Liver density measured by DEXA correlates with serum ferritin in patients with beta-Thalassemia Major

Low Vitamin D Levels Are Associated with Increased Cardiac Iron Uptake in Beta-Thalassemia Major

We evaluated the association of vitamin D and parathormone (PTH) levels with cardiac iron and function in beta-thalassemia major (β-TM) patients. Two-hundred and seventy-eight TM patients (39.04 ± 8.58 years, 56.8% females) underwent magnetic resonance imaging for the assessment of iron overload (T2* technique), biventricular function parameters (cine images), and replacement myocardial fibrosis (late gadolinium enhancement technique). Vitamin D levels were deficient (<20 ng/dL) in 107 (38.5%) patients, insufficient (20-30 ng/dL) in 96 (34.5%) patients, and sufficient (≥30 ng/dL) in 75 (27.0%) patients. Deficient vitamin D patients had a significantly higher frequency of myocardial iron overload (MIO; global heart T2* < 20 ms) than patients with sufficient and insufficient vitamin D levels and a significantly higher left ventricular end-diastolic volume index and mass index than patients with sufficient vitamin D levels. PTH was not associated with cardiac iron, function, or fibrosis. In the multivariate regression analysis, vitamin D, serum ferritin, and pancreatic iron levels were the strongest predictors of global heart T2* values. In receiver operating characteristic curve analysis, a vitamin D level ≤ 17.3 ng/dL predicted MIO with a sensitivity of 81.5% and a specificity of 75.3% (p < 0.0001). In TM, the periodic and regular assessment of vitamin D levels can be beneficial for the prevention of cardiac iron accumulation and subsequent overt dysfunction.

TNF-alpha gene polymorphism and its relation to vitamin D, calcium, alkaline phosphatase and ferritin status in Iraqi beta thalassemia patients

Introduction and Aim: Due to a lack of effective medications, beta-thalassemia is a serious issue in Iraq. Thus, the current investigation aimed to explore the relationship between TNF-alpha gene polymorphism G/A (rs 1800629), Vitamin D (Vit D), Calcium (Ca), alkaline phosphatase (ALP), and ferritin status in Iraqi beta thalassemia major and intermediate patients.   Materials and Methods: Blood samples were collected from 46 patients suffering from thalassemia major (TM) plus 48 patients suffering from thalassemia intermediate (TI) and 48 of apparently healthy volunteers as control group aged 18-60 years, from Ibn Al-Baladi Hospital, Baghdad.   Results: Studies for the distribution of TNF- alpha G/A (rs 1800629) genotype showed that among TM patients and TI patients, the prevalence of the mutant AA genotype (rs 1800629) was higher in TM patients, while in the control group, it was lower.  Similarly, for the wild genotype (GG), the prevalence was highest in control group followed by T1 and TM patients. The frequency of A allele was high in TM patients, while the G allele frequency was more in the control group. Results also showed that the TNF- alpha genotype variations influenced Vitamin D, Calcium, ALP, and ferritin levels in TM and TI patients, wherein the patients with TNF-alpha mutant genotype (AA) were associated with highest levels of ferritin and ALP among all genotypes groups, while the patients of with TNF-alpha wild genotype (GG) were associated with high levels of Vitamin D and Calcium among all genotypes groups.   Conclusion: Patients with at least one copy of (A) allele had a higher risk of TM and TI and there was an association between the heterogeneous (GA) and mutant (AA) genotypes, also presence of (A) allele with status differences of Vit D, Ca, ALP, and ferritin in Iraqi beta thalassemia major and intermediate patients.

Assessment of Bone Density by DXA in Poorly Controlled Children With β-Thalassemia: Correction for Hepatic Iron Overload by Manual Analysis

INTRODUCTION

Beta thalassemia major (BTM) is characterized by anemia and iron overload, especially with inadequate chelation therapy. Dual energy x-ray absorptiometry software (DXA) may misanalyse bone measurements due to iron deposition in organs such as the liver. Our objective was to study difference between the posterior-anterior spine measurements of bone mineral content (BMC), area (BA) and density (BMD) in poorly chelated beta thalassemia patients with and without inclusion of the liver in the DXA analysis.

METHODS

We studied hemoglobin and serum ferritin concentrations in 208 patients with BTM (children n = 177, young adults n = 31). Posteroanterior spine measurements BMC, BA and areal BMD were performed using a GE iDXA. Using the tissue point typing feature (EnCore software, version 16), analysis was carried out including and excluding (manually) the iron overloaded liver. Machine generated Z-scores of L1-L4 BMD were used for analysis.

RESULTS

The mean age of the study group was 12.9 ± 5.4 yr. Mean hemoglobin and serum ferritin concentrations were 8.0 ± 1.7 g/dl and 2256.9 ± 1978.0 ng/ml, respectively. The mean BMC, BA, and aBMD at the lumbar spine were 23.2 ± 11.4 g, 29.9 ± 8.5 cm² and 0.736 ± 0.173 g/cm² respectively with inclusion of liver that is standard machine analysis. After the liver was excluded from the analysis, the mean BMC, BA, and aBMD were 23.9 ± 11.6 g, 30.0 ± 8.6 cm² and 0.757 ±0.173 g/cm^2, respectively and the BMC and aBMD were significantly greater (p < 0.05). Mean BMD Z-score was -1.5 ± 1.2, which significantly (p < 0.05) improved to -1.3 ± 1.2 after exclusion of the liver from the analysis.

CONCLUSION

In poorly chelated patients with thalassemia, inclusion of the iron-overloaded liver in the tissue analysis may exaggerate the deficit in bone parameters. Iron overloaded tissues need to be manually excluded during analysis of the PA spine.

Vitamin D Receptor (VDR) Gene Polymorphisms (FokI, BsmI) and their Relation to Vitamin D Status in Pediatrics βeta Thalassemia Major

Vitamin D is critical for calcium, phosphate homeostasis and for mineralization of the skeleton, especially during periods of rapid growth. Vitamin D Deficiency leads to rickets (in children) and osteomalacia (in adults). Expression and activation of the vitamin D receptor (VDR) are necessary for the effects of vitamin D, in which several single nucleotide polymorphisms have been identified especially (FokI, BsmI). In this study serum 25 (OH) vitamin D3 levels were estimated by Enzyme Linked Immunosorbent Assay [ELISA], VDR (FokI, BsmI) gene polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism assay [PCR-RFLP].Serum levels of calcium, phosphorus, alkaline phosphatase and ferritin were determined in 50 Pediatrics beta thalassemia major patients and 60 controls. Patients had significantly lower serum calcium (p < 0.001) lower serum vitamin D3 (p < 0.001) with elevated levels of phosphorus (p < 0.001) and alkaline phosphatase than controls (p = 0.04). Of the patients studied, 60 % had vitamin D deficiency (<20 ng/ml), 20 % had vitamin D insufficiency (21-30 ng/ml) and 20 % had sufficient vitamin D status (>30 ng/ml). Patients harboring mutant (Ff,ff) and wild (BB) genotypes were associated with lower serum calcium (p = 0.08, 0.02) respectively, lower vitamin D3 levels (p < 0.001, 0.01) respectively. They were also suffering from more bony complications although the difference was not statistically significant (p > 0.05). In conclusion, these results suggest that the VDR (FokI, BsmI) gene polymorphisms influence vitamin D status, (Ff,ff), BB genotypes had lower vitamin D levels, so they might influence risk of development of bone diseases in beta thalassemia major.

A sequence variation: 713-8delC in the transforming growth factor beta 1 gene polymorphism in thalassemia major patients

Osteoporosis remains an important cause of morbidity in β-thalassemia major. Although several factors have been implicated to play an important role in the pathogenesis of osteoporosis and several candidate gene polymorphisms have been found to regulate this process, its pathogenesis has not been completely elucidated. Deletion of a C in the fourth intron sequence 8 base before exon 5 (713-8delC) of transforming growth factor beta 1 (TGF-β1) gene which has been reported significantly higher in the osteoporotic group was studied for its prevalence and association with bone mineral density (BMD) in thalassemia major patients. The aim of this study was to find out the distribution of TGF-β1 (713-8delC) sequence variation and its relationship with BMD in thalassemia major patients. 713-8delC Sequence variation polymorphism was detected in 150 β-thalassemia major patients and their BMD was measured by dual-energy X-ray absorptiometry. Biochemical levels were estimated by enzyme-linked immunosorbent assay. We have found a remarkable incidence (90%) of osteopenia and osteoporosis among regularly transfused patients. We have found no association of 713-8delC variant of TGF-β1 gene with Z-score of BMD at lumbar spine (p = 0.061) and hips (p = 0.773). However, Cc genotype of TGF-β1 gene was found as a risk factor (odds ratio: 3.3) for low bone density in these patients.

Use of hormone replacement therapy for correction of high turnover bone disease in hypogonadal β-Thalassemia major patients presenting with osteoporosis: comparison with idiopathic premature ovarian failure

Osteopenia-osteoporosis syndrome (OOS) causes considerable morbidity in 60-80% β-thalassemia major (β-TM) patients. We evaluated the effect of sex hormone replacement therapy (HRT) in β-TM patients with hypogonadism presenting with OOS using premature ovarian failure (POF) for comparative purposes. We undertook a 10-year prospective study of in 50 β-TM and 375 patients with POF and OOS. All were treated with HRT for 2-5 years. We used dual X-ray absorptiometry (DEXA), and plasma type 1-collagen markers of bone turnover for monitoring of response to therapy. Our results suggest that prior to HRT, both groups had comparable degrees of OOS. Both groups had significant improvement but the POF group had normalization of spinal T scores following HRT in contrast to the β-TM patients. Femoral T scores did not normalize in both groups. These data indicate for the first time from comparative POF control studies that hypogonadism is not the only cause of OOS in β-TM.

Dual-energy X-ray absorptiometry with serum ferritin predicts liver iron concentration and changes in concentration better than ferritin alone

Accurate assessment of liver iron concentration (LIC) is critical for optimal monitoring of iron toxicity in multitransfused patients. Serum ferritin is the most widely used although its association to LIC is only modest. We studied if a liver-specific measure using dual-energy X-ray absorptiometry (DXA) systems could improve LIC estimates over ferritin alone in Thalassemia (Thal) patients. Thirty-seven patients with Thal (19.2 ± 9.0 yr, 20 male) were studied and 10 had multiple visits. Height, weight, ferritin, whole-body DXA, and hepatic superconducting quantum interference device (SQUID) were measured within 5 wk. DXA hepatic density was measured using right rib, whole liver, and multiple subliver regions. The best agreement to SQUID LIC was found using a combination of ferritin, weight, DXA subliver region 3 bone mineral content (BMC), and right rib BMC. DXA with ferritin improved the ferritin alone correlation from R(2)=0.35 to R(2)=0.62. Serial LIC changes using DXA were associated with serial SQUID changes (r=0.73, p=0.02). Changes in ferritin alone were not significant (p=0.06). We conclude that the addition of whole-body DXA measures and body weight substantially increased the accuracy of LIC and change in LIC estimates over the use of ferritin alone and could be useful when magnetic resonance imaging or SQUID is not available.

Soft tissue density variations in thalassemia major: a possible pitfall in lumbar bone mineral density measurements by dual-energy X-ray absorptiometry

Osteoporosis is common in patients with thalassemia major. A 16-year-old patient with thalassemia major was referred for evaluation of osteoporosis. The results of dual-energy X-ray absorptiometry in a patient with thalassemia major are presented. The patient underwent measurements of the spine in both AP and lateral position. The DXA scan of the spine in AP projection showed diffusely increased density overlying the lower thoracic and upper lumbar vertebrae. The overall density of L(2)-L(4) was 0.6465 g/cm(2) (4.93 SD as compared with young adults). The DXA scan of the spine in lateral projection showed diffusely increased density in front part of the spine. The BMD of the L(3) vertebra was 0.3669 g/cm(2) (0.30 SD as compared with young adults). It is important to interpret the images visually in order to obtain true values of BMD, and preclude invalid BMD measurements.