PTLD
Post-transplant lymphoproliferative disorder (PTLD) is a lymphoma linked with the Epstein–Barr virus (EBV) that can complicate transplantation, especially when initial EBV infection arises after transplantation.
Risk factors
- This predominantly happens in children.
- Patients who are EBV-naive and receive a donor organ from an EBV-infected donor are at the greatest risk of developing PTLD. In individuals with PTLD, EBV serostatus is not linked with overall survival.
Clinical features
PTLD symptoms are quite varied and vague and may include fever, weight loss, night sweats, and exhaustion. The symptoms may resemble those of infectious mononucleosis (caused by EBV). Lymphadenopathy or the bulk effect of developing tumors can cause pain or discomfort. Organs impacted by PTLD may experience dysfunction. Shortness of breath may occur as a result of lung or cardiac involvement.
Laboratory results may reveal abnormally low levels of white blood cells, red blood cells, and platelets. Additionally, serum levels of uric acid and lactate dehydrogenase may be increased, while serum calcium levels may decrease. Taken together, these findings may suggest tumor lysis syndrome.
Types
There are four distinct subtypes of PTLD, which range from precancerous conditions to more malignant lymphomas:
- Lymphocytes and other immune cells divide more often than usual in early PTLD and may accumulate in lymph nodes. The cells are not malignant, and the lymph nodes appear normal when viewed under a microscope. Early PTLD is classified into three subtypes: ‘plasmacytic hyperplasia,’ ‘infectious mononucleosis-like PTLD,’ and ‘florid follicular hyperplasia.’ Early PTLD frequently improves when immune-suppressing medications are lowered or discontinued.
- Polymorphic PTLD results in the development of a combination of aberrant B and T cells. Certain cells may be malignant. They can accumulate in lymph nodes and in locations other than lymph nodes (extranodal sites). Under a microscope, the afflicted lymph nodes appear aberrant.
- Monomorphic PTLD is the most prevalent kind. The aberrant cells in monomorphic PTLD are malignant. They are all of the same cell types. Monomorphic PTLD is most frequently caused by B cells, however, it can also be caused by T or NK cells. Monomorphic PTLD is characterized according to the type of lymphoma that it resembles when viewed under the microscope. While diffuse large B-cell lymphoma (DLBCL) is the most prevalent kind, Burkitt lymphoma and other, less common lymphomas such as peripheral T-cell lymphoma not otherwise specified (PTCL-NOS) can also occur.
- Hodgkin lymphoma PTLD is uncommon. It is a late complication of transplantation that can occur. Reed-Sternberg cells, which are malignant, are visible under a microscope. These symptoms are specific to Hodgkin lymphoma.
Diagnosis
A post-transplant lymphoproliferative disease is diagnosed based on the presence of characteristic symptoms, a detailed patient history, a thorough clinical examination, and a battery of specialized tests, including a complete blood count (CBC), a chemical panel, specialized imaging (x-ray) techniques, an Epstein-Barr virus test, and a tissue biopsy.
Management
Reduce iatrogenic immunosuppression used to avoid transplant rejection as a first step in managing these patients, whereas rituximab (CD20 monoclonal antibody) is successful in more than two-thirds of instances. The success of rituximab or different kinds of conventional chemotherapy may frequently be determined by monitoring EBV DNA load in the blood and, if necessary, the central nervous system. Additionally, infusion of EBV-specific cytotoxic T-cell lymphocytes (adoptive cell therapy) is employed, but its relevance is less proven. Oral mucocutaneous ulcerative disease in HIV-positive individuals might be caused by EBV.
Associated conditions
The following illnesses may present with symptoms comparable to post-transplant lymphoproliferative disease. Comparisons may be beneficial in establishing a differential diagnosis.
The signs and symptoms of PTLD vary considerably, and these disorders may mimic a variety of other conditions, including various bacterial, mycobacterial, and fungal infections; a potentially fatal, widespread infection of the blood (sepsis); and lymphomas that are not associated with immunosuppression. In individuals who have had a solid organ transplant, the symptoms of PTLD may mirror those associated with organ rejection.
