Johnson Mr

Increased Incidence of Lymphoproliferative Disorder after Immunosuppression with the Monoclonal Antibody OKT3 in Cardiac-Transplant Recipients

BACKGROUND A sudden increase in the incidence of post-transplantation lymphoproliferative disorder among the patients in our cardiac-transplantation program was temporally related to introduction of the immunosuppressive drug OKT3. This monoclonal antibody has come to be widely used in recent years both to prevent and to treat rejection after cardiac transplantation. METHODS In order to identify variables that predict the development of post-transplantation lymphoproliferative disorder, we analyzed retrospectively a series of 154 consecutive cardiac-transplant recipients at a single institution. Univariate analyses and multivariate analysis by logistic regression were performed. RESULTS Among 75 patients who did not receive OKT3, post-transplantation lymphoproliferative disorder developed in 1 (1.3 percent), as compared with 9 of 79 patients who received the drug (11.4 percent); the incidence among the OKT3-treated patients was ninefold higher (odds ratio, 9.5; 95 percent confidence interval, 1.6 to 54.7). According to multivariate analysis, the only factor significantly associated with the development of post-transplantation lymphoproliferative disorder was the use of OKT3 (P = 0.001). A significant increase in risk with increasing doses was also apparent: 4 of 65 patients who received a cumulative dose of 75 mg of OKT3 or less (6.2 percent) had post-transplantation lymphoproliferative disorder, whereas 5 of 14 patients who received more than 75 mg had the disorder (35.7 percent; P less than 0.001). CONCLUSION The addition of OKT3 to the immunosuppressive regimen increases the incidence of post-transplantation lymphoproliferative disorder after cardiac transplantation, and the risk increases sharply after cumulative doses greater than 75 mg. We suggest that the risks and benefits of prophylactic OKT3 administration be reassessed in the light of these findings, particularly since the value of prophylactic immunotherapy in cardiac-transplant recipients remains to be clearly established.

Endomyocardial biopsy findings after photopheresis treatment of cardiac transplant rejection

Photopheresis is a potential therapy for allograft rejection in which reinfusion of mononuclear cells exposed to ultraviolet-A irradiation after pretreatment with 8-methoxypsoralen may initiate immunosuppressive responses. Endomyocardial biopsies (EMBs) of cardiac transplant recipients with moderate acute rejection (IHSLT grades 2 and 3) treated with photopheresis (7 patients/9 treatments) and followed for six months or more were evaluated and compared with biopsies of patients treated with corticosteroids (7 patients/8 treatments) and followed for a similar time period. The first posttreatment EMB showed improvement in 100% of corticosteroid-treated patients, compared with 56% of photopheresis-treated patients (p < 0.005). Interstitial infiltrates of >90% T-lymphocytes were present in a greater percentage of photopheresis-treated patients than in corticosteroid-treated patients on the first five posttreatment EMBs (p < 0.005) as follows: EMB 1, 90% vs. 25%; EMB 2, 90% vs. 25%; EMB 3, 78% vs. 0%; EMB 4, 56% vs. 0%, EMB 5, 56% vs. 0%. Postphotopheresis EMBs also showed giant cell reaction in 1 patient and extensive band-like infiltrates in 3 patients. Our results suggest that interstitial T-cell infiltrates are more prevalent and persist longer after photopheresis than after corticosteroid treatment of heart allograft rejection. Whether these T-lymphocytes are alloreactive or mediate immunosuppressive signals is unknown. The use of new immunosuppressive therapies may modify endomyocardial biopsy findings, requiring adjustment of the diagnostic criteria for assessing and grading allograft rejection.