A Novel Diagnostic Marker for the Severity of Bronchopulmonary Dysplasia in Very Low Birth Weight Infants: Interleukin-33

Abstract

Background: Bronchopulmonary dysplasia (BPD) is an important clinical problem for premature infants. Previously, some biomarkers associated with severity of BPD have been studied. In our study, we aimed to investigate the value of interleukin-33 (IL-33) levels as a new biomarker in the follow-up of BPD severity and response to treatment. Materials and Methods: Premature infants of <32 weeks of gestational age and birth weight <1,500 g were included in the study. Infants with BPD were divided into moderate and severe BPD groups. Infants without BPD were assigned as the control group. Cord blood samples were taken from both groups immediately after birth. In addition, blood samples were obtained at the time of diagnosis of BPD and after the end of hydrocortisone (HC) treatment to measure IL-33 values in the serum. Results: During the study period, a total of 192 infants were eligible: 96 infants in the BPD group and 96 in the control group. Cord IL-33 values were similar between control (1.29 ± 0.68 pg/mL) and BPD (moderate/severe) (1.31 ± 0.84 pg/mL) groups (P = 0.813). The levels of IL-33 were higher in BPD group (3.43 ± 0.98 pg/mL) than in the control group (0.98 ± 0.51 pg/mL) (P < 0.001). IL-33 values decreased significantly after HC treatment (pretreatment: 3.43 ± 0.98 pg/mL versus post-treatment: 2.97 ± 0.28 pg/mL) (P < 0.001). In addition, IL-33 levels were significantly higher in severe BPD (3.91 ± 1.22 pg/mL) than in moderate BPD (2.82 ± 0.74) group (P < 0.001). Conclusions: Although the IL-33 level was not predictive of the development of BPD immediately after birth, it may be used as a new biomarker to diagnose, monitor, and follow the response to treatment of BPD.