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Aims: Anemia is commonly observed among patients with chronic kidney disease (CKD). No such information is available for patients with a history of systemic vasculitis. Methods: We examined the prevalence of anemia, the response to therapy with erythropoiesis-stimulating agents (ESA), and the association of anemia with the kidney function in clinically stable patients with Wegener's granulomatosis in a retrospective, single-center study. Results: The mean hemoglobin concentration of 36 patients (mean age: 58 years; 15 female, 21 male; mean duration of disease: 4.6 years) was 13.0 ±2.1 g/dl, and the mean estimated glomerular filtration rate (eGFR) was 41 ± 21 ml/min/1.73 m 2 . 14 of 36 patients (38.8%) presented with anemia (hemoglobin conccntration < 12 g/dl in women, < 13 g/dl in men, or ESA therapy). In patients with a CKD Stage 3 or 4, anemia was present about twice as much as compared to the Third National Health and Nutrition Examination Survey (NHANES III) population. The hemoglobin concentration, however, was not associated with a change of kidney function (p = 0.1578). Conclusions: We found a higher prevalence of anemia in patients with Wegener's granulomatosis, as compared to the NHANES III population. The hemoglobin concentrations showed no association with changes of kidney function.

Dose-dependent effect of parenteral iron therapy on bleomycin-detectable iron in immune apheresis patients. Background Iron deficiency and anemia are commonly encountered in patients with autoimmune diseases undergoing immune apheresis. This makes erythropoietin and iron substitution necessary in most patients. However, intravenous iron therapy may result in an increase of potentially toxic nontransferrin-bound iron. Methods We examined the effect of 50 mg or 100 mg of iron (III) sucrose on bleomycin-detectable iron (BDI) in immune apheresis patients. Six patients with autoimmune disorders and normal kidney function were enrolled. Before and after the injection of 50 mg or 100 mg of iron (III) sucrose, BDI was measured in serum samples at five different time points. Results There was no BDI traceable before injection of iron (III) sucrose. BDI was present in serum of all patients after the administration of 100 mg of iron (III) sucrose in concentrations up to 0.49 μmol/L. In contrast, only one patient showed BDI at a concentration of 0.16 μmol/L after the administration of 50 mg of iron (III) sucrose. Conclusion We conclude that if parenteral iron is administered after apheresis treatment, despite the equal tolerability, use of 50 mg of iron (III) sucrose is superior to 100 mg of iron (III) sucrose in avoiding the formation of potentially toxic nontransferrin-bound iron.

We hypothesized that TGF-beta1 influences the metabolism of homocysteine (Hcy) and increases its cellular export, which may lead to hyperhomocysteinemia in patients with renal transplants. We exposed human renal proximal tubule epithelial cells (huRPTECs) to different concentrations of TGF-beta1, IL-1alpha, IL-10, or methionine and measured total Hcy (tHcy) in culture supernatants. We then examined the relationship between plasma levels of tHcy and TGF-beta1 in renal graft recipients. In multivariate analysis, the factors mediator (TGF-beta1, IL-1alpha, IL-10), mediator concentration, methionine concentration, and "mediator x concentration" interaction independently influenced tHcy concentrations in culture supernatants. A 31% increase in tHcy was observed after exposure of huRPTECs to TGF-beta1 compared to medium alone. However, TGF-beta1 plasma levels in kidney graft recipients showed no independent association with tHcy plasma concentrations. We demonstrated that the release of Hcy from huRPTECs is enhanced by TGF-beta1, but that TGF-beta1 plasma levels in renal graft recipients show no independent relationship with hyperhomocysteinemia.

Although iron sucrose and iron gluconate are generally well tolerated in patients who are treated for renal anemia, recent clinical studies and cell culture experiments suggested significant toxicity and long-term side effects arising from the use of these iron complexes. Because of the possible role of iron in infection or cardiovascular disease, it was theorized that parenteral iron compounds influence endothelial and PMN interaction in vitro. A well-established double-chamber method was used to assess the effect of different concentrations of iron sucrose and iron gluconate (1, 25, 50, and 100 micro g/ml) on the transendothelial migration of PMN. Preincubation of PMN and endothelial cells as well as preincubation of PMN alone with 25, 50, or 100 micro g/ml iron resulted in a significant decrease in PMN migration. In contrast, after incubation of the endothelial cells alone with iron, no reduction in the transendothelial migration of PMN was observed. Preincubation of PMN and/or endothelial cells with 1 micro g/ml iron did not lead to any decrease in the rate of migrated PMN. The only significant change in experiments with 1 micro g/ml was an increase in PMN migration after preincubation of endothelial cells and PMN with iron gluconate. A four-way ANOVA showed a significant effect of the iron concentration (P0.000001), of type of iron complex (P0.005), of the preincubation of endothelial cell (P0.001), and of the preincubation of PMN with iron (P0.000001) on PMN diapedesis. It is concluded that iron sucrose and iron gluconate cause a significant inhibition of transendothelial migration of PMN.

Endothelial cell adhesion molecule and PMNL response to inflammatory stimuli and AGE-modified fibronectin. Background Atherosclerotic vascular disease is the leading cause of death in patients with diabetes mellitus and end-stage renal disease. Advanced glycation end products (AGEs) are strongly suggested to be involved in the pathogenesis of atherosclerosis in these patients who also frequently experience infectious complications. We hypothesized that the interaction of AGEs and inflammatory mediators contributes to the up-regulation of endothelial cell activation. Methods We investigated the effect of advanced glycated fibronectin in the presence or absence of inflammatory stimuli on the endothelial cell surface and mRNA expression of cell adhesion molecules. Furthermore, the influence of advanced glycated fibronectin on the transendothelial migration pattern of polymorphonuclear cells was analyzed. Results Exposure to advanced glycated fibronectin together with inflammatory stimuli such as interleukin (IL)-1α, tumor necrosis factor-α (TNF-α) or lipopolysaccharide (LPS) led to a significant increase in the surface expression of the cell adhesion molecules E-selectin, ICAM-1, VCAM-1 and PECAM-1 on endothelial cells. Soluble AGEs in combination with advanced glycated fibronectin significantly enhanced the endothelial cell surface expression of ICAM-1, VCAM-1 and PECAM-1, whereas this was not the case for E-selectin. At the transcriptional level short-time exposure of endothelial cells to advanced glycated fibronectin and inflammatory mediators resulted in an increased expression of E-selectin, ICAM-1 and VCAM-1 mRNA levels, whereas PECAM-1 repeatedly showed a significant decrease of gene transcript levels. An increase of mRNA levels was also observed for E-selectin, ICAM-1, VCAM-1 and PECAM-1 following incubation with a combination of advanced glycated fibronectin and soluble advanced glycation end-products. Furthermore, polymorphonuclear cells responded with a sevenfold increase in transendothelial migration following exposure of endothelial cells to advanced glycated fibronectin and inflammatory mediators. Conclusions These results suggest that the combination of matrix glycation and inflammation up-regulates the activation of the endothelial cell adhesion cascade, a mechanism that might contribute to the increased burden of atherosclerotic morbidity and mortality in patients suffering from diabetes mellitus or chronic renal failure.

Endothelial cells have many characteristics in common, but significant morphological and functional differences exist between endothelial cells from different anatomic sites. The specific glomerular endothelial (GEn) cell transcript repertoire is unknown. We sought to determine whether endothelial cells derived from bovine glomeruli display a distinct transcriptional profile compared with bovine aortic endothelium (BAE) under identical conditions. Serial analysis of gene expression (SAGE), which includes known and unknown transcripts, was used to make the comparison. The GEn and BAE SAGE libraries contain 36,844 and 26,452 total tag sequences, respectively. Among 6,524 unique tag sequences represented at least 2 times in the 2 libraries, 2,094 (32%) were matched to well-characterized bovine cDNA sequences (358 tags) or expressed sequence tags (EST). Identification of the human homolog was achieved for 1,035 of these tags. Forty-two tags were differentially expressed in GEn. For 25 of these, the bovine cDNA or EST, and for 17 the human homolog was identified. Among all transcripts with a known bovine and human tag, seven were expressed at levels more than 10-fold higher in cultured GEn cells compared with all other SAGE libraries. The transcript “DKFZp564B076” was localized by in situ hybridization to glomerular endothelium in vivo and was shown by real-time RT-PCR to be highly abundant in glomeruli compared with aortic intima. This work supports the concept that differences in the transcriptional profile of endothelial cells from distinct origins are observed under otherwise equivalent conditions. Furthermore, we have identified the first known transcript predominant in glomerular endothelium in vivo.