Poor cell survival limits the beneficial impact of mesenchymal stem cell transplantation on acute kidney injury.

BACKGROUND: Although renal tubular epithelium has a great capacity for repair it has been suggested that the administration of mesenchymal stem cells may accelerate the recovery following severe ischemic injury. METHODS: Here we analyzed the survival rate and organ distribution of transplanted mesenchymal stem cells as well as their contribution to kidney regeneration after ischemic renal injury using functional tests, histological examination as well as quantitative real-time PCR. RESULTS: Intravenously injected stem cells were mainly trapped in lungs and liver. One hour after injection, less than 1% of the injected stem cells could be detected in the injured kidneys. These cells disappeared within the first few days and did not replace renal epithelial cells precluding substantial transdifferentiation. To clarify whether reinforced stem cell delivery might promote sustained survival or conversion to tubular epithelia, stem cells were directly injected into the injured kidneys. Although these grafted cells also did not show sustained survival or contribute to structural renal repair, stem cell injection was associated with a significant but transient initial decrease in serum creatinine. CONCLUSION: These data suggest that mesenchymal stem cells do not significantly contribute to epithelial renewal after ischemic injury, promoting the idea that the major impact of cell-based therapy for acute kidney injury may result from paracrine or endocrine effects unrelated to stem cell transdifferentiation.

Prevalence of anti-erythropoietin antibodies in hemodialysis patients without clinical signs of pure red cell aplasia. Comparison between hypo- and normoresponsive patients treated with epoetins for renal anemia.

BACKGROUND/AIMS: The prevalence of anti-erythropoietin antibodies in renal patients without clinical evidence of pure red cell aplasia (PRCA) who respond poorly to epoetin is unknown. This study tested for anti-erythropoietin antibodies in hemodialysis patients who were either hypo- or normoresponsive to epoetin treatment. METHODS: Epoetin hyporesponsiveness (hemoglobin < or =10.5 g/dl and epoetin > or =9,000 IU/week) and normoresponsiveness (hemoglobin >10.5 g/dl and epoetin <7,000 IU/week) were arbitrarily defined. Prevalence of anti-erythropoietin antibodies in hemodialysis patients without symptoms of PRCA was determined by screening sera of 536 patients from 35 German KfH dialysis units, using enzyme-linked immunosorbent assay (ELISA). Positive results were verified by radioimmunoprecipitation assay (RIP) and neutralizing activity was determined by bioassay. RESULTS: Anti-erythropoietin antibodies were detected in 3 hyporesponsive and 3 normoresponsive patients using ELISA. One patient per group was verified as borderline by RIP testing; the other 4 were negative. The bioassay was negative for 1 patient; the other died unrelated to PRCA before testing. Follow-up with RIP testing after 15 months under continuous epoetin treatment was negative (4 patients, 2 deceased). CONCLUSION: This survey did not identify anti-erythropoietin antibodies in hemodialysis patient's hyporesponsive to epoetin and does not support presumptive antibody screening as a routine work-up in these patients.

[Shared decision-making as a new quality indicator in nephrology: a nationwide survey in Germany]. / Partizipative Entscheidungsfindung als neuer Qualitätsindikator in der Nephrologie Eine bundesweite empirische Untersuchung.

BACKGROUND AND PURPOSE: Shared decision-making (SDM) as a model in physician-patient interaction is gaining relevance in the German health system. By applying this model, mid- and long-term improvements are expected especially in the outcomes of chronic diseases. Up to now, there has hardly been any empirical data available in German health services research regarding the state and development of SDM. This study establishes a baseline and provides actual data on this subject based on a German-wide survey of end-stage renal disease (ESRD) patients. METHODS: Standardized German-wide survey of 6,614 patients with ESRD. The questionnaire included an instrument to measure the patients' perceived involvement in care (PICS) which had been translated and validated before. RESULTS: 82% of the questioned patients feel their physicians facilitated involvement in decision making. 81% of the patients actively inform themselves concerning their disease and treatment options. 69% state that SDM has taken place. Age, years on dialysis and gender correlate with perceived involvement. CONCLUSION: This paper provides a valid baseline for the prospective research of SDM in ESRD. The results indicate that dialysis patients are willing to participate in the process of medical decision-making. Characteristics and preferences of the patients should be taken into account not only in everyday clinical interactions. They could be monitored systematically within the framework of quality management and used as potential for quality improvement.

[Guideline-based medical quality management in dialysis. Motivation and structuring of a quality-management system and integration of earlier disease stages of chronic renal failure]. / Leitlinien-gestütztes medizinisches Qualitätsmanagement in der Dialyse. Motivation und Aufbau eines Qualitätsmanagement-Systems sowie Integration früherer Erkrankungsstadien der chronischen Niereninsuffizienz.

BACKGROUND AND PURPOSE: Health services are challenged by increasingly complex medical processes and economic restraints in an aging population. Under these circumstances, medical quality management is developed and increasingly applied to survey especially complex and expensive clinical processes in the sense of controlling. In this process, practicability and relevance are fundamental. METHODS: This paper presents the well-established quality management system QiN (quality in nephrology) in the context of dialysis in end-stage renal disease. RESULTS: A quality-management system is well applicable in the case of dialysis. It can positively influence relevant indicators of process and outcome quality, as demonstrated here by the example of dialysis quantity. CONCLUSIONS: Outcome and process quality in dialysis are quantifiable via defined indicators oriented on evidence-based medicine. The program based on benchmarking of basic clinical indicators leads to improved care of dialysis patients. A quality-management program of this type can represent an essential component of interdisciplinary, structured treatment programs, thereby influencing the whole treatment process.

Mutations of the Uromodulin gene in MCKD type 2 patients cluster in exon 4, which encodes three EGF-like domains.

BACKGROUND: Autosomal-dominant medullary cystic kidney disease type 2 (MCKD2) is a tubulointerstitial nephropathy that causes renal salt wasting, hyperuricemia, gout, and end-stage renal failure in the fifth decade of life. The chromosomal locus for MCKD2 was localized on chromosome 16p12. Within this chromosomal region, Uromodulin (UMOD) was located as a candidate gene. UMOD encodes the Tamm-Horsfall protein. By sequence analysis, one group formerly excluded UMOD as the disease-causing gene. In contrast, recently, another group described mutations in the UMOD gene as responsible for MCKD2 and familial juvenile hyperuricemic nephropathy (FJHN). METHODS: Haplotype analysis for linkage to MCKD2 was performed in 25 MCKD families. In the kindreds showing linkage to the MCKD2 locus on chromosome 16p12, mutational analysis of the UMOD gene was performed by exon polymerase chain reaction (PCR) and direct sequencing. RESULTS: In 19 families, haplotype analysis was compatible with linkage to the MCKD2 locus. All these kindreds were examined for mutations in the UMOD gene. In three different families, three novel heterozygous mutations in the UMOD gene were found and segregated with the phenotype in affected individuals. Mutations were found only in exon 4. CONCLUSION: We confirm the UMOD gene as the disease-causing gene for MCKD2. All three novel mutations were found in the fourth exon of UMOD, in which all mutations except one (this is located in the neighboring exon 5) published so far are located. These data point to a specific role of exon 4 encoded sequence of UMOD in the generation of the MCKD2 renal phenotype.

Once-weekly compared with three-times-weekly subcutaneous epoetin beta: results from a randomized, multicenter, therapeutic-equivalence study.

BACKGROUND: The ability to reduce the administration frequency of subcutaneous (SC) epoetin could provide benefits. This multicenter open-label study investigated the therapeutic equivalence of SC epoetin beta once-weekly and thrice-weekly administration regimens in maintaining anemia correction in stable hemodialysis (HD) patients. METHODS: One hundred seventy-three patients were randomly assigned to either once-weekly epoetin beta (n = 84) or their original thrice-weekly regimen (n = 89) for 24 weeks. All patients were administered intravenous iron supplementation, as required. RESULTS: The per-protocol analysis included 134 patients (69 patients, once-weekly group; 65 patients, thrice-weekly group). Mean hematocrits in both groups remained stable throughout the study. The difference in mean time-adjusted area under the curve for hematocrits between the once-weekly and thrice-weekly groups (-0.54 vol%) and 90% confidence intervals (-1.27 to 0.19) were within the prespecified equivalence range (-2 to +2 vol%). There was no significant change in epoetin beta dose during the study. The ratio of mean weekly epoetin beta doses in the once-weekly and thrice-weekly groups (1.11) and 90% confidence interval (0.99 to 1.23) also remained within the prespecified range (0.8 to 1.25). Intention-to-treat analysis results were similar to per-protocol analysis results. Both regimens were well tolerated. CONCLUSION: Once-weekly and thrice-weekly SC epoetin beta administrations are statistically equivalent in terms of maintaining both stable hematocrits and epoetin beta dose requirements in HD patients. These findings may improve compliance among patients.