Korean Journal of Transplantation最新文献

Background: Solid organ transplant recipients exhibit decreased antibody responses, mainly due to their weakened immune systems. However, data are limited on antibody responses after the primary series of coronavirus disease 2019 (COVID-19) vaccines among recipients of various solid organ transplant types. Thus, we compared the antibody responses after three COVID-19 vaccine doses between liver transplant (LT) and kidney transplant (KT) recipients.

Methods: We prospectively enrolled solid organ transplant recipients who received three COVID-19 vaccine doses from June 2021 to February 2022 and measured S1-specific immunoglobulin G antibodies using an enzyme-linked immunosorbent assay.

Results: Seventy-six LT and 17 KT recipients were included in the final analysis. KT recipients showed consistently lower antibody responses even after the third vaccine dose (86.2% vs. 52.9%, P=0.008) and lower antibody titers (median, 423.0 IU/mL [interquartile range, 99.6-2,057 IU/mL] vs. 19.7 IU/mL [interquartile range, 6.9-339.4 IU/mL]; P=0.006) than were observed in LT recipients. Mycophenolic acid was a significant risk factor for a seropositive antibody response after the third vaccine dose in the multivariable analysis (odds ratio, 0.06; 95% confidence interval, 0.00-0.39; P=0.02).

Conclusions: We found a weaker antibody response despite the completion of the primary series of COVID-19 vaccines in KT recipients than in LT recipients. Mycophenolic acid use in KT recipients might be the main contributor to this observation.

Adrenal and spinal metastases of hepatocellular carcinoma (HCC) are rare entities with significant morbidity and mortality, particularly after liver transplantation (LT). We report a case of a 49-year-old man who underwent LT for hepatitis B-related end-stage liver disease and HCC (single 4.5 cm lesion [T1N0], without vascular invasion) in 2016. Eighteen months later, adrenal metastasis and hepatitis B seropositive conversion were developed with normal serum tumor. Adrenal metastasis was treated with radiation therapy (RT) and hepatitis B showed spontaneous seronegative conversion. However, 35 months later, spinal metastasis occurred with elevation of the protein induced by vitamin K absence or antagonist-II (PIVKA-II) level (197 mAU/mL), along with hepatitis B seropositive conversion. After sorafenib, sequential regorafenib with RT led to partial response of the spinal lesions, along with hepatitis B seronegative conversion and normal PIVKA-II levels. After 9 months of regorafenib combined with RT, two recurrent lesions were found, as well as hepatitis B seropositive conversion and lesions were treated with transarterial chemoembolization. The patient survived for more than 71 months after LT and 53 months after recurrence under various combinations of therapy. Combined systemic and locoregional therapies can be a treatment option for HCC recurrence, even in LT patients.

Atypical hemolytic uremic syndrome (aHUS) is a form of thrombotic microangiopathy (TMA) that can result in end-stage renal disease. Patients with aHUS often have predisposing dysfunction in the complement pathway, and continuous activation of complement proteins can be triggered after transplantation. Here, we report the first successful case of aHUS treatment in a kidney transplant recipient with early use of a C5 inhibitor, eculizumab, in South Korea. The patient was a 32-year-old man, and the donor was his 60-year-old mother. The graft showed immediate good function. On postoperative day (POD) 3, the clinical diagnosis of TMA was made. Persistent renal dysfunction despite 10 plasma exchange (PE) sessions prompted eculizumab treatment on POD 18 under suspicion of aHUS. Next-generation sequencing reported gene mutations classified as variants of unknown significance in coagulation-associated genes. The patient was discharged after three doses of eculizumab with serum creatinine of 1.82 mg/dL. In total, 16 doses of eculizumab were administered. At the last follow-up, 21 months after eculizumab discontinuation, the graft was well functioning. De novo TMA after kidney transplantation can be caused by sustained activation of the complement pathway, and early eculizumab treatment appears important in the successful treatment of aHUS refractory to PE.

Background: This study compared everolimus and mycophenolate mofetil, each paired with calcineurin inhibitors (CNIs) and used with or without steroids, for maintaining immunosuppression in kidney transplant (KT) patients.

Methods: Relevant studies published before August 21, 2022 were retrieved from PubMed, the Cochrane Central Register of Controlled Trials, and the gray literature. The risk of bias was assessed independently using the revised Cochrane risk of bias assessment tool (RoB 2). RevMan ver. 5.4 was used to calculate the risk ratios (RRs) with corresponding 95% confidence intervals (CIs) for biopsy-proven acute rejection, death, and infection. The mean difference (MD) was used to compare the estimated glomerular filtration rate (eGFR) between the groups.

Results: Sixteen randomized controlled trials with a total of 5,403 patients were synthesized to compare everolimus (n=2,763) with mycophenolate (n=2,542) for maintaining post-KT immunosuppression. The meta-analysis showed no significant difference in the risk for biopsy-proven acute rejection (RR=1.12; 95% CI, 0.92-1.35; I²=29%) and death (RR=0.85; 95% CI, 0.63-1.16; I²=0%). The eGFR had no significant difference between the two groups (MD=0.93; 95% CI, -2.25 to 4.1; I²=84%). The risk for any infection was significantly higher in the mycophenolate group than in the everolimus group (RR=0.83; 95% CI, 0.73-0.93; I²=66%).

Conclusions: Our meta-analysis showed that when paired with a CNI, everolimus and mycophenolate had no difference in risk for biopsy-proven acute rejection, death, or increase in eGFR. However, the mycophenolate group exhibited a significantly higher risk of infection.

Background: The C-reactive protein (CRP)-to-albumin ratio (CAR) is a more effective prognostic indicator than CRP or albumin alone in various diseases. This study aimed to evaluate the predictive value of the CAR for mortality in kidney transplant recipients (KTRs).

Methods: A total of 924 patients who underwent their first kidney transplantation at Kyungpook National University Hospital during 2006-2020 were enrolled and classified into quartile (Q) groups according to their pretransplant CAR values. A Cox regression analysis was conducted to analyze the hazard ratios (HRs) of mortality.

Results: Fifty-nine patients died during the posttransplant period (mean, 85.2±44.2 months). All-cause mortality (Q1, 3.0%; Q2, 4.8%; Q3, 7.8%; Q4, 10.0%; P for trend <0.001) and infection-related mortality increased linearly with an increase in CAR (P for trend=0.004). The Q3 and Q4 had higher risks of all-cause mortality than Q1 after adjusting for confounding factors (Q3 adjusted HR [aHR] 2.49, 95% confidence interval [CI] 1.04-5.99, P=0.041; Q4 aHR 3.09, 95% CI 1.31-7.27, P=0.010). Q4 was also independently associated with infection-related mortality (aHR 5.83, 95% CI 1.27-26.8, P=0.023). The area under the curve of the CAR for all-cause and infection-related mortality was higher than that of CRP or albumin alone. There was no association between CAR and death-censored graft failure or acute rejection.

Conclusions: A higher pretransplant CAR increases the risk of posttransplant mortality, particularly infection-related, in KTRs. Pretransplant CAR can be an effective and easily accessible predictor of posttransplant mortality.

Background: Socioeconomic status is an important factor affecting the accessibility and prognosis of kidney transplantation. We aimed to investigate changes in kidney transplant recipients' socioeconomic status in South Korea and whether such changes were associated with patient prognosis.

Methods: This retrospective nationwide observational cohort study in South Korea included kidney transplant recipients between 2007 and 2016. South Korea provides a single-insurer health insurance service, and information on the socioeconomic status of the recipients is identifiable through the claims database. First, a generalized linear mixed model was used to investigate changes in recipients' socioeconomic status as an outcome. Second, the risk of graft failure was analyzed using Cox regression as another outcome to investigate whether changes in socioeconomic status were associated with patient prognosis.

Results: Among the 15,215 kidney transplant recipients included in the study, economic levels (defined based on insurance fee percentiles) and employment rates declined within the first 2 years after transplantation. Beyond 2 years, the employment rate increased significantly, while no significant changes were observed in economic status. Patients whose economic status did not improve 3 years after kidney transplantation showed a higher risk of death than those whose status improved. When compared to those who remained employed after kidney transplantation, unemployment was associated with a significantly higher risk of death-censored graft failure.

Conclusions: The socioeconomic status of kidney transplant recipients changed dynamically after kidney transplantation, and these changes were associated with patient prognosis.

Solid organ transplantation is distinguished from other high-risk surgical procedures by the fact that it utilizes an extremely limited and precious resource and requires a multidisciplinary team approach. For several decades, institutional experience, as quantified by center volume, has been shown to be strongly associated with patient outcomes and graft survival after solid organ transplantation. The United States has implemented a minimum case volume requirement and performance standards for accreditation as a validated transplantation center. Solid organ transplantation in Europe is also governed by the European Union, which monitors patient outcomes and organ allocation. The number of solid organ transplantation cases in Korea is increasing, with patient outcomes comparable to international standards. However, Korea has outdated regulations regarding hospital facilities, and performance indicators including patient outcomes after transplantation are not monitored. Therefore, centers perform solid organ transplantation with no meaningful oversight. In this review, data regarding the impact of institutional case volume of kidney, liver, lung, and heart transplantation are summarized, followed by a description of current transplantation center regulations in the United States and Europe. The basis for the necessity of adequate transplantation center regulations in Korea is presented.

Coronavirus disease 2019 (COVID-19) increases the risk of mortality and hospitalization in immunocompromised patients, including kidney transplant recipients (KTRs) receiving immunosuppressants. Several vaccines for COVID-19 have been developed and proven effective in decreasing the incidence of COVID-19 and the rate of progression to severe COVID-19. However, breakthrough infections have also been reported in vaccinated patients. We report cases from our center of delayed exacerbated pneumonia from COVID-19 in vaccinated KTRs receiving immunosuppressants. Of the 900 KTRs who had been vaccinated for COVID-19 and were followed up at our center from January 1, 2022, to April 30, 2022 (during the Omicron variant outbreak), 126 contracted COVID-19 (incidence rate, 14%). Thirty-four (27%) in this group were hospitalized due to COVID-19. Twenty patients did not have pneumonia but had symptoms of upper respiratory tract infection or diarrhea, which improved with conservative treatment. Nine of the 14 patients with pneumonia had delayed onset or exacerbated pneumonia 1 week after their COVID-19 diagnosis. They were treated with remdesivir, and most recovered. One patient died due to progressive pneumonia and pneumothorax. It is important that KTRs who are taking immunosuppressants be observed closely and for a prolonged period after a COVID-19 diagnosis, irrespective of their COVID-19 vaccination status.

Background: During transplantation, a kidney graft undergoes a cascade of pathological changes, referred to as ischemia-reperfusion injury (IRI), as it is incorporated into the bloodstream. Various studies have reported that retrograde reperfusion (RRP) leads to improved myocardial recovery and could reduce IRI in liver transplantation. This study investigated the effect of RRP in renal transplantation with a focus on reduction of kidney IRI.

Methods: Between December 2019 and July 2022, 15 consecutive kidney transplants were performed with retrograde venous reperfusion. To conduct a comparative study and to recruit a control group, 15 kidney transplants that had been performed in the same center by the same two surgeons were retrospectively analyzed. Differences between the two groups were considered statistically significant at P<0.05.

Results: The baseline characteristics of the two groups were statistically comparable (P>0.05). The surgical technique for kidney transplantation was the same in both groups. On the first postoperative day, polyuria was less pronounced in the RRP group (P<0.01). Serum creatinine and urea levels and estimated glomerular filtration rates on postoperative days 1, 4, 7, and 30 were lower in the RRP group (P<0.05).

Conclusions: Retrograde venous reperfusion of a kidney transplant, preceding antegrade arterial reperfusion, reduced the effects of renal parenchyma IRI. To validate the results of this study, it is necessary to conduct further studies on a larger cohort of patients with a longer follow-up period.