Risk of lymphoid neoplasia after cardiothoracic transplantation: the influence of underlying disease and human leukocyte antigen type and matching

Natural killer cell lymphoma in a pediatric patient with inflammatory bowel disease

Tumor necrosis factor α (TNF-α) antibody agents are an effective therapy for the treatment of inflammatory bowel disease (IBD); however, because of the potential for immune suppression with these drugs, TNF-α antibody agents can increase the risk of malignancy. We report here the case of an 11-year-old boy who presented with bowel obstruction. He also had a history of periodic fever, aphthous stomatitis, and cervical adenitis (PFAPA). Intestinal inflammation continued and impaired his quality of life; he was diagnosed with IBD of an undetermined type (IBD-U). Symptoms improved with infliximab, but he developed elevated transaminase levels with hepatosplenomegaly 1 year after scheduled infusions. Skin biopsy revealed an atypical lymphoid infiltrate consistent with an Epstein-Barr virus (EBV)-positive natural killer (NK)/T-cell lymphoma with associated hemophagocytic lymphohistiocytosis. Bone marrow biopsy revealed a similar EBV-positive lymphoid infiltrate consistent with an NK/T-cell lymphoma. EBV-positive tissue was present in gastrointestinal biopsies. Flow-cytometric analysis revealed an atypical, clonal NK-cell population, and biopsy specimens from several tissue sites tested positive for CD3, CD56, and CD30. The patient died soon after the diagnosis was made. This patient developed an EBV-driven malignancy while receiving infliximab. All patients with IBD who receive infliximab should be monitored for malignancy, especially young patients. This case underscores the need for future studies to better understand the biology of lymphoproliferative disorders.

Case-control study of risk factors for the development of post-transplant lymphoproliferative disease in a pediatric heart transplant cohort

PTLD is an important complication following heart transplantation. To better define the risk factors of PTLD in children, we performed a case-control study. All pediatric cardiac transplant recipients who developed their first episode of PTLD were matched by age (+/-1 yr) and time since transplant (+/-1 yr) with those who did not. PTLD occurred in nine of 95 cardiac transplant recipients (9%), 0.3-7.8 yr following cardiac transplantation (median = 2.5 yr). Patients were 0.1-16.4 yr (median = 3.7) at transplantation. Biopsies revealed polymorphic B cell hyperplasia (three), polymorphic B cell lymphoma (one), monomorphic diffuse large cell B cell lymphoma (three) and monomorphic Burkitt's-like lymphoma (two). Patients who developed PTLD were at no greater risk of death (p = 0.31). Recipient EBV seronegativity at time of transplant (p = 0.08), EBV seroconversion (p = 0.013) and recipient CMV seronegativity (p = 0.015) were associated with the development of PTLD by conditional logistic regression; sex, race, donor age, recipient diagnosis, donor CMV seropositivity, recipient treatment for CMV infection, EBV seropositivity at the time of PTLD diagnosis, and number of rejection episodes, treated rejection episodes, and lympholytics used were not. There was no significant association between PTLD and death in our recipients. EBV seroconversion and recipient CMV seronegativity were associated with the development of PTLD.

Lymphoid neogenesis in chronic rejection: the murderer is in the house

Although chronic rejection is currently the main cause of long-term allograft failure, its pathogenesis remains elusive, hereby preventing the development of effective therapy. Recent advances in the comprehension of the pathophysiology of chronic inflammatory diseases could shed new light on the pathogenesis of chronic rejection. Lymphoid neogenesis is a mechanism responsible for the progressive organization of chronic inflammatory infiltrates into functional ectopic germinal centers, and has been evidenced recently in various pathological situations sharing a common feature: the failure of the immune response to eradicate the targeted antigen(s). Chronic rejection is such a situation as it results from a sustained alloimmune response against the donor's antigens that are constantly replenished by the grafted tissue. Accordingly, functional ectopic germinal centers develop within chronically rejected organs. This implies that, during chronic rejection, graft is at the same time the target and the site of elicitation of the alloimmune response.

Incidence of cancer after immunosuppressive treatment for heart transplantation

Prolonged or intensive immunosuppressive therapy used after organ transplantation is complicated by an increased incidence of cancer. Striking differences in incidence are observed in heart and heart-lung transplant recipients when compared with renal transplant patients. The most significant increase was in the incidence of lymphomas in cardiac versus renal patients. Moreover, a two-fold greater increase of all neoplasms was found in cardiac recipients, with nearly a six-fold increase in visceral tumors. Several factors may account for these differences. In cardiac allograft recipients, intensive immunosuppression is frequently used to reverse acute rejection and the highest number of cardiac transplants was performed in the era of polypharmacy, usually consisting of triple therapy.

HLA antigens and post renal transplant lymphoproliferative disease: HLA-B matching is critical

Although several risk factors for posttransplant lymphoproliferative disease (PTLD) after solid organ transplantation have been identified, the immunosuppressive regimen probably as most important one, their exact pathogenic role and relevance is still unclear. In hematopoietic stem cell transplantation, HLA mismatching also is a risk factor. We analyzed factors possibly associated with development of PTLD in patients receiving a kidney transplant at our hospital between 1985 and 2002. PTLD was observed in 20 out of 1,013 patients (2.0%). Mismatches at the HLA-B locus, but not at the HLA-A or HLA-DR loci, and anti T-cell antibody therapy were both independently associated with development of PTLD. Hazard ratios increased from 1.4 (0.5-4.1) with one mismatch to 5.1 (1.4-19.0) in case of two HLA-B mismatches. Decreased surveillance by T-cells with dual specificity for Epstein-Barr virus (EBV) as well as for allo HLA antigens on the allograft might facilitate clonal expansion of B-cells latently infected with EBV.

Epstein-Barr Virus Primary Mismatching and HLA Matching: Key Risk Factors for Post Lung Transplant Lymphoproliferative Disease

BACKGROUND

Posttransplant lymphoproliferative disease (PTLD) in lung transplant recipients (LTRs) is potentially lethal with considerable morbidity. The role of donor (D)/recipient (R) HLA matching is unknown.

METHOD

We reviewed our LTRs from January 1994, when routine D/R Epstein-Barr virus (EBV) serologic screening was begun, through to January 2000. We examined whether D/R HLA match status influenced the risk of PTLD in EBV D+/R- mismatched LTRs.

RESULTS

There were 16 D+/R- EBV-mismatched LTRs, 5 (31%) of whom developed PTLD (from a total of 237 LTRs; 218 survived >30 days). There were only two other cases of PTLD among the non-EBV primary mismatched patients. All patients received baseline immunosuppression of cyclosporine, azathioprine, and prednisolone without cytolytics and ganciclovir prophylaxis if "at risk" from cytomegalovirus. The five PTLD cases were diagnosed 81 to 734 (median 116) days from transplantation; three involved the lung allograft and two others involved lymph nodes. All PTLD patients seroconverted for EBV, whereas 7 of the 11 remaining EBV-mismatched patients who did not develop PTLD did not seroconvert. In the 16 EBV primary mismatched patients, there were 4 of 66 HLA allele matches in the 11 PTLD-free patients versus 15 of 30 matches in the 5 PTLD patients (P<0.001). This resulted in 2 or more HLA (A/B/DR) matches in 4 of 5 patients with PTLD versus 0 of 11 in the PTLD-free group (P=0.003). All PTLD patients were treated with reduced immunosuppression and antiviral therapy. Only two of the five LTRs who developed PTLD died, one with progressive disease despite chemotherapy and the other from chronic allograft rejection.

CONCLUSION

A high degree of HLA matching in D/R EBV-mismatched LTRs significantly increases the risk of PTLD.