Individuals with chronic myeloid leukemia (CML) constitute a unique group within individuals with oncohematological disease (OHD). They receive treatment with tyrosine kinase inhibitors (TKIs) that present immunomodulatory properties, and they may eventually be candidates for treatment discontinuation under certain conditions despite the chronic nature of the disease. In addition, these individuals present a lower risk of infection than other immunocompromised patients. For this study, we recruited a cohort of 29 individuals with CML in deep molecular response who were on treatment with TKIs (n = 23) or were on treatment-free remission (TFR) (n = 6), and compared both humoral and cellular immune responses with 20 healthy donors after receiving the complete vaccination schedule against SARS-CoV-2. All participants were followed up for 17 months to record the development of COVID-19 due to breakthrough infections. All CML individuals developed an increased humoral response, with similar seroconversion rates and neutralizing titers to healthy donors, despite the presence of high levels of immature B cells. On the whole, the cellular immune response was also comparable to that of healthy donors, although the antibody dependent cytotoxic activity (ADCC) was significantly reduced. Similar rates of mild breakthrough infections were observed between groups, although the proportion was higher in the CML individuals on TFR, most likely due to the immunomodulatory effect of these drugs. In conclusion, as with the healthy donors, the vaccination did not impede breakthrough infections completely in individuals with CML, although it prevented the development of severe or critical illness in this special population of individuals with OHD.
慢性粒细胞白血病（CML）患者是肿瘤血液病（OHD）患者中的一个特殊群体。他们接受具有免疫调节特性的酪氨酸激酶抑制剂（TKI）治疗，尽管疾病呈慢性病程，但在特定条件下最终可能成为治疗中止的候选者。此外，这类患者相比其他免疫功能低下患者具有更低的感染风险。本研究招募了29例处于深度分子学缓解的CML患者队列，其中23例正在接受TKI治疗，6例处于无治疗缓解期（TFR），并在完成SARS-CoV-2全程疫苗接种后，将其体液与细胞免疫应答与20例健康供者进行对比。所有参与者接受为期17个月的随访，以记录突破性感染导致的COVID-19发病情况。尽管存在高水平未成熟B细胞，所有CML患者均产生增强的体液免疫应答，其血清转化率与中和抗体滴度与健康供者相似。总体而言，虽然抗体依赖性细胞毒活性（ADCC）显著降低，但其细胞免疫应答与健康供者相当。两组间观察到轻度突破性感染发生率相近，但TFR期CML患者比例更高，这很可能与TKI药物的免疫调节作用相关。综上所述，与健康供者类似，疫苗接种虽未能完全阻止CML患者的突破性感染，但有效预防了这一特殊OHD人群发生重症或危重症疾病。
肿瘤(癌症)患者之家