Erythrocytic phosphatidylserine exposure and hemostatic alterations in β-thalassemia intermediate patients

Introduction

Hypercoagulable state is one of the common findings in beta-thalassemia intermedia (β-TI), particularly in splenectomized patients, with infrequent blood transfusion. Abnormality of the red blood cells (RBC) membrane due to oxidative damage is suggestive of possible etiologies. Membrane lipid peroxidation increases the exposure of phosphatidylserine (PS) that plays a role in the activation of coagulation factors V and X, subsequently initiating thrombosis. Our aim of this study was to find the probable correlation of the alteration of the PS on the RBC outer membrane with the hypercoagulable state in the β-TI patients.

Materials and methods

Our cross-sectional study was conducted on 39 splenectomized β-TI patients and 38 age-matched healthy controls. The mean age was 37 years. Analysis of the PS exposure on the RBCs was performed by fluorescein isothiocyanate (FITC) conjugated AV protein .Measurement of the coagulation factors X, V and antithrombin III (AT-III) was performed. We also checked the D-dimer levels .Analysis was performed by SPSS16.

Results

Fluorescence of FITC-Annexin V labeling on patients RBCs were higher than healthy controls; (2.8 ± 2.2%) of the patients versus (0.4 ± 0.18%) in the control group and was statistically significant (P < 0.05). Mean levels of factor X and AT-III of the patients as compared with the control group decreased and showed significant difference (P < 0.05).

Conclusions

Circulation of thalassemic RBCs, which abnormally possess PS on RBC membrane outer surface, suggests the possibility of the gradual consumption of the coagulation factors in the presence of a chronic coagulability state.     

Compliance and satisfaction with deferasirox (Exjade®) compared with deferoxamine in patients with transfusion-dependent beta-thalassemia

Objective

The current standard option for iron chelation therapy (ICT) in transfusion-dependent patients with beta-thalassemia is deferoxamine (DFO). We aimed to compare the compliance with DFO vs. deferasirox (Exjade^®), a novel oral iron chelator, in patients with transfusion-dependent beta-thalassemia.

Methods

In this cross-sectional study, 220 patients from Southern Iran who were receiving DFO or Exjade^® for the last 2 years were investigated in 2012. Satisfaction, compliance, convenience, and life disturbances of the patients with ICT were evaluated. Assessments were performed at four different occasions during 1 year.

Results

According to the results, 114 patients received treatment with DFO and 106 patients were treated with Exjade^®. In comparison with the patients who were treated with DFO, those receiving Exjade^® reported a significantly higher rate of compliance and convenience (P < 0.05). However, no significant difference was observed between the two groups regarding their satisfaction (P > 0.05). In the DFO group, 44.9% of the patients reported irritation and pain at the injection site.

Conclusions

Considering higher rate of compliance and convenience with Exjade^® and the comparable efficacy of these two modalities of ICT documented in previous studies, Exjade^® can be used as a preferable choice of ICT in iron-overload patients with beta-thalassemia.     

Double knockout of pendrin and Na-Cl cotransporter (NCC) causes severe salt wasting, volume depletion, and renal failure

The Na-Cl cotransporter (NCC), which is the target of inhibition by thiazides, is located in close proximity to the chloride-absorbing transporter pendrin in the kidney distal nephron. Single deletion of pendrin or NCC does not cause salt wasting or excessive diuresis under basal conditions, raising the possibility that these transporters are predominantly active during salt depletion or in response to excess aldosterone. We hypothesized that pendrin and NCC compensate for loss of function of the other under basal conditions, thereby masking the role that each plays in salt absorption. To test our hypothesis, we generated pendrin/NCC double knockout (KO) mice by crossing pendrin KO mice with NCC KO mice. Pendrin/NCC double KO mice displayed severe salt wasting and sharp increase in urine output under basal conditions. As a result, animals developed profound volume depletion, renal failure, and metabolic alkalosis without hypokalemia, which were all corrected with salt replacement. We propose that the combined inhibition of pendrin and NCC can provide a strong diuretic regimen without causing hypokalemia for patients with fluid overload, including patients with congestive heart failure, nephrotic syndrome, diuretic resistance, or generalized edema.     

Advances in genetics show the need for extending screening strategies for autosomal dominant hypercholesterolaemia

Aims Autosomal dominant hypercholesterolaemia (ADH) is a major risk factor for coronary artery disease. This disorder is caused by mutations in the genes coding for the low-density lipoprotein receptor (LDLR), apolipoprotein B (APOB), and proprotein convertase subtilisin/kexin 9 (PCSK9). However, in 41% of the cases, we cannot find mutations in these genes. In this study, new genetic approaches were used for the identification and validation of new variants that cause ADH. Methods and results Using exome sequencing, we unexpectedly identified a novel APOB mutation, p.R3059C, in a small-sized ADH family. Since this mutation was located outside the regularly screened APOB region, we extended our routine sequencing strategy and identified another novel APOB mutation (p.K3394N) in a second family. In vitro analyses show that both mutations attenuate binding to the LDLR significantly. Despite this, both mutations were not always associated with ADH in both families, which prompted us to validate causality through using a novel genetic approach. Conclusion This study shows that advances in genetics help increasing our understanding of the causes of ADH. We identified two novel functional APOB mutations located outside the routinely analysed APOB region, suggesting that screening for mutations causing ADH should encompass the entire APOB coding sequence involved in LDL binding to help identifying and treating patients at increased cardiovascular risk.     

Ultrasonographic findings of experimental glaucoma in rabbits

Ocular ultrasonography is a valid and non-invasive diagnostic method used to evaluate ocular and retrobulbar structures, especially when opacity of the anterior segments precludes ophthalmic examination of deeper structures of the eye or when exophthalmos is present. This study describes the B-mode ultrasonographic findings of the globe in 10 rabbits with experimental glaucoma. Ultrasonography of the eyes, using Titan TM machine and 7 MHz linear array transducer, was performed transpalpebrally. Ocular ultrasonographic findings revealed two cases of increased corneal thickness, seven cases of change in the anterior chamber depth, one case of increased echogenicity in the anterior chamber, three cases of retinal detachment, one case of increased iris and ciliary body thickness and six cases of change in axial globe length. Increased echogenicity of the capsule, cortex and nucleus was found in two cases. Six cases showed change in lens diameter. Increased echogenicity and altered lens diameter are typical of cataract. Two cases of point-like lesions, mass and/or linear echodensities in mild extent were observed within the vitreous representing haemorrhage, vitreous degeneration or detachment. The B-mode ultrasonographic imaging technique has become an essential diagnostic tool in most ocular disease. This method provides additional information allowing the clinician to offer more accurate diagnosis, treatment and prognosis in glaucoma.