Erythropoiesis-stimulating agent withdrawal and oxidative stress in hemodialysis.

AIMS: Variation of the action of erythropoiesis-stimulating agent (ESA) may modify oxidative stress in hemodialyzed (HD) patients. Our aim was to follow changes of oxidative stress during withdrawal and subsequent resumption of ESA therapy. PATIENTS AND METHODS: After a 14-day suspension of epoietin-beta treatment, 11 HD patients received epoietin-beta and 10 patients darbepoietin-alpha. The whole blood oxidized and reduced glutathione (GSSG, GSH) and erythrocyte malondialdehyde (E-MDA) concentrations and the erythrocyte superoxide dismutase (E-SOD) and catalase (E-CAT) activities were determined before the ESA-free interval (baseline) and at Weeks 2, 6, 10 and 14. RESULTS: In both groups, the ratios GSSG/ GSH were increased at Weeks 2 and 6 (p < 0.001). The E-MDA levels were elevated (p < 0.01) and the E-SOD activities were decreased (p < 0.001) at Week 6. By Week 14, these markers had returned to the baseline, whereas the GSH (p < 0.001) and E-CAT activity levels (p < 0.001) had increased. CONCLUSIONS: An increase in oxidative stress was revealed by the ratio GSSG/GSH directly after the short-term withdrawal of epoietin-b therapy in HD. This new finding may have implications in conditions involving transiently depressed ESA action. For both ESAs, the early phase of readministration was associated with similarly increased oxidative stress, with a subsequent return to the baseline level.

[Primary cerebral T-cell lymphoma]. / Elsödleges agyi T-sejt-lymphoma.

The authors describe a case of primary cerebral T-cell lymphoma observed in a 68-year-old man. The patient suffered from disseminated follicular carcinoma of the thyroid and the clinical picture has been dominated by neurological symptoms of presumed metastatic origin. Primary cerebral lymphoma was discovered at autopsy. Histologically, it proved to be a high-grade malignant pleomorphic non Hodgkin's lymphoma whose T-cell lineage was confirmed by immunohistochemistry. The patient did not manifest any congenital or acquired immune deficiency. There were neither cerebral metastases of the thyroid cancer nor any evidence for extracranial involvement by a lymphoma. Providing a brief literature review of cerebral T-cell lymphomas, the authors discuss some major traits of this exceptional form of lymphoid neoplasia of the central nervous system. Differential diagnostic and theoretical implications raised by cerebral lymphomas as second malignant tumors synchronously or metachronously associated with other malignant diseases are envisaged.