Open AccessPS1292 LINK BETWEEN IRON AND TRYPTOPHAN METABOLISM OBSERVED IN INDIVIDUALS WITH IRON DEFICIENCY AND ANEMIA
Author(s) -
Enko D.,
Meinitzer A.,
Kriegshäuser G.,
Baumann G.,
Schnedl W.J.,
Zelzer S.,
Mangge H.,
Herrmann M.,
Holasek S.J.,
Wenninger J.
Publication year - 2019
Publication title -
hemasphere
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.677
H-Index - 11
ISSN - 2572-9241
DOI - 10.1097/01.hs9.0000563448.02657.46
Subject(s) - hepcidin , anemia , ineffective erythropoiesis , ferritin , myelodysplastic syndromes , medicine , erythropoiesis , hemoglobin , gastroenterology , blood transfusion , iron deficiency , immunology , physiology , bone marrow
Background: Current literature proposes associations between tryptophan (TRP) metabolism and anemia. However, previous studies were designed with rather small patient groups with anemia of chronic disease (ACD) or performed as animal models with different degrees of renal insufficiency. Furthermore, the question raises if the TRP metabolism has a potential link to iron deficiency (ID) or iron deficiency anemia (IDA). This issue is not covered in the current literature. Aims: This prospective study aimed at evaluating the potential association between iron metabolism and hemoglobin (Hb) concentrations and the TRP metabolism in a large cohort of patients sub‐grouped by the presence or absence ID or anemia. Methods: In this prospective study, 430 patients, who were admitted by general practitioners and specialists to the outpatient clinic of the Institute of Clinical Chemistry and Laboratory Medicine of the General Hospital Steyr (Steyr, Austria) for a medical check‐up of their actual iron status, were included. All participants provided their written informed consent. They underwent venous blood sampling after an overnight fasting state in the morning (between 8.00 and 10.00 a.m.). The samples were used to investigate the iron metabolism (i.e., Hb, mean corpuscular volume [MCV], mean corpuscular hemoglobin [MCH], ferritin, transferrin saturation [TSAT], serum iron, transferrin, soluble transferrin receptor [sTfR], reticulocyte hemoglobin [CHr]), and also the TRP metabolism (TRP, kynurenine [KYN], kynurenic acid [KYNA], KYN/TRP ratio, KYNA/KYN index). Serum concentrations of TRP, KYN, and KYNA were measured by high‐pressure liquid‐chromatography Results: Serum TRP, KYN and KYNA concentrations were positively correlated with Hb (p‐values <0.001, 0.029, and <0.001) and ferritin (p‐values 0.033, 0.008, and <0.001) measurements. In total, 159 patients with ID had significantly lower median (interquartile range) TRP (58.5 [52.8 – 64.8] vs. 61.1 [54.5 – 66.4] μmol/L, p = 0.008) and KYNA serum concentrations (27.8 [20.4 – 34.5] vs. 33.6 [25.4 – 43.9] μmol/L, p <0.001) compared to 271 individuals without ID. Six patients with anemia of chronic disease (ACD) showed the lowest median TRP concentration and the highest KYN/TRP ratio compared to 11 individuals with iron deficiency anemia (IDA) and 413 non‐anemic patients (p‐ values 0.001 and 0.011), respectively. Summary/Conclusion: Parameters of TRP metabolism correlated with Hb concentrations and iron metabolism. Individuals with ID or anemia were found with significantly lower TRP values compared to individuals without ID or anemia. These findings suggest an association between TRP and iron metabolism. However, the authors of this work propose performing prospective longitudinal studies to assess the clinical course of associations between iron and TRP metabolism.