Fermented goat's milk modulates immune response during iron deficiency anemia recovery.

BACKGROUND: Iron deficiency and iron overload can affect the normal functioning of the innate and adaptive immune responses. Fermented milk products may enhance immune functions, but little is known about the effect of fermented milks on modulation of the immune response during iron deficiency anemia and recovery with normal or high dietary iron intake. Eighty male Wistar rats were randomly assigned to a control group fed a standard diet or to an anemic group fed a diet deficit in iron. Control and anemic groups were fed for 30 days with diets based on a fermented goat's or cow's milk product, with normal iron content or iron overload. RESULTS: In general, during anemia recovery lectin and alternative complement pathway activity and lactoferrin decreased, because it improves iron homeostasis, which is critically important in immune system functions. Fermented goat's milk diet enhanced immune function during iron deficiency recovery, suppressed oxidant-induced eotaxin and fractalkine expression due to the concurrent reduction of free radical production and pro-inflammatory cytokines, and decreased monocyte chemoattractant protein-1 and monocyte migration and adhesion. The increase in interferon-γ can confer immunological colonization of gut microbiota and downregulate inflammation. CONCLUSION: Fermented goat's milk consumption enhances immune function, modifying complement pathway activity and decreasing pro-inflammatory cytokines as well as lactoferrin concentration, due to the improvement of iron homeostasis, which is critically important in the normal function of the immune system. © 2021 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Analysis of Iron and Iron-Interacting Protein Dynamics During T-Cell Activation.

Recent findings have shown that iron is a powerful regulator of immune responses, which is of broad importance because iron deficiency is highly prevalent worldwide. However, the underlying reasons of why iron is needed by lymphocytes remain unclear. Using a combination of mathematical modelling, bioinformatic analysis and experimental work, we studied how iron influences T-cells. We identified iron-interacting proteins in CD4+ and CD8+ T-cell proteomes that were differentially expressed during activation, suggesting that pathways enriched with such proteins, including histone demethylation, may be impaired by iron deficiency. Consistent with this, iron-starved Th17 cells showed elevated expression of the repressive histone mark H3K27me3 and displayed reduced RORγt and IL-17a, highlighting a previously unappreciated role for iron in T-cell differentiation. Quantitatively, we estimated T-cell iron content and calculated that T-cell iron demand rapidly and substantially increases after activation. We modelled that these increased requirements will not be met during clinically defined iron deficiency, indicating that normalizing serum iron may benefit adaptive immunity. Conversely, modelling predicted that excess serum iron would not enhance CD8+ T-cell responses, which we confirmed by immunising inducible hepcidin knock-out mice that have very high serum iron concentrations. Therefore, iron deficiency impairs multiple aspects of T-cell responses, while iron overload likely has milder effects.

Perturbation of monocyte subsets in iron-deficient children - a shift to a pro-inflammatory state?

BACKGROUND: Iron deficiency anemia (IDA) is the most prevalent micronutrient deficiency in preschool children in developing countries including India. IDA is associated with immune perturbation, which is reflected in greater frequency of infections in these children. Recent research has shown three distinct monocyte subsets with distinct functions linked to infectious, inflammatory, and autoimmune diseases. These subsets have not been studied in children with IDA. OBJECTIVE: The aim of the study was to assess the percentage of monocyte population and the three subset populations in children with IDA and to compare the data with age-matched healthy controls. METHODS: Venous blood samples (5 mL) from 40 IDA children and 20 controls were collected after taking informed consent. Monocyte subpopulations were compared across the two groups. The outcome variables were calculated using Students Independent t-test or Mann-Whitney U test. P value of <0.05 was taken as significant. RESULTS: No significant difference was found in the absolute numbers as well as percentages of total monocytes between the control and case (study) group. Children in the IDA group showed a significant (p = 0.03) decrease in the nonclassical subset population when compared to the control group. CONCLUSION: This is the first study done on monocyte subsets in iron-deficient children. Decrease in nonclassical monocytes observed may be associated with a pro-inflammatory state and increased risk of inflammatory and auto immune diseases. Follow-up studies are needed to confirm these findings.

Effect of increased blood flow rate on renal anemia and hepcidin concentration in hemodialysis patients.

BACKGROUND: Increasing the blood flow rate (BFR) is a useful method for increasing Kt/V and the clearance for low molecular solutes. Hemodialysis patients are often anemic due to hypoerythropoiesis and their chronic inflammatory state. Hepcidin, a hormone that regulates iron homeostasis, is considered as an indicator of iron deficiency in patients with end-stage renal disease. This study aimed to investigate the effects of an increased BFR during hemodialysis on serum hepcidin levels and anemia. METHODS: Between April 2014 and March 2016, 22 chronic dialysis patients (11 men [50.0 %]; mean [± standard deviation] age, 72 ± 12 years) undergoing maintenance hemodialysis treatment, thrice weekly, were enrolled and followed prospectively for 24 months. In April 2014, the BFR was 200 mL/min; in April 2015 this was increased to 400 mL/min, which was within acceptable limits. The dialysate flow rate remained stable at; 500mlL/min. Blood samples were collected in March 2015 and 2016. The primary endpoint was the comparison of the amounts of erythropoiesis-stimulating agent (ESA) required. RESULTS: The increased BFR increased the Kt/V and contributed to significantly decreased urea nitrogen (UN) (p = 0.015) and creatinine (Cr) (p = 0.005) levels. The dialysis efficiency was improved by increasing the BFR. Ferritin (p = 0.038), hepcidin (p = 0.041) and high-sensitivity interleukin-6 (p = 0.038) levels were also significantly reduced. The ESA administered was significantly reduced (p = 0.004) and the Erythropoietin Resistant Index (ERI) significantly improved (p = 0.031). The reduction rates in UN (p < 0.001), Cr (p < 0.001), and beta-2 microglobulin (p = 0.017) levels were significantly greater post the BFR increase compared to those prior to the BFR increase. However, hepcidin was not affected by the BFR change. CONCLUSIONS: Increasing BFR was associated with hemodialysis efficiency, and led to reduce inflammatory cytokine interleukin-6, but did not contribute to reduce C-reactive protein. This reduced hepcidin levels, ESA dosage and ERI. Hepcidin levels were significantly correlated with ferritin levels, and it remains to be seen whether reducing hepcidin leads to improve ESA and iron availability during anemia management.