International Journal of Organ Transplantation Medicine
Volume:1 Issue: 4, Autumn 2010

Progress in understanding the cellular and molecular biology of the immune system, in the second half of the 20th century brings the transplantation of replacement organs and tissues in clinical reality to cure disease. Immunosuppressive agents that are part of nearly every transplantation procedure, are toxic to some extent and their chronic use predisposes the patient to the development of infection and cancer. Alternatives to immunosuppression include modulation of host immune system to reduce the immune response and the induction of a state of immunologic tolerance. Induction of hematopoietic mixed chimerism through donor bone marrow transplantation offers a promising approach for tolerance induction as a prelude to organ transplantation. Furthermore, mesenchymal stromal cells have important effects on the host immune system and possess immune modulation properties that make them attractive for potential use in organ transplantation as immunosuppressant. Both modalities might potentially provide novel therapeutic options for treatment/prevention of rejection and/or repair of organ allografts through their multifaceted properties. In this review, evidences for the tolerogenic properties and mechanisms of hematopoietic mixed chimerism as well as mesenchymal stromal cells effects on allograft surveillance are summarized.

Ishak and METAVIR scoring systems are among the most commonly used histopathological systems to evaluate chronic hepatitis. To assess the level of agreement between these two scoring systems in patients with chronic hepatitis B. Liver biopsy samples taken from 92 patients with chronic hepatitis B were considered as the training set; 57 more biopsy specimens were used as the validation set. In the training set, grade of necroinflammation and stage of fibrosis for each liver biopsy specimen were determined by two expert liver pathologists using both Ishak and METAVIR systems. Inter-observer variability between the two pathologists was evaluated. Biopsy specimens of the validation set were seen and scored by a third expert pathologist. In the training set, criteria were developed to categorize Ishak grading and staging systems separately to best fit with the METAVIR scoring system. The criteria found in the training set, was then tested in the validation set. The level of agreement between the two scoring systems was assessed by weighted kappa statistics. For the training set, agreement between the two pathologists was excellent. Using our proposed criteria in the training set, there was excellent level of agreement in grading (κ = 0.89) and staging (κ = 0.99) between Ishak and METAVIR systems. In the validation set, the criteria led to substantial correlation (κ = 0.61) in grading, and excellent correlation (κ = 0.94) in staging between the two systems. Using our proposed criteria, excellent or at least substantial concordance between Ishak and METAVIR scoring systems can be achieved for the degree of both necro-inflammatory changes and fibrosis.

Concomitant pulmonary infections with Cryptococcus neoformans and Burkholderia cepacia in lung transplant recipients are very rare and create unique diagnostic and therapeutic dilemmas. Herein, we present a double lung transplant patient with cystic fibrosis who was found to have coinfection with these two rare organisms, though he was completely asymptomatic.