Development and Evaluation of a Novel Radiotracer 125I-rIL-27 to Monitor Allotransplant Rejection by Specifically Targeting IL-27Rα

Noninvasive monitoring of allograft rejection is beneficial for the prognosis of patients with organ transplantation. Recently, IL-27/IL-27Rα was proved in close relation with inflammatory diseases, and 125I-anti-IL-27Rα mAb our group developed demonstrated high accumulation in the rejection of the allograft. However, antibody imaging has limitations in the imaging background due to its large molecular weight. Therefore, we developed a novel radiotracer (iodine-125-labeled recombinant IL-27) to evaluate the advantage in the targeting and imaging of allograft rejection. In vitro specific binding of 125I-rIL-27 was determined by saturation and competitive assay. Blood clearance, biodistribution, phosphor autoradioimaging, and IL-27Rα expression were studied on day 10 after transplantation (top period of allorejection). Our results indicated that 125I-rIL-27 could bind with IL-27Rα specifically and selectively in vitro. The blood clearance assay demonstrated fast blood clearance with 13.20 μl/h of 125I-rIL-27 staying in the blood after 24 h. The whole-body phosphor autoradiography and biodistribution assay indicated a higher specific uptake of 125I-rIL-27 and a clear radioimage in allograft than in syngraft at 24 h, while a similar result was obtained at 48 h in the group of 125I-anti-IL-27Rα mAb injection. Meanwhile, a higher expression of IL-27Rα was found in the allograft by Western blot. The accumulation of radioactivity of 125I-rIL-27 was highly correlated with the expression of IL-27Rα in the allograft. In conclusion, 125I-rIL-27 could be a promising probe for acutely monitoring allograft rejection with high specific binding towards IL-27Rα on allograft and low imaging background.

Deep sequencing of DNA from urine of kidney allograft recipients to estimate donor/recipient-specific DNA fractions

Kidney transplantation is the treatment of choice for patients with end-stage kidney failure, but transplanted allograft could be affected by viral and bacterial infections and by immune rejection. The standard test for the diagnosis of acute pathologies in kidney transplants is kidney biopsy. However, noninvasive tests would be desirable. Various methods using different techniques have been developed by the transplantation community. But these methods require improvements. We present here a cost-effective method for kidney rejection diagnosis that estimates donor/recipient-specific DNA fraction in recipient urine by sequencing urinary cell DNA. We hypothesized that in the no-pathology stage, the largest tissue types present in recipient urine are donor kidney cells, and in case of rejection, a larger number of recipient immune cells would be observed. Extensive in-silico simulation was used to tune the sequencing parameters: number of variants and depth of coverage. Sequencing of DNA mixture from 2 healthy individuals showed the method is highly predictive (maximum error < 0.04). We then demonstrated the insignificant impact of familial relationship and ethnicity using an in-house and public database. Lastly, we performed deep DNA sequencing of urinary cell pellets from 32 biopsy-matched samples representing two pathology groups: acute rejection (AR, 11 samples) and acute tubular injury (ATI, 12 samples) and 9 samples with no pathology. We found a significant association between the donor/recipient-specific DNA fraction in the two pathology groups compared to no pathology (P = 0.0064 for AR and P = 0.026 for ATI). We conclude that deep DNA sequencing of urinary cells from kidney allograft recipients offers a noninvasive means of diagnosing acute pathologies in the human kidney allograft.

IL-27Rα: A Novel Molecular Imaging Marker for Allograft Rejection

Non-invasively monitoring allogeneic graft rejection with a specific marker is of great importance for prognosis of patients. Recently, data revealed that IL-27Rα was up-regulated in alloreactive CD4⁺ T cells and participated in inflammatory diseases. Here, we evaluated whether IL-27Rα could be used in monitoring allogeneic graft rejection both in vitro and in vivo. Allogeneic (C57BL/6 donor to BALB/c recipient) and syngeneic (BALB/c both as donor and recipient) skin grafted mouse models were established. The expression of IL-27Rα in grafts was detected. The radio-probe, ¹²⁵I-anti-IL-27Rα mAb, was prepared. Dynamic whole-body phosphor-autoradiography, ex vivo biodistribution and immunofluorescence staining were performed. The results showed that the highest expression of IL-27Rα was detected in allogeneic grafts on day 10 post transplantation (top period of allorejection). ¹²⁵I-anti-IL-27Rα mAb was successfully prepared with higher specificity and affinity. Whole-body phosphor-autoradiography showed higher radioactivity accumulation in allogeneic grafts than syngeneic grafts on day 10. The uptake of ¹²⁵I-anti-IL-27Rα mAb in allogeneic grafts could be almost totally blocked by pre-injection with excess unlabeled anti-IL-27Rα mAb. Interestingly, we found that ¹²⁵I-anti-IL-27Rα mAb accumulated in allogeneic grafts, along with weaker inflammation earlier on day 6. The high uptake of ¹²⁵I-anti-IL-27Rα mAb was correlated with the higher infiltrated IL-27Rα positive cells (CD3⁺/CD68⁺) in allogeneic grafts. In conclusion, IL-27Rα may be a novel molecular imaging marker to predict allorejection.

Sirolimus-Based Immunosuppressive Regimens in Renal Transplantation: A Systemic Review

Sirolimus (SRL)-based immunosuppressive regimens have been used for preventing rejection after kidney transplantation. This review analyzes their merits and demerits compared with other conventional regimes from the aspects of acute rejection rate, graft function, as well as patient/graft survival rates. In general, SRL is mostly recommended to be used as conversion therapy from calcineurin inhibitor (CNI) after kidney transplantation in most studies. Minimization or withdrawal of cyclosporine A (CsA) could also be considered when it was combined with SRL. SRL can replace mycophenolate mofetil (MMF), and the CNI dose should be reduced appropriately in this setting. Quadruple maintenance regimens containing SRL need future study to clarify their superiority. De novo use of low-dose CNI combined with SRL has no apparent merits and thus is not recommended. De novo use of standard-dose CNI combined with SRL followed by maintenance, de novo use of CNI-free regimens, as well as SRL use in delayed graft function (DGF) patients who spare antibody induction and postpone CNI administration should also be avoided. SRL supports steroids withdrawal after kidney transplantation, and SRL combined with tacrolimus is recommended in this setting. Loading dose is recommended when initiating SRL treatment and its trough blood level should be routinely monitored.

The impact of acute rejection in kidney transplantation on long-term allograft and patient outcome

BACKGROUND

Patients with end stage renal disease (ESRD) can be sustained with dialysis therapy.

OBJECTIVES

In this study, we followed up the effect of early acute and late acute rejections on survival rates of patients' grafts.

PATIENTS AND METHODS

We investigated the timing and frequency of acute rejection episodes related to long-term patient-graft survival in Taleghani hospital between 1990 and 2011. Recipients were divided into three groups as Group-1 (no rejection), Group-2 (early acute rejection [EAR]: less than 3-months) and Group-3 (late acute rejection [LAR]: after 3 months of transplant).

RESULTS

One and five-year patient's survival rates were 94.87% and 93.8%, and graft survival (GS) rates were 92.6% and 81.9%. EAR and LAR occurred in 125 (18.8%) and 77 (11.7%) patients, respectively. Graft and patient survival rates at one and five years were as follows; Group-1 (Graft 96.7% and 94.5% patient: 97.4% and 96.8%), Group-2 (Graft: 72% and 61%, patient: 85.6% and 84%), Group-3 (Graft: 84.4% and 36.8%, patient: 92.2% and 89.4%). Recipient age, type and length of dialysis, number of transplantations and the status of panel reactivity antibody (PRA) had no effect on the type of rejection. LAR was more commonly associated with males (P = 0.001) and donors' age was associated with rejection (P = 0.0002). Five-year GS rate among the three groups was lower in the LAR group (P < 0.0001).

CONCLUSIONS

LAR had a negative impact on long-term renal allograft survival and the risk of chronic graft dysfunction increased in patients with a history of LAR.

Strategies for the management of adverse events associated with mTOR inhibitors

Mammalian target of rapamycin (mTOR) inhibitors are used as potent immunosuppressive agents in solid-organ transplant recipients (everolimus and sirolimus) and as antineoplastic therapies for various cancers (eg, advanced renal cell carcinoma; everolimus, temsirolimus, ridaforolimus). Relevant literature, obtained from specific PubMed searches, was reviewed to evaluate the incidence and mechanistic features of specific adverse events (AEs) associated with mTOR inhibitor treatment, and to present strategies to effectively manage these events. The AEs examined in this review include stomatitis and other cutaneous AEs, wound-healing complications (eg, lymphocele, incisional hernia), diabetes/hyperglycemia, dyslipidemia, proteinuria, nephrotoxicity, delayed graft function, pneumonitis, anemia, hypertension, gonadal dysfunction, and ovarian toxicity. Strategies for selecting appropriate patients for mTOR inhibitor therapy and minimizing the risks of AEs are discussed, along with best practices for identifying and managing side effects. mTOR inhibitors are promising therapeutic options in immunosuppression and oncology; most AEs can be effectively detected and managed or reversed with careful monitoring and appropriate interventions.

Robot-assisted renal transplantation in the retroperitoneum

Minimally invasive surgery for renal transplantation is still under development. We employed the robotic surgical system to perform renal transplantation with a minimally invasive wound. The operation was performed with a Gibson incision and two working ports. The space for the transplantation was created by retroperitoneal dissection with the robot lifting the abdominal wall. Vascular reconstruction was performed with two robotic needle drivers. We successfully performed robot-assisted renal transplantation in five female and five male patients with an average wound length of 7.7 ± 1.04 cm. Nine of the renal allografts functioned immediately, but one with prolonged warm ischemia during the live donor nephrectomy had delayed function. The average creatinine level and estimated glomerular filtration rate at discharge were 1.31 ± 0.31 mg/dl and 58.2 ± 8.1 ml/min, respectively. All the transplants are currently functioning at 6.9 ± 3.9 months after operations. In conclusion, with robot assistance, minimal invasive renal transplantation can be performed successfully in the retroperitoneum.

Trauma after transplant: hold the antibiotics please

OBJECTIVE

Despite the increase in transplantation and the prevalence of trauma as a major disease entity, few data exist about transplant patients who suffer trauma. We conducted a study to determine whether transplant patients (TP) have worse outcomes, particularly of infections, than do their non-transplant (NTP) counterparts after trauma.

METHODS

We performed a retrospective review of trauma patients from 2006 to 2010. All patients who had undergone organ transplantation were included and compared through 1:3 propensity matching with their NTP counterparts. Data for the groups were compared to determine differences in outcomes.

RESULTS

The review included 17 TP (13 kidney, 2 liver, 1 kidney/liver, and 1 kidney/pancreas) as compared with 51 NTP. The patients were matched for injury severity score (ISS), age, and gender, with most suffering blunt trauma (82.4% [14/17] TP vs. 90% [46/51] NTP, p = 0.5). The groups had similar initial Glasgow Coma Scale (GCS) scores (13.2 ± 4.5 TP vs. 13.9 ± 2.5 NTP, p=0.6), serum lactate concentrations (2.0 ± 1.8 mmol/L TP vs. 2.3 ± 1.5 mmol/L NTP, p=0.39), and base deficits (-1.5 ± 4.0 TP vs. 0.6 ± 3.0 NTP, p=0.21). Comorbidities were more common in the TP than in the NTP group. The groups had similar lengths of stay (days on ventilator: 0.1 ± 0.3 TP vs. 0.4 ± 1.6 NTP, p=0.9; days in ICU: 0.2 ± 0.6 TP vs. 2.4 ± 5.9 NTP, p=0.16; days in hospital: 5.2 ± 6.8 TP vs. 7.5 ± 10.2 NTP, p=0.86), and two deaths occurred in each of the two groups (p=0.26). Overall complications were similar (52.94% [9/17] TP vs. 62.75% [32/51] NTP, p=0.57), and there were only two infections, both in the NTP group (p=1.0). Antibiotics were given to 59% of the TP vs. 39% of the NTP, with an average duration of 8.4 days for the TP vs. 3.9 days for the NTP.

CONCLUSION

When matched equally for degree of injury, the TP and NTP had similar outcomes. There also appeared to be no differences in infectious complications in the two groups, yet more of the TP had exposure to more days of antibiotics. Similar protocols of antimicrobial therapy should apply to both TP and NTP to avoid the overuse of antimicrobial agents and ensure maintenance of the susceptibility patterns of pathogens.

Conversion of calcineurin inhibitors with mammalian target of rapamycin inhibitors after kidney transplant

One way to overcome chronic allograft nephropathy induced by calcineurin inhibitors in immunosuppression protocols for organ transplants is to replace such inhibitors with mammalian target of rapamycin inhibitors, which are not clinically nephrotoxic because they have better renal function. If patients tolerate replacement, there could be a clear preference for mammalian target of rapamycin inhibitors as a maintenance immunosuppressant after renal transplant. This replacement could be sufficient if it were used for a certain time after calcineurin inhibitors. This review considers the conversion effects of calcineurin inhibitors with mammalian target of rapamycin inhibitors from the view point of kidney function during different periods after a kidney transplant.

Sirolimus as renal and immunological rescue agent in pediatric liver transplant recipients

CNI have improved the outcome of LT. However, their inherent potential to nephrotoxic and sometimes-inadequate immunosuppressive effect has lead to the usage of newer drugs like SRL. Aim of this study was to review children who received SRL. Thirty-seven (20 women) children post-LT, median age 10.4 yr (0.8-17.4) with a minimum follow-up of six months comprised the study group. Indications for SRL were biopsy-proven resistant acute allograft rejection (n = 12), early CR (n = 12), and CNI-induced nephropathy with MMF intolerance (n = 11). In two patients, the indication was the recurrence of BSEP disease in the allograft. In patients with acute rejection, AST normalized in 10/12 patients. In patients with CR, AST normalized in 6/12 patients. Those with renal impairment showed improvement in their creatinine levels from a mean baseline of 99-56.7 μm (p = 0.03) and their mean cystatin C was 1.02 after SRL. Side effects leading to discontinuation of SRL were seen in three patients. SRL was effective in rescuing patients with acute and chronic allograft rejection and improving renal function in CNI-induced nephropathy group.

One thousand consecutive primary liver transplants under tacrolimus immunosuppression: a 17- to 20-year longitudinal follow-up

BACKGROUND

Tacrolimus has proven to be a potent immunosuppressive agent in orthotopic liver transplantation (OLT). The aim of this study is to examine its long-term efficacy and safety.

METHODS AND RESULTS

One thousand consecutive primary OLTs performed between August 1989 and December 1992 and maintained under tacrolimus-based immunosuppression were followed up until January 2009. Patient and graft survivals with corresponding causes of death and retransplantation, maintenance immunosuppression, and adverse effects were examined. The study population includes 600 males and 400 females comprising 166 children, 630 adults, and 204 seniors. The mean follow-up was 17.83 (range, 16.1-19.50) years. The overall 20-year actuarial patient and graft survivals were 35.8% and 32.6%, respectively. At the last follow-up, 442 patients were alive; 133 (77.1%) children, 265 (34.5%) adults, and 44 (16.1%) seniors (P=0.0001). After the first post-OLT year, cardiopulmonary events, recurrence of primary disease, and malignancy were the main causes of death. Overall, 183 recipients underwent retransplants; mainly for primary nonfunction, hepatic artery thrombosis, and recurrent primary disease, 180 required dialysis, and 45 underwent kidney transplant. A total of 97.7% of the survivors were on tacrolimus and 26.2% were also receiving adjunctive immunosuppressants at the last follow-up.

CONCLUSIONS

The overall 20-year actuarial patient and graft survivals were 35.8% and 32.6%, respectively, with significantly better survival among children. Age-related complications, recurrence of primary disease, and malignancy were the major causes of late graft loss. Graft loss related to immunologic reasons was rare. The prevention of recurrent disease and newer immunosuppressive regimen will further improve these results.

De novo malignancy is associated with renal transplant tourism

Despite the objections to transplant tourism raised by the transplant community, many patients continue travel to other countries to receive commercial transplants. To evaluate some long-term complications, we reviewed medical records of 215 Taiwanese patients (touring group) who received commercial cadaveric renal transplants in China and compared them with those of 321 transplant recipients receiving domestic cadaveric renal transplants (domestic group) over the same 20-year period. Ten years after transplant, the graft and patient survival rates of the touring group were 55 and 81.5%, respectively, compared with 60 and 89.3%, respectively, of the domestic group. The difference between the two groups was not statistically significant. The 10-year cumulative cancer incidence of the touring group (21.5%) was significantly higher than that of the domestic group (6.8%). Univariate and multivariate stepwise regression analyses (excluding time on immunosuppression, an uncontrollable factor) indicated that transplant tourism was associated with significantly higher cancer incidence. Older age at transplantation was associated with a significantly increased cancer risk; however, the risk of de novo malignancy significantly decreased with longer graft survival. Thus, renal transplant tourism may be associated with a higher risk of post-transplant malignancy, especially in patients of older age at transplantation.

Cyclosporine-induced immune suppression alters establishment of HTLV-1 infection in a rabbit model

Human T-lymphotropic virus type 1 (HTLV-1) infection causes adult T-cell leukemia and several lymphocyte-mediated inflammatory diseases. Persistent HTLV-1 infection is determined by a balance between host immune responses and virus spread. Immunomodulatory therapy involving HTLV-1-infected patients occurs in a variety of clinical settings. Knowledge of how these treatments influence host-virus relationships is not understood. In this study, we examined the effects of cyclosporine A (CsA)-induced immune suppression during early infection of HTLV-1. Twenty-four New Zealand white rabbits were split into 4 groups. Three groups were treated with either 10 or 20 mg/kg CsA or saline before infection. The fourth group was treated with 20 mg/kg CsA 1 week after infection. Immune suppression, plasma CsA concentration, ex vivo lymphocyte HTLV-1 p19 production, anti-HTLV-1 serologic responses, and proviral load levels were measured during infection. Our data indicated that CsA treatment before HTLV-1 infection enhanced early viral expression compared with untreated HTLV-1-infected rabbits, and altered long-term viral expression parameters. However, CsA treatment 1 week after infection diminished HTLV-1 expression throughout the 10-week study course. Collectively, these data indicate immunologic control is a key determinant of early HTLV-1 spread and have important implications for therapeutic intervention during HTLV-1-associated diseases.