Effect of Kidney Transplantation on Accelerated Immunosenescence and Vascular Changes Induced by Chronic Kidney Disease

Abstract

Kidney transplantation is the best option for patients with end-stage renal disease. Despite the improvement in cardiovascular burden (leading cause of mortality among patients with chronic kidney disease), cardiovascular adverse outcomes related to the inflammatory process remain a problem. Thus, the aim of the present study was to characterize the immune profile and microvesicles of patients who underwent transplantation. We investigated the lymphocyte phenotype (CD3, CD4, CD8, CD19, and CD56) and monocyte phenotype (CD14, CD16, CD86, and CD54) in peripheral blood, and endothelium-derived microvesicles (annexin V+CD31+CD41-) in plasma of patients with advanced chronic kidney disease (n = 40), patients with transplantation (n = 40), and healthy subjects (n = 18) recruited from the University Hospital "12 de Octubre" (Madrid, Spain). Patients with kidney transplantation had B-cell lymphopenia, an impairment in co-stimulatory (CD86) and adhesion (CD54) molecules in monocytes, and a reduction in endothelium-derived microvesicles in plasma. The correlations between those parameters explained the modifications in the expression of co-stimulatory and adhesion molecules in monocytes caused by changes in lymphocyte populations, as well as the increase in the levels of endothelial-derived microvesicles in plasma caused by changes in lymphocyte and monocytes populations. Immunosuppressive treatment could directly or indirectly induce those changes. Nevertheless, the particular characteristics of these cells may partly explain the persistence of cardiovascular and renal alterations in patients who underwent transplantation, along with the decrease in arteriosclerotic events compared with advanced chronic kidney disease. In conclusion, the expression of adhesion molecules by monocytes and endothelial-derived microvesicles is related to lymphocyte alterations in patients with kidney transplantation.

Keywords: chronic kidney disease; immunity; immunosenescence; microvesicles; renal transplantation.

Figure 1

Description of cross-sectional study population.

Figure 2

Representative flow cytometry findings of monocyte subsets and CD54/CD86 expression in the three groups: healthy subjects (HS), patients with advanced chronic kidney disease (ACKD), and patients with renal transplantation (RT). Monocyte subpopulations were assessed within the FSC-height/SSC-height. The classical (CD14++CD16–), intermediate (CD14++CD16+), and non-classical (CD14+CD16+) monocytes were evaluated using anti-CD16-FITC and anti-CD14–TRICOLOR. For each subpopulation, the expression of CD54 or CD86 was analyzed using anti-CD54-PE or anti-CD86-PE. FITC, fluorescein isothiocyanate; FSC, forward scatter; PE, phycoerythrin; SSC, side scatter.

Figure 3

Description of lymphocyte subpopulations. Number of total lymphocytes^Ψ (A), T lymphocytes^Ω (B) (CD3+), B lymphocytes^Ω (C) (CD3–CD19+), and natural killer cells^Ψ (D) (CD56+CD16+CD3–) in healthy subjects (HS), patients with advanced chronic kidney disease (ACKD), and patients with kidney transplantation (KT). ^*p ≤ 0.05, ^**p ≤ 0.01 vs. HS. Statistical analysis: ^ΨANOVA (Tukey test). ^ΩANOVA (Games–Howell test). ANOVA, analysis of variance.

Figure 4

Description of T lymphocyte subpopulations. Number^Ψ (A) and percentage^Ψ (B) of T-helper lymphocytes (CD3+CD4+); number^Ψ (C) and percentage^Ψ (D) of T-cytotoxic lymphocytes (CD3+CD8+); relationship between helper and cytotoxic lymphocytes^Ω (E) (CD4/CD8 ratio) in healthy subjects (HS), patients with advanced chronic kidney disease (ACKD), and patients with kidney transplantation (KT). ^*p ≤ 0.05, ^***p ≤ 0.001 vs. HS; ^#p ≤ 0.05, ^##p ≤ 0.01, and ^###p ≤ 0.001 vs. ACKD. Statistical analysis: ^ΨANOVA (Tukey test). ^ΩANOVA (Games–Howell test). ANOVA, analysis of variance.

Figure 5

Description of monocyte subsets. Percentage of classical^Φ (A) (CD14++CD16−); intermediate^Ψ (B) (CD14++CD16+) and non-classical^Ψ (C) (CD14+CD16+) monocytes in healthy subjects (HS), patients with advanced chronic kidney disease (ACKD), and patients with kidney transplantation (KT). ^*p ≤ 0.05 vs. HS. Statistical analysis: ^ΨANOVA (Tukey test). ^ΨMann–Whitney U-test. ANOVA, analysis of variance.

Figure 6

Expression of CD86/B7.2 in different monocyte subsets. Percentage of classical^Φ (A) (CD14++CD16–), intermediate^Ω (B) (CD14++CD16+), and non-classical^Ψ (C) (CD14+CD16+) monocytes expressing CD86. Mean fluorescence intensity of CD86 in classical^Ω (D) (CD14++CD16–), intermediate^Ω (E) (CD14++CD16+), and non-classical^Ω (F) (CD14+CD16+) monocytes in healthy subjects (HS), patients with advanced chronic kidney disease (ACKD), and patients with kidney transplantation (KT). ^**p ≤ 0.01, ^***p ≤ 0.001 vs. HS; ^#p ≤ 0.05 vs. ACKD. Statistical analysis: ^ΨANOVA (Tukey test). ^ΩANOVA (Games–Howell test). ^ΦMann–Whitney U-test. ANOVA, analysis of variance.

Figure 7

Expression of CD54/ICAM1 in different monocyte subsets. Percentage of classical^Ω (A) (CD14++CD16−), intermediate^Ψ (B) (CD14++CD16+), and non-classical^Ψ (C) (CD14+CD16+) monocytes expressing CD54. Mean fluorescence intensity of CD54 in classical^Ω (D) (CD14++CD16−), intermediate^Ψ (E) (CD14++CD16+), and non-classical^Ψ (F) (CD14+CD16+) monocytes in healthy subjects (HS), patients with advanced chronic kidney disease (ACKD), and patients with kidney transplantation (KT). ^**p ≤ 0.01, ^***p ≤ 0.001 vs. HS; ^#p ≤ 0.05, ^##p ≤ 0.01, ^###p ≤ 0.001 vs. ACKD. Statistical analysis: ^ΨANOVA (Tukey test). ^ΩANOVA (Games-Howell test). ANOVA, analysis of variance.

Figure 8

Description of the microvesicles phenotype. Total number of microvesicles^Φ (A) (annexin V+); number^Ω (B) and percentage^Ω (C) of endothelial microvesicles (annexin V+CD31+CD41–); and percentage^Ψ (D) and number^Φ (E) of endothelial microvesicles expressing tissue factor (CD142) in healthy subjects (HS), patients with advanced chronic kidney disease (ACKD), and patients with kidney transplantation (KT). ^*p ≤ 0.05, ^**p ≤ 0.01, and ^***p ≤ 0.001 vs. HS; ^###p ≤ 0.001 vs. ACKD. Statistical analysis: ^ΨANOVA (Tukey test). ^ΩANOVA (Games–Howell test). ^ΦMann–Whitney U-test. ANOVA, analysis of variance.

Figure 9

Correlation between the number of total lymphocytes and T lymphocytes with monocytes in renal transplantation. Correlation of the total number of lymphocytes with the percentage of non-classical monocytes CD86+ (A), expression of CD86 in non-classical monocytes (B), percentage of non-classical monocytes expressing CD54 (C), and expression of CD54 in non-classical monocytes (D). Correlations of T lymphocytes with the expression of CD86 in non-classical monocytes (E), percentage of classical (F), intermediate (G), and non-classical (H) CD54+ monocytes, and the expression of CD54 in non-classical monocytes (I) are shown.

Figure 10

Correlation between the number of B lymphocytes and natural killer (NK) cells with monocytes in renal transplantation. Correlation between B lymphocytes and the percentage of intermediate (A) and non-classical (B) monocytes, the percentage of intermediate (C) and non-classical (D) CD86+ monocytes and the expression of CD86 in classical (E) and intermediate (F) monocytes. Correlations of NK cells with the percentage of CD86+ monocytes (G), expression of CD86 in classical (H), intermediate (I), and non-classical (J) monocytes, and the percentage of non-classical monocytes expressing CD54 (K) are shown.

Figure 11

Correlation between T-cytotoxic lymphocytes and monocytes in renal transplantation. Correlations between T-cytotoxic lymphocytes and the percentage of classical (A) and non-classical (B) CD54+ monocytes, and the expression of CD54 in classical (C) and intermediate (D) monocytes are shown.

Figure 12

Correlation between lymphocytes and microvesicles in renal transplantation. Correlation between T-helper lymphocytes and the number (A) and percentage (B) of endothelium microvesicles. Correlation between T-cytotoxic lymphocytes and percentage of endothelium microvesicles (C). Correlation of CD4/CD8 ratio with the number (D) and percentage (E) of endothelium microvesicles.

Figure 13

Correlation between monocytes and microvesicles in renal transplantation. Correlations between the percentage of CD86+ non-classical monocytes and the total number of microvesicles (A), the expression of CD86 in classical monocytes and the percentage of 142+ endothelium microvesicles (B), the expression of CD86 in intermediate monocytes and the total number of microvesicles (C), the expression of CD86 in non-classical monocytes and the total number of microvesicles (D), the percentage of CD54+ intermediate monocytes and the total number of microvesicles (E), and the percentage of CD54+ intermediate monocytes and the number of endothelium microvesicles (F) are shown.