Athanasiou Labrini V, Tsokana Constantina N, Pardali Dimitra, Moraitou Katerina Adamama
Department of Medicine, Faculty of Veterinary Medicine, University of Thessaly, Karditsa, Greece.
Department of Microbiology and Parasitology, Faculty of Veterinary Medicine, University of Thessaly, Karditsa, Greece.
Top Companion Anim Med. 2018 Dec;33(4):141-146. doi: 10.1053/j.tcam.2018.06.001. Epub 2018 Jun 3.
Histograms, which are an integral part of the automated complete blood count, are now available through most of the automatic hematology analyzers used in veterinary clinical practice. Data concerning the size and number of blood cells are graphically presented in histograms, and their variations are also illustrated. Important information that is not apparent from numerical results are sometimes provided by histograms. Histograms are also referred to as frequency distribution curves and are essentially graphs resulting from the placement of the sizes of cells on the x-axis and the number of cells on the y-axis. Typically, automated analyzers provide histograms for each class of blood cells, that is, for erythrocytes, leukocytes, and platelets. Thus, when the erythrocyte histogram shows asymmetry with a right shift, it means the size of the erythrocytes is greater than normal (macrocytosis); when it presents a left shift, the size of the erythrocytes is less than normal (microcytosis). When two peaks are found in the curve, two populations of erythrocytes coexist, as in the case of a blood transfusion or therapeutic response. In the leukocyte histogram, three peaks are found: the closest to the y-axis (left) corresponds to the lymphocytes, the middle to the monocytes, and the right to the polymorphonuclear cells (neutrophils, eosinophils, and basophils). Finally, in platelet histogram, asymmetry with a right shift suggests the presence of giant platelets or schistocytes. Although the histogram is not recommended as a stand-alone test, it allows the practitioner to observe abnormalities in the distribution curve that correspond to abnormalities in the size or number of cells, and to quickly make diagnostic or therapeutic decisions that are particularly important in emergencies.
直方图是自动全血细胞计数不可或缺的一部分，目前在兽医临床实践中使用的大多数自动血液分析仪均可提供。有关血细胞大小和数量的数据以直方图的形式直观呈现，同时也展示了它们的变化情况。直方图有时能提供从数值结果中不明显的重要信息。直方图也被称为频率分布曲线，本质上是一种图表，将细胞大小置于x轴，细胞数量置于y轴绘制而成。通常，自动分析仪会为每一类血细胞提供直方图，即红细胞、白细胞和血小板。因此，当红细胞直方图出现右移不对称时，意味着红细胞大小大于正常（大红细胞症）；当出现左移时，红细胞大小小于正常（小红细胞症）。当曲线中出现两个峰值时，表明存在两种红细胞群体，如输血或治疗反应的情况。在白细胞直方图中，会出现三个峰值：最靠近y轴（左侧）的对应淋巴细胞，中间的对应单核细胞，右侧的对应多形核细胞（中性粒细胞、嗜酸性粒细胞和嗜碱性粒细胞）。最后，在血小板直方图中，右移不对称表明存在巨大血小板或裂红细胞。尽管不建议将直方图作为独立检测手段，但它能让从业者观察到与细胞大小或数量异常相对应的分布曲线异常情况，并迅速做出在紧急情况下尤为重要的诊断或治疗决策。
