Chang C C, Kass L
Department of Pathology, MetroHealth Medical Center and Case Western Reserve University School of Medicine, Cleveland, Ohio 44109-1998, USA.
Am J Clin Pathol. 1997 Jul;108(1):69-73.
The Sysmex R-3000 (TOA Medical Electronics, Kobe, Japan) evaluates maturation of reticulocytes by quantitating the fraction of reticulocytes within low-, middle-, and high-fluorescence intensity regions. We defined the immature reticulocyte fraction (IRF) as the sum of the fraction of high-fluorescence intensity regions plus the fraction of middle-fluorescence intensity regions. Then, we studied the clinical significance of IRF in the evaluation of anemia by comparing the IRF with the absolute reticulocyte count (ARC) and with the reticulocyte production index (RPI) and by reviewing pertinent clinical information about the patients. In the study, 132 specimens from 102 patients undergoing evaluation of anemia were analyzed. By using simple regression analysis, our results showed that the IRF has a weak but significantly positive correlation with ARC and with RPI, indicating that IRF is an additional useful parameter to evaluate the erythropoietic activity in anemia. Interpretation by integrating IRF and reticulocyte enumeration (ARC and RPI) provided useful information for further subclassification of anemia. Increased IRF (IRF > or = 0.23) and increased ARC generally indicated an adequate erythroid response to anemia. All but three specimens with an IRF less than 0.23 showed an RPI of 2 or less. These specimens were from patients with underlying diseases known to lead to decreased erythropoietic activity, predominantly chronic renal insufficiency. Specimens with a subnormal or normal ARC (with a corresponding RPI < or = 2) but with an IRF of more than 0.23 were from patients with various underlying conditions, including acute infection, iron deficiency anemia, human immunodeficiency virus infection, sickle disease with crisis, pregnancy, and myelodysplastic syndrome. Our results indicate that an IRF of 0.23 or less in patients with anemia reflects bone marrow that is nonresponsive or underresponsive to the anemia. Patients with an increased IRF (IRF > or = 0.23) may require further examination to clarify the cause of the anemia.
Sysmex R - 3000（日本神户东亚医用电子株式会社）通过对低、中、高荧光强度区域内网织红细胞的比例进行定量分析来评估网织红细胞的成熟度。我们将未成熟网织红细胞比例（IRF）定义为高荧光强度区域比例与中荧光强度区域比例之和。然后，我们通过将IRF与绝对网织红细胞计数（ARC）、网织红细胞生成指数（RPI）进行比较，并回顾患者的相关临床信息，研究了IRF在贫血评估中的临床意义。在该研究中，对102例接受贫血评估的患者的132份标本进行了分析。通过简单回归分析，我们的结果显示IRF与ARC和RPI呈弱但显著的正相关，表明IRF是评估贫血时红细胞生成活性的一个额外有用参数。综合IRF和网织红细胞计数（ARC和RPI）进行解读，为贫血的进一步亚分类提供了有用信息。IRF升高（IRF≥0.23）和ARC升高通常表明对贫血有足够的红系反应。除了3份IRF低于0.23的标本外，所有标本的RPI均为2或更低。这些标本来自已知会导致红细胞生成活性降低的基础疾病患者，主要是慢性肾功能不全患者。ARC低于正常或正常（相应RPI≤2）但IRF高于0.23的标本来自患有各种基础疾病的患者，包括急性感染、缺铁性贫血、人类免疫缺陷病毒感染、镰状细胞病危象、妊娠和骨髓增生异常综合征。我们的结果表明，贫血患者的IRF为0.23或更低反映骨髓对贫血无反应或反应不足。IRF升高（IRF≥0.23）的患者可能需要进一步检查以明确贫血的原因。
