Neonatal high-permeability pulmonary edema based on serial cytokine profiles and KL-6 in serum: case report

Tools for assessing lung fluid in neonates with respiratory distress

Background

Transient tachypnea of the newborn (TTN), as a common cause of neonatal respiratory distress, needs to be distinguished from respiratory distress syndrome (RDS). Various modalities such as lung ultrasonography, cytokine analysis, and electrical cardiometry for the evaluation of lung fluid can be helpful for the exact diagnosis, however, clinical diagnosis has been applied mainly. This study aimed to evaluate the usefulness of the various tools for the diagnosis of TTN and RDS in neonates.

Methods

This study evaluated 22 late-preterm and term infants admitted to the neonatal intensive care unit of Gangnam Severance Hospital because of respiratory distress. Total 9 neonates were diagnosed with TTN and 13 had RDS. In addition to chest radiography, the LUS score was calculated by a neonatologist using the portable ultrasound device. Cytokines in the bronchoalveolar lavage fluid supernatant were measured. Thoracic fluid content was measured using an electrical cardiometry device.

Results

We enrolled 22 patients with median gestational age, 37.1 weeks, and birth weight 3100 g. There is no difference in patient characteristics between RDS and TTN group. Lung ultrasound score was significantly higher in RDS than TTN (11 vs 6, p = 0.001). Score 0 is shown in all infants with TTN. Score 1 is shown as significantly more in RDS than TTN. Between the TTN and RDS groups, there were significant differences in the changes of thoracic fluid content (2 vs − 1.5, p < 0.001), IL-1β levels (2.5 vs 11.3, p = 0.02), and TNF-α levels (20.1 vs 11.2, p = 0.04).

Conclusion

We found lung ultrasound and electrical cardiometry to be reliable diagnostic tools for assessing infants with respiratory distress among late-preterm and term infants. Further studies with a large number of patients are needed to confirm their clinical usefulness.

Diagnostic value of KL-6 in idiopathic interstitial pneumonia

Background

Idiopathic interstitial pneumonia (IIP) can induce type II alveolar epithelial cell proliferation and pulmonary basement membrane damage and subsequent release of Krebs von den Lungen-6 antigen (KL-6) to the bloodstream. This study investigated the diagnostic and prognostic value of serum KL-6 levels for IIP.

Methods

One hundred five patients with lung disease were divided into IIP (n=75) and non-IIP groups (n=30) according to pathological and computed tomography findings. Serum KL-6 levels were evaluated in blood samples from all subjects. Nineteen IIP group patients were also subjected to a longitudinal study of disease progression and serum KL-6 levels over time.

Results

Serum KL-6 levels were significantly higher in the IIP group vs. the non-IIP group [1,096.0 (565.0-1,544.0) vs. 226.0 (173.5-346.5) U/mL; P<0.01]. Within the IIP group, serum KL-6 levels differed significantly between patients with and without concomitant disease or pulmonary infection (Z=-2.475, P=0.013). In a receiver operating characteristic (ROC) curve analysis, the area below the curve for serum KL-6 was 0.911 [95% confidence interval (CI): 0.847-0.975, P<0.001], indicating a good diagnostic performance for IIP, with a cut-off level of 485 U/mL, sensitivity of 85.33%, specificity of 90.00%, positive predictive value (PPV) of 95.52%, negative predictive value (NPV) of 71.05%, and Kappa value of 0.70. Accordingly, the serum KL-6 and clinical diagnostic results were consistent. Moreover, in the longitudinal study, the serum KL-6 levels differed significantly from before to after treatment in patients with exacerbated or improved disease (P=0.004 and P=0.043, respectively), whereas no obvious changes were observed in patients with stable disease (P=0.692).

Conclusions

The serum KL-6 level is a valuable and significant diagnostic marker of IIP and a useful predictor of clinical prognosis.