Slade H B, Greenwood J H, Hudson J L, Beekman R H, Riedy M C, Schwartz S A
Division of Immunology, University of Michigan Hospitals, Ann Arbor.
Diagn Clin Immunol. 1988;5(5):249-55.
The diagnostic evaluation of infants with suspected DiGeorge syndrome includes peripheral blood lymphocyte phenotype analysis by flow cytometry. Mononuclear cells are typically concentrated from infants' blood samples by Ficoll-Hypaque (FH) density gradient centrifugation prior to monoclonal antibody (Mab) staining. Having observed that lymphocyte percentages in samples prepared by this technique were low more often than anticipated based on the prevalence of the suspected diagnosis, we undertook a prospective study of 55 infants with congenital heart disease comparing FH with a whole-blood (WB) technique. Sixty healthy adult controls were similarly studied. We report the observation that FH-prepared mononuclear cells from blood samples of infants less than 4 months of age yield substantially different phenotypes than WB-prepared samples. The differences are related to red blood cell (RBC) contamination. No such difference was seen with adult samples. Unlike FH-prepared adult samples, contaminating RBCs are indistinguishable from lymphocytes through at least 4 months of age when assessed by the standard cytometric gating parameters of forward and 90 degrees light scatter. The use of a WB ammonium chloride lysis technique is recommended as most appropriate for the preparation of infants' blood samples.
对疑似22q11.2微缺失综合征（DiGeorge syndrome）的婴儿进行诊断评估，包括通过流式细胞术分析外周血淋巴细胞表型。在进行单克隆抗体（Mab）染色之前，通常通过Ficoll-Hypaque（FH）密度梯度离心法从婴儿血样中富集单核细胞。鉴于观察到用该技术制备的样本中淋巴细胞百分比低于基于疑似诊断患病率预期的情况，我们对55例先天性心脏病婴儿进行了一项前瞻性研究，比较了FH法与全血（WB）法。对60名健康成人对照进行了类似研究。我们报告了这样一个观察结果：来自4个月龄以下婴儿血样的FH法制备的单核细胞产生的表型与WB法制备的样本有显著差异。这些差异与红细胞（RBC）污染有关。成人样本未观察到这种差异。与FH法制备的成人样本不同，通过前向散射和90度光散射的标准细胞术门控参数评估时，至少在4个月龄之前，污染的红细胞与淋巴细胞无法区分。建议使用WB氯化铵裂解技术来制备婴儿血样最为合适。
