Background and Objectives: A great amount of evidence shows that Oxidative stress is high among hemodialysis patients. The purpose of present investigation is examination of the effect of zinc supplementation on improvement of oxidative stress in chronic hemodialysis patients.

  Methods: In this double blind clinical trial 65 chronic hemodialysis patients were studied in two groups Group one (35 patients) received placebo and group two (30 patients) received 100 mg elemental zinc (as zinc sulfate) daily for 2 months. The placebo and supplement discontinued in next 2 months. Then, the study continued for two other months in the cross-over from. The levels of serum zinc, total glutathione, malondialdehyde (MDA), total serum antioxidant capacity and the activity of whole blood superoxide dismutase (SOD) were determined on 0^th, 60^th,120^th,180^th days, in fasting, predialysis samples. Food record was recorded for one day prior to dialysis in above-mentioned days and their dietary zinc was assessed.

  Results: Basal serum zinc levels in both groups were below 80 μ g/dl. The zinc upplementation led to significant increase in the levels of serum zinc in both groups .The levels of serum total antioxidant capacity, total glutathione and activity of whole blood SOD increased significantly during zinc supplementation period. The concentrations of serum MDA decreased significantly in zinc supplementation period in both groups. During the placebo period the levels of MDA in first group increased significantly, whereas the concentration of glutathione in second group decreased significantly. The body mass index (BMI) values did not change significantly during the study.

  Conclusion: It can be concluded that in patients undergoing hemodialysis the oxidative stress enhanced during nonsupplementation period (zinc sulfate). Low serum zinc levels are improved by zinc administration and zinc supplementation improves oxidative stress.

  Background & Objectives : Panel-reactive antibody (PRA) is a routine test to evaluate for sensitized human leukocyte antigens (HLA) before kidney transplantation. The present study evaluates the correlation of renin-angiotensin system (RAS) polymorphisms with the level of PRA in renal transplant candidates.

  Methods: This study included 108 renal transplant candidates. The current patients sera were screened by standard complement-dependent microlymphocytotoxicity technique. RAS polymorphisms were determined by polymerase chain reaction. PRA<10, 10-29, 30-49, and ≥50 considered as negative, mild, moderate, and highly positive PRA, respectively.

  Results: Twelve (11.1%) patients had positive PRA, among them 10 (83.3%) had mild and 2 (16.7%) of them had moderate PRA levels we had no highly positive PRA. Ninety-six of cases (88.9%) were negative for PRA. There was no significant correlation between discrete RAS polymorphisms (alone or together) and the degree of panel antibody reactivity (P>0.05).

 Conclusion: We suggest that none of the RAS polymorphisms could predict the positivity degree of PRA level.

 Background & Objective: As renin-angiotensin system (RAS) activity could affect the severity of oxidative stress and inflammatory markers the effect of enalapril and losartan on these markers in renal transplant recipients (RTRs) with RAS polymorphisms was assessed.

 Methods: After determination of RAS genotypes including angiotensin converting enzyme (ACE I/D), Angiotensinogen (AGT M235T) and angiotensin II type 1 receptor (ATR1 A1166C) by PCR, seventy-six RTRs recruited to four groups randomly: first group (17 patients) and second group (24 patients) were treated with E (E⁺: 10mg/daily) and L (L⁺: 50 mg/daily) alone, respectively. The third group (17 patients as positive control) received E+L (E⁺L⁺: 10mg/daily + 50 mg/daily) and the 4^th group (18 patients as negative control) received no medication (E^-L^-). Hs-CRP and total anti-oxidant (TA) as inflammatory and anti-oxidative markers were measured after 2 months. After 2 weeks as washout period, E group changed to L and vice versa as a cross-over design. They were followed for another 8 weeks and hs-CRP and TA were retested.

 Results: Following up the patients (after 2, 4 months of treatment) in treated groups revealed that hs-CRP and TA levels were significantly decreased and increased (consequently) in E⁺L⁺, L⁺, E⁺ groups (P<0.05). On analyzing the relationship between RAS polymorphisms with baseline hs-CRP and TA levels, CC genotype of ATR1 had lower hs-CRP levels (P=0.04). But none of the RAS polymorphisms could predict the anti-oxidative and anti-inflammatory response rate to the drugs (P>0.05).

 Conclusion: E and/or L reduce hs-CRP and increase TA regardless of the RAS genotypes.