Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD.
Clinical Haematology Unit, Department of Medicine, Chris Hani Baragwanath Academic Hospital and Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
JCO Glob Oncol. 2021 Apr;7:611-621. doi: 10.1200/GO.20.00651.
Diagnosis of AIDS lymphoma in low-resource settings, like South Africa, is often delayed, leaving patients with limited treatment options. In tuberculosis (TB) endemic regions, overlapping signs and symptoms often lead to diagnostic delays. Assessment of plasma cell-free DNA (cfDNA) by next-generation sequencing (NGS) may expedite the diagnosis of lymphoma but requires high-quality cfDNA.
People living with HIV with newly diagnosed aggressive B-cell lymphoma and those with newly diagnosed TB seeking care at Chris Hani Baragwanath Academic Hospital and its surrounding clinics, in Soweto, South Africa, were enrolled in this study. Each participant provided a whole blood specimen collected in cell-stabilizing tubes. Quantity and quality of plasma cfDNA were assessed. NGS of the immunoglobulin heavy chain was performed.
Nine HIV+ patients with untreated lymphoma and eight HIV+ patients with TB, but without lymphoma, were enrolled. All cfDNA quantity and quality metrics were similar between the two groups, except that cfDNA accounted for a larger fraction of recovered plasma DNA in patients with lymphoma. The concentration of cfDNA in plasma also trended higher in patients with lymphoma. NGS of immunoglobulin heavy chain showed robust amplification of DNA, with large amplicons (> 250 bp) being more readily detected in patients with lymphoma. Clonal sequences were detected in five of nine patients with lymphoma, and none of the patients with TB.
This proof-of-principle study demonstrates that whole blood collected for cfDNA in a low-resource setting is suitable for sophisticated sequencing analyses, including clonal immunoglobulin NGS. The detection of clonal sequences in more than half of patients with lymphoma shows promise as a diagnostic marker that may be explored in future studies.
在资源匮乏的环境中，如南非，艾滋病淋巴瘤的诊断常常被延误，使患者的治疗选择有限。在结核病（TB）流行地区，重叠的症状常常导致诊断延迟。通过下一代测序（NGS）评估无细胞浆游离 DNA（cfDNA）可能会加速淋巴瘤的诊断，但需要高质量的 cfDNA。
本研究纳入了在南非索韦托的克里斯·哈尼·巴哈加万萨医院及其周边诊所新诊断为侵袭性 B 细胞淋巴瘤的 HIV 感染者和新诊断为结核病但无淋巴瘤的 HIV 感染者。每位参与者提供了一份用细胞稳定管采集的全血标本。评估血浆 cfDNA 的数量和质量。对免疫球蛋白重链进行 NGS 分析。
纳入了 9 例未经治疗的淋巴瘤 HIV+患者和 8 例 HIV+的结核病但无淋巴瘤患者。除了淋巴瘤患者的 cfDNA 占血浆回收 DNA 的比例较大外，两组的所有 cfDNA 数量和质量指标均相似。cfDNA 在血浆中的浓度在淋巴瘤患者中也呈上升趋势。免疫球蛋白重链的 NGS 显示出 DNA 的强烈扩增，在淋巴瘤患者中更容易检测到大的扩增子（>250 bp）。在 9 例淋巴瘤患者中有 5 例检测到克隆序列，而在结核病患者中均未检测到。
这项初步研究表明，在资源匮乏的环境中采集的全血适用于复杂的测序分析，包括克隆免疫球蛋白 NGS。在一半以上的淋巴瘤患者中检测到克隆序列显示出作为诊断标志物的潜力，未来的研究可能会对此进行探索。
