Label-free SERS assay combined with multivariate spectral data analysis for lamotrigine quantification in human serum

Considering the need for a more time and cost-effective method for lamotrigine (LTG) detection in clinics we developed a fast and robust label-free assay based on surface-enhanced Raman scattering (SERS) for LTG quantification from human serum. The optimization and application of the developed assay is presented  showing the: (i) exploration of different methods for LTG separation from human serum; (ii) implementation of a molecular adsorption step on an ordered Au nanopillar SERS substrate; (iii) adaptation of a fast scanning of the SERS substrate, performed with a custom-built compact Raman spectrometer; and (iv) development of LTG quantification methods with univariate and multivariate spectral data analysis. Our results showed, for the first time, the SERS-based characterization of LTG and its label-free identification in human serum. We found that combining a miniaturized solid phase extraction, as sample pre-treatment with the SERS assay, and using a multivariate model is an optimal strategy for LTG quantification in human serum in a linear range from 9.5 to 75 μM, with LoD and LoQ of 3.2 μM and 9.5 μM, respectively, covering the suggested clinical therapeutic window. We also showed that the developed assay allowed for quantifying LTG from human serum in the presence of other drugs, thereby demonstrating the robustness of label-free SERS. The sensing approach and instrumentation can be further automated and integrated in devices that can advance the drug monitoring in real clinical settings.

'You're never pregnant in the same way again': prior early pregnancy loss influences need for health care and support in subsequent pregnancy

STUDY QUESTION

What are couples' needs for health care and support in a subsequent pregnancy after prior early pregnancy loss (PL) and how do needs change across the pregnancy?

SUMMARY ANSWER

Couples described unmet needs for pregnancy care in the first 20 weeks of pregnancy and were more satisfied with the care provided during the remainder of the pregnancy.

WHAT IS KNOWN ALREADY

Despite early PL being common (∼25% of pregnancies), there is a paucity of research to guide practice to optimize treatment and support future pregnancies. There has been low priority for the issue in research and a pervasive acceptance that couples should 'just try again' after experiencing PL. Women with prior PL report increased anxiety during the first trimester of pregnancy compared to those without previous PL. No longitudinal studies explore what couples' needs are throughout the pregnancy and how these needs shift across time.

STUDY DESIGN SIZE DURATION

This was a qualitative longitudinal dyadic (joint) interview study. In total, 15 couples who were pregnant after a prior PL were interviewed four times over their pregnancy. Couples were recruited from the Copenhagen Pregnancy Loss Cohort Research Programme. Interviews were held in person at the hospital or university, or online. Interviews ranged from 20 to 91 min (mean = 54 min).

PARTICIPANTS/MATERIALS SETTING METHODS

Inclusion criteria included couples with one to two prior early PL(s) who self-reported a new pregnancy and were willing to be interviewed together and in English. Couples were interviewed four times: after a positive pregnancy test and once in each trimester. Interviews were transcribed and data were analysed using thematic analysis to compare and contrast needs of the couples at each of the four time periods in the pregnancy and across the entire pregnancy. One same-sex couple and 14 heterosexual couples participated.

MAIN RESULTS AND THE ROLE OF CHANCE

Couples' needs were categorized into two main longitudinal themes across the pregnancy, divided by the 20-week scan. Within each longitudinal theme, there were two themes to represent each time period. In the longitudinal theme 'The first 20 weeks: a 'scary' gap in care' there were two themes: Positive pregnancy test: 'Tell them it's not the same pregnancy' and First trimester: 'We craved that someone was taking care of us'. The standard pregnancy care offered in the public healthcare system in Denmark includes a scan at 12 and 20 weeks. While all couples wished for additional access to scans and monitoring of the foetus in early pregnancy to provide reassurance and detect problems early, they described considerable variation in the referrals and care they were offered. Both partners expressed a high degree of worry and anxiety about the pregnancy, with pregnant women in particular describing 'surviv[ing] from scan to scan' in the early weeks. Couples took scans wherever offered or paid for comfort scans, but this resulted in fragmented care. Instead, they wished for continuity in care, and acknowledgement and sensitivity that a pregnancy after PL is not the same as a first pregnancy. In the longitudinal theme 'The second 20 weeks: Safety in the care system' there were two themes: Second trimester: 'I think we are in good hands' and Third trimester: 'It's more of a 'nice to know' everything is OK than a 'need to know'. Couples reported their distress was lower and overall needs for care were met during this time. They expressed general satisfaction with regular or extended antenatal support although, as in the first 20 weeks, additional acknowledgement and sensitivity regarding their history of PL was desired. Couples said they felt more secure given that they had access to a 24-hour telephone support by midwife/nurse if they had any concerns or questions.

LIMITATIONS REASONS FOR CAUTION

Participants were self-selected from an ongoing cohort study of patients presenting at hospital with PL. Single women were not included in the study. This study was limited to data collection in Denmark; however, other countries with public healthcare systems may have similar offerings with regard to their provision of antenatal care, care provided in recurrent pregnancy loss (RPL) clinics and the availability of private scans.

WIDER IMPLICATIONS OF THE FINDINGS

The findings underscore that an early PL creates an increased need for monitoring and care in a subsequent pregnancy. This study highlights a gap in pregnancy care for those with a history of PL given that their need for monitoring and support is high in the early weeks of a new pregnancy before they have access to antenatal care, and before they have had multiple PLs and can be referred to the RPL unit.

STUDY FUNDING/COMPETING INTERESTS

This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 101028172 for E.K. The Copenhagen Pregnancy Loss Cohort is funded by a grant from the BioInnovation Institute Foundation. H.S.N. has received scientific grants from Freya Biosciences, Ferring Pharmaceuticals, BioInnovation Institute, Ministry of Education, Novo Nordisk Foundation, Augustinus Fonden, Oda og Hans Svenningsens Fond, Demant Fonden, Ole Kirks Fond, and Independent Research Fund Denmark. H.S.N. received personal payment or honoraria for lectures and presentations from Ferring Pharmaceuticals, Merck, Astra Zeneca, Cook Medical, Gedeon Richter, and Ibsa Nordic. All other authors declare no competing interests.