Off-resonance saturation as an MRI method to quantify ferritin-bound iron in the post-mortem brain

PurposeTo employ an Off-Resonance Saturation (ORS) method to measure the ferritin-bound iron pool, which is an endogenous contrast agent which can give information on cellular iron status.MethodsAn ORS acquisition protocol was implemented on a 7T preclinical scanner and the contrast maps were fitted to an established analytical model. The method was validated by correlation and Bland-Altman analysis on a ferritin-containing phantom. Ferritin-iron maps were obtained from post-mortem tissue of patients with neurological diseases characterized by brain iron accumulation, i. e. Alzheimer’s disease, Huntington’s disease and aceruloplasminemia, and validated with histology. Transverse relaxation rate and magnetic susceptibility values were also obtained for comparison.ResultsIn post-mortem tissue, the ferritin-iron contrast strongly co-localizes with histological iron staining, in all the cases. Quantitative iron values obtained via the ORS method are in agreement with literature.ConclusionsOff-resonance saturation is an effective way to detect iron in grey matter structures, while mitigating for the presence of myelin. If a reference region with little iron is available in the tissue, the method can produce quantitative iron maps. This method is applicable in the study of brain diseases characterized by brain iron accumulation and complement existing iron-sensitive parametric methods.

Evaluation of Iron Status in Children with Autism Spectral Disorder: A Case-control Study

Introduction: Iron is an important factor in neural development. Iron Deficiency (ID) and Iron Deficiency Anaemia (IDA) anaemia is highly prevalent in patients of autism. There are a very small number of studies to show association between iron profile and autism. Aim: To investigate factors affecting iron status such as hemoglobin (%), serum iron, ferritin, and Total Iron Binding Capacity (TIBC) level in children with Autism Spectral Disorder (ASD) and healthy control. Materials and Methods: It was a case-control study done from April 2018 to April 2019. Total 100 participants were recruited of which 50 autistic patients were taken as cases, and 50 healthy subjects were taken as control. Childhood Autism Rating Scale (CARS) was used to evaluate the severity of autistic symptoms. Cut-off value of serum ferritin was <10 ng/mL for preschoolers (<6 years) and <12 ng/mL for school-aged (>6 years) children to evaluate ID. Anaemia was defined as haemoglobin <11.0 g/dL for preschoolers and <12.0 g/dL for school-aged categorical variables and were compared by using chi-square test. Normally distributed parametric variables were compared between groups by using independent samples t-test. Serum ferritin, iron, TIBC values were compared between severe, mild-moderate and control groups with ANOVA. The p-value <0.05 was accepted to be statistically significant. Results: Mean serum levels of ferritin iron TIBC were significantly reduced in ASD patients (p<0.001). The level of haemoglobin was also lower in ASD patients but it was not significant. Risk of ID and IDA was higher than normal subjects (RR for ID 1.74). Level of serum ferritin, iron and TIBC was lowest in severe autism as compared to mild-moderate autism and control groups. Conclusion: These findings suggest iron and ferritin levels should be measured in autistic patients as a baseline investigation and it may be used as a screening test for ASD.

FeRIC-based magnetogenetics: evaluation of methods and protocols in in vitro models

FeRIC (Ferritin iron Redistribution to Ion Channels) is a magnetogenetic technique that uses radiofrequency (RF) waves to activate the transient receptor potential channels, such as TRPV1 and TRPV4, coupled to cellular ferritins. In cells expressing ferritin-tagged TRPV, RF stimulation increases the cytosolic Ca2+ levels via a biochemical pathway. The interaction between RF and ferritin increases the free cytosolic iron level that in turn, triggers chemical reactions producing reactive oxygen species and oxidized lipids that activate the ferritin-tagged TRPV. In this pathway, it is expected that experimental factors that disturb the ferritin expression, the ferritin iron load, the TRPV functional expression, or the cellular redox state will impact the RF efficacy to activate ferritin-tagged TRPV. Here, three in vitro protocols were compared for using FeRIC to remotely activate ferritin-tagged TRPV. Further, several experimental factors were examined that either enhance or abolish the RF control of ferritin-tagged TRPV. The findings may help establish reproducible magnetogenetic experimental protocols.

Initial study of anaemia profile for primary care centres with automated laboratory algorithms reduces the demand for ferritin, iron, transferrin, vitamin B12 and folate tests

AimTo evaluate the influence of an algorithm designed to incorporate reflex testing according to haemogram results for analytical tests ordered to investigate anaemia.MethodsIn 2020, a new request for ‘initial study of anaemia’ was created in three primary care pilot centres for suspected anaemia or new anaemias. A haemogram was ordered and the remainder of the tests were created in a reflex manner according to an algorithm integrated in the laboratory information system that also generates a comment that is completed and validated by a haematologist. The demand for tests was evaluated over three time periods.ResultsOf 396 requests, anaemia was detected in 80 (20.2%), with 26 microcytic anaemias (6.57%), 20 iron deficiency anaemias, 41 (10.3%) normocytic anaemias and 13 macrocytic anaemias (3.28%); 4 with folate deficiency; and 1 haemolytic anaemia. No haematological diseases were detected. Twenty-four (6.06%) cases exhibited microcytosis/hypochromia without anaemia, 12 of which exhibited iron deficiency. Four young women exhibiting within-limit haemoglobin levels had iron deficiency. There were 56 (14.1%) cases of macrocytosis without anaemia.With the new profile of ‘initial study of anaemia’, the demand for tests was reduced and was significantly lower than in the remainder of primary centres for iron, transferrin, ferritin, vitamin B12 and folate.ConclusionsA new profile of ‘initial study of anaemia’ in the request form with algorithms integrated in the laboratory information system enabled submission of orders and decreased the demand for unnecessary iron, transferrin, ferritin, vitamin B12 and folate tests.

Measuring Reticulocyte Hemoglobin Content As a Marker for Iron Deficiency and Response to Therapy Represents a Paradigm Shift in Care

It is estimated anemia affects over 30% of the world's population, with iron deficiency (ID) the overwhelmingly most common cause. Whether absolute due to blood loss and/or iron sequestration to underlying morbidity, the need for repletion especially in females, is a formidable medical issue. The diagnosis of iron deficient erythropoiesis has been traditionally based on the biochemical parameters ferritin and percent transferrin saturation (TSAT), mean cell volume and hemoglobin (Hb) concentration. In recent years, reticulocyte Hb content has emerged as a parameter helpful in identifying iron deficient erythropoiesis and informing a need, or lack thereof, for replacement. 556 consecutive, non-selected patients referred for diagnosis and/or treatment of anemia were included in this diagnostic study to compare the performance of reticulocyte hemoglobin equivalent (RET-He) versus traditional biochemical markers for diagnosis and treatment of IDA. CBC, serum ferritin, iron and TSAT were performed as clinically indicated. RET-He was measured with a Sysmex XN-450 analyzer on the residual CBC sample. 556 patients were studied at baseline and 150 were subsequently treated with intravenous (IV) iron. 240/556 were seen at follow-up, with 57 treated and 183 not treated with IV iron. At baseline, ret-He, positively correlated with Hb (Spearman correlation (rho)=0.365, P &lt; 0.001), MCV (rho=0.576, P &lt; 0.001), MCH (rho=0.777, P &lt; 0.001), serum iron (rho=0.526, P &lt; 0.001) and TSAT (rho=0.492, P &lt; 0.001). Serum iron, and TSAT (but not serum ferritin or MCV, or absolute reticulocyte count) positively correlated with Hb concentrations. Based on either a serum ferritin &lt;30 ng/ml and/or a TSAT&lt; 20%, 241/556 (43.4%) patients were diagnosed as iron deficient. Anemia was present in 64/241 of the iron deficient patients (26.6%). Despite the limitations of the biochemical markers outlined above, we performed ROC analysis assessing the value of RET-He in identifying iron deficiency as defined by serum ferritin &lt;30 ng/mL or transferrin saturation &lt;20%. ROC analysis demonstrates a reasonable performance for RET-He (AUC= 0.733, 95% CI: 0.692, 0.775), with a cut-off value of &lt;30.7 pg yielding 68.2% sensitivity and 69.7% specificity. Using both Hb and RET-He in a multivariable ROC analysis does not provide an improved AUC, as compared to just using RET-He (AUC=0.605 vs.0.733). IV iron administration was associated with significant increases in Hb, MCV, MCH, RET-He, serum ferritin, iron and TSAT, whereas in the no-IV iron cohort, there was a small reduction in RET-He and small increases in MCV and MCH, with no significant variations in Hb and in the other parameters. Serum ferritin was below 30 ng/mL in 18/57 (32%) of the patients requiring IV iron and in 19/183 (10.4%) of those not requiring iron at visit 1. These values changed to 4/57 (7%) (P=0.002) and 23/183 (13%) (P=0.623) at visit 2, respectively. Regression analysis for Hb response following IV iron showed that baseline RET-He values are predictive of Hb response, with every unitary increase in RET-He corresponding to a blunting of the Hb change by -0.19 g/dl (95% CI: -0.27, -0.11; P &lt; 0.001). Changes in RE-He associated with IV iron administration are also predictive of the Hb response, with every additional unit increase in RET-He corresponding to a 0.21 g/dL increase in Hb (95% CI: 0.13, 0.28; P &lt; 0.009). ROC analysis for the capability to predict Hb response among the 57 patients receiving IV iron shows that a value of baseline RET-He &lt; 28.5 pg together with a baseline Hb value &lt; 10.3 g/dL provide the highest Youden's index for predicting Hb response &gt; 1.0 g/dl, with sensitivity of 84% and specificity of 78%. The Figure presents data for the 21/57 patients who had RET-He &lt; 28.5 pg and Hb &lt; 10.3 g/dL vs the 36/57 who did not. The present data show that an abnormally low ret-He value (&lt; 28.5 pg) identifies patients who will respond to iron replacement, obviating delays to obtain standard iron parameters. Baseline and changes in ret-He also associate with Hb response. Given the enormous prevalence of ID in the general population the use of the ret-He, which is available with the CBC on the autoanalyzer, informs need for iron replacement, or lack thereof, represents an increase in convenience for patient and physician, decreases costs, streamlines care and represents an improvement in the treatment paradigm of one of the commonest maladies on the planet. Figure 1 Disclosures Auerbach: AMAG: Research Funding; Sysmex: Research Funding. Brugnara:American Journal of Hematology: Other; Sysmex America Inc.: Consultancy.