I. INTRODUCTION

According to a 2023 statistic, nearly 80 million people worldwide suffer from chronic kidney disease, of which nearly 4.5 million require renal replacement therapy, putting a huge pressure on the healthcare system and society as a whole [1]. Besides serum creatinine, which is the traditional marker in chronic kidney disease, several novel biomarkers have been introduced to diagnose and predict chronic kidney disease as well as monitor kidney transplant function. Galectin-3 is one such biomarker. Galectin-3 is a member of the lectin family, the only chimera galectin characterized by a carbohydrate recognition domain. Increased galectin-3 levels have been reported to be associated with renal fibrosis. Elevated serum galectin-3 levels are also associated with the risk of rapid renal function decline, new-onset chronic kidney disease, and progressive CKD [2]. Furthermore, much scientific evidence has shown positive changes in serum galectin-3 in the post-kidney transplant period [3]. The goal of this study was to investigate the serum galectin-3 concentration values ​​in patients with chronic kidney disease and to find out the changes in serum galectin-3 values ​​after kidney transplantation.

II. MATERIALS AND METHODS

2.1. Study design

We conducted a cross-sectional analytical study at Hue Central Hospital, Vietnam, from October 2024 to October 2025.

2.2. Study population

The study included the following groups: Patients with CKD stage 3; Patients with CKD stage 4; Patients with CKD stage 5 not receiving dialysis; Patients receiving maintenance hemodialysis. Stable kidney transplant recipients evaluated at 3 months after transplantation.

Inclusion criteria: Participants were aged ≥16 years and had a confirmed diagnosis of CKD or had undergone kidney transplantation with stable renal function.

Exclusion criteria: Patients with malignancy, pulmonary fibrosis, cirrhosis, chronic obstructive pulmonary disease, septic shock, acute exacerbation of CKD, dialysis duration <3 months, unstable graft function, or refusal to participate were excluded.

2.3. Laboratory measurements

Blood samples were collected for serum galectin-3 measurement using chemiluminescent microparticle immunoassay on the Abbott Alinity analyzer. The reference range was 9.3-27.5 ng/mL.

Sample size: Estimated mean using the formula:

- n: minimum sample size required for the study, unit of measurement is people

- Z: normal distribution value, with 95% confidence level, Z1-α/2 = 1.96

- α: Type I error probability, α = 0.05

- d: allowable error (choose d = 3 ng/mL)

- Standard deviation (σ) σ = 15.8 ng/mL

- Sample size is: n ≥ 107 patients

The sample size was determined for comparison of mean serum galectin-3 levels across multiple independent groups (CKD stages and hemodialysis group). A minimum of 30 participants per group was targeted to ensure approximate normality and adequate power for group comparisons. The final pre-transplant cohort included 172 patients, exceeding the minimum requirement. An additional 32 stable kidney transplant recipients were enrolled for exploratory post-transplant analysis.

2.4. Data collection and processing

Patients meeting the criteria and agreeing to participate in the study had their information collected according to the form. Galectin-3 testing was performed at the Biochemistry Department of Hue Central Hospital using chemiluminescent microparticle immunoassay on an Alinity machine, Abbott, USA.

2.5. Statistical analysis

Data were analyzed using SPSS version 26.0. Continuous variables are presented as mean ± standard deviation (SD), and categorical variables as frequency and percentage. Group comparisons were performed using appropriate statistical tests. Correlations were assessed using Pearson’s correlation coefficient. A two-sided p value <0.05 was considered statistically significant.

2.6. Ethical considerations

The study protocol was approved by the institutional ethics committee of Hue Central Hospital. Written informed consent was obtained from all participants.

III. RESULTS

From October 2024 to October 2025, we analyzed two groups: the pre-transplant group and the post-transplant group. The results are as follows:

The average age of the pre-transplant group was 52.56 years, with males accounting for 48.8% and females 51.2%. The average serum galectin-3 value was 53.97 ± 25.68 ng/mL, with no significant difference between males and females (Table 1).

Table 1: General characteristics of the pre-transplant group of patients with CKD.

Fatigue due to elevated blood urea levels was the most common symptom (46.45%), followed by hypertension (43%) and anorexia (21.5%), both of which are common symptoms in advanced-stage kidney disease (Table 2).

Table 2: Clinical characteristics

Table 3 shows that serum Galectin-3 concentrations increased progressively with the severity of chronic kidney disease. The lowest mean level was observed in Stage 3 patients, at 28.87 ± 8.02 ng/mL, while the highest level was found in patients receiving maintenance dialysis, at 72.75 ± 24.86 ng/mL. The difference in Galectin-3 levels among CKD stages was statistically significant, with p < 0.001.

Table 3: Serum galectin-3 concentrations at different stages of chronic kidney disease.

Table 4 shows the baseline characteristics of patients at three months after kidney transplantation. Among 32 patients, males accounted for 56.3%, which was slightly higher than females at 43.7%. The mean age was 48.72 ± 16.24 years. The mean serum Galectin-3 concentration was 15.25 ± 5.97 ng/mL.

Table 4: Characteristics of the patient group post kidney transplantation (T-3m)

Figure 1 illustrates the variation in serum Galectin-3 concentrations before and after kidney transplantation. Galectin-3 levels increased progressively from CKD stage 3 to stage 5 and reached the highest level in patients on maintenance dialysis. At three months after kidney transplantation, serum Galectin-3 decreased markedly to 15.25 ng/mL, which was lower than all pre-transplant CKD groups.

Figure 1: Variation of galectin-3 concentration pre- and post kidney transplantation

Serum galectin-3 concentration was inversely correlated with glomerular filtration rate, with a statistically significant difference. (p< 0.001) (Table 5).

Table 5: Correlation of serum galectin-3 and glomerular filtration rate

IV. DISCUSSION

The average age in group pre-transplant was 52.56 ± 14.83 ng/mL, similar to the study of Le Thi Ve and Nguyen Dung (2018) on the same subjects which was 58.70 ± 14.03 [4] and the study of Hoang Thi Phuong (2023) which was 50.5 ± 18.4 years [5]

The average serum galectin-3 level in CKD group was 53.97 ± 25.68 ng/mL, with a gradual increase from stage 3 which was 28.87 ± 8.02 ng/mL, stage 4 which was 44.77 ± 17.07 ng/mL, stage 5 which was 56.69 ± 20.66 ng/mL and the hemodialysis stage which was 72.75 ± 24.86 ng/mL. Differences among CKD stages were statistically significant (p < 0.001). There were no differences in concentration between men and women with p = 0.368. Galectin-3, a protein with a molecular weight of 29 to 35 kDa, is a member of the soluble β-galactoside-binding lectins. It is ubiquitous in cells, but can also be secreted into the extracellular space in the kidney and heart, playing role in regulating the cell cycle, regulating inflammatory/immune function, and promoting fibrosis. Recent studies have also shown that circulating galectin-3 concentrations are inversely related to kidney function and are only associated with clinical outcomes in patients with impaired kidney function. Therefore, galectin-3 has potential value as a diagnostic and prognostic marker of chronic kidney disease [2]. A study by Drechler et al. on the association between galectin-3 and clinical endpoints in patients with chronic kidney disease of various stages due to diabetes-related or non-diabetic causes yielded mean galectin-3 concentrations of 12.8 ± 4.0 ng/mL (eGFR ≥ 90 ml/min/1.73 m2), 15.6 ± 5.4 ng/mL (eGFR 60-89 ml/min/1.73 m2), 23.1 ± 9.9 ng/mL (eGFR< 60 ml/min/1.73 m2) and 54.1 ± 19.6 ng/mL (hemodialysis patients in the 4D study) [6]. These results are lower than those of our study. This may be due to our smaller sample size, different follow-up time and different subjects. This study also showed that the change in serum galectin-3 values ​​between phases (Figure 2) was significant in hemodialysis. Serum galectin-3 concentrations were significantly associated with clinical endpoints in participants with impaired kidney function, but not in participants with normal kidney function. In hemodialysis patients, serum galectin-3 level was associated with the combined outcome of cardiovascular events. [1]

Figure 2: Galectin-3 ​​in different stages according to 4D and LURIC studies [1]

In the group of patients who had undergone kidney transplantation, alongside the stabilization of kidney function as evidenced by the return to normal serum creatinine levels, the serum galectin-3 test results in our study also similarly returned to normal values ​​after transplantation. Our study only examined patients at the 3rd month post-transplant follow-up visit, and we had to separate the group to investigate galectin-3 results because the clinical symptoms of patients after kidney transplantation are often no longer the same as those of patients with chronic kidney disease. In this study, we also found a strong positive correlation between serum galectin-3 levels and serum creatinine (p < 0.001, r = 0.605), and a negative correlation with glomerular filtration rate (r = -0.627) - a valuable indicator in the diagnosis of chronic kidney disease. These correlations were also found similarly in the study by Jin Ook Chung et al., further demonstrating the role of galectin-3 in chronic kidney disease [7].

A study of O'Seaghdha et al. published on J Am Soc Nephro journal (2013) about the predictive value of galectin-3 in chronic kidney disease, the results included the following factors: higher galectin-3 concentrations were associated with an increased risk of new-onset CKD in the general population. These findings were highly reliable in continuous and categorical analyses after adjusting for known clinical predictors of CKD, as well as circulating biomarkers known to potentially enhance CKD prediction; Serum Galectin-3 showed a similarly strong association with rapid renal function loss over more than 10 years of follow-up. Data from this study showed that galectin-3 can identify individuals at risk for CKD many years before clinical onset and showed the important role of fibrosis in the early stages of CKD pathogenesis [8].

Another study by Camilo G et al., which followed up on kidney transplant patients for 10 years, showed that the mean post-transplant galectin-3 concentration was 21.1ng/mL, with 3-month, 6-month, 1-year, and 2-year post-transplant follow-up concentrations of 16.6, 15.4, 15.8, and 16.7 ng/mL, respectively. Furthermore, changes in galectin-3 concentration were also an independent prognostic factor for the likelihood of loss of transplant function [3].

The most frequently observed clinical symptom in the study group was fatigue due to uremia (46.5%), followed by hypertension (43.0%) and anorexia (21.5%). These symptoms appeared with high frequency in the late stage and were rarely seen in the early stage. The symptoms were similar to the study by Hoang Thi Phuong et al. on 157 patients with chronic kidney disease at various stages at Bach Mai Hospital, where the most frequently encountered clinical symptom was fatigue due to uremia (45%), followed by edema (35%) [5]. Also in this study, the most frequently encountered etiology of chronic kidney disease was chronic glomerulonephritis, accounting for 47.1%, compared to our study where the rate was 45.90%.

Thus, through this study, we have demonstrated the value of serum galectin-3 in the stages of chronic kidney disease, including the preservation and dialysis stages and post-kidney transplantation. Specifically for patients undergoing renal replacement therapy via kidney transplantation, numerous large-scale studies have described changes in galectin-3 levels after long-term transplantation, as well as its role in predicting graft failure. Post-transplantation renal fibrosis has been shown to be dependent on galectin-3 expression and secretion.

Furthermore, from these long-term studies, the authors found the prognostic value of galectin-3 for long-term graft survival, as shown by the results of a 9.5-year average follow-up showing that 31% of patients died and 13% experienced graft failure. The main causes of death were cardiovascular disease, malignancies, and infections; the main causes of graft failure were chronic graft dysfunction (73%), acute rejection (10%), and recurrence of original kidney disease (3%). In both unadjusted and multivariate adjusted Cox regression analyses, a direct and independent association was also found between galectin-3 concentration and the aforementioned graft failure risk [3].

V. CONCLUSION

Serum galectin-3 levels increased progressively with CKD severity and were significantly reduced after 3 months received kidney transplantation. Galectin-3 was correlated with creatinine and eGFR, suggesting potential utility as a biomarker for CKD severity and post-transplant monitoring.

Conflict of interest: The authors declare that they have no conflict of interest.