The 10th Banff Conference on Allograft Pathology was held in Banff, Canada from August 9 to 14, 2009. A total of 263 transplant clinicians, pathologists, surgeons, immunologists and researchers discussed several aspects of solid organ transplants with a special focus on antibody mediated graft injury. The willingness of the Banff process to adapt continuously in response to new research and improve potential weaknesses, led to the implementation of six working groups on the following areas: isolated v-lesion, fibrosis scoring, glomerular lesions, molecular pathology, polyomavirus nephropathy and quality assurance. Banff working groups will conduct multicenter trials to evaluate the clinical relevance, practical feasibility and reproducibility of potential changes to the Banff classification. There were also sessions on quality improvement in biopsy reading and utilization of virtual microscopy for maintaining competence in transplant biopsy interpretation. In addition, compelling molecular research data led to the discussion of incorporation of omics-technologies and discovery of new tissue markers with the goal of combining histopathology and molecular parameters within the Banff working classification in the near future.

SummaryEndogenous formaldehyde is produced by numerous biochemical pathways fundamental to life, and it can crosslink both DNA and proteins. However, the consequences of its accumulation are unclear. Here we show that endogenous formaldehyde is removed by the enzyme alcohol dehydrogenase 5 (ADH5/GSNOR), and Adh5−/− mice therefore accumulate formaldehyde adducts in DNA. The repair of this damage is mediated by FANCD2, a DNA crosslink repair protein. Adh5−/−Fancd2−/− mice reveal an essential requirement for these protection mechanisms in hematopoietic stem cells (HSCs), leading to their depletion and precipitating bone marrow failure. More widespread formaldehyde-induced DNA damage also causes karyomegaly and dysfunction of hepatocytes and nephrons. Bone marrow transplantation not only rescued hematopoiesis but, surprisingly, also preserved nephron function. Nevertheless, all of these animals eventually developed fatal malignancies. Formaldehyde is therefore an important source of endogenous DNA damage that is counteracted in mammals by a conserved protection mechanism.

Until now, absolute uterine factor infertility has been the major untreatable form of female infertility. Uterus transplantation has recently proven to be the first successful treatment for absolute uterine factor infertility, with demonstration of live births. In this study, live donation uterus transplantation was performed in nine women. In total, 163 cervical biopsies (149 protocol, 14 follow-up) were taken to detect histopathological signs of rejection. Based on experience from animal experiments, we used a three-grade scoring system to evaluate biopsies systematically. Nine episodes of rejection were diagnosed in five patients: grade 1 in six episodes, grade 2 in two episodes, and grade 3 in one episode. Treatment decisions were based on histopathology, and all rejection episodes were reversed after treatment. The biopsies were reviewed retrospectively, and immunohistochemistry was performed to characterize the inflammatory infiltrates. A borderline category was introduced to avoid overtreatment of patients. Based on our review of all biopsies, we put forward a simple grading system for monitoring of rejection and to guide immunosuppressive treatment in uterus transplantation.