1.
B Vitamins and One-Carbon Metabolism: Implications in Human Health and Disease.
Lyon, P, Strippoli, V, Fang, B, Cimmino, L
Nutrients. 2020;(9)
Abstract
Vitamins B9 (folate) and B12 are essential water-soluble vitamins that play a crucial role in the maintenance of one-carbon metabolism: a set of interconnected biochemical pathways driven by folate and methionine to generate methyl groups for use in DNA synthesis, amino acid homeostasis, antioxidant generation, and epigenetic regulation. Dietary deficiencies in B9 and B12, or genetic polymorphisms that influence the activity of enzymes involved in the folate or methionine cycles, are known to cause developmental defects, impair cognitive function, or block normal blood production. Nutritional deficiencies have historically been treated with dietary supplementation or high-dose parenteral administration that can reverse symptoms in the majority of cases. Elevated levels of these vitamins have more recently been shown to correlate with immune dysfunction, cancer, and increased mortality. Therapies that specifically target one-carbon metabolism are therefore currently being explored for the treatment of immune disorders and cancer. In this review, we will highlight recent studies aimed at elucidating the role of folate, B12, and methionine in one-carbon metabolism during normal cellular processes and in the context of disease progression.
2.
Incidence, Risk Factors, and Outcome of Immune-Mediated Neuropathies (IMNs) following Haploidentical Hematopoietic Stem Cell Transplantation.
Ren, XY, Liu, X, Huang, QS, Wang, QM, He, Y, Zhu, XL, Han, W, Chen, H, Chen, YH, Wang, FR, et al
Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation. 2019;(8):1629-1636
Abstract
Immune-mediated neuropathies (IMNs) following hematopoietic stem cell transplantation have been described recently, which, excluding Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy, may present with atypical patterns. This retrospective, nested, case-control study reviewed data from 3858 patients who received haploidentical hematopoietic stem cell transplantation (haplo-HSCT) during the past 10 years at a single center, and 40 patients (1.04%) with IMN following haplo-HSCT were identified. Chronic graft-versus-host disease (cGVHD) (P = .043) and cytomegalovirus (CMV) viremia (P = .035) were recognized as independent risk factors for the development of IMN after haplo-HSCT. There were no significant differences in overall survival (P = .619), disease-free survival (P = .609), nonrelapse mortality (P = .87), or the incidence of relapse (P = .583) between patients with and without IMN after haplo-HSCT. However, patients with post-transplant IMN were at higher risk of developing cGVHD (P = .012) than patients who did not develop IMN. Twenty-four of the 40 patients with IMN (60%) attained neurologic improvement after treatments including vitamins B1 and B12 and/or immunomodulatory agents. However, 19 (47.5%) patients still had persistent motor/sensory deficits despite receiving timely treatment. More studies are needed to help develop standardized diagnostic and therapeutic strategies for patients with post-transplant IMN.
3.
Iron Deficiency and Other Types of Anemia in Infants and Children.
Wang, M
American family physician. 2016;(4):270-8
Abstract
Anemia, defined as a hemoglobin level two standard deviations below the mean for age, is prevalent in infants and children worldwide. The evaluation of a child with anemia should begin with a thorough history and risk assessment. Characterizing the anemia as microcytic, normocytic, or macrocytic based on the mean corpuscular volume will aid in the workup and management. Microcytic anemia due to iron deficiency is the most common type of anemia in children. The American Academy of Pediatrics and the World Health Organization recommend routine screening for anemia at 12 months of age; the U.S. Preventive Services Task Force found insufficient evidence to assess the benefits vs. harms of screening. Iron deficiency anemia, which can be associated with cognitive issues, is prevented and treated with iron supplements or increased intake of dietary iron. The U.S. Preventive Services Task Force found insufficient evidence to recommend screening or treating pregnant women for iron deficiency anemia to improve maternal or neonatal outcomes. Delayed cord clamping can improve iron status in infancy, especially for at-risk populations, such as those who are preterm or small for gestational age. Normocytic anemia may be caused by congenital membranopathies, hemoglobinopathies, enzymopathies, metabolic defects, and immune-mediated destruction. An initial reticulocyte count is needed to determine bone marrow function. Macrocytic anemia, which is uncommon in children, warrants subsequent evaluation for vitamin B12 and folate deficiencies, hypothyroidism, hepatic disease, and bone marrow disorders.
4.
Effects of cyanocobalamin on immunity in patients with pernicious anemia.
Erkurt, MA, Aydogdu, I, Dikilitaş, M, Kuku, I, Kaya, E, Bayraktar, N, Ozhan, O, Ozkan, I, Sonmez, A
Medical principles and practice : international journal of the Kuwait University, Health Science Centre. 2008;(2):131-5
Abstract
OBJECTIVE The aim of the study was to evaluate the role of vitamin B(12) in patients with pernicious anemia. MATERIALS AND METHODS This study was conducted prospectively at the Turgut Ozal Medical Center, Department of Hematology, between April and November 2002. Absolute numbers and ratio of the surface antigens of T and B lymphocyte subgroups, CD4/CD8 ratio were calculated in order to evaluate changes in leukocyte and lymphocyte numbers; natural killer (NK) cell count, serum C3, C4, and levels of immunoglobulins G, A, and M were also measured to evaluate vitamin B(12) effect on immunity. Values obtained before treatment with cyanocobalamin were compared with those found during peak reticulocyte count. RESULTS In vitamin B(12)-deficient patients, absolute numbers of CD4+ and especially CD8+ lymphocytes were found to be decreased; CD4/CD8 ratio increased, and NK cell activity was depressed. After cyanocobalamin treatment, absolute numbers and percentage of lymphocyte subgroups were elevated. Increased CD4/CD8 ratio and depressed NK cell activity were restored and levels of C3, C4, and immunoglobulins were elevated. CONCLUSION These findings suggest that vitamin B(12) has important immunomodulatory effects on cellular immunity, and abnormalities in the immune system in pernicious anemia are restored by vitamin B(12) replacement therapy.