells and thrombus. The constellation of laboratory and imaging findings has prompted the consideration of atypical HUS associated with chronic lymphocytic leukemia. This complication may be attributed to significant tumor lysis subsequent to rituximab administration. Her renal and hematologic conditions improved after administration of treatment including methylprednisolone injection 40mg qd intravenously. Currently the methylprednisolone is being tapered and combined with bendamustine to treat the hematologic disease.