Epidemiological evaluation of circulating levels of Copeptin and Fibronectin during pregnancy

Abstract

Background: Despite efforts to reduce problems associated with child and maternal health, the United Nations International Children’s Emergency Fund (UNICEF) corporation reported, that low and middle-income countries such as South Africa remains burdened with this issue. Based on this premise and the recent interest in copeptin (CPP) and fibronectin (Fn) as promising biomarkers in pregnancy related disorders, this study aimed to establish baseline levels of CPP and Fn in normotensive pregnancies complicated with HIV. Objectives: The objectives of this study were to determine circulating levels of CPP and Fn together with leucyl/cystinyl aminopeptidase (LNPEP) and cystatin C in normotensive pregnancies and to evaluate the association between these biomarkers and different demographic and clinical parameters (e.g. BMI, BP, Hb levels, maternal age and HIV status) throughout gestation. Methodology: This study stemmed from a previous cohort study conducted between 2015 and 2016 at the Cato Manor Primary Health Care facility in KwaZulu-Natal, South Africa. A total of 41 normotensive pregnant women aged between 18-45 years were selected through convenient sampling and evaluated at 10-20 weeks, 22-30 weeks and 32-38 weeks gestation. Archived serum samples were evaluated using Enzyme Linked Immunosorbent Assays to measure circulating levels of CPP and Fn. Additionally, markers of renal function were evaluated by measuring serum levels of cystatin C and LNPEP. Biomarker profiles and epidemiological and demographic characteristics were quantitatively analysed using STATA (version 15). P<0.05 was considered statistically significant. Results: Among the 41 participants, 28 were HIV positive of which 18 were on the Prevention of Mother to Child Transmission programme. A total of 23 participants were anaemic. Less than half the population were nulliparous and nulligravida. Fluctuations in biomarker concentrations were observed throughout pregnancy with CPP, LNPEP and cystatin C showing an overall decrease between 10 and 38 weeks gestation whilst Fn increased in the second gestational period and then decreased in the third gestational period. Slightly lower recordings were indicated for both systolic and diastolic blood pressures within the HIV positive group, except at gestational period 3, where systolic blood pressure was higher amongst the HIV positive group. On the other hand, haemoglobin levels were higher in the HIV positive group throughout pregnancy. Conclusion: The baseline levels of CPP, Fn, LNPEP and cystatin C measured in this study are expected to be used for comparison or as reference values to identify the presence of pregnancy related disorders in other studies of similar design and control groups.