Department of Clinical Science, Intervention and Technology, Division of Paediatrics, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden.
Department of Microbiology, Tumour and Cell Biology, Division of Clinical Microbiology, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden.
Acta Paediatr. 2019 Mar;108(3):551-556. doi: 10.1111/apa.14499. Epub 2018 Aug 7.
Vitamin D stimulates production of the endogenous antimicrobial peptides cathelicidin and β-defensin-2, which are expressed in the urinary tract. We investigated vitamin D status and levels of cathelicidin and β-defensin-2 and their association with urinary tract infection (UTI).
The study included 120 children under three years of age: 76 children with UTIs and 44 otherwise healthy children with congenital hydronephrosis. Serum 25-hydroxycholecalciferol levels were measured by direct competitive electro-chemiluminescence immunoassay, and plasma cathelicidin and β-defensin-2 concentrations were analysed by enzyme-linked immunosorbent assay.
We found that vitamin D insufficiency and deficiency are prevalent in young children (21%). Serum vitamin D levels negatively correlated with age and were significantly lower in girls. Levels of vitamin D positively correlated with levels of cathelicidin but not with β-defensin-2. Low concentrations of vitamin D were associated with UTIs in girls, but we did not see any correlation with the recurrence of infection at one-year follow-up.
Vitamin D deficiency is common and may prove to be a risk factor for UTIs especially in girls. We hypothesise that adequate supplementation with vitamin D may become a way to prevent first-time UTIs.
维生素 D 可刺激内源性抗菌肽（如 cathelicidin 和 β-防御素-2）的产生，这些肽在尿路中表达。我们研究了维生素 D 状况以及 cathelicidin 和 β-防御素-2 的水平，及其与尿路感染（UTI）的关系。
该研究纳入了 120 名三岁以下的儿童：76 名患有 UTI 的儿童和 44 名患有先天性肾积水但健康的儿童。采用直接竞争电化学发光免疫分析法检测血清 25-羟胆钙化醇水平，采用酶联免疫吸附试验分析血浆 cathelicidin 和 β-防御素-2 的浓度。
我们发现，维生素 D 不足和缺乏在幼儿中很常见（21%）。血清维生素 D 水平与年龄呈负相关，且女孩中的水平明显更低。维生素 D 水平与 cathelicidin 水平呈正相关，但与 β-防御素-2 无关。低浓度的维生素 D 与女孩的 UTI 相关，但我们未发现其与一年后感染复发有任何相关性。
维生素 D 缺乏很常见，可能成为 UTI 的一个危险因素，尤其是在女孩中。我们假设，充足的维生素 D 补充可能成为预防首次 UTI 的一种方法。
