The association of TMPRSS6 gene polymorphism with iron status in Egyptian children (a pilot study)

Several studies have shown association of single nucleotide polymorphisms (SNPs) of hepcidin regulatory pathways genes with impaired iron status. The most common is in the TMPRSS6 gene. In Africa, very few studies have been reported. We aimed to investigate the correlation between the common SNPs in the transmembrane protease, serine 6 (TMPRSS6) gene and iron indicators in a sample of Egyptian children for identifying the suitable candidate for iron supplementation.Patients and methods One hundred and sixty children aged 5-13 years were included & classified into iron deficient, iron deficient anemia and normal healthy controls. All were subjected to assessment of serum iron, serum ferritin, total iron binding capacity, complete blood count, reticulocyte count, serum soluble transferrin receptor and serum hepcidin. Molecular study of TMPRSS6 genotyping polymorphisms (rs4820268, rs855791 and rs11704654) were also evaluated.Results There was an association of iron deficiency with AG of rs855791 SNP, (P = 0.01). The minor allele frequency for included children were 0.43, 0.45 & 0.17 for rs4820268, rs855791 & rs11704654 respectively. Genotype GG of rs4820268 expressed the highest hepcidin gene expression fold, the lowest serum ferroportin & iron store compared to AA and AG genotypes (p = 0.05, p = 0.05, p = 0.03 respectively). GG of rs855791 had lower serum ferritin than AA (p = 0.04), lowest iron store & highest serum hepcidin compared to AA and AG genotypes (p = 0.04, p = 0.01 respectively). Children having CC of rs11704654 had lower level of hemoglobin, serum ferritin and serum hepcidin compared with CT genotype (p = 0.01, p = 0.01, p = 0.02) respectively.Conclusion Possible contribution of SNPs (rs855791, rs4820268 and rs11704654) to low iron status.

Detection of exosomal miR-18a and miR-222 levels in Egyptian patients with hepatic cirrhosis and hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is known to be the second leading cause of cancer-related mortality worldwide. For improving the prognosis as well as reducing the rate of mortality, early diagnosis of HCC is a must.

AIMS

This study was conducted to assess the ability of the serum expression of exosomal miR-18a and miR-222 to differentiate and diagnose patients with HCC, patients with liver cirrhosis, and healthy controls.

METHODS

This study included 51 patients with liver cirrhosis, 51 patients with HCC on top of hepatitis C virus (HCV) infection, and 50 healthy controls.

RESULTS

miR-18a and miR-222 were assessed using reverse transcription-polymerase chain reaction. MiR-18a and miR-222 levels were significantly higher in the liver cirrhosis and HCC groups than the control group (p ˂ 0.001). However, no statistically significant difference was found between patients with HCC and liver cirrhosis (p = 0.4 for miR-18a and p = 0.1 for miR-222). ROC curve analyses to evaluate the diagnostic performances of the two miRNAs as important noninvasive diagnostic markers revealed a best cutoff value of 2 for miR-18a to differentiate between liver cirrhosis, HCC, and healthy controls. And for mir-222, a cutoff value of 1.7 and 1.9 showed the highest specificity for discrimination between liver cirrhosis, HCC, and healthy controls, respectively. Moreover, logistic regression model revealed that miR-18a expression was independent predictive factor in HCC patients (p = 0.004), while miR-222 expression was independent predictive factor in liver cirrhosis patients (p < 0.001).

CONCLUSION

miR-18a and miR-222 were significantly discriminative markers between patients with liver cirrhosis and HCC and healthy individuals. Therefore, they have a prognostic rather than a diagnostic value. Moreover, miR-18a and miR-222 could be useful in identifying liver injuries, including fibrosis and cirrhosis.

Oxidative stress and hepcidin expression in pediatric sickle cell anemia with iron overload

BACKGROUND

Blood transfusion (BT) is essential in treating sickle cell disease (SCD); however, it leads to iron overload (IO) and oxidative stress. We studied the relationship between oxidative stress, iron status parameters, hepcidin mRNA gene expression, and IO in SCD patients.

METHODS

We classified all SCD patients (n = 90) into two groups: Group I, 45 children (s.ferritin ≥ 938 ng/mL) and Group II, 45 children (s.ferritin < 938 ng/mL). A total of 55 children, age and sex matched, participated as a control group. Malondialdehyde (MDA), nitrite, s.iron, s.total iron-binding capacity (sTIBC), transferrin saturation %, s.ferritin, s.hepcidin, and hepcidin mRNA gene expression were assessed.

RESULTS

Among SCD BT-dependent patients (>3 times/year), 63% were from Group I and 37% from Group II, p < .01. The two patient groups had significantly lower s.hepcidin and hepcidin gene expression than controls (p < .001). TIBC, s.iron, s.ferritin, transferrin saturation %, ferritin/hepcidin ratio, and MDA levels were higher among SCD patients than controls (p < .001). Group I had higher mean level of ferritin/hepcidin ratio and MDA than Group II (p < .01). The higher level of MDA and increased frequency of BT were the significant predicting risk factors for IO (p < .05). A receiver-operating characteristic curve indicates that MDA is the outstanding significant biomarker for high level of s.ferritin with subsequent IO progression.

CONCLUSION

MDA may serve as a biomarker of oxidative stress and IO in SCD patients. This result paid attention for urgent initiation of antioxidant and chelation therapy on detecting increased MDA level.

Hepcidin and its Related Hematological Biomarkers of Anemia in Children on Hemodialysis: Role of Carnitine Deficiency

BACKGROUND: Anemia is one of the most common complications in end-stage renal disease (ESRD) patients. Hepcidin is a hormone that regulates iron homeostasis in patients with ESRD. Carnitine deficiency is commonly seen in hemodialysis (HD) patients. AIM: This study aimed to investigate the relationship between hepcidin and inflammatory and other anemia markers in children with ESRD and to evaluate the association of carnitine deficiency with anemia in these patients. SUBJECTS AND METHODS: Thirty pediatric patients with ESRD undergoing HD, and thirty healthy, age- and sex-matched children served as controls were included in the study. Serum levels hepcidin, iron status, high-sensitivity C-reactive protein, and total carnitine were measured. RESULTS: Statistically significant increases in serum levels of hepcidin (100.7 ± 0.99 ng\ml vs. 77.43 ± 0.8 ng\ml, p = 0.000), was found in HD children as compared to healthy controls. Statistically significant increase in serum levels of hs-CRP (3.94 ± 0.19 mg/l vs. 1.36 ± 0.07 mg/l, p = 0.04) was found in HD children as compared to healthy controls. However, serum levels of carnitine (29.59 ± 2.46 μmol/L vs. 36 ± 2.39 μmol/L, p = 0.000) showed statistically significant decreases in HD children as compared to healthy controls positive correlation was found between hepcidin and hs-CRP (r = 0.059, p = 0.042). Furthermore, a positive correlation was present between serum carnitine levels and serum iron levels (r = 0.651, p = 0.042). CONCLUSION: Serum hepcidin may be a more useful biomarker of functional iron deficiency in children on HD. The efficacy of carnitine treatment for children on HD with carnitine deficiency and its effect on anemia needs to be studied.

The Relation between Serum Hepcidin, Ferritin, Hepcidin: Ferritin Ratio, Hydroxyurea and Splenectomy in Children with β-Thalassemia

BACKGROUND:

Hepcidin, a small peptide hormone, is established as the main regulator of iron homeostasis.

AIM:

To estimate serum hepcidin, ferritin, and hepcidin: ferritin ratio in β-thalassemia patients and to determine the effect of splenectomy and hydroxyurea on serum hepcidin.

METHODS:

A study was conducted on 30 thalassemia major (βTM), 29 thalassemia intermedia (βTI) and 29 healthy children’s controls. Data were collected by patient interviewing where detailed history-taking and thorough clinical examinations were carried out. Serum ferritin and hepcidin were measured by ELISA assay (Bioneovan Co. Ltd Beijing, China).

RESULTS:

Βeta-thalassemia patients had higher serum ferritin, serum hepcidin and lower Hb and hepcidin: ferritin ratio compared to the controls (p < 0.001, 0.010, 0.001, 0.001) respectively. Β-TM patients had higher mean serum hepcidin and serum ferritin compared to β-TI, with statistically significant difference (P = 0.042, P < 0.001, respectively). Twenty-one patients out of 29 βTI was on hydroxyurea therapy; these patients had significantly lower levels of serum ferritin (P < 0.004) and significantly higher levels of Hb (P < 0.004). Serum ferritin was statistically significantly higher in splenectomized patients P < 0.009. Serum hepcidin level was insignificantly higher in splenectomized patients than non-splenectomized patients (21.6 ± 14.75, 17.76 ± 10.01 ng/mL). Hepcidin showed a significantly positive correlation with hepcidin: ferritin ratio in all studied groups.

CONCLUSION:

Serum hepcidin was elevated in β-thalassemia children with more evident elevation in βTM patients. Splenectomy played no major role in hepcidin regulation. Knowing that hepcidin in serum has a dynamic and multi-factorial regulation, individual evaluation of serum hepcidin and follow up, e.g. every 6 months could be valuable, and future therapeutic hepcidin agonists could be helpful in management of iron burden in such patient.

Matrix Metalloproteinase (MMP)-9 Levels in Children on Hemodialysis: Association with MMP-9 C-1562T Gene Polymorphism and Vitamin D Levels

BACKGROUND AND OBJECTIVES

Data concerning the concentration of matrix metalloproteinase-9 (MMP-9) and its functional polymorphisms in chronic kidney diseases (CKD) are conflicting. The present study aimed to evaluate the levels of MMP-9in children with end stage renal diseases (ESRD) on hemodialysis (HD) and to explore its association with MMP-9 polymorphism and vitamin D levels as an important risk factors for cardiovascular diseases (CVD).

METHODS

We studied 55 children with ESRD on hemodialysis and 18 healthy children served as controls. MMP-9 and vitamin D levels were measured by ELISA in serum of all patients and controls. Genotypes for MMP-9 polymorphism(C^-1562T) were determined by RFLP for only 28 of the patients and all the controls.

RESULTS

There were insignificantly reduced MMP-9levels of patients vs. controls, however, there was significant increase in MMP-9 levels associated with CC genotypes for(C^-1562T) polymorphism compared with CT genotype (p=0.01). We found that at MMP-9 base position-1562, the frequencies of the genotypes CC and CT in Children on HD were 71.4% and 28.6% respectively while all our controls were of the CC genotype. The alleles frequencies of C and T in patients were 85.7% and 14.29% as compared to 100% and 0%, respectively in the controls. Significant decrease in vitamin D was observed in children on HD versus that in controls (p=0.008). Serum MMP9 levels and age were variables that were independently associated with CVD.

CONCLUSIONS

MMP9 genetic polymorphism (C^-1562T) affects MMP9alterations in ESRD children on HD and vitamin D deficiency is common in our HD pediatric patients who require attention in accordance with current practice guidelines. They probably require supplementation with higher doses of cholecalciferol.

Lymphocyte Activation Markers in Pediatric Kidney Transplant Recipients

BACKGROUND AND OBJECTIVES

The role of CD4+CD25+ T regulatory cells (Tregs) in immune tolerance in experimental transplantation is very important but the clinical significance of circulating Tregs in the peripheral blood is undetermined. We evaluated the association between the frequency of T cell activation markers CD25 and CD71 and clinical parameters that may affect the level of these T cell markers.

METHODS

In 47peditric kidney transplant (KT) recipients and 20 healthy controls, the frequency of T cell activation markers, CD25 and CD71 was measured with flow cytometry after transplantation. Two clinical protocols of induction immunosuppression were used: (1) anti-thymocyte globulin (THYMO) group (n =29) and Basiliximab (BSX) group (n=10).

RESULTS

The percentage of circulating CD25 after KT was significantly lower than that in the controls. There is no significant difference between KT and the controls s regard to circulating CD71. The percentage of CD25 was significantly increased in children with acute rejection compared with those without acute rejection. Calcineurin inhibitors (CNIs) decreased the frequency of CD25 but mammalian target rapamycin (mTOR) inhibitor did not. The proportion of CD25 significantly decreased in THYMO group during the first year after transplantation.

CONCLUSION

The frequency of circulating T cell activation marker CD25 in pediatric KT recipients is strongly affected by CNIs, and a high frequency of CD25 is associated with acute rejection during the early posttransplant period. The measurement of T cell activation markers, may become a useful immune monitoring tool after kidney transplantation.

Some amino acids levels: glutamine,glutamate, and homocysteine, in plasma of children with chronic kidney disease

BACKGROUND

The high prevalence of protein-energy malnutrition is a critical issue for patients with chronic kidney disease (CKD). Serum albumin is the most commonly used nutritional marker. Another index is plasma amino acid (AA) profile. Of these, the plasma levels of glutamine, glutamate and homocysteine, correlate well with nutritional status. We measured some plasma AAs in children with different stages CKD to provide information in monitoring the therapeutic strategy, particularly in AA supplementary therapy or protein restriction.

METHODS

Three amino acids were evaluated along with albumin and high sensitivity C-reactive protein (hs-CRP) in 30 patients with advanced CKD stages 4 and 5. They were divided into two groups undergoing conservative treatment (CT) (n=15) or hemodialysis (HD) (n=15). An additional group of patients with nephrotic syndrome [CKD stage 2] was also studied to assess the alterations of plasma free amino acids with the early stage of CKD. Another 30 age- and sex-matched healthy children served as controls.

RESULTS

A significant increase in plasma concentration of amino acid glutamine was observed in children with advanced CKD stages 4 and 5 when compared with controls (P=0.02).Plasma glutamine level was significantly higher in ESRD children on HD than in children with nephrotic syndrome (P=0.02). We did not find a significant difference between HD children and CT children as regard to glutamine level. Notable differences were in the plasma homocysteine level detected in the CKD groups patients, which was greater than that in controls (P=0.0001). Plasma homocysteine level was significantly higher in children on HD than in children with nephrotic syndrome (P=0.01). A significant differences was observed in hs-CRP levels between the CKD groups and the controls (P=0.04). Albumin levels were lower in CKD groups than in controls (p=0.01). Glutamine showed significant positive correlations with blood urea level (r=0.84, P=0.002) and blood ammonia level (r=0.72, P=0.0001). On multiple linear regression, urea was the only variable independently associated with an elevated plasma glutamine level (Beta=0.77, P=0.02).

CONCLUSION

This study indicates that the advanced stages of CKD are associated with increased plasma concentrations of glutamine and homocysteine. Glutamine retained in the plasma of children with CRF, possibly producing higher levels of the waste products (urea and NH3). Dialysis alone is insufficient to redress completely the abnormalities in AA metabolism in ESRD children. Careful consideration of dialysis and dietary measures are necessary.

Adiponectin: an adipocyte-derived hormone, and its gene encoding in children with chronic kidney disease

Background

The prevalence of cardiovascular disease (CVD) and inflammation is high in patients with chronic kidney disease (CKD). Adiponectin (ADPN) is an adipocytokine that may have significant anti-inflammatory and anti-atherosclerotic effects. Low adiponectin levels have previously been found in patients with high risk for CVD.

Methods

On seventy eight advanced CKD (stages 4 and 5) pediatric patients undergoing maintenance hemodialysis( MHD) or conservative treatment (CT) the following parameters were studied: body mass index, left ventricular mass index(LVMI), serum adiponectin , cholesterol, HDL-cholesterol, high sensitivity C-reactive protein (hs CRP),interleukin 6(IL6) and single-nucleotide polymorphisms (SNPs) in the ADIPOQ gene at positions 45, and 276. Seventy age-and gender-matched healthy subjects served as control subjects.

Results

Markedly (P = 0.01) elevated plasma adiponectin levels were observed in CKD patients, especially CT patients, compared to control subjects. The wild type of ADIPOQ 45T > G (T) allele is the main gene for patients and controls. MHD and CT patients had significantly higher frequency of the TT genotypes of +276G > T gene (P = 0.04) compared with control subjects. A significant positive correlation was observed between plasma adiponectin and IL6 level, whereas negative correlations were found between adiponectin level, cholesterol, HDL cholesterol and hs CRP. In a stepwise backward multiple regression model only IL6 (P = 0.001) was independently associated with plasma adiponectin levels. The adiponectin gene the 276 GT+TT genotypes were associated with a higher level of adiponectin .

Conclusions

The present study demonstrated that ADPN is related to several metabolic and inflammatory CV risk factors in a manner consistent with the hypothesis that this protein might have a protective role against these factors. We observed an association between the +276G>T SNP in the adiponectin gene and CKD in children. Genetic variation of +276 gene seemed to have a positive impact on circulating adiponectin levels in CKD patients.

Genetic polymorphism of ACE and the angiotensin II type1 receptor genes in children with chronic kidney disease

AIM AND METHODS

We investigated the association between polymorphisms of the angiotensin converting enzyme-1 (ACE-1) and angiotensin II type one receptor (AT1RA1166C) genes and the causation of renal disease in 76 advanced chronic kidney disease (CKD) pediatric patients undergoing maintenance hemodialysis (MHD) or conservative treatment (CT). Serum ACE activity and creatine kinase-MB fraction (CK-MB) were measured in all groups. Left ventricular mass index (LVMI) was calculated according to echocardiographic measurements. Seventy healthy controls were also genotyped.

RESULTS

The differences of D allele and DI genotype of ACE were found significant between MHD group and the controls (p = 0.0001). ACE-activity and LVMI were higher in MHD, while CK-MB was higher in CT patients than in all other groups. The combined genotype DD v/s ID+II comparison validated that DD genotype was a high risk genotype for hypertension .~89% of the DD CKD patients were found hypertensive in comparison to ~ 61% of patients of non DD genotype(p = 0.02). The MHD group showed an increased frequency of the C allele and CC genotype of the AT1RA1166C polymorphism (P = 0.0001). On multiple linear regression analysis, C-allele was independently associated with hypertension (P = 0.04).

CONCLUSION

ACE DD and AT1R A/C genotypes implicated possible roles in the hypertensive state and in renal damage among children with ESRD. This result might be useful in planning therapeutic strategies for individual patients.