Detection of opioids in umbilical cord lysates: an antibody-based rapid screening approach

Abstract

In pregnancy, opioids may be used medically and also misused. We hypothesized that the umbilical cord (UC) could be a good screening tool for determining opioid exposure and improving medical care. One hundred and one UC, each with 50 associated ICD9/ICD10 codes were used. Using predictive pharmacokinetic analysis we determined that opioids could be detected since last ingestion prior to birth. The UC were lysed and screened using ELISA detecting multiple opioids and their metabolites. Statistical comparisons to obstetric and neonatal outcomes were performed. Although the commercial ELISA was less sensitive in UC than blood or urine, there was perfect method selectivity as compared to a subset of cords designated positive or negative by clinical diagnostics, so our results are accurate and reliable. Absolute quantitation was not possible because the antibody cross reacts with multiple compounds, but "low" or "high" levels of exposure were assigned. Prevalence of opioids was 11%, which reduced to 7% when caesarean-section births were eliminated. For non-caesarean-section infants adjusted for preterm birth, advanced maternal age and smoking (independent risk factors), opioids were significantly associated with intra-uterine growth restriction (p = 0.017) and admission to neonatal intensive care (p = 0.002). UC can be collected non-invasively and rapidly providing a reliable tools for semi-quantitative opioid screening using ELISA. Moreover, as UC are usually discarded collection presents few technical or safety concerns for staff or patients. Further development of this methodology may provide a rapid, non-invasive clinical screening tool to identify NAS and/or opioid use in late pregnancy.

Screening Pregnant Women and Their Neonates for Illicit Drug Use: Consideration of the Integrated Technical, Medical, Ethical, Legal, and Social Issues

“…Umbilical cord was found to be a suitable tissue for the screening of these drugs, and limits of detection were greatly improved compared to previously available methods. Recently, a commercial ELISA for detection of opioids was validated in umbilical cord tissues ( Knight et al, 2018 ). Absolute quantitation could not be determined due to cross reactivity in excess of 100% for certain opioid metabolites, but the method showed perfect selectivity for cords in the study that were deemed opioid positive by clinical diagnostics.…”

Detection and quantitation of non-steroidal anti-inflammatory drug use close to the time of birth using umbilical cord tissue

“…Umbilical cord tissue pieces were thawed at room temperature, wet-weight recorded, then mechanically homogenized 1:3 (w:v) in 100 mM Tris-HCl buffer containing 5 mM MgCl 2 (pH 7.4) and 2 mM phenylmethylsulfonylfluoride as previously described [ 35 , 37 ]. All samples were processed into lysates at the University of British Columbia in 2016 and archived at −80 °C for future studies.…”

“…Presence of a drug in fetal tissues demonstrates that some level of exposure is occurring, but there are no currently defined dose:concentration relationships that would make this process predictive of maternal ingestion or absolute fetal exposure levels. With our prior experience using reproductive tissues for detection and quantification of drugs, endo- and xenobiotics and their effects on reproductive outcomes [ [31] , [32] , [33] , [34] , [35] , [36] ], we developed the hypothesis that UC would be a reliable matrix for detecting NSAID use, more reflective of fetal NSAID exposure than maternal blood alone. In this study, we retrospectively screened 380 UC lysates for five of the most commonly used NSAIDs: diclofenac, ibuprofen, indomethacin, naproxen, and salicylic acid, to determine maternal ingestion of these drugs close to birth, fetal exposure, and relationships (if any) between NSAID use and obstetric and neonatal outcomes.…”

Intrauterine and Neonatal Exposure to Opioids: Toxicological, Clinical, and Medico-Legal Issues

“…Another disadvantage for these matrices, which is due to the quick elimination of most drugs, is the reduced ability to detect remote drug intakes [ 5 ]. The detection window is narrow in the case of urine, blood, oral fluids, and sweat, rendering these matrices to be not helpful in identifying sporadic use [ 5 , 6 , 7 , 8 , 9 ]. As such, testing a biological matrix with a long detection window would provide a better opportunity to identify drug exposure.…”

“…It must be noted that there are two methods of identifying drug users: self-reports or biological sample testing. Although no single approach can accurately determine the presence and quantity of drugs used during pregnancy, combining the toxicological examination with a structured interview could improve the identification of drug exposure [ 5 , 7 , 9 , 10 ]. Medical history derived from a self-report is a practical method for the purposes of identifying antenatal drug exposure.…”