[Liver transplantation program at the Burnasyan Federal Biophysical Center: experience in 500 procedures]. / Programma transplantatsii pecheni v Federal'nom meditsinskom biofizicheskom tsentre im. A.I. Burnazyana: opyt 500 operatsii.

OBJECTIVE: To analyze the features and outcomes of 500 liver transplantations in adults over a 12-year period. MATERIALS AND METHODS: The study included data on 500 liver transplantations between May 2010 and April 2023. We analyzed 483 adults who underwent transplantation and 438 candidates for this procedure. All data were obtained from local liver transplantation registry. Clinical outcomes were recorded as of June 1, 2023. Statistical analysis was performed using the Statistica 12 (StatSoft Inc., USA) and Jamovi version 2.3.21.0 software (Jamovi project). RESULTS: Among 438 patients in the waiting list between January 2012 and May 2023, liver transplantation was performed in 198 (45%) cases including 27 (6%) transplantations from living-related donors and 37 (8%) procedures in other centers. There were 109 (25%) deaths. The 1- and 3-year survival rates were 81% (95% CI 76-85%) and 50% (95% CI 42-59%), respectively. Organs from deceased donors (n=134, 27%) and living-related donors (n=366, 73%) were used for transplantations. Redo transplantations were necessary in 21 (4%) cases. The median age of recipients was 45 years (range 18-72), median MELD-Na score - 16 (range 6-43). The most common indications for transplantation were viral cirrhosis (37%), cholestatic liver disease (16%), and hepatocellular carcinoma (14%). Monotherapy with calcineurin inhibitors was performed in 39% of cases, combination of calcineurin inhibitors and glucocorticoids, antimetabolites or mTOR inhibitors - 52%, three-component schemes - 8% of cases. Annual, 5- and 7-year survival rates of recipients after primary transplantation were 87% (95% CI: 84-90%), 79% (95% CI: 75-83%) and 75% (95% CI: 70-80%), respectively. In case of liver transplantation from living-related donors, these values were 89% (95% CI: 86-92%), 84% (95% CI: 80-88%) and 80% (95% CI: 75-85%), after transplantation from deceased donors - 81% (95% CI: 74-88%), 66% (95% CI: 57-76%) and 58% (95% CI: 45-72%), respectively. CONCLUSION: Liver transplantation is highly effective for patients with diffuse and focal liver diseases. Living donors not only significantly improve availability of this technology, but also provide substantial advantages in outcomes compared to liver transplantation from deceased donors, reducing the likelihood of recipient mortality by 10% after one post-transplantation year and by more than 20% after five years.

What is said about #donateliver or #liverdonor? Reflexive thematic analysis of Twitter (X) posts from 2012 to 2022.

BACKGROUND: There is sustained interest in understanding the perspectives of liver transplant recipients and living donors, with several qualitative studies shedding light on this emotionally charged subject. However, these studies have relied primarily on traditional semi-structured interviews, which, while valuable, come with inherent limitations. Consequently, there remains a gap in our comprehension of the broader public discourse surrounding living liver donation. This study aims to bridge this gap by delving into public conversations related to living liver donation through a qualitative analysis of Twitter (now X) posts, offering a fresh perspective on this critical issue. METHODS: To compile a comprehensive dataset, we extracted original tweets containing the hashtags "#donateliver" OR "#liverdonor", all posted in English from January 1, 2012, to December 31, 2022. We then selected tweets from individual users whose Twitter (X) accounts featured authentic human names, ensuring the credibility of our data. Employing Braun and Clarke's reflexive thematic analysis approach, the study investigators read and analysed the included tweets, identifying two main themes and six subthemes. The Health Policy Triangle framework was applied to understand the roles of different stakeholders involved in the discourse and suggest areas for policy improvement. RESULTS: A total of 361 unique tweets from individual users were analysed. The major theme that emerged was the persistent shortage of liver donors, underscoring the desperation faced by individuals in need of life-saving liver transplants and the urgency of addressing the organ shortage problem. The second theme delved into the experiences of liver donors post-surgery, shedding light on a variety of aspects related to the transplantation process, including the visibility of surgical scars, and the significance of returning to physical activity and exercise post-surgery. CONCLUSION: The multifaceted experiences of individuals involved in the transplantation process, both recipients and donors, should be further studied in our efforts to improve the critical shortage of liver donors.

Effect of Hemodynamic Monitoring Systems on Short-Term Outcomes after Living Donor Liver Transplantation.

Background and Objectives: To evaluate the effects of the pulse index continuous cardiac output and MostCare Pressure Recording Analytical Method hemodynamic monitoring systems on short-term graft and patient outcomes during living donor liver transplantation in adult patients. Materials and Methods: Overall, 163 adult patients who underwent living donor liver transplantation between January 2018 and March 2022 and met the study inclusion criteria were divided into two groups based on the hemodynamic monitoring systems used during surgery: the MostCare Pressure Recording Analytical Method group (n = 73) and the pulse index continuous cardiac output group (n = 90). The groups were compared with respect to preoperative clinicodemographic features (age, sex, body mass index, graft-to-recipient weight ratio, and Model for End-stage Liver Disease score), intraoperative clinical characteristics, and postoperative biochemical parameters (aspartate aminotransferase, alanine aminotransferase, total bilirubin, direct bilirubin, prothrombin time, international normalized ratio, and platelet count). Results: There were no significant between-group differences with respect to recipient age, sex, body mass index, graft-to-recipient weight ratio, Child, Model for End-stage Liver Disease score, ejection fraction, systolic pulmonary artery pressure, surgery time, anhepatic phase, cold ischemia time, warm ischemia time, erythrocyte suspension use, human albumin use, crystalloid use, urine output, hospital stay, and intensive care unit stay. However, there was a significant difference in fresh frozen plasma use (p < 0.001) and platelet use (p = 0.037). Conclusions: The clinical and biochemical outcomes are not significantly different between pulse index continuous cardiac output and MostCare Pressure Recording Analytical Method as hemodynamic monitoring systems in living donor liver transplantation. However, the MostCare Pressure Recording Analytical Method is more economical and minimally invasive.

Factors associated with the quality of life of living kidney donors in Korea: A cross-sectional study.

This study investigated the relationship between self-determination, physical health status, and Health related Quality of Life (=HRQoL) among living kidney donors. A descriptive survey was conducted between 2019 and 2020 and included 111 kidney donors. Data were collected using a self-report questionnaire on general and donation-related characteristics, self-determination, and HRQoL. The data also included medical records reflecting the physical health status at the time of the survey. Data were analyzed using a multiple regression model. Factors associated with HRQoL were perceived health recovery after donation (ß = 0.42, P < .001), up to 1 year since donation (ß = 0.33, P = .008), more than 1 up to 5 years since donation (ß = 0.52, P < .001), more than 5 up to 10 years since donation (ß = 0.53, P < .001), and competence of self-determination (ß = 0.23, P = .033). The explanatory power of these variables was 43.3%. HRQoL of living kidney donors can be affected by subjective and psychological factors. Therefore, health care providers should help living kidney donors have high self-determination during pre and post donation and concentrate on the subjective and psychological factors as well as objective health status.

Pursuing living donor liver transplantation improves outcomes of patients with autoimmune liver diseases: An intention-to-treat analysis.

Living donor liver transplantation (LDLT) offers the opportunity to decrease waitlist time and mortality for patients with autoimmune liver disease (AILD), autoimmune hepatitis, primary biliary cholangitis, and primary sclerosing cholangitis. We compared the survival of patients with a potential living donor (pLDLT) on the waitlist versus no potential living donor (pDDLT) on an intention-to-treat basis. Our retrospective cohort study investigated adults with AILD listed for a liver transplant in our program between 2000 and 2021. The pLDLT group comprised recipients with a potential living donor. Otherwise, they were included in the pDDLT group. Intention-to-treat survival was assessed from the time of listing. Of the 533 patients included, 244 (43.8%) had a potential living donor. Waitlist dropout was higher for the pDDLT groups among all AILDs (pDDLT 85 [29.4%] vs. pLDLT 9 [3.7%], p < 0.001). The 1-, 3-, and 5-year intention-to-treat survival rates were higher for pLDLT versus pDDLT among all AILDs (95.7% vs. 78.1%, 89.0% vs. 70.1%, and 87.1% vs. 65.5%, p < 0.001). After adjusting for covariates, pLDLT was associated with a 38% reduction in the risk of death among the AILD cohort (HR: 0.62, 95% CI: 0.42-0.93 [ p <0.05]), and 60% among the primary sclerosing cholangitis cohort (HR: 0.40, 95% CI: 0.22-0.74 [ p <0.05]). There were no differences in the 1-, 3-, and 5-year post-transplant survival between LDLT and DDLT (AILD: 95.6% vs. 92.1%, 89.9% vs. 89.4%, and 89.1% vs. 87.1%, p =0.41). This was consistent after adjusting for covariates (HR: 0.97, 95% CI: 0.56-1.68 [ p >0.9]). Our study suggests that having a potential living donor could decrease the risk of death in patients with primary sclerosing cholangitis on the waitlist. Importantly, the post-transplant outcomes in this population are similar between the LDLT and DDLT groups.

Evaluation of liver transplantation services in Kazakhstan from 2012 to 2023.

There is a scarcity of publications evaluating the performance of the national liver transplantation (LTx) program in Kazakhstan. Spanning from 2012 to 2023, it delves into historical trends in LTx surgeries, liver transplant centers, and the national cohort of patients awaiting LTx. Survival analysis for those awaiting LTx, using life tables and Kaplan-Meier, is complemented by time series analysis projecting developments until 2030. The overall per million population (pmp) LTx rate varied from 0.35 to 3.77, predominantly favoring living donor LTx. Liver transplant center rates ranged from 0.06 to 0.40. Of 474 LTx patients, 364 on the waiting list did not receive transplantation. The 30-day and 1-year survival rates on the waiting list were 87.0% and 68.0%, respectively. Viral hepatitis and cirrhosis prevalence steadily rose from 2015 to 2023, with projections indicating a persistent trend until 2030. Absent targeted interventions, stable pmp rates of LTx and liver transplant centers may exacerbate the backlog of unoperated patients. This study sheds light on critical aspects of the LTx landscape in Kazakhstan, emphasizing the urgency of strategic interventions to alleviate the burden on patients awaiting transplantation.

Performance of risk prediction models for post-liver transplant patient and graft survival over time.

Given liver transplantation organ scarcity, selection of recipients and donors to maximize post-transplant benefit is paramount. Several scores predict post-transplant outcomes by isolating elements of donor and recipient risk, including the donor risk index, Balance of Risk, pre-allocation score to predict survival outcomes following liver transplantation/survival outcomes following liver transplantation (SOFT), improved donor-to-recipient allocation score for deceased donors only/improved donor-to-recipient allocation score for both deceased and living donors (ID2EAL-D/-DR), and survival benefit (SB) models. No studies have examined the performance of these models over time, which is critical in an ever-evolving transplant landscape. This was a retrospective cohort study of liver transplantation events in the UNOS database from 2002 to 2021. We used Cox regression to evaluate model discrimination (Harrell's C) and calibration (testing of calibration curves) for post-transplant patient and graft survival at specified post-transplant timepoints. Sub-analyses were performed in the modern transplant era (post-2014) and for key donor-recipient characteristics. A total of 112,357 transplants were included. The SB and SOFT scores had the highest discrimination for short-term patient and graft survival, including in the modern transplant era, where only the SB model had good discrimination (C ≥ 0.60) for all patient and graft outcome timepoints. However, these models had evidence of poor calibration at 3- and 5-year patient survival timepoints. The ID2EAL-DR score had lower discrimination but adequate calibration at all patient survival timepoints. In stratified analyses, SB and SOFT scores performed better in younger (< 40 y) and higher Model for End-Stage Liver Disease (≥ 25) patients. All prediction scores had declining discrimination over time, and scores relying on donor factors alone had poor performance. Although the SB and SOFT scores had the best overall performance, all models demonstrated declining performance over time. This underscores the importance of periodically updating and/or developing new prediction models to reflect the evolving transplant field. Scores relying on donor factors alone do not meaningfully inform post-transplant risk.

Longitudinal mortality risks and kidney functional outcomes in Japanese living kidney donors.

OBJECTIVES: Previous studies suggested that living kidney donors do not have a higher risk of death or kidney failure than the general population. However, living kidney donor risk is controversial. Furthermore, only a few studies have evaluated long-term kidney function after kidney donation. METHODS: This study evaluated Japanese kidney donor' long-term outcomes, including mortality and kidney function. From 1965 to 2015, 230 donors (76 males, 154 females, and a median age of 54) were enrolled in this study. The median observation period was 11.0 (range, 0.3-41.0) years. RESULTS: In total, 215 donors were still alive, and 15 had died. Causes of death included malignancies, cardiovascular disease, pneumonia, suicide, gastrointestinal bleeding, and kidney failure. Actual donor survival rates at 10, 20, and 30 years were 95.3%, 90.7%, and 80.9%, respectively. These values were comparable to age- and gender-matched expected survival. Long-term kidney function after donation was evaluated in 211 donors with serum creatinine data. Two donors developed kidney failure 24 and 26 years post-donation, respectively. The percentage of donors whose estimated glomerular filtration rate (eGFR) remained ≥45 mL/min/1.73 m2 at 10, 20, and 30 years after donation were 84.2%, 73.0%, and 63.9%, respectively. Survival rates of donors with eGFR <45 mL/min/1.73 m2 were comparable to those in persons with eGFR >45 mL/min/1.73 m2. CONCLUSION: Our findings revealed that kidney donors did not have a higher long-term risk of death than the general population. Although some donors showed decreased kidney function after donation, kidney function did not impact their survival.

Neighborhood-level social determinants of health measures independently predict receipt of living donor liver transplantation in the United States.

Disparities exist in the access to living donor liver transplantation (LDLT) in the United States. However, the association of neighborhood-level social determinants of health (SDoH) on the receipt of LDLT is not well-established. This was a retrospective cohort study of adult liver transplant recipients between January 1, 2005 and December 31, 2021 at centers performing LDLT using the United Network for Organ Sharing database, which was linked through patients' ZIP code to a set of 24 neighborhood-level SDoH measures from different data sources. Temporal trends and center differences in neighborhood Social Deprivation Index (SDI), a validated scale of socioeconomic deprivation ranging from 0 to 100 (0=least disadvantaged), were assessed by transplant type. Multivariable logistic regression evaluated the association of increasing SDI on receipt of LDLT [vs. deceased donor liver transplantation (DDLT)]. There were 51,721 DDLT and 4026 LDLT recipients at 59 LDLT-performing centers during the study period. Of the 24 neighborhood-level SDoH measures studied, the SDI was most different between the 2 transplant types, with LDLT recipients having lower SDI (ie, less socioeconomic disadvantage) than DDLT recipients (median SDI 37 vs. 47; p < 0.001). The median difference in SDI between the LDLT and DDLT groups significantly decreased from 13 in 2005 to 3 in 2021 ( p = 0.003). In the final model, the SDI quintile was independently associated with transplant type ( p < 0.001) with a threshold SDI of ~40, above which increasing SDI was significantly associated with reduced odds of LDLT (vs. reference SDI 1-20). As a neighborhood-level SDoH measure, SDI is useful for evaluating disparities in the context of LDLT. Center outreach efforts that aim to reduce disparities in LDLT could preferentially target US ZIP codes with SDI > 40.

Increasing Living Donor Liver Transplantation Using Liver Paired Exchange.

BACKGROUND: Living donor liver transplantation (LDLT) continues to be the primary modality of liver transplantation in Asia, but it accounts for about 5% of all liver transplantations in the US. ABO incompatibility is the primary reason motivated donors are declined. Although kidney paired exchanges are common, liver paired exchange (LPE) is still evolving in the US. STUDY DESIGN: This is a retrospective review (between January 1, 2019, and July 31, 2021) of our initial experience with LPE. RESULTS: A total of 10 LPEs (20 LDLTs) were performed during the study period. Seven LPEs were initiated by a nondirected O donor. The other 3 pair sets involved 1 ABO compatible and 1 ABO incompatible pair. Transplantations in a pair set were completed within a mean of 4.8 (range 1-14) days of each other. All 20 donors are doing well with no major complications at 12.7 (range 1-20) months. Seventeen of 20 recipients are alive and have good allograft function. One recipient died in the early postoperative period. Two late deaths of patients with functioning allografts were due to COVID-19 (at 8 months) and peritoneal carcinomatosis and gram-negative sepsis (at 9 months). CONCLUSIONS: LPE is feasible in a high-volume LDLT center and is a useful option to increase LDLT by overcoming ABO incompatibility. Nondirected donors can be utilized to initiate an LPE.

Barriers to the donation of living kidneys for kidney transplantation.

Since the waiting time for deceased donor kidney transplantation continues to increase, living donor kidney transplantation is an important treatment for end stage kidney disease patients. Barriers to living kidney donation have been rarely investigated despite a growing interest in the utilization of living donor transplantation and the satisfaction of donor safety. Here, we retrospectively analyzed 1658 potential donors and 1273 potential recipients who visited the Seoul National University Hospital for living kidney transplantation between 2010 and 2017 to study the causes of donation discontinuation. Among 1658 potential donors, 902 (54.4%) failed to donate kidneys. The average number of potential donors that received work-up was 1.30 ± 0.66 per recipient. Among living donor kidney transplant patients, 75.1% received kidneys after work-up of the first donor and 24.9% needed work-up of two or more donors. Donor-related factors (49.2%) were the most common causes of donation discontinuation, followed by immunologic or size mismatches between donors and recipients (25.4%) and recipient-related factors (16.2%). Interestingly, withdrawal of donation consent along with refusal by recipients or family were the commonest causes, suggesting the importance of non-biomedical aspects. The elucidation of the barriers to living kidney donation could ensure more efficient and safer living kidney donation.

European Liver Transplant Registry: Donor and transplant surgery aspects of 16,641 liver transplantations in children.

BACKGROUND AND AIMS: The European Liver Transplant Registry (ELTR) has collected data on liver transplant procedures performed in Europe since 1968. APPROACH AND RESULTS: Over a 50-year period (1968-2017), clinical and laboratory data were collected from 133 transplant centers and analyzed retrospectively (16,641 liver transplants in 14,515 children). Data were analyzed according to three successive periods (A, before 2000; B, 2000-2009; and C, since 2010), studying donor and graft characteristics and graft outcome. The use of living donors steadily increased from A to C (A, n = 296 [7%]; B, n = 1131 [23%]; and C, n = 1985 [39%]; p = 0.0001). Overall, the 5-year graft survival rate has improved from 65% in group A to 75% in group B (p < 0.0001) and to 79% in group C (B versus C, p < 0.0001). Graft half-life was 31 years, overall; it was 41 years for children who survived the first year after transplant. The late annual graft loss rate in teenagers is higher than that in children aged <12 years and similar to that of young adults. No evidence for accelerated graft loss after age 18 years was found. CONCLUSIONS: Pediatric liver transplantation has reached a high efficacy as a cure or treatment for severe liver disease in infants and children. Grafts that survived the first year had a half-life similar to standard human half-life. Transplantation before or after puberty may be the pivot-point for lower long-term outcome in children. Further studies are necessary to revisit some old concepts regarding transplant benefit (survival time) for small children, the role of recipient pathophysiology versus graft aging, and risk at transition to adult age.

Outcomes of living liver donors are worse than those of matched healthy controls.

BACKGROUND & AIMS: Donor death is the most serious complication of living liver donation but is reported rarely. We investigated the actual mortality of living liver donors (LLDs) compared with matched control groups based on analysis of the Korean National Health Insurance Services (NHIS) database. METHODS: This cohort study included 12,372 LLDs who donated a liver graft between 2002 and 2018, and were registered in the Korean Network for Organ Sharing. They were compared to 3 matched control groups selected from the Korean NHIS and comprising a total of 123,710 individuals: healthy population (Group I); general population without comorbidities (Group II); and general population with comorbidities (Group III). RESULTS: In this population, 78.5% of living liver donors were 20-39 years old, and 64.7% of all donors were male. Eighty-nine donors (0.7%) in the LLD group died (68 males and 21 females), a mortality rate (/1,000 person-years) of 0.91 (0.74-1.12). Mortality rate ratio and the adjusted hazard ratio of the LLD group was 2.03 (1.61-2.55) and 1.71 (1.31-2.25) compared to Control Group I, 0.75 (0.60-0.93) and 0.63 (0.49-0.82) compared to Control Group II, and 0.58 (0.46-0.71) and 0.49 (0.39-0.60) compared to Control Group III. LLD group, depression, and lower income were risk factors for adjusted mortality. The incidence of liver failure, depression, cancer, diabetes, hypertension, brain infarction, brain hemorrhage, and end-stage renal disease in the LLD group was significantly higher than in Control Group I. CONCLUSIONS: Outcomes of the LLD group were worse than those of the matched healthy control group despite the small number of deaths and medical morbidities in this group. LLDs should receive careful medical attention for an extended period after donation. LAY SUMMARY: The incidence of mortality, liver failure, depression, cancer, diabetes, hypertension, brain infarction, brain hemorrhage, and end-stage renal disease in the living liver donor group was significantly higher than in the matched healthy group. Careful donor evaluation and selection processes can improve donor safety and enable safe living donor liver transplantation.

Decreased access to pediatric liver transplantation during the COVID-19 pandemic.

BACKGROUND: The COVID-19 pandemic has affected all aspects of the US healthcare system, including liver transplantation. The objective of this study was to understand national changes to pediatric liver transplantation during COVID-19. METHODS: Using SRTR data, we compared waitlist additions, removals, and liver transplantations for pre-COVID-19 (March-November 2016-2019), early COVID-19 (March-May 2020), and late COVID-19 (June-November 2020). RESULTS: Waitlist additions decreased by 25% during early COVID-19 (41.3/month vs. 55.4/month, p < .001) with black candidates most affected (p = .04). Children spent longer on the waitlist during early COVID-19 compared to pre-COVID-19 (140 vs. 96 days, p < .001). There was a 38% decrease in liver transplantations during early COVID-19 (IRR 0.62, 95% CI 0.49-0.78), recovering to pre-pandemic rates during late COVID-19 (IRR 1.03, NS), and no change in percentage of living and deceased donors. White children had a 30% decrease in overall liver transplantation but no change in living donor liver transplantation (IRR 0.7, 95% CI 0.50-0.95; IRR 0.96, NS), while non-white children had a 44% decrease in overall liver transplantation (IRR 0.56, 95% CI 0.40-0.77) and 81% decrease in living donor liver transplantation (IRR 0.19, 95% CI 0.02-0.76). CONCLUSIONS: The COVID-19 pandemic decreased access to pediatric liver transplantation, particularly in its early stage. There were no regional differences in liver transplantation during COVID-19 despite the increased national sharing of organs. While pediatric liver transplantation has resumed pre-pandemic levels, ongoing racial disparities must be addressed.

Intermediate Renal Outcomes, Kidney Failure, and Mortality in Obese Kidney Donors.

BACKGROUND: Obesity is associated with the two archetypal kidney disease risk factors: hypertension and diabetes. Concerns that the effects of diabetes and hypertension in obese kidney donors might be magnified in their remaining kidney have led to the exclusion of many obese candidates from kidney donation. METHODS: We compared mortality, diabetes, hypertension, proteinuria, reduced eGFR and its trajectory, and the development of kidney failure in 8583 kidney donors, according to body mass index (BMI). The study included 6822 individuals with a BMI of <30 kg/m2, 1338 with a BMI of 30-34.9 kg/m2, and 423 with a BMI of ≥35 kg/m2. We used Cox regression models, adjusting for baseline covariates only, and models adjusting for postdonation diabetes, hypertension, and kidney failure as time-varying covariates. RESULTS: Obese donors were more likely than nonobese donors to develop diabetes, hypertension, and proteinuria. The increase in eGFR in obese versus nonobese donors was significantly higher in the first 10 years (3.5 ml/min per 1.73m2 per year versus 2.4 ml/min per 1.73m2 per year; P<0.001), but comparable thereafter. At a mean±SD follow-up of 19.3±10.3 years after donation, 31 (0.5%) nonobese and 12 (0.7%) obese donors developed ESKD. Of the 12 patients with ESKD in obese donors, 10 occurred in 1445 White donors who were related to the recipient (0.9%). Risk of death in obese donors was not significantly increased compared with nonobese donors. CONCLUSIONS: Obesity in kidney donors, as in nondonors, is associated with increased risk of developing diabetes and hypertension. The absolute risk of ESKD is small and the risk of death is comparable to that of nonobese donors.

Why Are Black People Less Likely to Find a Stem Cell Donor Match?

Building trust in the health care system could increase the number of donors.

Aggravation of fibrin deposition and microthrombus formation within the graft during kidney transplantation.

In kidney transplantation, microthrombi and fibrin deposition may lead to local perfusion disorders and subsequently poor initial graft function. Microthrombi are often regarded as donor-derived. However, the incidence, time of development, and potential difference between living donor kidneys (LDK) and deceased donor kidneys(DDK), remains unclear. Two open-needle biopsies, taken at preimplantation and after reperfusion, were obtained from 17 LDK and 28 DDK transplanted between 2005 and 2008. Paraffin-embedded sections were immunohistochemically stained with anti-fibrinogen antibody. Fibrin deposition intensity in peritubular capillaries(PTC) and glomeruli was categorized as negative, weak, moderate or strong and the number of microthrombi/mm2 was quantified. Reperfusion biopsies showed more fibrin deposition (20% to 100% moderate/strong, p < 0.001) and more microthrombi/mm2 (0.97 ± 1.12 vs. 0.28 ± 0.53, p < 0.01) than preimplantation biopsies. In addition, more microthrombi/mm2 (0.38 ± 0.61 vs. 0.09 ± 0.22, p = 0.02) and stronger fibrin intensity in glomeruli (28% vs. 0%, p < 0.01) and PTC (14% vs. 0%, p = 0.02) were observed in preimplantation DDK than LDK biopsies. After reperfusion, microthrombi/mm2 were comparable (p = 0.23) for LDK (0.09 ± 0.22 to 0.76 ± 0.49, p = 0.03) and DDK (0.38 ± 0.61 to 0.90 ± 1.11, p = 0.07). Upon reperfusion, there is an aggravation of microthrombus formation and fibrin deposition within the graft. The prominent increase of microthrombi in LDK indicates that they are not merely donor-derived.