Modification of renal homograft rejection by irradiation

Implementation of a blood irradiation program at a community cancer center

BACKGROUND

Blood component irradiation is an accepted method of preventing transfusion-associated GVHD. Previous publications have largely focused on the technical aspects of the irradiation process itself, but relatively little attention has been paid to the details associated with the implementation of a blood irradiation program at the level of a community cancer center.

STUDY DESIGN AND METHODS

An observational study was performed, detailing the specific operational, documentation, and quality assurance measures employed in providing a blood component-irradiation service within the institutional context of a community cancer center.

RESULTS

The Montgomery Cancer Center irradiated 589 units of blood components in 1998 and 1999 to provide a local blood bank with an alternative for procurement of irradiated blood components while complying with applicable quality assurance and regulatory requirements.

CONCLUSION

Blood component irradiation is within the scope of most well-equipped and adequately staffed community cancer centers. Establishment of a blood component irradiation program requires scrupulous physics and dosimetry support, both to ensure the quality of the irradiated component and to satisfy governmental agency regulatory requirements.

Local graft irradiation after failure of modern immunosuppression in acute cellular and vascular graft rejection

PURPOSE

With improved chemical immunosuppressive agents, approximately 90% of rejection episodes can be reversed. However, in situations of failed immunosuppression, graft loss becomes inevitable. Our objective is to assess the efficacy of local graft irradiation (LGI) as an effort of last resort in a contemporary group of patients in whom graft failure to irreversible cellular and vascular rejection is imminent.

METHODS AND MATERIALS

A total of 308 renal transplantations were performed at our institution from 1992 to 1995, and an overall 1-year graft survival rate of 90% has been seen as a result of improvement in chemical immunosuppression. However, 6 patients were referred for LGI when all other measures failed to reverse the rejection crisis. Parameters that were studied in these patients included graft function and postirradiation graft histology.

RESULTS

Irradiation was associated with reversal of the rejection crisis and resulted in documented histological long-term graft survival in 1 of the 6 patients (17%). Two of the six patients (33%) had reversal of the rejection episode based on postirradiation biopsy of the renal allograft. Three of the six patients showed some level of clinical improvement of graft function for varying periods of time. One patient maintained stable allograft function without deterioration and with continued independence from hemodialysis. One recipient died from sepsis despite histologic improvement after irradiation.

CONCLUSIONS

Our impression is that LGI is indicated when all other measures have failed to reverse an acute rejection episode in the transplanted renal allograft. The role of radiation in this setting should be studied further.

Radiation therapy for renal transplant rejection refractory to pulse steroids and OKT3

PURPOSE

To determine the response rate and kidney graft survival following local irradiation to the transplanted renal graft undergoing persistent rejection after medical management including pulse steroids and OKT3. The role of radiation for renal transplant rejection after failure of OKT3 has not been previously reported.

METHODS AND MATERIALS

From July 1, 1988 to July 1, 1994, 72 consecutive patients with kidney graft rejection were treated with local irradiation to the transplanted renal graft following failure of medical management. All patients received pulse steroids and OKT3, an anti-CD3 immunosuppressant. Patients who failed to respond to methylprednisolone and OKT3 therapy were referred for radiation therapy. The median time from the diagnosis of rejection to irradiation was 8 days. All kidney grafts received local graft irradiation to a total of 8 Gy delivered in four daily fractions.

RESULTS

Sixty (83%) patients initially responded to radiotherapy at 7 days after completion of radiotherapy, as defined by a decrease in serum creatinine. Thirty-five responding patients have not experienced a second episode of graft rejection. Overall, 43 (60%) patients have renal graft survival, with a median follow-up of 16 months (range of 6-73 months)>

CONCLUSION

It is concluded that there is a subgroup of kidney graft patients undergoing graft rejection who are refractory to pulse steroids and OKT3 therapy where irradiation may be an effective modality with high rates of response and a moderate rate of graft survival. However, a prospective, randomized trial in these medically refractory patients is needed to ascertain whether these results are clinically significant.

A randomized study of the efficacy of adjuvant local graft irradiation following renal transplantation

A prospective randomized study investigating the effectiveness of adjuvant local graft irradiation (LGI) following renal transplantation was performed at Georgetown University Hospital from 1983 until 1988. One hundred and thirty-eight patients were enrolled in the study with 117 patients receiving cadaver kidney transplantations and 21 patients receiving living related kidney transplantations. Seventy-one patients were randomized to receive adjuvant local graft irradiation consisting of 600 cGy in four fractions with chemical immunosuppression whereas the remaining 67 patients received chemical immunosuppression only (control group). The two groups were comparable at entry with respect to potentially important prognostic variables. Median follow-up for all patients was 30 months. The 3-year actuarial allograft success rate was 75% and 68% for the local graft irradiation and control groups, respectively. A nonsignificant trend favoring the irradiated group was noted. Subgroup analysis of the 21 recipients of kidneys from living related donors suggested an improvement in allograft survival for the local graft irradiation arm. Cadaver allograft survival was not significantly different between the two treatment arms. There was no apparent benefit in kidney function or time to the first rejection episode in the group receiving local graft irradiation.

The use of local allograft irradiation following renal transplantation

Over a 10 year period, 67 recipients of 71 renal allografts received graft irradiation following the diagnosis of rejection. The majority of kidneys were treated with a total dose of 600 rad, 150 rad per fraction, in 4 daily fractions. Fifty-three kidneys were irradiated following the failure of standard systemic immunosuppression and maximally tolerated antirejection measures (pulse high dose steroids, Actinomycin, ATG) to reverse an episode of acute rejection. Seven of these patients (13%) had greater than a 50% improvement in serum creatinine (Cr) 1 week following completion of the irradiation. Twenty-two (42%) of these allografts were noted to have stable (i.e. no deterioration) or improved function 1 month following the treatment with irradiation. Eleven (21%) of these allografts maintained function 1 year following transplantation. There were 10 patients whose allografts were irradiated because of renal dysfunction in a clinical setting which did not permit the administration of further immunosuppression, i.e., infection or hematologic dyscrasias. Three of these patients (30%) had greater than a 50% improvement in serum Cr 1 week following completion of the irradiation. Nine (90%) of these allografts had stable or improved function 1 month following the treatment with irradiation. Biopsies were obtained of 41 allografts. Of the 24 renal allografts with predominantly cellular rejection, 10 (42%) had the process reversed or stabilized at 1 month following irradiation. Five (21%) of these allografts were functioning at 1 year following irradiation. Rejection was reversed or stabilized in 6 of 17 (35%) allografts at 1 month when the histologic features of renal biopsy suggested predominantly vascular rejection. One (6%) of these allografts was functioning at 1 year following transplantation. Local graft irradiation has helped maintain a limited number of allografts in patients whose rejection has failed to respond to systemic immunosuppression. Irradiation may also benefit patients with ongoing rejection in whom further systemic immunosuppression is contra-indicated.

Fractionated total lymphoid irradiation as preparative immunosuppression in high risk renal transplantation: clinical and immunological studies

Twenty-two patients at high risk to reject renal allografts have been treated with fractionated total lymphoid irradiation (FTLI) prior to transplantation of primary (2), secondary (16) or teritary (4) renal allografts. All patients undergoing retransplantation had rapidly rejected previous grafts. At 24 months following transplantation, 72% of grafts were functioning in the TLI group compared with a 38% graft function in an historical control group of recipients receiving secondary or tertiary grafts and treated with conventional immunosuppression. Important variables in determining success of transplantation following fractionated TLI include the dose of TLI, the interval from radiation to transplantation, and maintenance, post-transplant immunosuppressive therapy. Optimal results were achieved with 2500 rads delivered in 100 rad fractions followed by transplantation within two weeks, and a tapering prednisone schedule and maintenance azathioprine post-transplantation. Seventeen patients had significant complications of the radiation treatment and there was one death, prior to transplantation, associated with pneumonitis. In vitro assessment of immune function demonstrated marked peripheral T cell depletion and loss of in vitro responsiveness to mitogen and allogeneic stimulation following FTLI. The administration of donor bone marrow at the time of transplantation did not produce chimerism. The results suggest that when properly utilized FTLI can produce effective adjunctive immunosuppression for clinical transplantation.

Effect of local irradiation on the acute rejection process in transplanted kidneys

The graft in 178 renal transplant patients was irradiated in an effort to halt acute rejection phenomena. Of the patients, 61 per cent received their transplant from either a sibling, parent or child and 38 per cent received cadaveric kidneys. Of the irradiated kidneys 61 per cent were functioning at 6 months, 58 per cent at 12 months and 49 per cent at 18 months. The rational for irradiation of transplanted kidneys with acute rejection is discussed.

Long-term survival of skin allografts in mice treated with fractionated total lymphoid irradiation

Treatment of recipient Balb/c mice with fractionated, high-dose total lymphoid irradiation, a procedure commonly used in the therapy of human malignant lymphomas, resulted in fivefold prolongation of the survival of C57BL/Ka skin allografts despite major histocompatibility differences between the strains (H-2d and H-2b, respectively). Infusion of 10(7) (C57BL/Ka x Balb/c)F1 bone marrow cells after total lymphoid irradiation further prolonged C57BL/Ka skin graft survival to more than 120 days. Total lymphoid irradiation may eventually prove useful in clinical organ transplantation.

Radiotherapy in treatment of acute rejection of human renal allografts

36 patients who received a renal transplant and who subsequently underwent a rejection episode were randomised into two groups. The first group received a standard form of rejection therapy consisting in high doses of steroid drugs, and the second group received in addition 600 rads of radiotherapy to the graft. After three years (minimum follow-up twelve months) the groups were compared with respect to patient and graft survival and level of transplant function. No benefit was obtained by the group receiving radiotherapy.

Correlation of tumor burden with in vitro lymphocyte reactivity and antibodies to herpesvirus tumor-associated antigens in head and neck squamous carcinoma

In 94 patients with squamous carcinoma of the head and neck region, the clinical extent of tumor was correlated with in vitro lymphocyte reactivity (LR) to phytohemagglutinin (PHA) and serum complement-fixing antibodies to herpes simplex virus (HSV)-induced tumor-associated antigen (TAA). Forty-six patients were tumor-bearing and 48 were considered cured. Controls were 41 age-matched normals with histories of similar cigarette consumption. In 15 patients with Stage I carcinomas of the larynx, among whom the tumor diameter was 5 mm or less, mean LR or PHA did not differ from controls and 7 of 11 tested (63%) had antibodies to HSV-TAA. In 83 patients with more extensive tumors, LR to PHA was significantly lower than controls and 42 of 44 tested (95%) had antibodies to HSV-TAA. In both groups, LR to PHA was similar among tumor-bearing and cured patients. The study delineates a clinical tumor burden associated with impaired LR to PHA and a high incidence of antibodies to HSV-TAA in patients with squamous carcinomas of the head and neck region, and shows a correlation between the immune defects in clinically cured patients and tumor extent prior to treatment.

Prolonged depression of cellular immunity in cured laryngopharyngeal cancer patients treated with radiation therapy

Immune competence was evaluated in cured patients who had been treated by irradiation for carcinoma of the laryngopharynx, and compared with that of similar patients treated by surgery alone, and normal controls. Cellular immunity was determined by quantitation of in vitro phytohemagglutinin (PHA)-induced lymphocyte reactivity and peripheral blood thymus-dependent lymphocyte (T cell) levels. Humoral immunity was assessed by measurement of serum immunoglobulin levels and by the effect of serum on in vitro normal lymphocyte reactivity to PHA. In 21 patients who were studied for 4-23 years (mean 8.4) after surgical treatment alone for laryngopharyngeal carcinoma, neither cellular nor humoral immunity differed from that of 44 controls. In contrast, 14 patients who had been irradiated and subsequently cured for 4-15 years (mean 9.0) prior to evaluation displayed significantly impaired cellular immune competence when compared to normals and patients treated by surgery alone. Since previous determinations of the effects of radiation therapy have been in patients who received irratiation to the thymic region or large area of bone marrow, this study indicates that radiation therapy for cancer administered via portals that encompass a minimal area of the immune system may be associated with prolonged impairment of cellular immunity.