Ischemia modified albumin: an oxidative stress marker in ß-thalassemia major.

BACKGROUND: Ischemia modified albumin (IMA) is an altered type of serum albumin that forms under conditions of oxidative stress. This study reports on the levels and clinical significance of IMA in patients with ß-thalassemia major. METHODS: Blood specimens were collected from 166 subjects (101 ß-thalassemia major patients and 65 healthy controls). Serum levels of IMA, ferritin, malondialdehyde (MDA), ferroxidase, transaminases, total protein, and albumin were determined using conventional methods. RESULTS: Serum levels of IMA (ABSU) were significantly higher in patients than in controls (0.725±0.155 vs 0.554±0.154, p=0.000). Similarly, higher levels were also observed for ferritin, MDA, ferroxidase, and transaminases. No significant differences were observed between patients and controls with respect to total protein and albumin. Spearman univariate analysis demonstrated significant correlation between IMA and ferritin, MDA, ferroxidase, and transaminases. Multiple linear regression analysis revealed significant association of IMA with ferritin and ferroxidase after adjusting for the other variables (r=0.343, p=0.002; r=0.228, p=0.029 respectively). MDA however, correlated significantly with ferritin only (r=0.654, p=0.000). CONCLUSION: Our findings suggest that increased levels of IMA in thalassemic patients are likely to be a result of iron-induced oxidative stress and hence its potential significance as a new marker of oxidative stress in such patients.

Association of haptoglobin phenotypes with ceruloplasmin ferroxidase activity in ß-thalassemia major.

BACKGROUND: Haptoglobin (Hp) and ceruloplasmin (CP) are 2 plasma antioxidants playing a role in preventing iron-induced oxidative damage. This study presents data related to Hp phenotypes and ceruloplasmin ferroxidase activity in relation to iron store markers in patients with ß-thalassemia major. METHODS: Blood specimens were collected from 196 subjects (124 ß-thalassemia major patients and 72 healthy controls). Serum levels of iron, total iron binding capacity (TIBC), ferritin, high sensitivity C-reactive protein (hs-CRP), ceruloplasmin, and ferroxidase activity were determined using conventional methods. Haptoglobin phenotypes were determined by polyacrylamide gel electrophoresis. RESULTS: As expected, the mean levels of iron store markers, except TIBC, were significantly higher in patients than in controls. Ceruloplasmin concentrations (mg/dl) and its ferroxidase activity (U/l) were significantly higher in patients than in controls (57.9±18.8 vs 46.9±14.2 and 159.9±47.8 vs 95.3±20.9; p<0.001, for CP and Hp, respectively). As for Hp phenotypes, no significant differences were observed between iron store markers and ferroxidase activity among the control group. In the patients group however, significantly higher concentrations of ceruloplasmin and its ferroxidase activity were observed among patients with Hp2-2 phenotype as compared to patients with the other phenotypes. Additionally, correlations according to Hp phenotypes revealed strong association between ceruloplasmin ferroxidase activity and serum ferritin in patients with Hp 2-2 phenotype and not in the others (r=0.331, p<0.05). CONCLUSION: Thalassemia patients with Hp 2-2 phenotype are under greater iron-driven oxidative stress than patients with other phenotypes.

Association of haptoglobin phenotypes with markers of diabetic nephropathy in Type 2 diabetes mellitus.

BACKGROUND: Recent studies have suggested an inheritable influence of haptoglobin phenotypes on the development of microalbuminuria in diabetic patients. In this study, we aimed to investigate whether microalbuminuria and serum levels of Cystatin C (Cys C) were correlated with haptoglobin phenotypes in patients with Type 2 diabetes mellitus. METHODS: Fasting blood samples and first morning urine specimens were collected from 216 patients with type 2 diabetes (mean age 60.8+/-6.8) and from 108 healthy controls (mean age 59.3+/-6.5 years). Serum was used for the determination of Cys C, creatinine, and haptoglobin (Hp) phenotypes, while urine specimens were used for the determination of microalbuminuria. Microalbuminuria was expressed as albumin (mg)/creatinine (g) ratio [ACR (mg/g)], and patients were divided into three groups according to the values of ACR: normoalbuminuria (<30), microalbuminuria (30-300) and macroalbuminuria (>300). RESULTS: Irrespective of Hp phenotypes, Cys C, but not creatinine, was significantly higher in patients than that in controls. According to haptoglobin phenotypes, however, the levels of Cys C, duration of diabetes, and age, were significantly higher in patients with Hp1-1 phenotype than that in patients with the other phenotypes. Moreover, micro- and/or macroalbuminuria were present in all diabetic patients, with no significant difference in frequency of occurrence among the three Hp phenotypes. Multiple linear regression revealed that duration of diabetes and age of patient were significant predictors of Cys C (P<.0001), whereas creatinine associated with age only (P=.016). Logistic regression analysis showed that duration of diabetes [P< or =.0001; odds ratio (OR)=1.678, 95% CI=1.43-1.97], and age (P=.0004; OR=0.847, 95% CI=0.77-0.93), significantly associated with micro- and/or macroalbuminuria. Hp phenotypes however, were not associated with any marker of kidney function. CONCLUSION: Findings from this study demonstrate no association between Hp phenotypes and markers of diabetic nephropathy. Markers of diabetic nephropathy however, are greatly influenced by duration of diabetes and age of patients.

Amifostine exerts anti-angiogenic activity and suppresses vascular endothelial growth factor secreted by hemopoietic stem/progenitor cells.

OBJECTIVE: To assess, in vitro, the effect of Amifostine (AMF, WR-2721) on angiogenesis and levels of vascular endothelial growth factor (VEGF) secreted from hemopoietic stem/progenitor cell populations. METHODS: We conducted the study in the research laboratories of the Hashemite University, Jordan between September 2003 and January 2005 where we took samples were from Myelodysplastic syndrome (MDS) patients and healthy donors attending Al-Hussein Cancer Center and We determined the proliferation of human umbilical vein endothelial cells (HUVECs) in cultures supplemented with media conditioned with AMF-treated and AMF-untreated pure hemopoietic cells [CD34+ cells, and erythroid, myeloid and megakaryocytic progenitors]. Furthermore, in the same conditioned media, we evaluated levels of elaborated VEGF by a sensitive enzyme linked immunosorbent assay. RESULTS: Biologically, media conditioned with AMF-treated cells reduced proliferation of HUVECs compared to media conditioned with untreated control cells (p<0.05). In cultures of AMF-untreated cells, elaboration of VEGF was higher (p<0.05) in media conditioned with cells from MDS patients compared to healthy donors. A 30 minutes pre-exposure of cells to AMF (500 mM) suppressed levels of VEGF secreted within 24 hours in 63 of 89 evaluated cultures. The percentage of reduction of VEGF in AMF-sensitive cultures was comparable in cultures of MDS cells (18%, 2-37%; median, range) and normal cells (12%, 2-45%). CONCLUSION: The results showed that AMF exerts an anti-angiogenic activity and suppresses the secretion of VEGF in hemopoietic stem/progenitor cells obtained from both healthy individuals and patients with MDS.