National registry on characteristics and outcomes of pediatric liver transplantation in a middle-income country

Abstract

Background

Due to the limited data available among middle-income countries, we aimed to determine the characteristics, outcomes and associated factors with death or graft failure in pediatric liver transplantation (LT).

Methods

Based on the Thai National Liver Transplantation Registry, we analyzed the data of patients under 18 years who underwent LT in Thailand from 2016 to 2024.

Results

The study included 324 liver transplants (five re-LT), mainly from living donors (246 donors, 75.9%). Among 319 recipients, the most prevalent underlying condition was cirrhosis (274 patients, 85.9%; mostly biliary atresia), followed by acute liver failure (30 patients, 9.4%). In comparison with deceased donor LT, patients who underwent living donor LT (LDLT) reported less waiting time (485 days vs. 146 days, P < 0.001) and a lower pediatric end-stage liver disease (PELD)/model for end-stage liver disease (MELD) score (20.9 vs. 18.1, P = 0.02). The registry revealed 1- and 5-year patient survival rates of 91.7% and 89.6%, respectively. Mortality was noted in 34 patients, with infection as the leading cause of death (19 patients, 55.9%). PELD/MELD score ≥ 20 was associated with death (HR: 2.95; 95% CI: 1.29–6.27) or graft failure (HR: 3.10; 95% CI: 1.37–7.06) in patients who underwent LT due to cirrhosis.

Conclusions

Pediatric LT in Thailand, mainly LDLT, has a satisfactory outcome. Patients with severe ESLD or high PELD/MELD scores are at risk for death and graft failure after LT. Infection is the most common cause of death. Therefore, timely LT and early effective treatment of infection are crucial.

Supplementary Information

The online version contains supplementary material available at https://doi.org/10.1186/s12887-026-07086-w.

Background

Liver transplantation (LT) is an essential treatment to improve survival in children with severe liver diseases, such as end-stage liver disease (ESLD), acute liver failure (ALF), unresectable liver tumors, and uncontrolled metabolic disorders [1]. According to the donor types, LT can be characterized as deceased donor LT (DDLT) and living donor LT (LDLT). The latter expands donor pools, thus increasing the survival of children on the LT waitlists [2]. Patients who underwent LT may experience surgical and/or medical complications that contribute to graft dysfunction, graft failure, and even death [3]. Moreover, immunosuppressive therapy increases the risk of developing bacterial and opportunistic viral infections, including cytomegalovirus (CMV) and Epstein-Barr virus (EBV). High-risk groups for CMV or EBV reactivation/infection are recipients with negative viral antibodies who receive grafts from donors with positive viral antibodies [4, 5].

In recent decades, pediatric LT has consistently developed, including advancing surgical techniques, effective immunosuppressive therapy, and appropriate infectious control; these have contributed to reduced complications and improved survival rates [2, 6]. There are multiple associated factors with patient and graft survival in pediatric LT, such as donor’s age or body mass index (BMI), types of LT (LDLT or DDLT, blood group compatibility), types of graft, recipient’s age or primary liver disease, center’s experience and volume of LT [3, 7–11]. Pediatric LT has reported favorable graft survival in high-income countries [7, 12]. Satisfactory outcomes are also demonstrated in several multi-center or single-center studies in middle-income countries [13–15]. Good health-related quality of life after pediatric LT has been shown in many studies [16, 17].

In Thailand, the first pediatric LT was started in 1987, and the National Health Security Office has allowed reimbursement for pediatric LT under the Universal Health Scheme (UCS) since 2012. However, it was not until 2018 that a National LT Registry was established by the Thai Transplant Society (TTS), which collected the data from all LT centers from 2016. Currently, there are five active pediatric LT centers in the country, consisting of three in the capital of Thailand (Bangkok) and one each in the northern and northeastern regions. Preliminary data in 2018 demonstrated comparable outcomes to those in high-income countries [18]. Due to the limited data at a national level among middle-income countries, we primarily aimed to study the outcomes of pediatric LT in Thailand. Secondary objectives included demonstrating the characteristics of pediatric LT donors, grafts, and recipients, as well as identifying associated factors with mortality and graft in primary LT.

Methods

Based on the Thai National LT Registry, patients aged < 18 years who underwent LT in Thailand from 2016 to 2024 were retrospectively recruited for analysis. The procedures were performed under Thai organ donation law and regulation with consents from the donors and recipients or their legal guardians. No organs were transferred from the prisoners. Patients with combined organ transplantation were excluded in the study. The registry collected data, including recipient and donor characteristics, liver grafts, and immunosuppressive therapy. Interested outcomes were the patient and graft survival. Graft failure was defined as the requirement for re-LT or recipient death with a functioning graft according to the definition by the Organ Procurement and Transplantation Network (OPTN) [19]. Final information was limited to being prior to 31 December 2024.

The patient characteristics were demonstrated as mean, percentage, median, and interquartile range (IQR). Comparative analysis was performed using Student’s t-test, Mann-Whitney U test, chi-squared test, and Fisher’s exact test. Survival analysis was performed by applying the Kaplan-Meier estimator and Cox proportional hazards regression models. P < 0.05 was considered statistically significant.

The study followed the Helsinki Declaration. We received permission to access the registry data from TTS, along with a data sharing agreement. The Human Ethics Committee, Faculty of Medicine Ramathibodi Hospital, Mahidol University, also approved the study, with a waiver of informed consent (MURA 2025/262) due to being a retrospective study.

Results

Pediatric LT in Thailand

According to the national LT registry, 324 liver transplants were performed in Thailand from 2016 to 2024, consisting of 319 primary transplants and 5 re-transplants. The latter was performed in the early postoperative period due to vascular thrombosis (four patients) and primary non-functioning graft (one patient). All the re-transplants applied grafts from deceased donors. Most LT (93.2%) was conducted at transplant centers in Bangkok (supplementary Fig. 1). Only 20 transplants (6.2%) were ABO-incompatible.

Characteristics of donors and grafts

The liver graft was mainly recovered from living donors (246 donors, 75.9%). Compared with deceased donors, living donors were described as having a lower proportion of male gender (37.4% vs. 67.9%, P < 0.001) and an older mean age (33.1 years vs. 25 years, P < 0.001). Deceased and living donors had comparable rates of positive anti-hepatitis B core antibody (anti-HBc) (15.9% and 16.7%, respectively). Liver grafts from deceased donors were recorded with longer cold ischemic time (446 min vs. 115 min, P < 0.001). Partial grafts accounted for 39.7% of deceased donor LT. Table 1 describes the characteristics of pediatric LT donors and grafts.

Table 1.

Characteristics of pediatric liver transplant donors and grafts (n = 324)

Characteristics	Deceased donor LT (n = 78) †	Living donor LT (n = 246)	P
Types of LT, n (%)
- ABO-compatibility	76 (97.4)	228 (92.7)	0.18
- ABO-incompatibility	2 (2.6)	18 (7.3)
Donors
Gender: male, n (%)	53 (67.9)	92 (37.4)	< 0.001
Age (years), mean (SD)	25 (13.7)	33.1 (7.4)	< 0.001
Body mass index (kg/m2), mean (SD)	20.7 (3.7)	22.8 (3.3)	< 0.001
Peak serum alanine transferase (IU/L), median (IQR)	34 (22, 56)	20 (15, 30)	< 0.001
Positive donor’s anti-hepatitis B core antibody, n (%)‡	13 (16.7)	39 (15.9)	0.92
Grafts
Types of graft, n (%)
- Partial graft	31 (39.7)	244 (99.2)	< 0.01
- Whole graft	47 (60.3)	2§ (0.8)
Cold ischemic time (min), median (IQR)	446 (368, 527)	115 (90, 137)	< 0.001

LT liver transplantation

^†Five donors for re-LT

^‡Data available in 323 donors: 78 deceased donors and 245 living donors

^§From Domino LT

Characteristics of recipients

Among 319 pediatric LT recipients, most (274 patients, 85.9%) were diagnosed with cirrhosis, followed by ALF (30 patients, 9.4%), and primary liver tumor (eight patients, 2.5%). The most common underlying disease of cirrhosis was biliary atresia (224 patients). Supplementary Table 1 shows the underlying diseases of patients who underwent pediatric LT.

Compared with DDLT, patients who underwent LDLT were younger (1.5 years vs. 11.1 years, P < 0.001) and had a lower body weight (8.8 kg vs. 24.2 kg, P < 0.001). Among patients with cirrhosis, LDLT was reported with less waiting time (146 days vs. 485 days, P < 0.001) and lower pediatric end-stage liver disease (PELD)/ model for end-stage liver disease (MELD) score (18.1 vs. 20.9, P = 0.02). Approximately two-thirds of children (173 patients, 63.1%) had growth stunting, defined as a height-for-age z-score of less than − 2 SD. The recipients exhibited different patterns of Epstein-Barr virus (EBV) serology between those who underwent LDLT and DDLT (P = 0.02). Patients who underwent LDLT had a higher prevalence of positive donor immunoglobulin G (IgG) and negative recipient IgG antibody (D+/R-) for EBV (38.4%) when compared to DDLT (0%). Nevertheless, the results of EBV serology were only available from 10 DDLT and 237 LDLT. Table 2 summarizes the characteristics of pediatric LT recipients according to the types of LT.

Table 2.

Characteristics of recipients who underwent primary liver transplantation (n = 319)

Characteristics	Deceased donor LT (n = 73)	Living donor LT (n = 246)	P
Gender: Male, n (%)	32 (43.8)	117 (47.6)	0.58
Age (years), median (IQR)	11.1 (2.1, 15.4)	1.5 (1.0, 2.9)	< 0.001
Weight (kg), median (IQR)	24.2 (10.0, 29.7)	8.8 (7.2, 12.0)	< 0.001
Waiting time (days), median (IQR)
- Cirrhosis (n = 274)	485 (84, 569)	146 (46, 269)	< 0.001
- Acute liver failure (n = 30)	6 (2, 15)	3 (2, 6)	0.27
PELD or MELD score, mean (SD)†	20.9 (7.8)	18.1 (7.7)	0.02
Complication of cirrhosis before LT, n (%)†
- Growth stunting‡	34 (58.6)	139 (64.4)	0.42
- Variceal bleeding	22 (37.9)	67 (31)	0.32
- Refractory ascites	7(12.1)	43 (19.9)	0.17
- Recurrent cholangitis	18 (31)	44 (20.4)	0.09
- Spontaneous bacterial peritonitis	1 (1.7)	16 (7.4)	0.14
- Hepatopulmonary syndrome	4 (6.9)	9 (4.2)	0.48
- Hepatorenal syndrome	0	2 (0.9)	> 0.99
- Recurrent hepatic encephalopathy	1 (1.7)	2 (0.9)	0.51
- Septicemia	0	12 (5.6)	0.08
Laboratory investigation before LT
- Serum total bilirubin (mg/dL), median (IQR)	19.9 (9.2, 26.1)	16.8 (9.8, 23.6)	0.13
- Serum albumin (g/dL), median (IQR)	2.9 (2.5, 3.4)	2.8 (2.3, 3.2)	0.17
- Serum creatinine (mg/dL), median (IQR)	0.3 (0.1, 0.5)	0.2 (0.1, 0.2)	0.17
- Serum sodium (mmol/L), mean (SD)	137.3 (5.1)	135.7 (9.8)	0.16
- International normalized ratio, median (IQR)	1.5 (1.3, 2.1)	1.3 (1.1, 1.6)	< 0.001
- Serum CMV IgG, n (%)§
- D+/R-	9 (12.5)	35 (14.4)	0.68
- Serum EBV IgG, n (%)¶
- D+/R-	0	91 (38.4)	0.02

CMV IgG cytomegalovirus immunoglobulin G, D donor’s antibody, EBV IgG Epstein-Barr virus immunoglobulin G, MELD score model for end-stage liver disease score, LT liver transplantation, PELD score pediatric end-stage liver disease score, R recipient’s antibody

^†Data available in 274 recipients with underlying cirrhosis: 58 patients underwent deceased donor LT, and 216 patients underwent living donor LT

^‡A height-for-age z-score of less than − 2 SD

^§Data available in 314 recipients: 72 in deceased donor LT and 242 in living donor LT groups

^¶Data available in 247 recipients: 10 in deceased donor LT and 237 in living donor LT groups

Immunosuppressive therapy

For induction, the most common immunosuppressive drugs used within the first 24 h after LT were methylprednisolone (98.5%) and tacrolimus (85.8%). Only a few patients (8.6%) received anti-interleukin-2 (IL-2) receptor antibody-based regimens. At discharge, most (99.7%) received calcineurin inhibitor-based regimens. Table 3; Fig. 1 demonstrate the immunosuppressive regimens and medication in pediatric LT, respectively.

Table 3.

Immunosuppressive therapy in pediatric liver transplantation

Immunosuppressive regimens	n	(%)
Induction within 24 h after liver transplantation (n = 324)
• Anti-interleukin-2-free regimens	296	91.4
• Anti-interleukin-2-based regimens	28	8.6
At discharge post- liver transplant operation (n = 293)†
• Calcineurin inhibitor-based regimens	292	99.7
• Calcineurin inhibitor-free regimens	1	0.3
Immunosuppressive therapy at the last follow-up (n = 276)†
Less than one year after LT (n = 31)
• Triple therapy	14	45.2
• Dual therapy	11	28.2
• Monotherapy	9	19.4
One to five years after LT (n = 135)	135
• Triple therapy	31	23
• Dual therapy	46	34.1
• Monotherapy	57	42.2
• None	1	0.7
Over five years after LT liver transplantation (n = 110)	110
• Triple therapy	19	17.3
• Dual therapy	38	34.5
• Monotherapy	51	46.4
• None	2	1.8

LT liver transplantation

^†Exclude death cases or patients in the liver transplant admission during the survey

Fig. 1.

Immunosuppressants in pediatric liver transplantation. Figure 1 illustrates the immunosuppressants used in the following periods: within 24 h after the transplant operation (1a), at discharge from the liver transplant operation (1b), and at the last follow-up at the outpatient clinic (1c)

^†Exclude death cases or patients in the post-operative LT admission at the survey

LT, liver transplantation; MPA, mycophenolic acid (mycophenolate mofetil or mycophenolate sodium)

According to the data at the last follow-up, the number of immunosuppressive drugs tended to decrease over time. Monotherapy was common in the long term, reported around 42.2% within 1 to 5 years after LT and 46.4% over 5 years after LT. Tacrolimus was the most prescribed immunosuppressive drug during long-term follow-up.

Outcomes of pediatric LT

From 2016 to 2024, the patient survival rates of primary LT at 30-day, 90-day, 1-year, and 5-year were 97.1%, 93.9%, 91.7%, and 89.6%, respectively. Mortality was noted in 34 patients, and most deaths occurred within one year after LT (73.5%). Common causes of death were infection (55.9%), graft-related problems, including vascular complications or primary non-functioning graft (11.9%), and post-transplant lymphoproliferative disorders (PTLD) (8.8%). One patient died after re-LT. Figure 2 illustrates survival, deaths, and graft failure in pediatric LT.

Fig. 2.

Survival, death, and graft failure in pediatric liver transplantation. Survival of patients who underwent primary liver transplantation and graft survival are displayed as follows: overall patient (2a) and graft survival (2b), patient (2c) and graft survival (2d) according to the pediatric end-stage liver disease (PELD)/ model for end-stage liver disease (MELD) scores. PELD or MELD score ≥ 20 was associated with death (HR: 2.95; 95% CI: 1.29–6.27) or graft failure (HR: 3.10; 95% CI: 1.37–7.06) after primary liver transplantation. The causes of death and graft failure are shown in Fig. 2e and 2f, respectively. †One with a re-liver transplant

A 30-day, 90-day, 1-year, and 5-year graft survival rates in primary LT were 96.2%, 93%, 90.8%, and 88.7%, respectively. The graft failed due to the patient’s death despite maintaining graft function (83.8%), vascular complications (10.8%), and primary non-function (5.4%).

According to the Cox proportional hazards regression model, a PELD or MELD score of ≥ 20 was associated with death (HR: 2.95; 95% CI: 1.29–6.27) or graft failure (HR: 3.10; 95% CI: 1.37–7.06). Death or graft failure was not significantly associated with type of donor (deceased or living donors), recipient’s or donor’s age, type of liver graft, or diagnosis of ALF (Table 4).

Table 4.

Associated factors with death or graft loss after primary liver transplantation in children and adolescents (n = 319)

Characteristics	Death (n = 33)			Graft loss (n = 36)
	HR	95% CI	P	HR	95% CI	P
Types of donors
- Deceased donors (n = 73)	Ref.			Ref.
- Living donors (n = 246)	0.67	0.31–1.41	0.29	0.76	0.37–1.57	0.46
Recipient’s age
- Less than 2 years (n = 180)	Ref.			Ref.
- 2 to 9 years (n = 82)	1.32	0.61–2.89	0.48	1.37	0.65–2.91	0.41
- 10 to 18 years (n = 57)	1.11	0.44–2.84	0.81	1.23	0.51–2.95	0.64
Donor’s age
- Less than 50 years (n = 307)	Ref.			Ref.
- 50 years and over (n = 12)	0.79	0.11–5.77	0.82	0.72	0.10–5.26	0.75
Types of liver graft
- Partial graft from living donors or whole graft (n = 290)	Ref.			Ref.
- Partial graft from deceased donors	2.35	0.97–5.68	0.06	2.11	0.88–5.07	0.1
Diagnosis
- Non-acute liver failure (n = 289)	Ref.			Ref.
- Acute liver failure (n = 30)	1.51	0.62–3.65	0.36	1.93	0.88–4.23	0.1
PELD or MELD score †
- Less than 20 (n = 149)	Ref.			Ref.
- 20 and over (n = 125)	2.95	1.29–6.74	0.01	3.1	1.37–7.06	< 0.01

MELD model for end-stage liver disease, PELD pediatric end-stage liver disease

^†In patients with cirrhosis (n = 274)

Discussion

This study, representing the national pediatric LT in Thailand, demonstrates the good outcomes and mainly were LDLT. The patient and graft survival rates in this study were comparable with the previous reports. One-year patient survival rates among high-income countries are approximately 89.4–97.3%, according to studies in North America [12], Europe [8], Korea [20], Japan [7], Australia, and New Zealand [11]. Other studies in Asia described 84.7–94% patient survival rates (Supplementary Table 2) [21–26]. In addition, a systematic review and meta-analysis of studies from around the world by Ghelichi-Ghojogh et al. mentioned 1-year and 5-year graft survival rates of 86.6% and 74%, respectively [27].

While DDLT was common in western countries, LDLT was mainly performed in this study, due to scarcity of deceased donors in the country, similar to a recent global survey by the International Liver Transplantation Society (ILTS) [28] and studies in the Asia-Pacific region [7, 20, 21, 29]. LDLT has several benefits, especially in terms of offering the opportunity to perform timely LT in young children, who require a lower volume of liver [6, 9]. Our findings showed that LDLT offered a shorter waiting time and was associated with less severity scores of ESLD at the operation. Although applying split graft from a deceased donor could be an alternative option, the outcomes are generally inferior to using living donors [9, 30], and the approach has been rarely performed in our country.

Unfortunately, the waiting time for pediatric LT in this study was longer than reports from high-income countries, of which the median waiting time was around 61–67 days [31, 32]. Pre-LT complications were common, particularly growth stunting. The long waiting time in Thailand was obvious in DDLT because of the limited deceased donors, while the long waiting time in LDLT could be due to the limited availability of pediatric LT centers. According to a survey by ILTS [28], Thailand has a higher proportion of pediatric LT centers per pediatric population than several middle-income countries; however, the percentage is still lower than that of most high-income countries. Therefore, establishing and expanding pediatric LT services to provide easy access to transplant services may help decrease waiting time. Importantly, promoting organ donation in the country is crucial for reducing waiting time, thereby reducing waiting list mortality. Interestingly, the waiting time was short in a few days for ALF patients, representing effective organ allocation and living donor evaluation for urgent LT.

This study revealed that the PELD/MELD score, particularly a score of ≥ 20, was associated with a higher risk of death or graft failure. Our findings are in line with other reports [33, 34]. Hong et al. [35] have reported that a high PELD score (≥ 30) before LT is a risk for lower survival rates after the operation. Hence, LT should be encouraged before patients experience severe ESLD. Sihaklang et al. [36] have demonstrated that registration for LT at a PELD score of < 15 is more cost-effective in alleviating mortality among LT candidates diagnosed with biliary atresia in Thailand. One of the parameters accounting for a higher PELD score is growth failure, which was highly prevalent in our report. The condition is common in cirrhotic children, which also contributes to risks of bleeding, hypoalbuminemia, and infection [37]. Patients with high ESLD scores have been described with greater risks of complications after LT, which may affect survival. Chung et al. [38] noted significant vascular and biliary complication rates among patients with biliary atresia who underwent LT at a PELD score of ≥ 25. Additionally, previous studies reported that higher PELD scores are associated with bloodstream [39] and carbapenem-resistant Enterobacteriaceae infection after pediatric LT, especially among patients with a PELD score over 21 [40]. Therefore, timely LT should be provided, which requires early referral and effective strategies to shorten the waiting time.

According to our data, infection was the leading cause of death after LT, consistent with the previous reports [8, 15, 35]. Patients required immunosuppressive therapy, thus carrying a greater risk of infection than the general population. Therefore, early detection and appropriate treatment of infection are crucial. A study conducted at one of the largest pediatric LT centers in Thailand identified the intra-abdominal cavity as the most common site of infection after LT, followed by bloodstream infections. The predominant microorganisms include Escherichia coli, Klebsiella spp., and Pseudomonas aeruginosa; notably, the prevalence of multidrug-resistant strains is 62.4% among the isolated gram-negative bacteria [40]. In addition to bacterial infection, management for viral infection/reactivation is also important. This report demonstrated prevalent donors’ anti-HBc, which are well-recognized risk factors for de novo hepatitis B virus (HBV) infection after LT [4, 5, 41]. Some Thai adults may not have received HBV vaccines, especially those born before the implementation of the national HBV immunization program in 1992. The recipients receiving grafts from donors with positive anti-HBc should receive anti-HBV prophylaxis [41]. In comparison with DDLT, patients who underwent LDLT in this study were younger at LT and had a higher incidence of D+/R- serology of EBV, a risk factor for post-LT EBV infection and PTLD [5]. Therefore, these patients should be monitored closely for the disorders, one of the causes of death after LT in our report.

The most common immunosuppressive drug in this study was tacrolimus, consistent with a recent survey by the Society of Pediatric Liver Transplantation (SPLIT) [42]. A randomized controlled trial revealed that the medication is effective with a lower cumulative incidence of treated biopsy-proven acute rejection in comparison to cyclosporin [43]. Similar to the SPLIT survey, our registry also showed that anti-IL-2-free regimens were more common in the induction phase after LT [42]. A prospective observational multi-center study demonstrated that steroids combined with tacrolimus are independent predictors of rejection-free survival [44]. However, a recent randomized controlled trial proposed that a postoperative anti-IL-2 with steroid-free regimen could lower the incidence of acute cellular rejection with a better improvement of the recipient’s weight and height gain [45]. Optimal immunosuppressive therapy in the induction phase requires further study for the effective prevention of graft rejection. Regarding long-term immunosuppression therapy, nearly half of the patients used monotherapy. Similarly, the SPLIT survey described tacrolimus as the most common monotherapy in maintenance (61%), followed by dual therapy using tacrolimus and mycophenolate mofetil (32%) [42].

The strength of this study is to provide eminent findings on a national level, which could lead to the improvement of pediatric LT services in middle-income countries. However, the study had some limitations, mainly due to the limited data collected in the registry. The registry did not include details of graft weight ratio, hepatic vascular and biliary issues, graft rejection, causative organisms of sepsis, and opportunistic viral infection. Additionally, data regarding surveillance or for-cause liver biopsies after LT were not available.

Conclusions

Pediatric LT in Thailand, mainly LDLT, has a satisfactory outcome. However, patients with severe ESLD, especially those with high PELD/MELD scores, are at risk for death and graft failure after LT. Therefore, timely LT should be provided, which requires early referral and effective strategies to shorten the waiting time. Infectious management after LT is also crucial, as infection was the most common cause of death after LT.

Supplementary Information

Supplementary Material 1. ^{(45.2KB, docx)}

Abbreviations

anti-HBc

Anti-hepatitis B core antibody

ALF

Acute liver failure

CMV

Cytomegalovirus

DDLT

Deceased donor liver transplantation

EBV

Epstein-Barr virus

ESLD

End-stage liver disease

HBV

Hepatitis B

ILTS

International Liver Transplantation Society

LDLT

Living donor liver transplantation

LT

Liver transplantation

MELD score

Model for end-stage liver disease score

OTPN

Organ Procurement and Transplantation Network

PELD score

Pediatric end-stage liver disease score

PTLD

Post-transplant lymphoproliferative disorders

TTS

Thai Transplant Society

UCS

Universal Health Scheme

Authors’ contributions

S.G., G.G., and S.T. designed this study; S.G. and G.G. collected and analyzed the data; S.G. drafted the manuscript; C.To., C.Tu, G.G., N.T., S.E., V.C., B.N., C.Th., S.J., C.L., A.P., A.L., and S.T. commented on the manuscript and conceptual advised; S.T. critically reviewed the manuscript and supervised the whole study process. All authors read and approved of the final manuscript.

Funding

The authors received no funds, grants, or other support during the preparation of this manuscript.

Data availability

The datasets used or analyzed during the current study are available from the corresponding author upon reasonable request under permission from the Thai Transplantation Society.

Declarations

Ethics approval and consent to participate

The Human Research Ethics Committee, Faculty of Medicine Ramathibodi Hospital, Mahidol University, approved this study and allowed waving of the need for informed consent (Reference Numbers: COA. MURA 2025/262). The study has followed the Helsinki Declaration. This retrospective study did not involve any clinical trial, and therefore the clinical trial number was not applicable.

Consent for publication

The study received permission from the Thai Transplantation Society to analyze and publish the data.

Competing interests

The authors declare no competing interests.

Clinical trial registration

NA due to being a retrospective study.