Department of Laboratory Medicine, Seoul National University Hospital, Seoul, Korea.
Department of Laboratory Medicine, Chungbuk National University Hospital, Cheongju, Korea.
Am J Clin Pathol. 2021 Jun 17;156(1):72-85. doi: 10.1093/ajcp/aqaa211.
We aimed to determine whether small paroxysmal nocturnal hemoglobinuria (PNH) clones detected by flow cytometry (FCM) harbor PIG gene mutations with quantitative correlation.
We analyzed 89 specimens from 63 patients whose PNH clone size was ≥0.1% by FCM. We performed ultradeep sequencing for the PIGA, PIGM, PIGT, and PIGX genes in these specimens.
A strong positive correlation between PNH clone size by FCM and variant allele frequency (VAF) of PIG gene mutation was identified (RBCs: r = 0.77, P < .001; granulocytes: r = 0.68, P < .001). Granulocyte clone size of 2.5% or greater and RBCs 0.4% or greater by FCM always harbored PIG gene mutations. Meanwhile, in patients with clone sizes of less than 2.5% in granulocytes or less than 0.4% in RBCs, PIG gene mutations were present in only 15.9% and 12.2% of cases, respectively. In addition, there was not a statistically significant positive correlation between FCM clone size and VAF or the presence or absence of a PIG mutation.
Our results showed that in small PNH clones PIG gene mutations were present in only a small portion without significant correlation to VAF or the presence or absence of a PIG mutation.
我们旨在确定通过流式细胞术（FCM）检测到的小阵发性睡眠性血红蛋白尿症（PNH）克隆是否与定量相关性存在 PIG 基因突变。
我们分析了 63 名患者的 89 份标本，这些患者的 PNH 克隆大小通过 FCM 检测≥0.1%。我们对这些标本中的 PIGA、PIGM、PIGT 和 PIGX 基因进行了超深度测序。
FCM 检测的 PNH 克隆大小与 PIG 基因突变的变异等位基因频率（VAF）之间存在很强的正相关（RBC：r=0.77，P<.001；粒细胞：r=0.68，P<.001）。FCM 检测的粒细胞克隆大小为 2.5%或更大和 RBC 为 0.4%或更大时，总是存在 PIG 基因突变。同时，在粒细胞克隆大小小于 2.5%或 RBC 克隆大小小于 0.4%的患者中，分别只有 15.9%和 12.2%的患者存在 PIG 基因突变。此外，FCM 克隆大小与 VAF 或 PIG 基因突变的存在与否之间没有统计学上的显著正相关。
我们的研究结果表明，在小的 PNH 克隆中，只有一小部分存在 PIG 基因突变，与 VAF 或 PIG 基因突变的存在与否没有显著相关性。
