Biochemical and imaging markers in patients with thalassaemia

CRISPR/Cas12a-triggered ordered concatemeric DNA probes signal-on/off multifunctional analytical sensing system for ultrasensitive detection of thalassemia

Based on CRISPR/Cas12a triggered ordered concatemeric DNA probes, a "on/off" self-powered biosensor is developed to achieve highly sensitive detection of thalassemia gene CD142 through open-circuit potential-assisted visual signal output. The ingeniously constructed glucose oxidase (GOD)-functionalized ordered concatemeric DNA probe structure can significantly amplify signal output, while the coupled CRISPR/Cas12a system is served as a "signal switch" with excellent signal-transducing capabilities. When the ordered concatemeric DNA probe structure is anchored on electrode, the response signal of the sensing system is in the "signal on" mode. While, the presence of the target activates the non-specific cleavage activity of the CRISPR/Cas12a system, causing the sensing system to switch to the "signal off" mode. In the detection system, GOD catalyzes the oxidation of glucose to produce hydrogen peroxide, which further catalyzes the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) to form a color product, enabling visual signal of the target through naked-eye color contrast. By employing a multifunctional analytical mode combining electrochemical and visual signal outputs, accurate determination of the target is achieved, with linear ranges of 0.0001-100 pM, and detection limits of 48.1 aM (S/N = 3). This work provides a reference method for sensitive detection of thalassemia genes and holds great diagnostic potential in biomedical applications.

Adipocyte fatty acid-binding protein (FABP4) as a potential biomarker for predicting metabolically driven low-grade and organ damage in thalassemia syndromes

Adipocyte fatty acid-binding protein (A-FABP; FABP4) plays a significant role in the pathogenesis and progression of metabolically driven low-grade inflammation and organ damage. This study aimed to evaluate the performance of circulating FABP4 as a predictive and diagnostic biomarker for thalassemia-associated cardiometabolic events. This case-control study enrolled 50 adults with β-thalassemia and 30 age-, sex-, and body mass index-matched controls. Participants underwent a comprehensive evaluation, including complete blood count, liver and kidney function tests, serum blood glucose, lipid profile, and ferritin levels, pelviabdominal ultrasound, ECG, and echocardiography after taking a full medical history and conducting a clinical examination. Serum levels of FABP4 were measured using an Enzyme-Linked-Immunosorbent-Assay. The diagnostic performance of FABP4 was assessed using receiver operator characteristic (ROC) curve analysis to determine optimal values for excluding and confirming cardiometabolic metflammation. The thalassemia cohort exhibited a statistically significant higher concentration of FABP4 compared to the control group (p-value < 0.001). Positive correlations were found between FABP4 and ferritin serum levels above 800 or 1000 ug/L, as well as with ALT, TGS, and LDL (p-value < 0.05). Circulating FABP4 was identified as a statistically significant risk factor for thalassemia-associated cardiometabolic comorbidities (OR = 84.00, 95%CI:18.6-378.6, p-value < 0.001). ROC analysis determined that the FABP4 exclusionary cut-off value > 2.30 ng/ml could effectively discriminate between thalassemia-associated adverse metaflammation and controls, while the FABP4 confirmatory cut-off value was > 2.58 ng/ml. In conclusion, circulating FABP4 appears to be a potential risk factor for predicting progression to cardiometabolic events in thalassemia-associated adverse metaflammation. FABP4 holds promise as a diagnostic and prognostic biomarker for disease monitoring and risk stratification. Further validation through large-scale, multicenter, prospective studies is warranted.

The Exploring of Growth Differentiation Factor-15 and H63D Gene Polymorphisms in β-thalassemia Major: Implications for Cardiovascular Risk and Iron Overload

BACKGROUND:

β-thalassemia major (βTM) is a genetic disorder characterized by a deficiency in hemoglobin production, ineffective erythropoiesis, chronic hemolysis, lifelong blood transfusions, iron overload, and increased risk of cardiac complications.

OBJECTIVE:

The study aimed to evaluate the growth differentiation factor-15 (GDF-15) concentration in βTM patients and its correlation with cardiac complications. H63D refers to a specific mutation in the HFE gene, which is associated with hereditary hemochromatosis (HH), a genetic disorder characterized by excessive accumulation of iron in the body. This mutation involves a change of histidine (H) to aspartic acid (D) at position 63 in the HFE protein. This mutation is often only written abbreviated as (H63D).

MATERIALS AND METHODS:

This case–control study was done on 120 subjects. A total of 60 patient samples were randomly collected from the Genetic Hematology Center at the Babylon Hospital, with an age range of 10–26 years. In addition, 60 samples were collected from healthy children in the same age range as the control group; patients and controls were subdivided into (10–18) and (18–26) year groups. GDF-15 was measured by enzyme-linked immunosorbent assay, and the genotyping of mutation was done by amplification refractory mutation system-polymerase chain reaction technique.

RESULTS:

The study revealed a significant increase in ferritin (FER) and GDF-15 levels in the patients compared to controls (P< 0.001). GDF-15 showed a direct correlation with age (r= 0.244,P= 0.02) and FER (r= 0.215,P= 0.04). There was a significant difference in H63D mutations between controls and patients (P = 0.044), with a higher proportion of the C-G (heterozygous for the mutant allele) genotype observed in βTM patients (31.67%). Additionally, a notable effect of the H63D mutation on serum ferritin (higher) levels within the βTM group was observed.

CONCLUSION:

Elevations of the GDF-15 in βTM patients indicate a high risk of cardiovascular complications in patients with βTM. The H63D mutation of the hemostatic iron regulator (HFE) gene is frequently found in βTM. Although a significant effect of the mutation was obtained on serum FER levels, it did not act as a risk factor in βTM patients. However, the frequent presence of the H63D mutation in patients indicated a possible association between single-nucleotide polymorphism and the iron regulation pathway.

The correlation of cardiac biomarkers and myocardial iron overload based on T2* MRI in major beta-thalassemia

Cardiac hemosiderosis is the primary factor to derive the pathogenesis of cardiac dysfunction in patients with transfusion dependent thalassemia. Biomarkers assessment along with T2 * MRI study could be employed to evaluate the severity of iron deposition-related damage and determination of the diagnostic and prognostic value of these inflammatory factors. The study was conducted on 62 patients (12-44 years old) with major thalassemia. The patients were under regular blood transfusion and they had no signs of cardiac defects, and chronic diseases. The serum levels of inflammatory factors (NT-proBNP, CRP, Copeptin HS) were determined before routine transfusion. Cardiac iron overload was assessed by T2* MRI (within the last three months), and T2* lower than 20 ms was considered as cardiac siderosis. The obtained results were analyzed using statistical methods. 92% of patients showed an increased level of hs-CRP (> 2 µg/dL). All cases showed increased levels of NT-proBNP (> 150 pg/mL). Only 29% of subjects showed high level of Copeptin, 25.8% of patients demonstrated cardiac siderosis based on the T2* MRI (< 20 ms) results. The serum levels of inflammatory factors were not significantly correlated with cardiac siderosis. Given the obtained results, it could be deduced that the serum levels of inflammatory factors could not be exploited for early detection of cardiac siderosis in major beta-thalassemia patients.

Early Detection of Iron Overload Cardiomyopathy in Transfusion Dependent Thalassemia Patients in Sulaimaniyah City, Iraq

Background

Lifelong blood transfusion is recommended for patients with transfusion-dependent thalassemia (TDT) that lead to iron overload and results in cardiomyopathy (CM).

Aim

To assess the accuracy of several electrocardiographic (ECG) data in patients at high risk of arrhythmia, early detection of structural and functional changes in left atrium and ventricle using ECG and echocardiography (two dimensional, M-mode echocardiography along with Doppler studies), and to observe the correlations between plasma B-type atrial natriuretic peptide (BNP)/serum ferritin and ECG with Doppler as well as echocardiographic changes in patients with TDT.

Methods

The current prospective case-control study included 75 TDT patients and 74 control subjects with the mean age of 9.55 and 9.93 years, respectively. Participants were assessed for the socio-demographic, physical examinations, serum ferritin, plasma BNP, ECG, 2D echocardiography, and tissue/pulse wave Doppler.

Results

The mean of serum ferritin and plasma BNP were significantly (p<0.001) higher in the cases (1475.19 ng/mL and 47.63 pg/mL, respectively) than controls (41.3 ng/mL and BNP 23.37 pg/mL, respectively). ECG findings showed significant higher P-wave dispersion, QRS duration, QT duration and dispersion, and JTc dispersion in cases than controls. Echocardiography findings revealed diastolic dysfunction with preserved ejection fraction (EF) in thalassemia cases, as well as significant higher left ventricular (LV) mass, LV internal diameters during systole and diastole (LVIDs and d) and LV posterior wall thickness during diastole (LVPWd) in cases than controls (p<0.05). Also, a significant (p<0.05) correlation between BNP and QT dispersion was found in patients.

Conclusion

These findings suggest the usefulness of ECG, 2D echocardiographic, Doppler studies and plasma BNP, with no significant beneficial effect of serum ferritin level in detecting early cardiac changes in patients with TDT.