De novo malignancy after lung transplantation in Japan

Timing of Mesenchymal Stromal Cell Therapy Defines its Immunosuppressive Effects in a Rat Lung Transplantation Model

Cell therapy using mesenchymal stromal cells (MSCs) is being studied for its immunosuppressive effects. In organ transplantation, the amount of MSCs that accumulate in transplanted organs and other organs may differ depending on administration timing, which may impact their immunosuppressive effects. In vitro, adipose-derived mesenchymal stem cells (ADMSCs) suppress lymphocyte activation under cell-to-cell contact conditions. However, in vivo, it is controversial whether ADMSCs are more effective in accumulating in transplanted organs or in secondary lymphoid organs. Herein, we aimed to investigate whether the timing of ADMSC administration affects its immunosuppression ability in a rat lung transplantation model. In the transplantation study, rats were intramuscularly administered half the usual dose of tacrolimus (0.5 mg/kg) every 24 h after lung transplantation. ADMSCs (1 × 106) were administered via the jugular vein before (PreTx) or after (PostTx) transplantation. Cell tracking using quantum dots was performed. ADMSCs accumulated predominantly in the lung and liver; fewer ADMSCs were distributed in the grafted lung in the PreTx group than in the PostTx group. The rejection rate was remarkably low in the ADMSC-administered groups, particularly in the PostTx group. Serum tumor necrosis factor-α (TNF-α), interferon-γ, and interleukin (IL)-6 levels showed a greater tendency to decrease in the PreTx group than in the PostTx group. The proportion of regulatory T cells in the grafted lung 10 days after transplantation was higher in the PostTx group than in the PreTx group. PostTx administration suppresses rejection better than PreTx administration, possibly due to regulatory T cell induction by ADMSCs accumulated in the transplanted lungs, suggesting a mechanism different from that in heart or kidney transplantation that PreTx administration is more effective than PostTx administration. These results could help establish cell therapy using MSCs in lung transplantation.

Current Status of Malignant Tumors after Organ Transplantation

Objective

To analyze the diagnosis and treatment of patients with concomitant malignant tumors after organ transplantation by compiling data from organ transplantation patients.

Methods

By searching CNKI and PubMed databases, we made a systematic analysis of the studies of postorgan transplantation complicating malignant tumors in the last decade.

Results

There were 10 articles on malignant tumors after renal transplantation, 8 articles on liver transplantation, 2 articles on heart transplantation, and 1 article on lung transplantation. The incidence of malignant tumors complicating renal transplantation is 10.4% in Europe, with skin cancer and Kaposi's sarcoma being common; the incidence in the United States is 3.4%, with PTLD having the highest incidence; the incidence of malignant tumors is relatively lowest in Asia, with gastrointestinal malignancies being the main ones. The mean time to complication of malignancy after renal transplantation is 3.83 years. The incidence of concurrent malignancies after liver transplantation is 8.8% in Europe, where skin cancer and Kaposi's sarcoma are common; 5.6% in Asia, where gastrointestinal tract tumors are prevalent; and 4.5% in the United States, where gastrointestinal tract tumors, PTLD, and hematologic diseases are predominant. The mean time to complication of malignancy after liver transplantation is 4.79 years. The incidence of malignancy after heart transplantation is 6.8-10.7%. The incidence of malignancy after lung transplantation is about 10.1%. Minimization of immunosuppression or modification of immunosuppression regimens may be a key component of cancer prevention. mTOR inhibitors and phenolate (MMF) reduce the incidence of de novo malignancies in patients after solid organ transplantation. Surgical treatment improves survival in patients with early malignancies. The use of external beam radiation therapy in the treatment of hepatocellular carcinoma is limited due to the risk of radiation liver disease.

Conclusions

The risk of concomitant malignancy needs to be guarded for 5 years of immunosuppressive therapy after organ transplantation surgery. Adjusting the immunosuppressive treatment regimen is an effective way to reduce concurrent malignancies. Systemic chemotherapy or radiotherapy requires vigilance against the toxic effects of drug metabolism kinetics on the transplanted organ.

Effect of preoperative long-term use of corticosteroids on the development of post-transplant lymphoproliferative disorders after lung transplantation: a single-center experience in Japan

PURPOSE

Post-transplant lymphoproliferative disorder (PTLD) is a major complication of lung transplantation (LTx). However, few studies on PTLD in Asian populations have been reported. We explored the characteristics of Japanese PTLD cases after LTx.

METHODS

We retrospectively reviewed 195 cases of LTx at our institute. We summarized the clinical experiences of 7 PTLD cases and analyzed the patient characteristics and survival outcomes of patients with (n = 7) and without (n = 188) PTLD.

RESULTS

All PTLD patients were taking corticosteroids preoperatively (p = 0.0030), and the duration of preoperative corticosteroid therapy was significantly longer in the PTLD group (p = 0.0064) than in the non-PTLD group. The overall survival after LTx was significantly worse in the PTLD group (p = 0.027) than in the non-PLTD group. Among the three patients who died within 1 year after the PTLD onset, two died of opportunistic infections without residual PTLD lesions. Chronic lung allograft dysfunction (CLAD) or bronchiolitis obliterans at an autopsy were diagnosed after PTLD treatment in four cases.

CONCLUSIONS

Long-term preoperative corticosteroid therapy may be a risk factor for PTLD after LTx. Opportunistic infections are lethal complications of PTLD, regardless of the effectiveness of PTLD treatment. CLAD occurs at a high rate after PTLD treatment, and close monitoring is required.

The role of radiotherapy in patients with solid tumours after solid organ transplantation: a systematic review

For patients diagnosed with cancer who have previously received an organ transplant, radiotherapy represents a challenging clinical scenario without well established care algorithms. Immunosuppressive therapy can be a cause for concern among clinicians treating this category of patients. Potential immune modulation following irradiation could affect recipient organ tolerance and the outcomes of the transplantation itself. The main aim of this systematic review was to define the safety and effectiveness of radiotherapy in patients diagnosed with cancer who have previously received an organ transplant. We searched PubMed and Embase for articles published between Jan 1, 1995, and April 30, 2020 for studies in patients who had undergone radiotherapy for post-transplantation malignancies. The Review is framed by the PICO (population, intervention, control, and outcomes) criteria, and primarily focuses on modern treatment techniques.

Late-Onset Central Nervous System Posttransplant Lymphoproliferative Disorder After Lung Transplantation:A Case Report

Posttransplant lymphoproliferative disorder (PTLD) is caused by uncontrolled proliferation of lymphoid cells after a hematopoietic stem cell or solid organ transplant procedure related to the Epstein-Barr virus (EBV) infection. A primary central nervous system (CNS) PTLD (CNS-PTLD) is rare and important to distinguish from an intracranial lesion after transplantation. A 66-year-old man with pulmonary arterial hypertension who underwent living-donor lung transplantation 9 years prior noticed disorientation regarding route and dates. Brain magnetic resonance imaging revealed multiple white matter lesions and fluorodeoxyglucose (FDG) positron emission tomography showed FDG uptake in the brain and skin. CNS-PTLD was diagnosed by craniotomy biopsy and EBV-encoded RNA was positive in in situ hybridization findings and elevated in brain tissue. The treatment was started with immunosuppressant reduction and whole brain radiotherapy. But the condition progressed rapidly over 2 months after the first symptom and the patient was passed away 25 days after hospitalization. CNS-PTLD can occur several years after transplantation and it is necessary to keep in mind to distinguish brain disease because early diagnosis and treatment are important.

Prognostic Factors in Lung Transplantation After Hematopoietic Stem Cell Transplantation

BACKGROUND

Lung transplantation is the final lifesaving option for patients with pulmonary complications after hematopoietic stem cell transplantation (HSCT). Patients undergoing HSCT for hematologic diseases are thought to be high-risk candidates for lung transplantation; therefore, few lung transplants are performed for these patients, and few studies have been reported. This study aimed to describe the characteristics and outcomes of lung transplantation in patients with pulmonary complications after HSCT.

METHODS

We retrospectively investigated 62 patients who underwent lung transplantation after HSCT. All data were collected from 6 lung transplant centers in Japan.

RESULTS

Seventeen patients underwent cadaveric lung transplantation, whereas 45 underwent living-donor lobar lung transplantation (LDLLT). In the LDLLT group, 18 patients underwent LDLLT after HSCT in which one of the donors had also served as a donor for HSCT. Seven patients underwent single LDLLT for which the donor was the same as the patient from whom stem cells were obtained for HSCT. Preoperative hypercapnia was observed in 52 patients (84%). Thirteen patients (21%) required mechanical ventilation preoperatively. Fifty-five patients underwent HSCT for hematologic malignancies, and 4 (7%) relapsed after lung transplantation. The 5-year survival rate was 64.2%. In a multivariable analysis, patients younger than 45 years and those with the same donor for both procedures exhibited significantly better survival (P = 0.012 and 0.041, respectively).

CONCLUSIONS

Lung transplantation for pulmonary complications after HSCT was performed safely and yielded better survival, especially in younger recipients for whom both lung transplantation and HSCT involved the same donor.

De novo malignancy in organ transplant recipients in Taiwan: a nationwide cohort population study

Organ transplant recipients appear to have a higher risk of de novo malignancy. The aim of the study was designed to estimate cancer risk in heart, lung, kidney and liver transplant recipients. The cohort study used the Taiwan National Health Insurance Research Database (1996-2011) and followed the outcomes of organ recipients until 2012. De novo cancer and mortality rates after organ transplantation were evaluated using standardized incidence ratios, excess absolute risks of cancer, and standardized mortality ratios in recipients were compared with those in the general population. We identified 40, 231, 2, and 115 patients who developed cancer after heart, kidney, lung, and liver transplantation, which corresponded to a cancer incidence of 878.4, 1101.2, 728.9, and 1361.4 cases per 100,000 person-years, respectively. In heart, kidney, lung, and liver recipients, the overall standardized incidence ratios were 1.65 (1.21-2.24), 3.33 (2.93-3.79), 1.82 (0.45-7.27) and 3.37 (2.81-4.05) and the overall standardized mortality ratios were 5.45 (4.96-5.98), 1.47 (1.34-1.61), 8.92 (7.10-11.20), and 3.83 (3.48-4.20), respectively. These results reveal a three-fold increase in de novo cancer risk in organ transplant patients compared with the general population. This study illustrated the importance of de novo malignancy after organ transplantation.