探讨急性血源性骨髓炎(AHO)患儿血清维生素C水平及其影响因素。

选择2020年1月至2023年3月济南市儿童医院收治采取手术治疗的64例AHO患儿为研究对象。回顾性收集这64例患儿的性别、年龄、病灶部位及其入院时实验室检测结果，包括血常规、凝血功能、血清维生素C水平、C反应蛋白(CRP)、红细胞沉降率等。血清维生素C水平采用超高效液相色谱-串联质谱分析法进行定量检测。采用Mann-Whitney U检验对不同临床特征AHO患儿血清维生素C水平进行比较。采用Spearman秩相关性分析方法，对AHO患儿相关实验室检测结果与其血清维生素C水平进行相关性分析。绘制AHO患儿相关实验室检测结果预测其发生血清维生素C缺乏症的受试者工作特征(ROC)曲线，并计算曲线下面积(AUC)，分析AHO患儿相关实验室检测结果，对预测其发生血清维生素C缺乏症的准确性。本研究遵循的程序符合济南市儿童医院伦理委员会制定的伦理学标准，并得到该伦理委员会批准(审批文号：SDFE-IRB/T-2023080)。

①本组64例AHO患儿均伴游走性或刺激性疼痛症状，中位年龄为5.9岁，男、女性患儿分别为34、30例，血清维生素C中位水平为3.10 μg/mL(较正常值降低)。②对不同临床特征AHO患儿血清维生素C水平进行比较的结果显示，男性患儿血清维生素C水平，低于女性患儿；AHO病灶位于长管状骨患儿的血清维生素C水平，低于非长管状骨患儿，并且差异均有统计学意义(Z＝－2.22、P＝0.026，Z＝－2.42、P＝0.016)。③Spearman秩相关性分析结果显示，AHO患儿白细胞计数、中性粒细胞计数、纤维蛋白原水平、红细胞沉降率与其血清维生素C水平呈负相关关系(r_s＝－0.412、P＝0.001，r_s＝－0.424、P＝0.001，r_s＝－0.246、P＝0.049，r_s＝－0.267、P＝0.033)。④ROC曲线分析结果显示，中性粒细胞计数预测AHO患儿血清维生素C缺乏症的AUC为0.753(95%CI：0.629～0.852，P<0.001)，根据约登指数最大原则，其预测AHO患儿血清维生素C缺乏症的最佳临界值为7.9×10⁹/L，此时对AHO患儿血清维生素C缺乏症诊断的敏感度为65.2%，特异度为83.3%。

AHO患儿血清维生素C水平明显降低。AHO患儿为男性、AHO病灶位于长管状骨、游走性或刺激性疼痛、中性粒细胞计数>7.9×10⁹ /L，可能是导致AHO患儿血清维生素C缺乏症的危险因素。

To explore the serum vitamin C level in children with acute hematogenous osteomyelitis (AHO) and its influencing factors.

A total of 64 AHO children who underwent surgery at Jinan Children′s Hospital from January 2020 to March 2023 were selected as research subjects. Gender, age, lesion site, and laboratory test results at admission, including routine blood tests, coagulation functions, serum vitamin C levels, C-reactive protein (CRP), and erythrocyte sedimentation rate were retrospectively collected. Serum vitamin C levels were quantitatively analyzed by ultra-high-performance liquid chromatography-tandem mass spectrometry. Comparison of serum vitamin C levels between AHO children with different clinical characteristics was performed by Mann-Whitney U test. Spearman rank correlation analysis was used to explore the correlation between laboratory test results and serum vitamin C levels. Receiver operating characteristic (ROC) curve of laboratory test results to predict the occurrence of serum vitamin C deficiency in AHO children was plotted, and area under the curve (AUC) was calculated to assess the accuracy of laboratory test results in predicting serum vitamin C deficiency in AHO children. The procedures followed in this study complied with the ethical standards established by the Ethics Committee of Jinan Children′s Hospital and received approval from the committee (Approval No. SDFE-IRB/T-2023080).

①Among 64 AHO children, all were accompanied by migratory or provocative pain symptoms, the median age was 5.9 years, with 34 males and 30 females, and the median serum vitamin C level was 3.10 μg/mL (lower than the normal range), and all were accompanied by pain symptoms. ②Results of the comparison of serum vitamin C levels in AHO children with different clinical characteristics showed that serum vitamin C level in male children was lower than that in female children, and serum vitamin C level in AHO children with lesions in long tubular bones was lower than that of children with lesions in non-long tubular bones, and both the differences were statistically significant (Z=-2.22, P=0.026; Z=-2.42, P=0.016). ③Spearman rank correlation analysis showed that the white blood cell count, neutrophil count, fibrinogen level, erythrocyte sedimentation rate in AHO children were negatively correlated with their serum vitamin C levels (r_s=-0.412, P=0.001; r_s=-0.424, P=0.001; r_s=-0.246, P=0.049; r_s=-0.267, P=0.033). ④ROC curve analysis showed that the AUC of neutrophil count in predicting serum vitamin C deficiency in AHO children was 0.753 (95%CI: 0.629-0.852, P<0.001). According to the principle of maximum Youden index, the optimal cutoff value for predicting serum vitamin C deficiency in AHO children was 7.9×10⁹/L, the sensitivity for diagnosis of serum vitamin C deficiency in AHO children was 65.2%, and the specificity was 83.3%.

The serum vitamin C level in AHO children is significantly decreased. Being male, having AHO lesions in long tubular bones, accompanied by migratory or provocative pain symptoms, and having a neutrophil count >7.9×10⁹ /L may be risk factors for serum vitamin C deficiency in AHO children.