Thrombotic Thrombocytopenic Purpura Triggered by Chronic Lymphocytic Leukemia: A Case Report

Chronic lymphocytic leukemia (CLL) is an incurable lymphoproliferative disorder characterized by the accumulation of mature malignant B cells in the blood, bone marrow, and secondary lymphoid tissues. While it has a heterogenous clinical course, individuals with CLL are at increased risk for autoimmune complications, infections, and secondary non-hematologic secondary malignancies. Peripheral autoimmune cytopenias are a well-known phenomenon in CLL. However, other autoimmune complications, including immune thrombotic thrombocytopenic purpura (TTP), are rare and less investigated. We hereby report the first case of a patient with TTP triggered by CLL.

A 74-year-old male presented with fatigue, cough, left upper quadrant abdominal pain, and diffuse petechiae over the proceeding several weeks. The initial laboratory work was suggestive of anemia and thrombocytopenia with hemoglobin of 9.4 g/dL and platelets at 6 × 10⁹/L. He was initially started on corticosteroids and intravenous immunoglobulin. Additional laboratory studies revealed a microangiopathic hemolytic with lactate dehydrogenase 1,124 U/L; total bilirubin 3.9; haptoglobin undetectable. The direct Coombs test was negative, and review of peripheral smear showed 5-6 schistocytes per high power field. Leukocyte count 15.6 × 10⁹/L with absolute lymphocyte count of 4.0 K/µL. ADAMTS13 activity was <9%. A diagnosis of TTP was made, and he was initiated on directed therapy. A bone marrow biopsy was ultimately performed, given the concern of immune-mediated- or disease-related cytopenias, and for confirmation of CLL. Subsequent bone marrow biopsy and flow cytometry confirmed the diagnosis of CLL.

Our case illustrates the first case of TTP precipitated by CLL. This case highlights the immune dysregulation underlying CLL and the autoimmune phenomena that may develop as a result.