Background: Urinary tract infection (UTI) is common in pediatrics. Infection of the upper urinary tract may cause renal scarring, and subsequently renal failure and hypertension. Permanent renal damage has been suggested to be caused by the host inflammatory response. Therefore, it is crucial to understand the host defense mechanisms against such infection in order to make timely diagnosis. The aim of this study was to evaluate interleukin-6 (IL-6) and IL-8 as potential biomarkers in differentiating acute pyelonephritis (AP) from cystitis (Cys) in children.
Methods: Forty-three children (21 with AP and 22 with Cys) were included. Serum and urinary IL-6 and IL-8 were measured during the acute phase (within 12 hours of presentation) and the convalescent phase (8 weeks post-infection). Thirty-eight healthy children were included as controls.
Results: During the acute phase, the mean urinary IL-6 level in the Cys group was significantly higher than that in the controls (17.8 pg/mL vs 14.8 pg/mL, P=0.03), while the serum levels were significantly higher in both the Cys and AP groups than in the controls (19.5 pg/mL, 19.4 pg/mL, 15 pg/mL, P=0.005 and 0.02, respectively). During the convalescent phase, serum and urinary IL-6 levels were higher in patients than in controls. Urinary IL-8 levels were significantly higher in both the AP and Cys groups compared to controls (206.5 pg/mL, 291.8 pg/mL, 89.4 pg/mL, P=0.05 and 0.02, respectively) during the acute phase. Serum IL-8 was not significantly different between the 3 groups. Nonetheless, no significant differences were found between the AP and Cys groups, in urinary or serum levels of IL-6 or IL-8, during both phases.
Conclusion: IL-6 and IL-8 levels are elevated in patients with UTI. However, the levels did not differentiate between AP and cystitis. Further studies are warranted to evaluate their roles as indicators of the site of UTIs.



中文翻译：

---

血清和尿液白细胞介素 6 和白细胞介素 8 水平不能区分儿童急性肾盂肾炎和下尿路感染

背景：尿路感染 (UTI) 在儿科中很常见。上尿路感染可能导致肾脏瘢痕形成，进而导致肾功能衰竭和高血压。永久性肾损伤被认为是由宿主炎症反应引起的。因此，了解宿主对此类感染的防御机制以便及时诊断至关重要。本研究的目的是评估白细胞介素 6 (IL-6) 和 IL-8 作为区分儿童急性肾盂肾炎 (AP) 和膀胱炎 (Cys) 的潜在生物标志物。
方法：包括 43 名儿童（21 名 AP 和 22 名 Cys）。在急性期（出现后 12 小时内）和恢复期（感染后 8 周）测量血清和尿 IL-6 和 IL-8。包括 38 名健康儿童作为对照。
结果：在急性期，Cys 组的平均尿 IL-6 水平显着高于对照组（17.8 pg/mL vs 14.8 pg/mL，P=0.03），而血清水平显着高于对照组。 Cys 和 AP 组高于对照组（分别为 19.5 pg/mL、19.4 pg/mL、15 pg/mL，P=0.005 和 0.02）。在恢复期，患者的血清和尿 IL-6 水平高于对照组。在急性期，AP 组和 Cys 组的尿 IL-8 水平均显着高于对照组（分别为 206.5 pg/mL、291.8 pg/mL、89.4 pg/mL、P=0.05 和 0.02）。血清IL-8在3组之间没有显着差异。尽管如此，在两个阶段，AP 组和 Cys 组之间在 IL-6 或 IL-8 的尿或血清水平方面没有发现显着差异。
结论： UTI患者IL-6和IL-8水平升高。然而，这些水平没有区分 AP 和膀胱炎。需要进一步的研究来评估它们作为尿路感染部位指标的作用。