Watts C L, Bruce M C
Department of Pediatrics, Rainbow Babies & Childrens Hospital, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.
J Pediatr. 1995 Jul;127(1):113-22. doi: 10.1016/s0022-3476(95)70270-9.
To determine whether the concentration of secretory component (SC) in tracheal aspirate samples is less altered by changes in alveolar-capillary permeability and thus is a more reliable reference standard than albumin for the measurement of other components obtained by saline lavage in preterm infants.
A total of 1229 tracheal aspirate and 1530 blood samples were collected from 195 neonates to evaluate the effects of advancing postnatal and gestational age, resolution of acute respiratory distress syndrome (RDS), steroid therapy for chronic lung disease, and acute sepsis on tracheal aspirate SC and albumin levels. The tracheal aspirate and blood samples were analyzed by enzyme-linked immunosorbent assay techniques for SC and albumin concentrations.
The mean values for the concentrations of aspirate and plasma SC did not vary significantly during an 8-week study period (n = 100) and did not vary with either gestational age (23 to 36 weeks) or postnatal age. Albumin concentration significantly decreased in aspirate samples from 1.67 +/- 0.77 mg/dl at week 1 to 0.41 +/- 0.21 mg/dl at week 8 (p < 0.001), whereas serum levels increased from 2.65 +/- 0.36 to 2.99 +/- 0.54 gm/dl (p < 0.001), suggesting a decrease in alveolar-capillary leakage with advancing postnatal age. The concentration of SC in aspirate samples from 51 infants who received dexamethasone remained constant during the first week of therapy, whereas the concentration of albumin decreased from 1.33 +/- 0.91 mg/dl at the initiation of therapy to 0.51 +/- 0.34 mg/dl on treatment day 7 (p < 0.001). The onset of sepsis (n = 40) was not accompanied by a significant change in either aspirate SC or albumin levels. However, in infants who had a deterioration in respiratory status concomitant with the onset of sepsis (n = 10), the levels of aspirate albumin increased whereas serum levels decreased (p < 0.001), suggesting an increase in alveolar-capillary leakage; the levels of aspirate SC remained unaltered.
Secretory component may serve as a more valid reference protein for the standardization of tracheal aspirate collection in preterm infants during evaluation of changes in inflammatory mediators in disease states and therapeutic interventions that alter alveolar-capillary integrity.
确定气管吸出物样本中分泌成分（SC）的浓度是否受肺泡 - 毛细血管通透性变化的影响较小，从而在测量早产儿盐水灌洗获得的其他成分时，SC比白蛋白是更可靠的参考标准。
从195名新生儿中收集了总共1229份气管吸出物样本和1530份血液样本，以评估出生后和胎龄的增长、急性呼吸窘迫综合征（RDS）的缓解、慢性肺病的类固醇治疗以及急性败血症对气管吸出物SC和白蛋白水平的影响。通过酶联免疫吸附测定技术分析气管吸出物和血液样本中的SC和白蛋白浓度。
在为期8周的研究期间（n = 100），吸出物和血浆SC浓度的平均值无显著变化，且不随胎龄（23至36周）或出生后年龄而变化。吸出物样本中的白蛋白浓度从第1周的1.67±0.77mg/dl显著降至第8周的0.41±0.21mg/dl（p < 0.001），而血清水平从2.65±0.36gm/dl升至2.99±0.54gm/dl（p < 0.001），表明随着出生后年龄的增长肺泡 - 毛细血管渗漏减少。51名接受地塞米松治疗的婴儿的吸出物样本中SC浓度在治疗的第一周保持恒定，而白蛋白浓度从治疗开始时的1.33±0.91mg/dl降至治疗第7天的0.51±0.34mg/dl（p < 0.001）。败血症发作（n = 40）时，吸出物SC或白蛋白水平均无显著变化。然而，在败血症发作时呼吸状况恶化的婴儿（n = 10）中，吸出物白蛋白水平升高而血清水平降低（p < 0.001），表明肺泡 - 毛细血管渗漏增加；吸出物SC水平保持不变。
在评估疾病状态下炎症介质变化以及改变肺泡 - 毛细血管完整性的治疗干预措施时，分泌成分可能是早产儿气管吸出物收集标准化的更有效参考蛋白。
