Acquired transdiaphragmatic hernia: an unusual cause of cardiac tamponade

Transdiaphragmatic peritoneopericardial hernia is a rare complication after peritoneopericardial window formation, coronary artery bypass grafting using the gastroepiploic artery, or subxiphoid epicardial pacemaker insertion. We describe two different clinical presentations of transdiaphragmatic peritoneopericardial hernia in patients who had undergone recent heart transplantation. One was an exceptional case of cardiac tamponade caused by small bowel strangulation through a diaphragmatic defect.

Late Failing Heart Allografts: Pathology of Cardiac Allograft Vasculopathy and Association With Antibody-Mediated Rejection

In heart transplantation, there is a lack of robust evidence of the specific causes of late allograft failure. We hypothesized that a substantial fraction of failing heart allografts may be associated with antibody-mediated injury and immune-mediated coronary arteriosclerosis. We included all patients undergoing a retransplantation for late terminal heart allograft failure in three referral centers. We performed an integrative strategy of heart allograft phenotyping by assessing the heart vascular tree including histopathology and immunohistochemistry together with circulating donor-specific antibodies. The main analysis included 40 explanted heart allografts patients and 402 endomyocardial biopsies performed before allograft loss. Overall, antibody-mediated rejection was observed in 19 (47.5%) failing heart allografts including 16 patients (40%) in whom unrecognized previous episodes of subclinical antibody-mediated rejection occurred 4.5 ± 3.5 years before allograft loss. Explanted allografts with evidence of antibody-mediated rejection demonstrated higher endothelitis and microvascular inflammation scores (0.89 ± 0.26 and 2.25 ± 0.28, respectively) compared with explanted allografts without antibody-mediated rejection (0.42 ± 0.11 and 0.36 ± 0.09, p = 0.046 and p < 0.0001, respectively). Antibody-mediated injury was observed in 62.1% of failing allografts with pure coronary arteriosclerosis and mixed (arteriosclerosis and atherosclerosis) pattern, while it was not observed in patients with pure coronary atherosclerosis (p = 0.0076). We demonstrate that antibody-mediated rejection is operating in a substantial fraction of failing heart allografts and is associated with severe coronary arteriosclerosis. Unrecognized subclinical antibody-mediated rejection episodes may be observed years before allograft failure.

Adapted treatment of Epstein-Barr virus infection to prevent posttransplant lymphoproliferative disorder after heart transplantation

Up to 35% of posttransplant lymphoproliferative disorder (PTLD) cases occur within 1 year of transplantation, and over 50% are associated with Epstein-Barr virus (EBV). EBV primary infection and reactivation are PTLD predictive factors, but there is no consensus for their treatment. We conducted a prospective single-center study on 299 consecutive heart-transplant patients treated with the same immunosuppressive regimen and monitored by repetitive EBV viral-load measurements and endomyocardial biopsies to detect graft rejection. Immunosuppression was tapered on EBV reactivation with EBV viral loads >10(5) copies/mL or primary infection. In the absence of response at 1 month or a viral load >10(6) copies/mL, patients received one rituximab infusion (375 mg/m(2) ). All patients responded to treatment without increased graft rejection. One primary infection case developed a possible PTLD, which completely responded to diminution of immunosuppression, and one patient, whose EBV load was unevaluable, died of respiratory complications secondary to PTLD. Compared with a historical cohort of 820 patients, PTLD incidence was decreased (p = 0.033) by a per-protocol analysis. This is the largest study on EBV primary infection/reactivation treatment, the first using rituximab following solid organ transplantation to prevent PTLD and the first to demonstrate an acceptable tolerability profile in this setting.

Human herpesvirus 8 (HHV8) transmission and related morbidity in organ recipients

The aims of the study were to assess the risk of HHV8 transmission resulting from organ transplantation, and related morbidity in liver, heart and kidney transplant recipients. Donor and recipient serologies were screened between January 1, 2004 and January 1, 2005 using HHV8 indirect immunofluorescence latent assay (latent IFA) and indirect immunofluorescent lytic assay (lytic IFA). Recipients negative for latent IFA with a donor positive for at least one test were sequentially monitored for HHV8 viremia and underwent serological tests over a period of 2 years. The results showed that among 2354 donors, HHV8 seroprevalence was 9.9% (lytic IFA) and 4.4% (latent IFA). A total of 454 organ recipients (281 renal, 116 liver and 57 heart) were monitored over a 2-year period. Seroconversion was observed in 12 patients (cumulative incidence 28%) whose donor had positive latent IFA and in 36 patients (cumulative incidence 29%) whose donors were positive only for lytic IFA, without differences across types of transplants. Positive HHV8 viremia was detected in only 4 out of 89 liver transplant recipients during follow-up and not in recipients of other types of transplant. Two liver transplant recipients and one kidney transplant recipient developed KS. In conclusion, although HHV8 transmission is a frequent event after organ transplantation, HHV8-related morbidity is rather rare but can be life threatening. Donor screening is advisable for monitoring HHV8 seronegative liver transplant recipients.