Effect of N(Epsilon)-(carboxymethyl)lysine on Laboratory Parameters and Its Association with βS Haplotype in Children with Sickle Cell Anemia

Effect of N(Epsilon)-(carboxymethyl)lysine on Laboratory Parameters and Its Association with βS Haplotype in Children with Sickle Cell Anemia Uche Samuel Ndidi,1,2 Corynne Stephanie Ahouefa Adanho,1 Rayra Pereira Santiago,1,3 Sètondji Cocou Modeste Alexandre Yahouédéhou,1,3 Sânzio Silva Santana,1 Vitor Valério Mafili,3 Thassila Nogueira Pitanga,1 Cleverson Alves Fonseca,3 Junia Raquel Dutra Ferreira,3 Elisângela Vitoria Adorno,3 Isa Menezes Lyra,4 Adekunle D. Adekile,5 Cynara Gomes Barbosa,3 and Marilda Souza Goncalves1,3 1Laboratório de Investigação em Genética e Hematologia Translacional, Instituto Gonçalo Moniz, Salvador, BA, Brazil 2Department of Biochemistry, Ahmadu Bello University, Zaria, Nigeria 3Laboratório de Pesquisa em Anemias, Departamento de Análises Clínicas e Toxicologicas, Faculdade de Farmácia, Universidade Federal da Bahia, Salvador, BA, Brazil 4Fundação de Hematologia e Hemoterapia da Bahia, Salvador, BA, Brazil 5Department of Pediatrics, Faculty of Medicine, Kuwait University, Kuwait Correspondence should be addressed to Marilda Souza Goncalves; rb.zurcoif.aihab@iram Received 28 February 2019; Accepted 17 August 2019; Published 15 September 2019 Academic Editor: Irene Rebelo Copyright © 2019 Uche Samuel Ndidi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract The present study aimed to investigate the association of Nε-carboxymethyllysine (CML) with laboratory parameters and βS haplotypes in pediatric sickle cell anemia (SCA) patients with or without hydroxyurea (HU) therapy. We included 55 children with SCA (SCAtotal), where 27 were on HU treatment (SCA-HU+) and 28 without HU treatment (SCA-HU-). Laboratory characteristics were determined using electronic methods while CML was measured using competitive ELISA. βS haplotypes were determined by RFLP-PCR. Significant increases in MCV and MCH and significant decreases in leukocytes, eosinophils, basophils, atypical lymphocytes, lymphocytes, and monocytes were found in SCA-HU+ compared to SCA-HU-. SCA-HU+ presented significant reduction in aspartate transaminase and lactate dehydrogenase and increase in creatinine levels compared to SCA-HU-. CML levels were significantly higher in both SCA-HU+ and SCA-HU- compared to the healthy control. In addition, a negative correlation was found between CML and alanine transaminase in SCA-HU+ and SCAtotal (). A significant association was found between CML levels and βS haplotypes. The results suggest that CML has a role to play in SCA complications, independent of HU therapy. 1. Introduction Sickle cell anemia (SCA) is a monogenic hematological disorder caused by substitution GAG>GTG at the 6th position of the beta globin gene (HBB) located in chromosome 11 [1]. SCA patients present a wide variability in clinical manifestations regarding the functions of vital organs as well as frequency and severity of vasoocclusive crises [2, 3]. This can be explained by factors such as fetal hemoglobin (HbF) levels, coexistence of alpha (α) thalassemia, haplotypes associated with the βS globin gene, oxidative stress, features intrinsic to the red blood cell (RBC), and extracellular environment [4, 5]. Higher HbF levels were associated with improved survival, decreased rates of painful crises, acute chest syndrome, and osteonecrosis [6–9]. Furthermore, Senegal (SEN), Cameroon (CAM), Bantu or Central African Republic (CAR), Benin (BEN), Arab-Indian (ARAB) and more recently the atypical (AT) βS haplotype are associated with variable HbF levels and, consequently, variable clinical features [10, 11]. Autooxidation of the HbS along with chronic intravascular hemolysis and ischemia is known to increase the generation of reactive oxygen species (ROS) that potentiates oxidative stress which, in association with other features intrinsic to the erythrocyte and extracellular environment, can mediate vasoocclusion and organ ischemia [5, 12]. Reports showed that advanced glycation end products (AGEs), such as Nε-carboxymethyllysine (CML), are markers of oxidative stress [13] and have been implicated in normal aging as well as pathophysiology of organ complications in diabetes, atherosclerosis, Alzheimer, and autoimmune inflammatory disease [14–17]. They are a complex group of compounds formed through nonenzymatic reactions between reducing sugars or derivatives (e.g., glucose-6-phosphate) and the N-terminal amino group of arginine and lysine side chains on proteins, lipids, and nucleic acids. It is known that AGEs lead to the formation of covalent cross-links between proteins that may be one of the central underlying processes by which they cause damage [18]. Studies of Nur et al. [15] and Somjee et al. [19] are the only known ones that tried to relate AGEs with sickle cell disease (SCD). They reported increase in AGE levels in SCD patients compared to healthy individuals (HbAA). Their results showed that circulating AGEs may play a significant role in vascular dysfunction, pathophysiology of hemolytic phenotype, and hemolysis-related organ complications such as priapism, leg ulcer, ischemic strokes, and pulmonary hypertension [15, 19]. To improve these clinical features presented by the SCA patients, hydroxyurea (HU) was the only drug approved in 1998 by the Food and Drug Administration (FDA) [20, 21] until 2017 when L-glutamine also became part of this therapeutic arsenal [22]. Reports suggest that HU is a relatively well-tolerated cytotoxic drug with limited side effects in the short term, though there are concerns over its long-term effect on male fertility [23]. The targets and mechanisms by which HU ameliorates clinical complications of SCA remain partially elucidated [24–27]. The efficacy of HU was initially attributed to pharmacological stimulation of HbF, but the fact that clinical benefits occur before its rise suggests that HU could act through other mechanisms [28, 29]. Therefore, understanding the genetic and other factors underlying the variability in the therapeutic effects of HU is critical for prospectively predicting good responders and for designing other effective therapies. The present study was aimed at evaluating the association of CML, the most abundant and researched advanced glycation product [30], with laboratory parameters and βS haplotypes in SCA patients with or without HU treatment. 2. Materials and Methods2.1. Subjects and Ethical Aspects The present transversal study carried out between August 2015 and August 2017 was performed with 55 SCA (HbSS) children from the Fundação de Hematologia e Hemoterapia da Bahia (HEMOBA), Salvador, Bahia, Brazil. They were divided into two groups: the SCA-HU+ group composed of 27 children with HU therapy (15–25 mg/kg/day) and the SCA-HU- group composed of 28 children without HU therapy. The median ages of the SCA-HU+ and SCA-HU- groups were (...truncated)