Miguel Hueso

Serial Protocol Biopsies to Quantify the Progression of Chronic Transplant Nephropathy in Stable Renal Allografts

Aim: To evaluate the utility of intimal thickness and interstitial width as a primary efficacy variable in the design of clinical trials aimed to modify the natural history of chronic allograft nephropathy.

Early subclinical rejection as a risk factor for late chronic humoral rejection.

Background. Subclinical rejection and interstitial fibrosis and tubular atrophy (IF/TA) in protocol biopsies are associated with outcome. We study the relationship between histologic lesions in early protocol biopsies and histologic diagnoses in late biopsies for cause. Materials and Methods. Renal transplants with a protocol biopsy performed within the first 6 months posttransplant between 1988 and 2006 were reviewed. Biopsies were evaluated according to Banff criteria, and C4d staining was available in biopsies for cause. Results. Of the 517 renal transplants with a protocol biopsy, 109 had a subsequent biopsy for cause which showed the following histological diagnoses: chronic humoral rejection (CHR) (n=44), IF/TA (n=42), recurrence of the primary disease (n=11), de novo glomerulonephritis (n=7), T-cell-mediated rejection (n=4), and polyoma virus nephropathy (n=1). The proportion of retransplants (15.9% vs. 2.3%, P=0.058) and the prevalence of subclinical rejection were higher in patients with CHR than in patients with IF/TA (52.3% vs. 28.6%, P=0.0253). Demographic donor and recipient characteristics and clinical data at the time of protocol biopsy were not different between groups. Logistic regression analysis showed that subclinical rejection (relative risk, 2.52; 95% confidence interval, 1.1–6.3; P=0.047) but not retransplantation (relative risk, 6.7; 95% confidence interval, 0.8–58.8; P=0.085) was associated with CHR. Conclusion. Subclinical rejection in early protocol biopsies is associated with late appearance of CHR.

Immunephenotype of Glomerular and Interstitial Infiltrating Cells in Protocol Renal Allograft Biopsies and Histological Diagnosis

Patients with a protocol renal allograft biopsy simultaneously displaying interstitial fibrosis/tubular atrophy (IF/TA) and subclinical rejection (SCR) have a shortened graft survival than patients with a normal biopsy, or with a biopsy only displaying IF/TA or SCR. The poor outcome of these patients could be related with a more severe inflammation. We evaluate the immunophenotype of infiltrating cells in these diagnostic categories. Nonexhausted paraffin blocks from protocol biopsies done during the first year were stained with anti‐CD45, CD3, CD20, CD68 and CD15 monoclonal antibodies. Glomerular and interstitial positive cells were counted. C4d deposition in peritubular capillaries was evaluated. Histological diagnoses were: normal (n = 80), SCR (n = 17), IF/TA (n = 42) and IF/TA + SCR (n = 17). Only interstitial CD20 positive cells were significantly increased in patients displaying IF/TA + SCR; normal (137 ± 117), SCR (202 ± 145), IF/TA (208 ± 151) and IF/TA + SCR (307 ± 180 cells/mm2), p < 0.01. The proportion of biopsies displaying C4d deposition was not different among groups. The upper tertile of CD20 positive interstitial cells was associated with a decreased death‐censored graft survival (relative risk: 3.01, 95% confidence interval: 1.23–7.35; p = 0.015). These data suggest that B‐cell interstitial infiltrates are associated with histological damage and outcome, but do not distinguish whether these infiltrates were the cause or the consequence of chronic tubulo‐interstitial damage.

Intragraft Expression of the IL-10 Gene Is Up-Regulated in Renal Protocol Biopsies with Early Interstitial Fibrosis, Tubular Atrophy, and Subclinical Rejection

Grafts with subclinical rejection associated with interstitial fibrosis and tubular atrophy (SCR+IF/TA) show poorer survival than grafts with subclinical rejection without IF/TA (SCR). Aiming to detect differences among SCR+IF/TA and SCR, we immunophenotyped the inflammatory infiltrate (CD45, CD3, CD20, CD68) and used a low-density array to determine levels of T(H)1 (interleukin IL-2, IL-3, gamma-interferon, tumor necrosis factor-alpha, lymphotoxin-alpha, lymphotoxin-beta, granulocyte-macrophage colony-stimulating factor) and T(H)2 (IL-4, IL-5, IL-6, IL-10, and IL-13) transcripts as well as of IL-2R (as marker for T-cell activation) in 31 protocol biopsies of renal allografts. Here we show that grafts with early IF/TA and SCR can be distinguished from grafts with SCR on the basis of the activation of IL-10 gene expression and of an increased infiltration by B-lymphocytes in a cellular context in which the degree of T-cell activation is similar in both groups of biopsies, as demonstrated by equivalent levels of IL-2R mRNA. These results suggest that the up-regulation of the IL-10 gene expression, as well as an increased proportion of B-lymphocytes in the inflammatory infiltrates, might be useful as markers of early chronic lesions in grafts with SCR.

Angiotensin Converting Enzyme Genotype and Chronic Allograft Nephropathy in Protocol Biopsies

Genotype DD of the angiotensin-converting enzyme (ACE) is not associated with an increased incidence of native renal diseases, although it could modulate progression to renal failure in patients who already display chronic lesions. Because its role in renal allograft degeneration is not well characterized, whether ACE genotype was associated with the prevalence of chronic allograft nephropathy (CAN) was studied, in a group of protocol biopsies from 180 patients, or with the incidence of CAN in 152 patients with at least two sequential biopsies. As a control group, ACE genotype was also studied in 41 donors and 72 healthy subjects. For analyzing the influence of ACE genotype in graft survival, patients were grouped into six categories (II-normal biopsy, ID-normal, DD-normal, II-CAN, ID-CAN and DD-CAN). Finally, relative renal ACE mRNA levels were measured in 67 cases by real-time PCR using the delta threshold cycle method. ACE-DD genotype was more frequent in patients who received a transplant than in control subjects (43.3% versus 30.1%, P = 0.026), but prevalence (DD = 42.7% versus non-DD = 42.2%) or incidence (DD = 24.6% versus non-DD = 29.9%) of CAN was not different regarding recipient ACE genotype. Furthermore, patients with the ACE-DD genotype and CAN had the poorest graft survival (II-normal = 100%, ID-normal = 91%, DD-normal = 84%, II-CAN = 100%, ID-CAN = 66%, and DD-CAN = 36%; P = 0.034) and higher ACE mRNA levels than non-DD and CAN (DD = -3.36 +/- 2.35 versus non-DD = -5.65 +/- 1.72-fold in ACE copies; P = 0.012). It is concluded that ACE-DD genotype is not associated with an increased prevalence or incidence of CAN but is actually associated with higher ACE mRNA levels and poorer graft survival in patients who already display CAN.

Silencing of CD40 in vivo reduces progression of experimental atherogenesis through an NF-κB/miR-125b axis and reveals new potential mediators in the pathogenesis of atherosclerosis

BACKGROUND AND AIMS CD40/CD40L signaling exerts a critical role in the development of atherosclerosis, and microRNAs (miRNAs) are key regulators in vascular inflammation and plaque formation. In this work, we investigated mRNA/miRNA expression during progression of atherosclerotic lesions through CD40 silencing. METHODS We silenced CD40 with a specific siRNA in ApoE-/- mice and compared expression of mRNA/miRNA in ascending aorta with scrambled treated mice. RESULTS siRNA-CD40 treated mice significantly reduced the extension and severity of atherosclerotic lesions, as well as the number of F4/80+, galectin-3+ macrophages and NF-κB+ cells in the intima. Genome-wide mRNA/miRNA profiling allowed the identification of transcripts, which were significantly upregulated during atherosclerosis; among them, miR-125b and miR-30a, Xpr1, a regulator of macrophage differentiation, Taf3, a core transcription factor and the NF-κB activator Ikkβ, whereas, the NF-κB inhibitor Ikbα was downregulated during disease progression. All those changes were reversed upon CD40 silencing. Interestingly, TAF3, XPR1 and miR-125b were also overexpressed in human atherosclerotic plaques. Murine Taf3 and Xpr1 were detected in the perivascular adipose tissue (PVAT), and Taf3 also in intimal foam cells. Finally, expression of miR-125b was regulated by the CD40-NF-κB signaling axis in RAW264.7 macrophages. CONCLUSIONS CD40 silencing with a specific siRNA ameliorates progression of experimental atherosclerosis in ApoE-/- mice, and evidences a role for NF-κB, Taf3, Xpr1, and miR-125b in the pathogenesis of atherosclerosis.

Chronic Kidney Disease is associated with an increase of Intimal Dendritic cells in a comparative autopsy study

BackgroundChronic Kidney Disease (CKD) and inflammation are risk factors for atherosclerotic vascular disease (ASVD). In inflammatory conditions, Nuclear Factor-κB (NF-κB) is frequently activated and it has been detected in human ASVD. In this work, we investigated if the degree of inflammation and of NF-κB activation were increased in the aorta of patients with CKD.MethodsThis is a case–control pilot study performed on 30 abdominal aorta samples from 10 human autopsies. Cases were patients with CKD and controls patients with normal glomerular filtration rate (eGFR). Infiltrating mononuclear cells (S100+, CD3+, CD40+, CD40L+) and activation of NF-κB were identified by immunohistochemistry.FindingsThe number of cells in the intima which showed activated nuclear NF-κB correlated with severity of ASVD lesions (r = 0.56, p = 0.003), with numbers of CD3+ lymphocytes in adventitia (r = 0.50, p = 0.008), with numbers of CD40+ cells in the intima (r = 0.59, p = 0.002) or in the adventitia (r = 0.45, p = 0.02), and with numbers of CD40L+ cells in the intima (r = 0.51, p = 0.011). Increased numbers of S100+ Intimal Dendritic cells (IDCs) were associated with ASVD (p = 0.03) and CKD (p = 0.01).ConclusionsNumber of CD3+ cells, of CD40+ cells, of CD40L+ cells and the degree of NF-κB activation were increased in ASVD lesions suggesting a role for the adaptive T cell in the development of ASVD lesions. IDCs were associated both with ASVD and CKD suggesting a role of these cells in the pathogenesis of ASVD in CKD.

Online haemodiafiltration improves inflammatory state in dialysis patients: A longitudinal study

Background Patients undergoing conventional hemodialysis (C-HD) present a greater immuno-inflammatory state probably related to uremia, sympathetic nervous system (SNS) activation and /or membrane bioincompatibility, which could improve with a technique-switching to online hemodiafiltration (OL-HD). The antigen-independent pathway activation of this modified immunologic state turns dendritic cells (DC) into an accurate cell model to study these patients. The aim of this study is to further evaluate the immune-inflammatory state of patients in C-HD assessed by DC maturation. Methods 31 patients were submitted to C-HD and after 4 months switched to the OL-HD technique. Monocytes-derived DCs from HD patients were cultured in the presence of IL-4/GM-CSF. DC-maturation was evaluated by assessing the maturation phenotype by flow cytometry (FACs). DCs-functional capacity to elicit T-cell alloresponse was studied by mixed leucocyte reaction. Cytokine release was assessed by FACs and SNS was evaluated measuring renalase levels by ELISA. Results An up-regulation of maturation markers was observed in C-HD DCs which induced two fold more T cells proliferation than OL-HD DCs. Also, C-HD-mDCs presented with over-production of pro-inflammatory cytokines (IL-6, IL-1β, IL-8, IL-10 and TNF-α) compared with OL-HD-mDC (P<0·05). Results were correlated with clinical data. When SNS was evaluated, hypotension events and blood pressure were significantly lower and renalase levels were significantly higher after conversion to OL-HD. Diabetes mellitus type 2 patients also found beneficial reduction of mDC when converted to OL-HD compared to non-diabetics. Conclusions OL-HD could interfere with immuno-inflammatory state in HD patients with an improvement of renalase levels as potential key mediators in the mechanistic pathway of down-regulation of DC maturation.

Pretransplant low CD3+CD25high cell counts or a low CD3+CD25high/CD3+HLA-DR+ ratio are associated with an increased risk to acute renal allograft rejection.

Background. Detection of markers predicting allograft rejection is important for risk assessment before kidney transplantation, as well as to minimize posttransplantation immunosuppression. Methods. We studied the expression of CD25, HLA-DR, CD134, CD62L, and CD44 by flow cytometry in CD4+, CD8+, and CD3+ cells, from pretransplant blood samples from 91 transplanted patients accounting for 16 episodes of acute renal rejection in the first month after transplantation. Results. None of the activation markers showed a significant association to acute rejection. Early rejectors showed less pretransplant CD3+CD25high cells than nonrejectors (0.79%±0.50% vs. 1.51%±0.79% of CD3+ cells; P=0.001) and a lower CD3+CD25high/CD3+HLA-DR+ ratio (0.043±0.034 vs. 0.111±0.079; P<0.00001). When levels of CD25high cells fell below 0.7% of CD3+ cells, the odds ratio of suffering an episode of acute rejection was 105 fold (95% confidence interval: 11.41–966.43, P<0.0001), with a sensitivity (true-positive results) of 0.63 and a specificity (true-negative results) of 0.98 for predicting the risk of acute rejection. Furthermore, when the CD3+CD25high/CD3+HLA-DR+ ratio fell below 0.04, the odds ratio of suffering an episode of acute rejection was 7.71 fold (95% confidence interval: 2.29–25.97, P=0.001), with a sensitivity of 0.56 and a specificity of 0.86 for predicting risk of acute rejection. Conclusions. Our results suggest that low pretransplant levels of CD3+CD25high cells or a low CD3+CD25high/CD3+HLA-DR+ ratio could identify those patients with an increased risk of early acute allograft rejection. If these data can be independently confirmed, pretransplant CD3+CD25high cells and the CD3+CD25high/CD3+HLA-DR+ ratio might provide additional information for risk assessment before kidney transplantation.

Data on genotypic distribution and linkage disequilibrium of several ANRIL polymorphisms in hemodialysis patients

A long non-coding RNA called ANRIL located on chromosome 9p21.3 has been identified as a novel genetic factor associated with cardiovascular disease. Investigation of several single nucleotide polymorphisms (SNPs) of Noncoding Antisense RNA in the INK4 Locus (ANRIL) gene are of particular interest. This article reports data related to the research article entitled: “Association of ANRIL gene polymorphisms with major adverse cardiovascular events in hemodialysis patients” (Arbiol-Roca et al. [1]). Data presented show the genotypic distribution of four selected ANRIL SNPs: rs10757278, rs4977574, rs10757274 and rs6475606 in a cohort constituted by 284 hemodialysis patients. This article analyzes the Hardy-Weinberg disequilibrium of each studied SNP, and the linkage disequilibrium between them.