Identification of risk factors, pathological changes and protein biomarkers of spontaneous preterm labour with intact membranes of Malay patients

Each year, there are about 15 million babies born prematurely and one million babies die from the syndrome. In Malaysia, 12.3% of the babies are born prematurely yearly and the Malay has the highest incidence rate (74.7%). Spontaneous preterm labour with intact membranes (sPTL-IM) is one of the most common types of preterm birth (PTB). To date, the reliability of all available prediction tools to predict pregnant women at risk of sPTL-IM is low. Therefore, the search for a more reliable screening tool is urgently needed. This study applies risk factor assessments as well as placental pathological and comparative proteome studies among Malay pregnant women in Malaysia to understand the pathophysiology of sPTL-IM syndrome for the improvement or development of a novel screening tool. To prove the former, a case-control study using secondary data (medical records) was conducted on 537 cases and 1022 controls to identify the risk factors associated with sPTL-IM-birth in Malay patients. Among the cases, preeclampsia, placenta previa, history of PTB, and teenage pregnancy are significantly more prevalent. Remarkably, 54.9% of sPTL-IM-births were due to spontaneous unexplained preterm labour with intact membranes (suPTL-IM). Among these Malay pregnant women, 16.6% were in potentially high-risk pregnancy. The resulting analyses have drawn attention to investigate the placental pathological changes and molecular impairment of suPTL-IM-high-risk-birth, since less attention has been paid by other researchers in this context. Pathological evaluation of the haematoxylin and eosinstained suPTL-IM-placenta sections revealed a higher degree of inflammation in the membranes compared to control. Prior to the study of molecular impairment of suPTLIM- delivered placentae, a total of 12 mechanical and chemical protein extraction protocols were carried out to determine the best protein extraction condition to extract proteins from placental cotyledon. The results demonstrated that DNase/lithium chloride-dense sucrose homogenisation coupled dichloromethane-methanol precipitation method exhibited the best extraction efficacy with excellent reproducibility. The extraction method was then applied to extract proteins from both foetal and maternal originated placental cotyledons and the differential protein expression profiles of suPTLIM- delivered placentae were studied using a gel-based proteomics approach. Two proteins were overexpressed, and nine proteins were underexpressed by at least 2-folds in the foetal side of suPTL-IM-placenta. Whereas in the maternal side of suPTL-IMplacenta, two proteins were underexpressed by at least 2-folds. These proteins are involved in four distinct functional classes namely inflammation, oxidative stress, anticoagulation, and extracellular matrix remodelling. These results had contributed to the selection of a panel biomarkers which consisted of vimentin, cytokeratin 8, S 100A9, peroxiredoxin 3, and protein PP4-X. These proteins are known to be related to maintenance of placental cytoplasm architecture, oxidative stress and anticoagulation and were successfully validated using Western blotting technique. The findings suggest a ‘defined’ set of risk factors associated with sPTL-IM but lack of predictive value. Furthermore, proteins involved in inflammation, oxidative stress, anticoagulation, and extracellular matrix remodelling functions could be used as potential biomarkers for screening of suPTL-IM-birth in high risk pregnancies. This study suggests that the differentially expressed proteins found in the suPTL-IM placenta provide an important first step towards developing a multiplex biomarker-based screening tool for early prediction of suPTL-IM-birth.

Text FPSK(p) 2019 13 ir.pdf Download (1MB)

Actions (login required)

View Item