Pediatrics and Neonatology Unit, University of Parma, Guglielmo da Saliceto Hospital, Piacenza, Italy.
Unit of Pediatrics, Department of Medicine and Surgery, University of Parma, Parma, Italy.
Front Endocrinol (Lausanne). 2023 Feb 2;14:1111445. doi: 10.3389/fendo.2023.1111445. eCollection 2023.
Serum alkaline phosphatase (ALP) and its isoenzymes reflect bone metabolism: ALP increases the ratio of inorganic phosphate to pyrophosphate systemically and facilitates mineralization as well as reduces extracellular pyrophosphate concentration, an inhibitor of mineral formation. On the contrary, low ALP activity is associated with reduction of bone turnover. ALP includes four isoenzymes depending on the site of tissue expression: intestinal ALP, placental ALP, germ cell ALP and tissue nonspecific ALP or liver/bone/kidney ALP. The bone isoenzyme (B-ALP) is involved in bone calcification and is a marker of bone turnover as a result of osteoblastic activity. ALP and its isoenzymes are crucial in the diagnostic process of all the forms of rickets.The most common cause of rickets is vitamin D nutritional deficiency. The aim of this review is to update on the role played by ALP serum concentrations as a relevant marker in thediagnosis and treatment of rickets. Indeed, the diagnosis of rickets is based on its clinical, radiological and laboratory characteristics. An elevated ALP level is one of the markers for the diagnosis of rickets in children, though it is also associated with bone formation process. ALP is also useful for the differentiation between rickets and other disorders that can mimic rickets because of their clinical and laboratory characteristics, and, together with other biochemical markers, is crucial for the differential diagnosis of the different forms of rickets. Age, severity and duration of rickets may also modulate ALP elevation. Finally, ALP measurements are useful in clinical and therapeutic follow-up.
血清碱性磷酸酶（ALP）及其同工酶反映骨代谢：ALP 增加无机磷酸盐与焦磷酸盐系统的比例，促进矿化并降低细胞外焦磷酸盐浓度，焦磷酸盐是矿化形成的抑制剂。相反，低 ALP 活性与骨转换减少有关。ALP 包括四种同工酶，取决于组织表达部位：肠道 ALP、胎盘 ALP、生殖细胞 ALP 和组织非特异性 ALP 或肝/骨/肾 ALP。骨同工酶（B-ALP）参与骨钙化，是成骨细胞活性导致骨转换的标志物。ALP 及其同工酶在所有佝偻病形式的诊断过程中都很重要。佝偻病最常见的原因是维生素 D 营养缺乏。本文旨在更新血清 ALP 浓度作为佝偻病诊断和治疗的相关标志物的作用。事实上，佝偻病的诊断基于其临床、放射学和实验室特征。升高的 ALP 水平是儿童佝偻病诊断的标志物之一，尽管它也与骨形成过程有关。ALP 还可用于区分佝偻病和其他因临床和实验室特征而类似于佝偻病的疾病，并且与其他生化标志物一起，对不同形式佝偻病的鉴别诊断至关重要。佝偻病的年龄、严重程度和持续时间也可能调节 ALP 升高。最后，ALP 测量值在临床和治疗随访中很有用。
