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S Jonas

Publications and source records attributed to S Jonas.

At least 217 records · Page 12Linked to original sources

Significant reduction of proinflammatory cytokines by treatment of the brain-dead donor.

INTRODUCTION: Experimental studies suggest that brain death in the donor has a significant impact on graft quality; however, there are no data correlating organ-specific cytokine expression and the corresponding serum protein levels in human organ donors. Furthermore, it is unknown whether donor treatment can reduce the up-regulation of proinflammatory cytokines and thereby optimize organ quality. METHODS: We investigated the expression pattern of cytokines comparing serum (n = 53) and tissue expression (n = 25) in brain-dead human donors. The controls were living donors (n = 25). Additionally 41 deceased donors were treated with steroids before organ harvest (250 mg initial, afterward 100 mg/h until laparotomy). Hepatic tissue samples were obtained immediately after donor laparotomy to assess transcription rates of tissue cytokines (IL-6, IL-10, CD3, TGFb, TNFa, BAG, HO-1, Mipla) by RT-PCR. Serum samples were obtained after declaration of brain death and before laparotomy. RESULTS: Transcription of proinflammatory cytokines was significantly increased in brain-dead compared to living donor grafts (P < .005). Donor treatment with steroids led to significantly decreased tissue and serum expression of proinflammatory cytokines (P < .01), which were comparable to living donors. Tissue levels of cytokines (IL-6, IL-10) correlated strongly with serum levels of the corresponding proteins. CONCLUSIONS: Serum protein levels of proinflammatory cytokines proffer a valuable, easy accessible marker to define the immunological status of a graft. Our data suggest a beneficial effect of anti-inflammatory treatment of brain-dead organ donors.

Brain Death↗

Grafts from elderly donors elicit a stronger immune response in the early period posttransplantation: a study in a rat model.

With a growing demand for transplants, grafts from older donors are increasingly used. However, altered immune responses associated with increasing donor age may influence graft survival. We dissected the effects of donor age on the immune response in an experimental model. Kidneys from young and old F-344 donors (3 and 18 months) transplanted into young Lewis recipients (3 months) were followed for 6 months. Renal function, structural changes, and immune activation were tested at serial time intervals. Splenocytes and peripheral blood mononuclear cells were examined by flow cytometry; alloantigen-specific intracellular IFN-gamma secretion was evaluated by ELISPOT. Grafts from both young and old donors survived the observation period. The ratio of structural changes (6/1 months) increased twofold in old vs young grafts. In parallel, the ratio of renal function declined by fivefold in recipients of old donor kidneys. Most interestingly, elderly grafts produced a modified immune response: the numbers of T/B cells and alloreactive T cells increased early following the transplantation of old grafts (P < .05). However, by 6 months, the amounts of T and B cells as well as alloantigen-specific immune responses were comparable in recipients of old versus young grafts. Older grafts elicit a stronger immune response during the early period posttransplantation. This process is associated with an increased immunogenicity in older grafts. Clinical immunosuppressive protocols need to consider these effects.

Aging↗