Inverse association between serum selenium concentrations and parameters of immune activation in patients with cardiac disorders
ABSTRACT As a component of the enzyme glutathione peroxidase, the essential trace element selenium contributes to the reduction of peroxides. Disturbed selenium availability may relate to an activated immune response. In humans, immune activation is reflected by increased neopterin production and accelerated tryptophan degradation, expressed as the kynurenine to tryptophan ratio (kyn/trp). Th1-type cytokine interferon-gamma induces both these immunobiological events in human macrophages and they are often activated in patients with cardiac disorders. The aim of this study was to determine the relationship between serum selenium concentrations and neopterin production and tryptophan degradation in patients with cardiac disorders.
In 56 patients (28 females) with cardiac disorders, serum selenium concentrations were determined by graphite-furnace atomic absorption spectrometry. Serum neopterin concentration was measured by ELISA and tryptophan degradation was examined by HPLC.
Selenium concentrations were in the range 0.41-1.90 micromol/L (median 1.02) and were well within the local normal range. Approximately two-thirds of patients presented with higher neopterin concentrations (median 16.4 nmol/L) and tryptophan degradation (median 57 micromol/mmol kyn/trp). There was an inverse correlation between serum selenium and kyn/trp (Spearman's rank correlation, r(s)=-0.431; p<0.001) and neopterin concentrations (r(s)=-0.300; p<0.05). Neopterin concentrations correlated strongly with kyn/trp (r(s)=0.712; p<0.0001).
A higher degree of tryptophan degradation and of neopterin production in patients with cardiac disorders coincides with lower, albeit still normal, serum selenium concentrations. Data show that in these patients immune activation is associated with lower serum selenium concentrations.
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ABSTRACT: ABSTRACT: We reported previously that sheep affected with footrot (FR) have lower whole-blood selenium (WB-Se) concentrations and that parenteral Se-supplementation in conjunction with routine control practices accelerates recovery from FR. The purpose of this follow-up study was to investigate the mechanisms by which Se facilitates recovery from FR. Sheep affected with FR (n = 38) were injected monthly for 15 months with either 5 mg Se (FR-Se) or saline (FR-Sal), whereas 19 healthy sheep received no treatment. Adaptive immune function was evaluated after 3 months of Se supplementation by immunizing all sheep with a novel protein, keyhole limpet hemocyanin (KLH). The antibody titer and delayed-type hypersensitivity (DTH) skin test to KLH were used to assess humoral immunity and cell-mediated immunity, respectively. Innate immunity was evaluated after 3 months of Se supplementation by measuring intradermal responses to histamine 30 min after injection compared to KLH and saline, and after 15 months of Se supplementation by isolating neutrophils and measuring their bacterial killing ability and relative abundance of mRNA for genes associated with neutrophil migration. Compared to healthy sheep, immune responses to a novel protein were suppressed in FR-affected sheep with smaller decreases in FR-affected sheep that received Se or had WB-Se concentrations above 250 ng/mL at the time of the immune assays. Neutrophil function was suppressed in FR-affected sheep, but was not changed by Se supplementation or WB-Se status. Sheep FR is associated with depressed immune responses to a novel protein, which may be partly restored by improving WB-Se status (> 250 ng/mL).Veterinary Research 09/2011; 42(1):99. DOI:10.1186/1297-9716-42-99 · 3.38 Impact Factor
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ABSTRACT: Low serum zinc concentrations are associated with adverse outcomes. To explain this phenomenon we aimed to investigate whether low zinc levels are related to immune activation, renal function and coronary artery disease (CAD). Serum concentrations of zinc and the immune activation markers neopterin and C-reactive protein (CRP) were measured in 2048 patients derived from the LUdwigshafen RIsk and Cardiovascular Health (LURIC) study, a cohort study among patients referred for coronary angiography. Zinc concentrations did not differ between patients with CAD (mean±SD: 13.3±2.4 μmol/L) and controls (13.3±2.2 μmol/L; Welch's t test: p=n.s.) but CAD patients had higher neopterin (8.6±7.4 nmol/L) and CRP (9.7±19.6 mg/L) concentrations compared to controls (neopterin: 7.5±4.8 nmol/L, p=0.0005; CRP: 5.5±10.0 mg/L, p<0.0001). There was an inverse correlation between serum zinc concentrations and neopterin (Spearman's rank correlation: r(s)=-0.222) and CRP (r(s)=-0.166; both p<0.0001) concentrations. Our results indicate increased inflammatory processes in patients with low zinc levels. Further studies should clarify whether inflammation related processes such as renal wasting contribute to zinc deficiency and underlie the adverse health consequences of low serum zinc levels.Journal of Trace Elements in Medicine and Biology 01/2012; 26(1):26-30. DOI:10.1016/j.jtemb.2011.11.004 · 2.49 Impact Factor
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ABSTRACT: Abstract Background: Low vitamin D concentrations are detected in patients suffering from various clinical conditions which are characterized also by inflammation and immune activation. We investigated whether vitamin D levels in patients with coronary artery disease (CAD) are related to markers of immune activation. Methods: Serum concentrations of 25-hydroxyvitamin D [25(OH)D] and 1,25-dihydroxyvitamin D [1,25(OH)2D] and the immune activation markers neopterin and high sensitivity C-reactive protein (hsCRP) were measured in 2015 patients derived from the LUdwigshafen RIsk and Cardiovascular Health (LURIC) study, a cohort study among patients referred for coronary angiography. Results: Serum concentrations of 25(OH)D and 1,25(OH)2D did not differ between patients with CAD [mean±SD: 25(OH)D: 17.4±9.4 μg/L; 1,25(OH)2D: 34.4±13.3 ng/L] and controls [25(OH)D: 18.4±11.7 μg/L; 1,25(OH)2D: 35.3±12.7 ng/L; Welch's t-test: p=n.s.] but CAD patients had higher neopterin (8.6±7.4 nmol/L) and hsCRP (9.6±19.6 mg/L) concentrations compared to controls (neopterin: 7.5±4.8 nmol/L; p=0.0004; hsCRP: 5.4±10.0 mg/L; p<0.0001). There was an inverse correlation between serum 25(OH)D or 1,25(OH)2D concentrations and serum neopterin [Spearman's rank correlation: 25(OH)D: rs=-0.183; 1,25(OH)2D: rs=-0.230] and hsCRP [25(OH)D: rs=-0.142; 1,25(OH)2D: rs=-0.130; all p<0.0001] concentrations. Conclusions: Our results indicate increased inflammatory processes in patients with low vitamin D status. Further studies should clarify the underlying mechanisms for the observed associations of vitamin D status and inflammatory parameters.Clinical Chemistry and Laboratory Medicine 07/2012; 50(12). DOI:10.1515/cclm-2012-0157 · 2.96 Impact Factor