Department of Internal Medicine II, Infectious Diseases, Pneumology, Rheumatology, Innsbruck Medical University, Innsbruck, Austria.
Division of Biological Chemistry, Biocenter, Innsbruck Medical University, Innsbruck, Austria.
Influenza Other Respir Viruses. 2019 Nov;13(6):603-609. doi: 10.1111/irv.12677. Epub 2019 Sep 6.
Seasonal influenza is an important cause of morbidity and mortality worldwide. Immune activation after stimulation with interferon-gamma leads to increased production of neopterin but also results in increased tryptophan catabolism through indoleamine 2,3-dioxygenase (IDO). Our pilot study determined neopterin serum levels and IDO activity in patients with influenza infection and investigated whether neopterin is linked to clinical outcome parameters (mortality ≤30 days, acute cardiac events (ACE) length of hospitalization, ICU admission).
Neopterin concentrations were analyzed in serum samples of 40 patients with a confirmed diagnosis of influenza infection and in-hospital treatment for >24 hours. Data were compared to values of 100 healthy blood donors and 48 age-matched pneumonia patients. In a subgroup of 14 patients, tryptophan and kynurenine concentrations, as well as kynurenine-to-tryptophan ratio, were analyzed.
In all influenza patients, neopterin concentrations were increased and significantly higher compared to those determined in patients with pneumonia and healthy controls. Positive correlations between the duration of hospitalization and neopterin were found. Significantly higher levels of kynurenine, kynurenine-to-tryptophan ratio, and lower levels of tryptophan were seen in influenza patients compared to healthy controls.
Neopterin seems to be related to the course of the disease and could be a valuable biomarker to identify patients at an elevated risk of a worsened outcome; however, further prospective validation studies are needed to support the here presented preliminary results.
季节性流感是全球发病率和死亡率的重要原因。干扰素-γ刺激后的免疫激活导致新蝶呤的产生增加,但也通过吲哚胺 2,3-双加氧酶(IDO)导致色氨酸分解代谢增加。我们的初步研究确定了流感感染患者的新蝶呤血清水平和 IDO 活性,并研究了新蝶呤是否与临床结局参数(30 天内死亡率、急性心脏事件(ACE)住院时间、入住 ICU)相关。
分析了 40 例确诊流感感染并住院治疗>24 小时的患者的血清样本中的新蝶呤浓度,并与 100 名健康献血者和 48 名年龄匹配的肺炎患者的数值进行比较。在 14 例患者的亚组中,分析了色氨酸和犬尿氨酸浓度以及犬尿氨酸与色氨酸的比值。
所有流感患者的新蝶呤浓度均升高,明显高于肺炎患者和健康对照组。住院时间与新蝶呤之间存在正相关。与健康对照组相比,流感患者的犬尿氨酸、犬尿氨酸与色氨酸的比值显著升高,而色氨酸水平显著降低。
新蝶呤似乎与疾病的病程有关,可能是识别病情恶化风险增加的患者的有价值的生物标志物;然而,需要进一步的前瞻性验证研究来支持这里提出的初步结果。