Evaluation of the influence of genetic variants in Cereblon gene on the response to the treatment of erythema nodosum leprosum with thalidomide.

BACKGROUND: Erythema nodosum leprosum (ENL) is an acute and systemic inflammatory reaction of leprosy characterised by painful nodules and involvement of various organs. Thalidomide is an immunomodulatory and anti-inflammatory drug currently used to treat this condition. Cereblon (CRBN) protein is the primary target of thalidomide, and it has been pointed out as necessary for the efficacy of this drug in others therapeutics settings. OBJECTIVES: In this study, we aimed to evaluate the influence of CRBN gene variants on the dose of thalidomide as well as its adverse effects during treatment of ENL. METHODS: A total of 103 ENL patients in treatment with thalidomide were included in this study. DNA samples were obtained from saliva and molecular analysis of CRBN gene were performed to investigate the variants rs1620675, rs1672770 and rs4183. Different genotypes of CRBN variants were evaluated in relation to their influence on the dose of thalidomide and on the occurrence of adverse effects. FINDINGS: No association was found between CRBN variants and thalidomide dose variation. However, the genotypes of rs1672770 showed association with gastrointestinal effects (p = 0.040). Moreover, the haplotype DEL/C/T (rs4183/rs1672770/rs1620675) was also associated with gastrointestinal adverse effects (p = 0.015). MAIN CONCLUSIONS: Our results show that CRBN variants affect the treatment of ENH with thalidomide, especially on the adverse effects related to the drug.

Evaluation of the influence of genetic variants in Cereblon gene on the response to the treatment of erythema nodosum leprosum with thalidomide

BACKGROUND Erythema nodosum leprosum (ENL) is an acute and systemic inflammatory reaction of leprosy characterised by painful nodules and involvement of various organs. Thalidomide is an immunomodulatory and anti-inflammatory drug currently used to treat this condition. Cereblon (CRBN) protein is the primary target of thalidomide, and it has been pointed out as necessary for the efficacy of this drug in others therapeutics settings. OBJECTIVES In this study, we aimed to evaluate the influence of CRBN gene variants on the dose of thalidomide as well as its adverse effects during treatment of ENL. METHODS A total of 103 ENL patients in treatment with thalidomide were included in this study. DNA samples were obtained from saliva and molecular analysis of CRBN gene were performed to investigate the variants rs1620675, rs1672770 and rs4183. Different genotypes of CRBN variants were evaluated in relation to their influence on the dose of thalidomide and on the occurrence of adverse effects. FINDINGS No association was found between CRBN variants and thalidomide dose variation. However, the genotypes of rs1672770 showed association with gastrointestinal effects (p = 0.040). Moreover, the haplotype DEL/C/T (rs4183/rs1672770/rs1620675) was also associated with gastrointestinal adverse effects (p = 0.015). MAIN CONCLUSIONS Our results show that CRBN variants affect the treatment of ENH with thalidomide, especially on the adverse effects related to the drug.

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.

Erythema Nodosum Leprosum: Update and challenges on the treatment of a neglected condition.

Erythema Nodosum Leprosum (ENL) occurs due to the immunological complication of multibacillary leprosy and is characterized by painful nodules and systemic compromising. It is usually recurrent and/or chronic and has both physical and economic impact on the patient, being a very important cause of disability. In addition, ENL is a major health problem in countries where leprosy is endemic. Therefore, adequate control of this condition is important. The management of ENL aims to control acute inflammation and neuritis and prevent the onset of new episodes. However, all currently available treatment modalities have one or two drawbacks and are not effective for all patients. Corticosteroid is the anti-inflammatory of choice in ENL but may cause dependence, especially for chronic patients. Thalidomide has a rapid action but its use is limited due the teratogenicity and neurotoxicity. Clofazimine and pentoxifylline have slow action and have important adverse effects. Finally, there is no pattern or guidelines for treating these patients, becoming more difficult to evaluate and to control this condition. This review aims to show the main drugs used in the treatment of ENL and the challenges in the management of the reaction.

The impact of thalidomide use in birth defects in Brazil.

Although the thalidomide tragedy occurred more than 50 years ago, the medication is still being used worldwide for different reasons, and several aspects regarding its teratogenicity remain unsolved. Despite the strict regulation implemented, new cases of thalidomide embryopathy (TE) are still being registered in Brazil. Furthermore, the molecular processes that lead to malformations when the embryo is exposed to thalidomide have not yet been fully identified. In this article, we perform a critical analysis of thalidomide's history in Brazil, highlighting aspects of the occurrence of TE over the decades. Finally, we present the main perspectives and challenges for ongoing surveillance and prevention of TE in Brazil. The effective control of dispensing thalidomide, especially in areas where leprosy is endemic, is one of the most important and challenging points. Furthermore, the emergence of thalidomide analogues is fast approaching, and their availability would pose additional concerns. The understanding of the molecular mechanisms and targets of thalidomide in both experimental and human models is essential for generating new insights into teratogenic mechanisms, so that safer thalidomide analogues can be developed.

Polymorphisms in the endothelial nitric oxide synthase gene in thalidomide embryopathy.

Thalidomide is one of the most potent teratogens known to humans. It is currently used for many clinical situations such as treatment of leprosy reactions and multiple myeloma. However, the teratogenic mechanisms by which it produces morphological defects still remain unclear. One of the hypotheses is the blockage of angiogenesis by reduction of nitric oxide (NO). In this study, we evaluated two functional polymorphisms of the endothelial nitric oxide synthase (eNOS) gene which is a constitutively expressed enzyme responsible for production of NO. The promoter -786T>C exon 7 (896G>T) polymorphisms were genotyped using real-time PCR for 28 individuals with thalidomide embryopathy (TE), 27 first-degree relatives of these individuals, and 68 individuals from the general population. Their allele, genotypic, and haplotypic frequencies were compared. A significant difference was observed in the -786T>C polymorphism genotypes (p=0.03) between the groups affected by TE and those unaffected (non-relatives). The TT genotype of the 896G>T polymorphism was observed in 10.7% of those affected and 2.9% of those unaffected, but the difference was not statistically significant (p=0.09). The haplotypic analysis indicated that the wild haplotype -786T/896G was distributed differently in the affected and unaffected groups (p=0.004). These results indicate that the individuals with TE have a higher frequency of alleles associated with lower expression of eNOS, indicating that this may be a genotype susceptible to TE.