Post-transplant lymphoproliferative disorder
As lymphoproliferative disease after transplantation or as post-transplant lymphoproliferative disease, after the English name Post- Transplant Lymphoproliferative Disorder abbreviated as PTLD, several lymphoma -like diseases are referred to, which can occur after an organ transplant or stem cell transplant. It is about a group of histologically and biologically heterogeneous molecular diseases whose spectrum ranges from benign propagation of T and B lymphocytes to malignant lymphoma. The PTLD after Kaposi's sarcoma and other skin cancers, the second most common tumor-like disease after organ transplantation.
Dissemination
From an epidemiological point of view of developing up to ten percent of all patients with organ transplantation in a PTLD. The individual risk depends on the transplanted organ, the immunosuppressive therapy, the presence of an infection with the Epstein -Barr virus ( EBV) at the time of transplantation as well as the age of the patient in question. With respect to the total load in the immunosuppression of the medication dose and duration of treatment is critical differences between different drugs or treatment regimens have not been shown. Children as well as patients who were EBV- negative before transplantation, while having a significantly higher risk to develop PTLD after transplantation.
Cause and pathogenesis
The cause of PTLD is true in most cases, the combination of an EBV infection and immunosuppressive treatment, which is necessary after organ transplantation to suppress the rejection of the foreign organ. In a PTLD within the first year after transplantation in approximately 90 percent of cases an association with Epstein -Barr virus is detectable, while at a later occurrence in up to 45 percent no evidence of EBV infection of the affected cells is possible. In Europe and the U.S., around 85 percent of all PTLD cases on B lymphocytes and about 15 percent are due to T- lymphocytes, in some other regions, the proportion of T- cell-associated diseases is higher.
Clinical manifestations
The clinical presentation of PTLD depends on the location. The symptoms are similar to those of glandular fever, with Hodgkin's disease or with the various forms of non-Hodgkin 's lymphoma, depending on the severity of the disease. A similar manifestation of infectious mononucleosis occurs in this case, especially in childhood. The symptoms are usually nonspecific and may be accompanied by fever, fatigue, night sweats, and weight loss and signs of tonsillitis, sinusitis or otitis media. In most patients, there is at least one overt tumor, which in turn is in most cases outside the lymph nodes and may cause symptoms such as pain, bleeding or localization in the central nervous system in neurological deficits. Depending on the transplanted organ may itself be affected by this.
Methods of investigation
The diagnosis of PTLD by means of a biopsy by histological methods and the detection of EBV - specific DNA by polymerase chain reaction (PCR). Pathological examination is especially important for the determination of the malignancy of the clonality and the PCR-based determination of the viral load is also suitable for monitoring the progress beyond.
Treatment and cure views
After slowing or stopping the immunosuppressive therapy is, in many cases, a regression of PTLD. The treatment is therefore on the one hand by adjusting the dosage of immunosuppressive drugs and on the other, as in other lymphoma diseases, depending on the severity of PTLD by surgical removal of solid tumors by chemotherapy and radiotherapy, as well as various methods of immune stimulation. An important role in the drug treatment plays the therapeutic antibody rituximab. Both the therapy and prophylaxis are also used antivirals.
The disease course is dependent on the individual form of PTLD, particularly the degree of malignancy and the localization in the body, as well as the response to treatment. Upon occurrence of a PTLD, more than two years after organ transplantation, reduction of the immunosuppressive treatment usually is less effective than that of a PTLD, which occurs within the first two years. The published data on mortality are partly at over 50 percent.