The impact of thalidomide use in birth defects in Brazil

Potential developmental effects of licit and illicit substances in humans: An approach to risk-specific dose and incidence

Teratogens encompass any agent capable of causing a birth defect or elevating the incidence of defects within the population. This category includes substances like drugs, both legal and illegal. These substances cause congenital anomalies depending on the stage of development at the time of exposure, the dose, and the exposure time associated with the embryo. The most sensitive period is the embryonic stage, when the three leaflets give rise to tissues and organs. Susceptibility to teratogenesis decreases during the fetal phase but morphological and functional disturbance of the fetus may still occur. Substance use during pregnancy and its adverse effects are a public health problem and the lay population does not have access to this information. Particularly concerning is the period within the first six weeks of pregnancy, often before a woman realizes she is pregnant. Developmental data for many substances are simply not available, which makes the problem more serious. The aim of this study is to reflect on the teratogenic effects of licit and illicit substances in humans, focusing particularly on the dose that can induce malformations and their incidence in humans.

PregTox: A Resource of Knowledge about Drug Fetal Toxicity

Background

It is of vital importance to determine the safety of drugs. Pregnant women, as a special group, need to evaluate the effects of drugs on pregnant women as well as the fetus. The use of drugs during pregnancy may be subject to fetal toxicity, thus affecting the development of the fetus or even leading to stillbirth. The U.S. Food and Drug Administration (FDA) issued a toxicity rating for drugs used during pregnancy in 1979. These toxicity ratings are denoted by the letters A, B, C, D, and X. However, the query of drug pregnancy category has yet to be well established as electronic service.

Results

Here, we presented PregTox, a publicly accessible resource for pregnancy category information of 1114 drugs. The PregTox database also included chemical structures, important physico-chemical properties, protein targets, and relevant signaling pathways. An advantage of the database is multiple search options which allow systematic analyses. In a case study, we demonstrated that a set of chemical descriptors could effectively discriminate high-risk drugs from others (area under ROC curve reached 0.81).

Conclusions

PregTox can serve as a unique drug safety data source for drug development and pharmacological research.

Synthesis and application of methyl itaconate-anthracene adducts in configuration assignment of chiral secondary alcohols by 1H NMR

Novel chiral derivatising agents (CDAs) such as methyl itaconate-anthracene adducts (MIAs) were reported for the absolute configuration determination of chiral secondary alcohols by the ¹H NMR technique. These adducts were facilely prepared through well-known reactions, and furthermore, commercially available starting materials. According to these synthetic routes, the desired MIAs were afforded in 6 steps with 49% overall yield from dimethyl itaconate. Moreover, the represented MIAs provided significantly large differences of chemical shift values (Δδ^SR). No racemisation from the tertiary characteristics of the adjacent alpha carbon was observed.

Implementation of a Pregnancy Prevention Programme (PPP) with a Controlled Distribution System (CDS) for the Generic Teratogenic Phthalimides Thalidomide, Lenalidomide and Pomalidomide

Thalidomide (α-phthalimidoglutaride) was marketed in the 1950s and early 1960s; it was promoted as a sedative-hypnotic agent with minimal hangover. It was available in some countries as an over-the-counter medicine. Publications reporting profound teratogenic effects with thalidomide brought about major revisions to the monitoring of the safety of medicines. As a consequence of previously unrecognised teratogenic effects, it has been estimated that over 12,000 children were born with a range of defects and disabilities, including severe congenital anomalies. Notably, it has been hypothesised that around 40% of babies with thalidomide-induced malformations born during the 1950s and 1960s died in the neonatal period. The commonest causes of death were atresia of the small bowel, cardiac or renal malformations. Nevertheless, phocomelia (as a typical manifestation of thalidomide´s teratogenic effects) has been reported once again after thalidomide was approved for use in areas where leprosy is endemic. As a result, thalidomide embryopathy remains an important topic in countries such as Brazil. Nowadays thalidomide is approved around the world for the treatment of a wide range of conditions, including leprosy, Crohn's disease, multiple myeloma, and certain malignant solid tumours. Second-generation immunmodulatory drugs including lenalidomide and pomalidomide have received approval for use in the management of various forms of neoplastic disease. Based on clinical experience with thalidomide and its derivatives, learnings have been transferred to further research on a subset of substituted phthalimides each of which has a high risk of causing teratogenic effects. This group of phthalimides is classified within regulatory science as human teratogens. In order to gain approval, a Pregnancy Prevention Programme (PPP), along with a Controlled Distribution System (CDS) is required. The challenges of PPPs in particular for a generic manufacturer have been described, including Raising of awareness, and education; Special aspects of data collection and evaluation; Ethically and socially relevant aspects, and Utilising existing information technology and infrastructure. This paper highlights the risks of unplanned pregnancies, provides information on the regulatory background, and regulatory expectations. Our aim is to provide insights and practical learnings that have impacted operational risk management with the teratogenic phthalimides. Opportunities are presented that may support the implementation of harmonised approaches for PPP and CDS using existing IT-systems across countries and companies.

Prevalence of congenital anomalies at birth among live births in the state of Maranhão from 2001 to 2016: temporal and spatial analysis

OBJECTIVES

To analyze the prevalence at birth and the spatial and temporal distribution of congenital anomalies (CAs) among live births in the state of Maranhão in 2001 to 2016. To describe demographic, gestational and neonatal variables of interest.

METHODS

Ecological, population-based study, using secondary data from the Live Birth Information System (SINASC). Annual prevalence of total and per-group CAs was calculated. Spatial analyzes were based on the Local Indicators of Spatial Association (LISA) and the Moran I Index, and interactive maps were generated. Demographic, gestational and neonatal variables of interest available from SINASC were described in the group of newborns with CAs.

RESULTS

1,831,830 live births, 6,110 with CAs (33.4/10,000) were included. Higher frequencies occurred in more recent years. Spatial clusters have been observed in specific years. The prevalence of newborns with CAs was different between categories of variables considered as risk factors for this outcome.

CONCLUSION

The prevalence at birth of total CAs was lower than expected for major human defects (3%). The temporal peak of records in 2015/2016 is probably related to the increase in CAs caused by gestational infection by the Zika virus. The spatial clusters were probably due to variations at random due to the small number of births as they are not repeated in other years. Studies like this are the basis for the establishment of CA surveillance programs.

Development of a caffeic acid–phthalimide hybrid compound for NADPH oxidase inhibition

NADPH oxidases are pharmacological targets for the treatment of inflammation-based diseases. This work presents the synthesis and study of a caffeic acid/phthalimide hybrid compound (C2) as a potential inhibitor of NADPH oxidases. Throughout the study, we have compared compound C2 with its precursor caffeic acid (C1). The redox properties were compared using three different antioxidant methodologies and showed that C2 was slightly less effective than C1, a well-established and robust antioxidant. However, C2 was three-fold more effective than albumin (used as a model protein). This chemical feature was decisive for the higher efficiency of C2 as an inhibitor of the release of superoxide anions by stimulated neutrophils and enzymatic activity of cell-free NADPH oxidase. Docking simulation studies were performed using the crystal structure of the recombinant dehydrogenase domain of the isoform NOX5 of C. stagnale, which retains the FAD cofactor (PDB: 5O0X). Considering that C2 could bind at the FAD redox site of NOX5, studies were conducted by comparing the interactions and binding energies of C1 and C2. The binding energies were −50.30 (C1) and −74.88 (C2) (kJ mol⁻¹), which is in agreement with the higher efficacy of the latter as an NADPH oxidase inhibitor. In conclusion, incorporating the phthalimide moiety into caffeic acid was decisive for its effectiveness as an NADPH oxidase inhibitor.

The incorporation of the phthalimide moiety into caffeic acid was decisive for its effectiveness as an NADPH oxidase inhibitor.

An update on maternal medication-related embryopathies

There is a general perception that any exposure to medication during pregnancy poses a potential risk to the fetus. Most available data about teratogenic drugs is derived from animal studies, case reports, or cohort studies. As a result, counseling women and their partners about the safety of drugs during pregnancy can be difficult due to limited information about efficacy, pharmacokinetics, and teratogenicity of some drugs. However, this should always be done in the context of weighing up potential teratogenic risks with the perinatal risks of an untreated medical or psychiatric condition. Ideally, this counseling should occur prior to a planned pregnancy so that medications and treatment of chronic medical conditions can be optimized. It is important that clinicians providing antenatal care are able to confidently manage women including utilizing appropriate resources. This paper aims at reviewing a selected (non-exhaustive) list of the most commonly prescribed medications considered significant human teratogens and provides recommendations for pre-conception and antenatal counseling.

The role of ESCO2, SALL4 and TBX5 genes in the susceptibility to thalidomide teratogenesis

Thalidomide is widely used for several diseases; however, it causes malformations in embryos exposed during pregnancy. The complete understanding of the mechanisms by which thalidomide affects the embryo development has not yet been obtained. The phenotypic similarity makes TE a phenocopy of syndromes caused by mutations in ESCO2, SALL4 and TBX5 genes. Recently, SALL4 and TBX5 were demonstrated to be thalidomide targets. To understand if these genes act in the TE development, we sequenced them in 27 individuals with TE; we verified how thalidomide affect them in human pluripotent stem cells (hPSCs) through a differential gene expression (DGE) analysis from GSE63935; and we evaluated how these genes are functionally related through an interaction network analysis. We identified 8 variants in ESCO2, 15 in SALL4 and 15 in TBX5. We compared allelic frequencies with data from ExAC, 1000 Genomes and ABraOM databases; eight variants were significantly different (p < 0.05). Eleven variants in SALL4 and TBX5 were previously associated with cardiac diseases or malformations; however, in TE sample there was no association. Variant effect prediction tools showed 97% of the variants with potential to influence in these genes regulation. DGE analysis showed a significant reduction of ESCO2 in hPSCs after thalidomide exposure.

Information and Diagnosis Networks - tools to improve diagnosis and treatment for patients with rare genetic diseases

Brazil is a country of continental dimensions and most genetic services are concentrated in the Southeast and South, including the Medical Genetics Service of the Hospital de Clínicas de Porto Alegre (MGS/HCPA). As many areas on the country do not have adequate medical genetics support, networks were designed to extend the service of the MGS/HCPA reference center. This paper presents the information and diagnosis networks that have their headquarters at MGS/HCPA: SIAT (National Information System on Teratogenic Agents), SIEM (Information Service on Inborn Errors of Metabolism), Alô Genética (Hello Genetics - Medical Genetics Information Service for Primary Health Care Professionals); Rede MPS Brasil (MPS-Mucopolysaccharidosis Brazil Network); Rede EIM Brasil (IEM-Inborn Errors of Metabolism Brazil Network), Rede NPC Brasil (Niemann-Pick C - NPC Brazil Network), Rede DLD Brasil (LSD-Lysosomal Storage Disorders Brazil Network), Rede DXB (MSUD-Maple Syrup Urine Disease Network), RedeBRIM (Brazilian Network of Reference and Information in Microdeletion Syndromes Project), Rede Neurogenética (Neurogenetics Network), and Rede Brasileira de Câncer Hereditário (Brazilian Hereditary Cancer Network). These tools are very useful to provide access to a qualified information and/or diagnostic service for specialized and non-specialized health services, bypassing difficulties that preclude patients to access reference centers.

From abortion-inducing medications to Zika Virus Syndrome: 27 years experience of the First Teratogen Information Service in Latin America

In 1990, the first Teratogen Information Service in Brazil (SIAT) was implemented in the Medical Genetics Service at Hospital de Clinicas de Porto Alegre. SIAT is a free-to-use information service both to health professionals and the general population, especially to women who are pregnant or planning pregnancy. The main objective of this paper is to present the activities of SIAT in its initial years (1990-2006), compared to those in the last decade (2007-2017). In addition we review the scientific contribution of SIAT in the field of human teratogenesis. Since 1990, SIAT received 10,533 calls. Use of medications were the main reason for concern, accounting for 74% of all questions, followed by other chemical exposures (occupational, cosmetics, environmental), and maternal infectious diseases. Among its main contributions to scientific knowledge was the collaboration for the identification of two new human teratogens: misoprostol in the 1990s and Zika virus in 2015/16. In conclusion, SIAT is still evolving, as is the Medical Genetics Service that hosts it. Through its 27 years of existence more than 300 undergraduate and graduate students have rotated at SIAT. Presently, SIAT is expanding the research to experimental teratogenesis and to investigation of molecular mechanisms of teratogens.

Assessment of Congenital Vascular and Organ Anomalies in Subjects With Thalidomide Embryopathy Using Non-Contrast Magnetic Resonance Angiography

BACKGROUND

To determine the type and frequency of vascular and organ malformations in adults with thalidomide embryopathy (TE) using non-contrast magnetic resonance angiography (MRA) and to assess the effect of the observed malformations on renal function. Methods and Results: The institutional ethics committee approved this prospective study and written informed consent was given by all 78 subjects (50 females) with TE (mean age: 55±1.1 years), who were examined by non-contrast MRA at 3T. ECG-triggered balanced turbo field echo images of the chest, abdomen and pelvis were obtained in coronal and sagittal orientations. Two observers assessed the frequency of vascular and organ malformations. Serum creatinine and estimated glomerular filtration rate (eGFR) were obtained to assess renal function. In 58 subjects, 99 vascular anomalies were observed, including 68 arterial (69%) and 31 venous anomalies (31%); 15 patients had 16 abdominal organ malformations including 12 kidney anomalies and 4 cases of gallbladder agenesis. Most vascular anomalies affected the renal vessels (n=66, 67%) or supraaortic arteries (n=28, 28%). Serum creatinine and eGFR revealed normal renal function in all subjects.

CONCLUSIONS

Vascular and organ anomalies occurred in a high number of subjects with TE without evidence of renal dysfunction. Information about the presence of malformations may be important for future surgical interventions in subjects with TE.