A study of spectrum of pulmonary pathology and expression of thyroid transcription factor-1 during neonatal period.

Abstract

Neonatal period is the single most hazardous period of life. The major causes of neonatal death are prematurity and respiratory distress syndrome. We report a series of neonatal autopsies in our Neonatal Intensive Care Unit with special emphasis on pulmonary pathology. The spectrum of pathological changes in the lungs and thyroid transcription factor-1 (TTF-1) expression was studied in detail with reference to its spatial distribution. This study aims to analyze the causes of neonatal death with special attention to pulmonary pathology along with associated histopathological changes in lungs. We also evaluated the expression of TTF-1 at different levels of the airway. After taking consent and anthropometric measurements, autopsy was performed. Weights of all organs were taken, and histological sections were examined under hematoxylin and eosin stain. TTF-1 immunostaining was done on lung sections. Localization of TTF-1 was evaluated at the intrapulmonary level of terminal bronchioles (TBs), distal bronchioles, and alveoli. We performed a series of 25 autopsies in neonates. In our series, most of the neonates were preterm (64%), had low birth weight (44%), and died within the first 7 days of life (80%). Majority (60%) of the neonates died due to pulmonary causes, followed by septicemia (24%), congenital anomalies (12%), and birth injury (4%). Among the respiratory causes, hyaline membrane disease (HMD) was diagnosed in maximum number of cases (32%), followed by pneumonia (12%) and pulmonary hemorrhage (12%). The TTF-1 expression in TBs, distal airways, and alveoli was significantly reduced or absent in cases of HMD compared to the control group. In this study, we observed that HMD is the most common cause of perinatal death among respiratory disorders, and in this disease, the expression of TTF-1 is significantly reduced in TBs, distal airways, and alveoli compared to the control group.