Sickle cell disease is a somewhat ambiguous term, sometimes used as a synonym for sickle cell anemia and sometimes as a generic term, encompassing also compound heterozygous states characterized by clinicopathological features that result from sickle cell formation. There are at least 13 compound heterozygous states of relevance, the most common being sickle cell/β thalassemia, sickle cell/hemoglobin C disease, and sickle cell/hemoglobin D disease. The thalassemia may be β⁰ or β⁺. The hemoglobin D is specifically hemoglobin D-Punjab/D-Los Angeles. In addition, rarely the phenotype of sickle cell disease results from heterozygosity for a variant hemoglobin with a second mutation in a β^S gene, specifically S-Oman, S-Antilles, and hemoglobin Jamaica Plain.

The hemoglobin concentration (Hb) in sickle cell anemia is typically 60–100 g/L with the blood film (top left, all images May–Grünwald–Giemsa, ×100 objective) showing sickle cells boat-shaped cells, target cells, features of hyposplenism (Howell–Jolly bodies, Pappenheimer bodies, large platelets), nucleated red blood cells, polychromasia and sometimes irregularly contracted cells or linear fragments. Some compound heterozygous states, for example, SD (top center), have hematological features very similar to those of sickle cell anemia.¹ Others differ. Microcytosis and hypochromia are additional features in sickle cell/β thalassemia (top right). Sickle cell/hemoglobin C disease also differs. The Hb tends to be higher and the blood film may show distinctive SC poikilocytes when the crystallization of hemoglobin C and polymerization of hemoglobin S occur in the same cell²; hemoglobin C crystals may also be present (bottom left and center). A distinctive poikilocyte is also associated with hemoglobin S-Oman in heterozygotes (bottom right), homozygotes, and compound heterozygotes; these poikilocytes have been referred to as Napolean hat cells.

The different types of sickle cell disease differ in their clinicopathological characteristics and disease outcomes. It is, therefore, important that the heterogeneity is recognized and that articles in scientific journals and presentations at congresses make clear in what sense the term “sickle cell disease” is being used.³

镰状细胞病是一个有点含糊的术语，有时用作镰状细胞性贫血的同义词，有时用作通用术语，还包括以镰状细胞形成导致的临床病理特征为特征的复合杂合状态。至少有 13 种相关的复合杂合状态，最常见的是镰状细胞/β 地中海贫血、镰状细胞/血红蛋白 C 病和镰状细胞/血红蛋白 D 病。地中海贫血可能是β ⁰或β ⁺ 。血红蛋白D具体是血红蛋白D-旁遮普/D-洛杉矶。此外，镰状细胞病的表型很少是由β ^S基因第二次突变的变异血红蛋白杂合性引起的，特别是 S-Oman、S-Antilles 和 Jamaica Plain 血红蛋白。

镰状细胞性贫血的血红蛋白浓度 (Hb) 通常为 60–100 g/L，血涂片（左上，所有图像 May–Grünwald–Giemsa，×100 物镜）显示镰状细胞、船形细胞、靶细胞、特征脾功能减退症（Howell-Jolly 小体、Pappenheimer 小体、大血小板）、有核红细胞、多染性，有时还有不规则收缩的细胞或线性碎片。一些复合杂合状态，例如 SD（顶部中心），具有与镰状细胞性贫血非常相似的血液学特征。 ¹其他不同。小红细胞增多症和低色素症是镰状细胞/β地中海贫血的其他特征（右上）。镰状细胞/血红蛋白 C 病也有所不同。当血红蛋白C的结晶和血红蛋白S的聚合发生在同一细胞内时，Hb往往较高，血涂片可显示独特的SC异形细胞² ；还可能存在血红蛋白 C 晶体（左下和中心）。在杂合子（右下）、纯合子和复合杂合子中，独特的异形细胞也与血红蛋白 S-Oman 相关。这些异形细胞被称为拿破仑帽细胞。

不同类型的镰状细胞病的临床病理特征和疾病结果不同。因此，重要的是要认识到异质性，科学期刊上的文章和大会上的演讲要明确“镰状细胞病”一词的使用意义。 ³