Intermediate term results of total lymphoid irradiation for the treatment of non-specific graft dysfunction after heart transplantation

Tailored total lymphoid irradiation in heart transplant patients: 10-years experience of one center

BACKGROUND

To assess safety and efficacy of tailored total lymphoid irradiation (tTLI) in cardiac transplant patients.

METHODS

A total of seven patients, of which five had recalcitrant cellular cardiac allograft rejection (RCCAR), confirmed by endomyocardial biopsies, and two had side effects of immunosuppressive drug therapy, were all treated with tTLI. tTLI was defined by the adjustment of both the fraction interval and the final irradiation dosage both being dependent on the patients general condition, irradiation-dependent response, and the white blood and platelet counts. A mean dose of 6.4 Gy (range, 1.6 - 8.8 Gy) was given. Median follow-up was 7 years (range, 1.8 - 12.2 years).

RESULTS

tTLI was well tolerated. Two patients experienced a severe infection during tTLI (pneumocystis jirovecii pneumonia, urosepsis and generalized herpes zoster) and one patient developed a lymphoproliferative disorder after tTLI. The rate of rejection episodes before tTLI was 0.43 episodes/patient/month and decreased to 0.02 episodes/patient/month after tTLI (P < .001). At the end of the observation time, all patients except one were alive.

CONCLUSIONS

tTLI is a useful treatment strategy for the management of RCCAR and in patients with significant side effects of immunosuppressive drug therapy. In this series tTLI demonstrated significantly decreased rejection rates without causing relevant treatment-related toxicity.

Helical tomotherapy for total lymphoid irradiation

Total lymphoid irradiation is employed in the preparative regimens for allogeneic bone marrow and solid organ transplantation, solid organ transplant rejection, and chronic graft-versus-host disease. Linear accelerator-based radiotherapy, typically involving opposed anteroposterior and posteroanterior beams, has been commonly used; however, extended source-to-skin patient setup and/or field matching are required, and all organs within the beam coverage receive the entire prescribed dose. Megavoltage helical tomotherapy represents a technological advance in terms of both treatment delivery and patient positioning. The continuously rotating multileaf collimated fan beam allows highly conformal coverage of complex target geometries, in turn allowing avoidance of radiosensitive adjacent organs. In addition, the megavoltage computed tomographic scans allow potentially more accurate, targetbased setup verification. The present case report describes tomotherapy-based total lymphoid irradiation in an adult patient with late-onset cardiac transplant rejection. Treatment planning allowed dose minimization to the spinal cord, kidneys, intestinal compartment, and lungs. The patient tolerated treatment well without acute adverse effects, and he is now in early follow-up.

Acute antibody-mediated rejection following heart transplantation

Acute antibody-mediated rejection (AMR) in heart transplantation is often associated with hemodynamic compromise, and is associated with increased mortality and development of accelerated transplant coronary artery disease (TCAD). The diagnosis of AMR has historically been controversial and outcomes with aggressive immunosuppressive therapy including plasmapheresis and cyclophosphamide are poor. Advances in diagnostic techniques like the demonstration of immunopathologic evidence for antibody-mediated rejection by deposition of the complement split product C4d in tissue and detection of anti-HLA antibodies by flow cytometry will assist in further characterizing AMR. Immunosuppression targeting B-lymphocytes and use of m-TOR inhibitors to alter the predilection to develop TCAD and improve survival in AMR remains to be proven.

The safety and efficacy of total lymphoid irradiation in progressive bronchiolitis obliterans syndrome after lung transplantation

Total lymphoid irradiation (TLI) has been used to control renal and cardiac allograft rejection. Data evaluating TLI in bronchiolitis obliterans syndrome (BOS), the physiological manifestation of chronic lung allograft rejection, is very limited. We present our single center experience of the safety and efficacy of TLI in controlling progressive BOS in a retrospective study. Over 12 years, 37 lung recipients (16 M:21 F) who had undergone 13 single; 12 bilateral and 12 heart-lung transplants were treated with TLI for progressive BOS. Grades at time TLI given were BOS 1 (n = 7) BOS 2 (n = 14) BOS 3 (n = 16). Twenty-seven (73%) completed >8/10 fractions, 10 (27%) failed to complete TLI. Two died from advanced BOS during treatment, 8 stopped early (range 3-7 fractions) due to marrow suppression (6) or infection (2). In the 27 recipients who completed >8/10 fractions, decline in FEV1 was 122.7 mls/month pre-TLI and 25.1 mls/month post-TLI, p = 0.0004, mean (95% CI) change in rate of decline was 97.5 (48.2-146.7) mls/month. TLI significantly reduces the rate of decline in graft function associated with BOS. TLI is well tolerated and associated with few serious complications and is an appropriate immunosuppressive approach in progressive BOS.

Delayed complete recovery of graft dysfunction after cardiac transplantation

Primary graft dysfunction is a major cause of morbidity and mortality early after cardiac transplantation. We present here a case of unspecific graft dysfunction in a 47-year-old female recipient of a heart transplant that could not be attributed to the unusual causes of this disorder. The patient manifested symptoms and signs of heart failure early postoperatively, and echocardiography together with right heart catheterization confirmed the diagnosis. There was no body size mismatch, graft preservation was optimal, pulmonary vascular resistance preoperatively was normal, and rejection episodes could not explain her deterioration. Standard medical therapy for heart failure was initiated, and the patient's symptoms improved, although graft dysfunction persisted for a period of 1.5 years. Afterward, a gradual spontaneous improvement occurred, resulting in complete recovery of graft function at six years postoperatively. In addition to the case presented, potential contributing factors to this syndrome, together with appropriate treatment options, are discussed.