Secondary hypogammaglobulinemia (SHG) is characterized by a decrease in total serum immunoglobulin (Ig) levels and can lead to immunodeficiency associated with recurrent and severe infections and is a common complication of chronic lymphocytic leukaemia (CLL). SHG also increases with the treatment of CLL. Ibrutinib is one of these treatments and acts by inhibiting bruton tyrosine kinase. Twenty-seven patients with relapsed/refractory (R/R) CLL who received ibrutinib monotherapy were included. IgG levels, stage, bulky disease, previous treatments, genetics and laboratory features, overall survival (OS) and progression free survival (PFS) were compared with and without SHG. Nine patients (33.3%) had SHG and 18 patients (66.6%) didn’t have SHG. The mean IgG levels after ibrutinib treatment first, third, 6th and 12th months were 684, 531.3, 452 and 360 mg/dL respectively in SHG arm (p < 0.001) and 1156, 1058.2, 1012.8 and 886.9 mg/dL respectively in without SHG arm (p < 0.001). All patients with SHG had ibrutinib related other adverse effects(AEs) but 2 (11.1%) patients without SHG had AEs (p < 0.001). In SHG arm 7 (77.7%) had complete and partial remission but in other arm only 6 (33.3%) had (p: 0.029). There was no significant difference in OS and PFS (p values 0.95 and 0.64, respectively). IgG levels at the beginning of ibrutinib treatment is the best predicted value for SHG development in our study (p = 0.001). As a result, we reported a significant decrease in IgG values after ibrutinib monotherapy in R/R CLL patients. This decrease occurs every month after ibrutinib use, but after a maximum of 1 year.

继发性低丙种球蛋白血症 (SHG) 的特点是血清总免疫球蛋白 (Ig) 水平降低，可导致与反复和严重感染相关的免疫缺陷，是慢性淋巴细胞白血病 (CLL) 的常见并发症。 SHG 也会随着 CLL 的治疗而增加。依鲁替尼是其中一种治疗方法，通过抑制布鲁顿酪氨酸激酶发挥作用。纳入了 27 名接受依鲁替尼单药治疗的复发/难治性 (R/R) CLL 患者。比较使用和不使用 SHG 的 IgG 水平、分期、大块疾病、既往治疗、遗传学和实验室特征、总生存期 (OS) 和无进展生存期 (PFS)。 9 名患者（33.3%）有 SHG，18 名患者（66.6%）没有 SHG。依鲁替尼治疗后第 1、3、6 和 12 个月的平均 IgG 水平在 SHG 组中分别为 684、531.3、452 和 360 mg/dL ( p < 0.001)，在无治疗组中分别为 1156、1058.2、1012.8 和 886.9 mg/dL。 SHG 臂（ p < 0.001）。所有 SHG 患者均出现依鲁替尼相关的其他不良反应 (AE)，但 2 名 (11.1%) 未出现 SHG 的患者出现 AE ( p < 0.001)。在 SHG 组中，第 7 组 (77.7%) 获得完全和部分缓解，但在其他组中，只有 6 组 (33.3%) 获得完全缓解和部分缓解 ( p : 0.029)。 OS 和 PFS 没有显着差异（ p值分别为 0.95 和 0.64）。在我们的研究中，依鲁替尼治疗开始时的 IgG 水平是 SHG 发展的最佳预测值 ( p = 0.001)。结果，我们报告 R/R CLL 患者在依鲁替尼单药治疗后 IgG 值显着下降。使用依鲁替尼后每个月都会出现这种下降，但最多 1 年后。