Maiolo Elena, Bellesi Silvia, Campana Fabrizia, Iacovelli Camilla, Malafronte Rosalia, Schiaffini Gabriele, Alma Eleonora, Bellisario Flaminia, Viscovo Marcello, D'Innocenzo Simone, Toscano Alessia, D'Alò Francesco, De Stefano Valerio, Larocca Luigi Maria, Hohaus Stefan
Dipartimento di Scienze di Laboratorio ed Ematologiche, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy.
Sezione di Ematologia, Dipartimento di Scienze Radiologiche ed Ematologiche, Università Cattolica del Sacro Cuore Facoltà di Medicina e Chirurgia, 00168 Rome, Italy.
Cancers (Basel). 2024 Nov 26;16(23):3968. doi: 10.3390/cancers16233968.
CD79b is a B-cell-specific antigen that is crucial to the B-cell receptor and is considered a key target for treatment in aggressive B-cell lymphomas. While immunohistochemical studies have shown widespread expression of CD79b in mature B-cell-derived lymphomas, flow cytometry allows for precise measurement and differentiation between surface and intracellular localization. In our comparative analysis, we discovered that CD79b expression percentages and mean fluorescence intensity (MFI) were lower in a group of 127 cases of aggressive B-cell lymphomas compared to a control group of benign reactive hyperplasia. We also observed significant variability in the surface expression of CD79b among lymphoma cases, with 18% showing predominantly intracellular positivity. There was a strong correlation between the surface expression of CD79b and clonal light chains. Notably, primary mediastinal B-cell lymphomas exhibited significantly lower surface CD79b expression compared to other lymphoma subtypes (median 0.8% IQR 0-48.5 vs. 80% IQR 24-97, = 0.0005). Furthermore, patients over 60 years old and those with a higher Revised International Prognostic Index (R-IPI) had significantly higher CD79b expression, both of which are associated with a significant benefit from adding an anti-CD79b drug conjugate to first-line chemotherapy in diffuse large B-cell lymphomas. In conclusion, the quantitative flow cytometric analysis of CD79b surface expression in aggressive B-cell lymphomas provides clinically relevant information, highlighting its potential usefulness in guiding therapeutic decisions.
CD79b是一种B细胞特异性抗原，对B细胞受体至关重要，被认为是侵袭性B细胞淋巴瘤治疗的关键靶点。虽然免疫组织化学研究表明CD79b在成熟B细胞来源的淋巴瘤中广泛表达，但流式细胞术可精确测量并区分表面和细胞内定位。在我们的比较分析中，我们发现与良性反应性增生对照组相比，127例侵袭性B细胞淋巴瘤患者的CD79b表达百分比和平均荧光强度（MFI）较低。我们还观察到淋巴瘤病例中CD79b的表面表达存在显著差异，18%的病例主要表现为细胞内阳性。CD79b的表面表达与克隆性轻链之间存在很强的相关性。值得注意的是，与其他淋巴瘤亚型相比，原发性纵隔B细胞淋巴瘤的表面CD79b表达显著降低（中位数0.8%，四分位间距0 - 48.5 vs. 80%，四分位间距24 - 97，P = 0.0005）。此外，60岁以上的患者和修订后的国际预后指数（R-IPI）较高的患者CD79b表达显著更高，这两者都与在弥漫性大B细胞淋巴瘤一线化疗中添加抗CD79b药物偶联物有显著获益相关。总之，对侵袭性B细胞淋巴瘤中CD79b表面表达进行定量流式细胞术分析可提供临床相关信息，突出了其在指导治疗决策方面的潜在用途。
