Einzelreferate und Buchbesprechungen

Ohne Zusammenfassung     

Einzelreferate und Buchbesprechungen

Ohne Zusammenfassung     

Antigen‐specific regulatory T cells can induce tolerance to immunogenic grafts without the need for chronic immunosuppression

Regulatory CD4⁺CD25⁺Foxp3⁺ T cells (Tregs) play an important role in the induction of allospecific tolerance. However tolerance in solid organ transplantation by mere transfer of Tregs has been difficult. Besides this the stability of the differentiation phenotype of Tregs has recently been questioned. We therefore aimed in generating large numbers of stable allospecific Tregs from naïve T cells by retroviral transduction with Foxp3. These were tested in an immunogenic skin transplantation model (C57BL/6→BALB/c). We established a system of transduction of mouse T cells with ecotropic retroviruses expressing Foxp3 and Thy1.1 as a surface marker to follow up transduced T cells. Alloantigen‐specific Tregs were generated by stimulating naïve recipient CD4⁺ T cells with irradiated donor splenocytes. CD25⁺ and/or CD69⁺ allospecific recipient CD4⁺ T cells were isolated and transduced with Foxp3. Alloantigen‐specific Foxp3 T cells (iTregs) showed high expression for the Treg markers Foxp3, CTLA4 and GITR. They could suppress a MLR in an alloantigen‐specific manner. Furthermore, they could be expanded up to 18 fold in vitro while maintaining their Treg phenotype and expression of lymph node homing markers like CCR7 and CD62L. iTregs prevented skin graft rejection without the need for chronic immunosuppression and recipients showed systemic allospecific allotolerance. Alloantigen‐specific Tregs were far more potent than polyspecific Tregs. Mechanisms of tolerance were graft specific homing, expansion and long‐term persistence of Tregs within the graft (>100 days, 90% of intragraft Tregs were alloantigen‐specific). In fact, tolerance could be transferred with re‐transplantation of the tolerant graft onto secondary recipients. Third party grafts were readily rejected demonstrating specificity of tolerance. Due to the Foxp3 transduction, iTregs did not lose their Treg phenotype. The results prove that large numbers of stable alloantigen‐specific Tregs can be generated from a polyclonal repertoire of naïve T cells. This is the first time that allotolerance was achieved in a non‐lymphopenic transplant model using skin grafts in an immunogenic strain combination. Therefore, antigen‐specific Tregs might have a huge therapeutic potential after solid organ transplantation.     

Primary primitive neuroectodermal tumor of the spinal cord: case report and review of the literature.

We present the clinical, radiological, and pathological features of a primary primitive neuroectodermal tumor (PNET) that occurred in the thoracic spinal cord of a 69-year-old man. Magnetic resonance imaging (MRI) demonstrated on T1-weighted images a 2x1x5 cm isointense intraspinal mass with homogeneous contrast enhancement extending from the C7 to the Th3 level. There was no clinical or radiological evidence for the existence of an intracranial tumor. Histological examination revealed a small round cell tumor with rosette formation and immunohistochemical characteristics of a PNET. The patient is the oldest among the 20 cases with this rare spinal cord neoplasm reported so far in the literature; the previously published cases are briefly reviewed.     

Cost‐of‐illness of chronic leg ulcers in Germany

Chronic wounds are important because of their frequency, their chronicity and high costs of treatment. However, there are few primary data on the cost‐of‐illness in Germany. The aim was to determine the cost‐of‐illness of venous leg ulcers (VLU) in Germany. Prospective cost‐of‐illness study was performed in 23 specialised wound centres throughout Germany. Direct, medical, non medical and indirect costs to the patient, statutory health insurers and society were documented. Thereover, health‐related quality of life (QoL) was recorded as intangible costs using the Freiburg quality of life assessment for wounds (FLQA‐w, Augustin). A total of 218 patients (62.1% female) were recruited consecutively. Mean age was 69.8 ± 12.0 years. The mean total cost of the ulcer per year and patient was € 9569, [ € 8658.10 (92%) direct and € 911.20 (8%) indirect costs]. Of the direct costs, € 7630.70 was accounted for by the statutory health insurance and € 1027.40 by the patient. Major cost factors were inpatient costs, outpatient care and non drug treatments. QoL was strikingly reduced in most patients. In Germany, VLU are associated with high direct and indirect costs. As a consequence, there is a need for early and qualified disease management. Deeper‐going cost‐of‐illness‐studies and cost‐benefit analyses are necessary if management of chronic wounds is to be improved.