Florida State University, Sarasota, FL, USA.
University of Connecticut, Farmington, CT, USA.
J Investig Med High Impact Case Rep. 2021 Jan-Dec;9:2324709621990767. doi: 10.1177/2324709621990767.
B-cell prolymphocytic leukemia (B-PLL) is a rare leukemia characterized by rapidly increasing leukocytosis with splenomegaly and lymphadenopathy. Treatment strategies are largely based on studies of chronic lymphocytic leukemia (CLL). Antibodies against the cell surface protein CD20 are considered to be first-line therapy. A 76-year-old male with known CLL presented 2 weeks after starting chemoimmunotherapy for newly refractory CLL after failing ibrutinib therapy. White blood cell count was elevated at 226.7 × 10/µL. Fluorescent in situ hybridization analysis of a bone marrow specimen showed new development of complex cytogenetics. Flow cytometry revealed B cells appearing slightly dimmer on CD45 and brighter on CD20 compared with typical B-CLL suggestive of less mature lymphocyte forms. The patient was diagnosed with B-PLL and started on obinutuzumab and venetoclax with rapid normalization of white blood cells. This case recapitulates the challenges in diagnosing and treating B-PLL. Ibrutinib resistance is a growing area of study with several proposed mechanisms of acquired resistance. The pathogenesis of B-PLL is not completely understood, although mutations in are presumed to play a role.
B 细胞前淋巴细胞白血病（B-PLL）是一种罕见的白血病，其特征是白细胞迅速增多，并伴有脾肿大和淋巴结病。治疗策略主要基于慢性淋巴细胞白血病（CLL）的研究。针对细胞表面蛋白 CD20 的抗体被认为是一线治疗药物。一名 76 岁男性，患有已知的 CLL，在伊布替尼治疗失败后出现新的难治性 CLL，开始化疗免疫治疗 2 周后出现该疾病。白细胞计数升高至 226.7×10/µL。骨髓标本的荧光原位杂交分析显示新出现复杂细胞遗传学。流式细胞术显示与典型 B-CLL 相比，B 细胞在 CD45 上的表现稍暗，在 CD20 上的表现更亮，提示淋巴细胞形态不成熟。该患者被诊断为 B-PLL，并开始接受奥滨尤妥珠单抗和维奈托克治疗，白细胞迅速恢复正常。该病例重现了诊断和治疗 B-PLL 的挑战。伊布替尼耐药是一个正在研究的领域，有几个提出的获得性耐药机制。B-PLL 的发病机制尚不完全清楚，尽管假定存在 基因突变。
