Youssef Mervat A M, Zahran Asmaa M, Hussien Al Montasser, Elsayh Khalid I, Askar Eman A, Farghaly Hekma Saad
a Children Hospital, Faculty of Medicine , Assiut University , Egypt.
b Clinical Pathology Department, South Egypt Cancer Institute , Assiut University , Assiut , Egypt.
Paediatr Int Child Health. 2019 May;39(2):111-118. doi: 10.1080/20469047.2018.1528755. Epub 2018 Oct 30.
: Vitamin D has regulatory effects on different cells of the immune system and low levels are associated with several immune-mediated diseases. : To investigate the association between neonatal 25-hydroxy vitamin D (25-OHD) level and the expression of lymphocyte activation markers (HLA-DR, CD69, CD25, CD45RA) on T-lymphocyte subpopulations and its impact in neonatal infection. : 25-OHD level was measured in the cord blood of 56 neonates and their mothers using an enzyme immune-assay method. Based on the 25-OHD level, infants were categorised into four groups: severe deficiency (7), moderate deficiency (21), mild deficiency (15) and normal 25-OHD level (13). Mothers were classified into deficient (18), insufficient (21) and normal levels (17). T-lymphocyte subpopulations and lymphocyte activation markers were investigated using flow cytometry. : There was a positive correlation between maternal and cord blood 25-OHD levels (= 0.503, = 0.001). The group with severe 25-OHD deficiency had the significantly lowest level of total lymphocytes, CD3+ T lymphocytes, CD4+ T-helper and CD8+ T-cytotoxic lymphocytes and CD4+CD45RA+ naïve T-cells compared with the other groups. The frequencies of CD8+CD25+, CD4+CD25+ and CD4+HLA-DR+ activated T-lymphocytes were significantly lower in the severe, moderate and mild deficiency groups than in the normal group. Seven of 43 (16.27%) infants with 25-OHD deficiency were admitted with sepsis to the neonatal intensive care unit and there were no cases of sepsis in the normal 25-OHD group. : Vitamin D deficiency is associated with a reduction of lymphocyte subsets and altered T-lymphocyte activation which are considered to be risk factors for neonatal infection.
维生素D对免疫系统的不同细胞具有调节作用，低水平的维生素D与多种免疫介导的疾病相关。
为了研究新生儿25-羟维生素D（25-OHD）水平与T淋巴细胞亚群上淋巴细胞活化标志物（HLA-DR、CD69、CD25、CD45RA）表达之间的关联及其对新生儿感染的影响。
采用酶免疫分析法测定了56例新生儿及其母亲脐带血中的25-OHD水平。根据25-OHD水平，将婴儿分为四组：严重缺乏组（7例）、中度缺乏组（21例）、轻度缺乏组（15例）和25-OHD水平正常组（13例）。母亲分为缺乏组（18例）、不足组（21例）和正常水平组（17例）。采用流式细胞术研究T淋巴细胞亚群和淋巴细胞活化标志物。
母亲和脐带血25-OHD水平之间存在正相关（r = 0.503，P = 0.001）。与其他组相比，25-OHD严重缺乏组的总淋巴细胞、CD3 + T淋巴细胞、CD4 + T辅助细胞和CD8 + T细胞毒性淋巴细胞以及CD4 + CD45RA + 初始T细胞水平显著最低。严重、中度和轻度缺乏组中CD8 + CD25 +、CD4 + CD25 + 和CD4 + HLA-DR + 活化T淋巴细胞的频率显著低于正常组。43例（16.27%）25-OHD缺乏的婴儿中有7例因败血症入住新生儿重症监护病房，25-OHD水平正常组无败血症病例。
维生素D缺乏与淋巴细胞亚群减少和T淋巴细胞活化改变有关，这些被认为是新生儿感染的危险因素。
