Graft-versus-host complications

The biological paradox of the placenta stems from the immunological makeup of the host tissue and fetus. Graft-versus-host complications relating to incompatibility between a mother and her otherwise healthy unborn child are extremely rare. The placental membranes of humans have evolved a molecular mechanism involving unique features of its cell surface architecture and biochemical properties that renders it virtually insusceptible to any form of maternal immune attack. " ... 

Differential diagnosis of graft-versus-host disease currently depends on organ biopsy to distinguish it from other common complications associated with transplantation. As a means of avoiding repeated biopsies, one group analyzed the urine of patients after hematopoietic stem cell transplantation... 

Complications after granulocyte transfusions occur in about 15-20% of the recipients (38), most frequently in patients given granulocytes prepared by filtration leukapheresis. The complications are predominantly severe febrile reactions, the transmission of cytomegalovirus infection, and graft-versus-host disease. Of particular importance are respiratory reactions with pulmonary edema, which mostly occur in allo-immunized recipients. Leukocjrte aggregation may be the cause, with sequestration microemboli and fluid overflow, but other causes have also been suspected. Reactions appear to be more common in patients with sepsis. 

The major risks associated with platelet transfusion are aUo-immunization and infection. Platelets rarely cause graft-versus-host disease (108,109). Allo-antibodies, especially anti-HLA antibodies, appear to be the major source of complications in patients given repeated platelet transfusions. These antibodies cause febrile reactions, but they can also be responsible for partial or complete... 

The efficacy of daclizumab in acute and chronic glucocorticoid-refractory graft-versus-host disease has been studied in 16 patients, of whom nine responded (2). However 14 developed infectious complications during treatment, with a high incidence of cytomegalovirus reactivation there were three infection-related deaths. 

Allogeneic transplantation is complicated by the immune recognition of host tissues by donor T lymphocytes, resulting in a syndrome called graft-versus-host disease (GVHD). Because immune... 

Onishi C, Ohashi K, Sawada T, Nakano M, Kobayashi T, Yamashita T, Akiyama H, Sakamaki H. A high risk of life-threatening infectious complications in mycophenolate mofetil treatment for acute or chronic graft-versus-host disease. Int J Hematol 2010 91(3) 464-70. 

Tens of thousands of patients undergo blood and marrow transplantation (BMT) annually, primarily for hematologic malignancies. Since both their innate and acquired immune systems are impaired, infectious and noninfectious complications occur frequently in BMT recipients. The recovery of the immune system following BMT depends on the underlying disorder, stem cell source, and complications such as graft versus host disease (GVHD). Pulmonary complications develop in 25% to 60% of BMT recipients and are the immediate cause of death in approximately 61% (1). The main pulmonary complications are listed in Table 1. 

Figure 1 Timing of the major noninfectious pulmonary complications following blood and marrow transplantation. Abbreviations. BO, bronchiolitis obUterans DAH, diffuse alveolar hemorrhage GVHD, graft versus host disease IPS, idiopathic pneumonia syndrome P edema, pulmonary edema PERDS, periengraftment respiratory distress syndrome phase I, preengraftment period phase II, early postengraftment period phase III, late postengraftment period.

Observational studies A retrospective survey reported life-threatening complications associated with cyclosporine A and azole antimycotes itraconazole and voriconazole in 10 out of 104 (9.6%) cases [12 ]. Six patients developed fatal acute graft-versus-host disease and another four patients presented fatal neurological complications. The authors suggest avoiding azole antimycotics during cyclosporine A treatment. 

Leukocyte-depleted blood products, particularly red blood cell concentrates, are clinically used to avoid negative side effects in recipients after transfusion. Possible leukocyte-associated post-transfusion complications include human leukocyte antigen alloimmunization, graft-versus-host disease, platelet refractoriness, and transmission of viruses. Amongst the various existing techniques for the selective removal of leukocytes from blood, filtration has become a popular method, because of its convenience and lowcosts. Leukocyte filters have been specially developed for the purpose they generally consist of fibrous materials made of Nylon, PAN, cotton wool, cellulose acetate,or polyester. Currendy available filters... 

Between 1949 and 1954, Jacobson, Lorenz, Barnes and Loutit made important experiments in mice showing that cells from the spleen or the bone marrow protected from death caused by radiation. Of note, a different evolution was observed after syngeneic and allogeneic transplantation, since mice in the latter group usually died due to complications defined as secondary disease . This experience anticipated the most relevant problem after this type of transplantation, graft-versus-host disease (GVHD). 

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