Susana Sampaio

Compared to mycophenolate mofetil, rapamycin induces significant changes on growth factors and growth factor receptors in the early days post-kidney transplantation.

BACKGROUND The new immunosuppressive drug Rapamycin (Rapa) is endowed with a mechanism of action that is distinct from that of calcineurin inhibitors. It has been claimed that Rapa does not significantly modulate either the cytokine expression or the transcription of several growth factors in mitogen-activated T cells. Previously, we reported that fine-needle aspiration biopsy (FNAB) sample cultures synthesize a large array of cytokines, and some of them may be powerful predictors of acute rejection in renal transplants. We hypothesized that Rapa may induce significant changes on cytokine production by FNAB sample cultures and on serum cytokine receptors when compared to other immunosuppressive drugs. METHODS Kidney transplants treated with CsA-Rapa-Pred (Rapa group) were compared with transplants treated with CsA-mycophenolate mofetil-Pred (MMF group). They were studied on day 7 posttransplantation, and they remained rejection free for at least the first 6 months. FNAB samples were cultured and the supernatants were collected at 48 hr of incubation and analyzed by ELISA for interleukin 1 receptor antagonist (IL-1ra), IL-2, IL-6, IL-10, IL-18, monocyte chemotactic protein 1 (MCP-1), soluble tumor necrosis factor I, and transforming growth factor (TGF)-beta(1). The soluble receptors for IL-1, IL-2, IL-6, and tumor necrosis factor alpha, together with IL-2 and IL-18 were also measured in serum. RESULTS Significant differences were observed when comparing Rapa with the MMF group. IL-18 and TGF-beta(1) synthesis were up-regulated, whereas IL-6 and MCP-1 were down-regulated in FNAB sample cultures. The Rapa group showed a significant down-regulation of each cytokine receptor and of IL-2 in serum. CONCLUSIONS Rapa was associated with a decreased synthesis of primarily monocyte-derived cytokines and enhanced production of TGF-beta(1), which in an appropriate cytokine milieu may promote allograft tolerance. The down-regulation of cytokine receptors and IL-2 may be associated with a depressed immune response towards the kidney allograft.

XM-ONE Detection of Endothelium Cell Antibodies Identifies a Subgroup of HLA-Antibody Negative Patients Undergoing Acute Rejection

BACKGROUND Kidney transplant recipients exhibiting antibodies (Ab) against either HLA or non-HLA antigens undergo frequent episodes of rejection and exhibit decreased long-term graft survival. The novel flow cytometry crossmatch kit XM-ONE, detects Abs to HLA antigens plus those directed to Tie-2-positive precursor endothelial cells (anti-endothelial cell antibodies, AECA). We studied the clinical importance of these lesser known antibodies. METHODS We retrospectively analyzed 208 sera from 160 recipients of deceased donor grafts for AECA using non-donor peripheral blood endothelial progenitor cells as targets and Luminex methodology for HLA antibodies. RESULTS AECA were detected in 64 patients (40%). A significantly higher proportion of patients showing a positive endothelial crossmatch experienced rejection (31 AECA-positive among 43 rejection cases, 72%) compared with those without rejection (33/117, 28.2%). Immunoglobulin M(IgM) predominated (66%) over IgG (14%) and IgG plus IgM (20%). HLA antibodies positively and significantly associated with rejection as expected. Of special interest were the 19 patients who presented with acute rejection episodes along with restricted AECA positivity. The relative-risk for an acute rejection episode with either AECA or HLA--13.87 and 2.43, respectively--was significant. When HLA was already positive, the relative risk for AECA was 1.24, a non-significant increase. CONCLUSIONS Our data identified AECA-positive patients that showed an increased risk to develop an acute rejection episode early after transplantation. Moreover, restricted AECA-positive patients with acute rejection are an important subgroup which otherwise may be wrongly labeled as non-humoral rejection. Among HLA-negative cases, AECA conferred a significantly greater risk for rejection.

Cerebral coccidioidomycosis after renal transplantation in a non‐endemic area

C. Carvalho, I. Ferreira, S. Gaião, S. Guimarães, R. Costa, J. Santos, S. Sampaio, M. Bustorff, G. Oliveira, M. Pestana. Cerebral coccidioidomycosis after renal transplantation in a non‐endemic area.
Transpl Infect Dis 2010: 12: 151–154. All rights reserved

The synthesis by fine-needle aspiration biopsy cultures of IL-7, IL-16 and IL-18 is significantly associated with acute rejection in kidney transplants.

Background: T-cell activation, the key event in the development of acute allograft rejection, depends on co-stimulatory signals delivered by antigen-presenting cells (APC). APC-derived cytokines may provide co-stimulation and modulate alloimmune reaction. We have studied cytokine synthesis by fine-needle aspiration biopsy (FNAB) culture and we found significant differences for interleukin (IL)-2, IL-6, IL-10, M-CSF and IL-1ra on comparing acute rejection versus stable kidney transplant patients. We report our findings on FNAB cultures synthesis of IL-7, IL-15, IL-16, IL-17, IL-18 and RANTES (regulated upon activation, normal T-cell expressed and secreted), all potential modulators of anti-graft reaction. Patients and Methods: Kidney transplants (KTX) treated with CsA-AZA-Pred from the beginning, were divided into four groups. Group I: day 7 post-KTX, stable; II: day 7 post-KTX, 6.5 ± 5.5 days before acute rejection; III: first day of acute rejection; IV: day 14 post-KTX, stable. Patients from I and IV remained rejection-free for the first 6 months, at least. All rejection episodes were confirmed by classical core renal biopsy. FNAB samples were cultured according to our published methodology and culture supernatants were collected at 48 h and analysed by ELISA for IL-7, IL-15, IL-16, IL-17, IL-18 and RANTES. Results: Group III synthesized significantly higher amounts of IL-7, IL-16 and IL-18 than stable patients (groups I and IV). RANTES production did not show significant differences among the four groups. We did not find any trace of IL-15. Conclusions: IL-18 may play the activation role that has been attributed to IL-12 which previously, we did not find to correlate significantly with acute rejection in KTX. IL-16 seems to play an activation role rather than an inhibition of anti-graft reaction. We confirm that RANTES is not significantly associated with acute rejection in KTX.

sTNFRI and sTNFRII synthesis by fine-needle aspiration biopsy sample cultures is significantly associated with acute rejection in kidney transplantation.

Background. Previously we reported that cultures of fine-needle aspiration biopsy (FNAB) samples synthesize different cytokine pattern depending on the alloimmune response towards the kidney graft. However, we failed to find a clear picture for growth factors implicated in early T-cell activation (interferon-&ggr;, interleukin [IL]-4, IL-12), although we observed that interleukin-1 receptor antagonist (IL-1ra) was associated with absence of acute rejection. We have now studied tumor necrosis factor-&agr; (TNF-&agr;) and its two soluble receptors, sTNFRI and sTNFRII, IL-1&bgr; and soluble IL-1 receptor II (sIL-1RII), and leukemia inhibitory factor (LIF), all potential modulators of T-cell activation. Methods. Sixty-six cadaver kidney transplants (KTX) were divided into four groups: group 1, day 7 after KTX, stable (n=30); group 2, day 7 after KTX, 8±4.5 days before acute rejection (n=12); group 3, first day of acute rejection (n=17); and group 4, day 14 after KTX, stable (n=32). Patients from groups 1 and 4 remained rejection-free for the first 6 months. All rejection episodes were confirmed by core renal biopsy. FNAB samples were cultured according to our published methodology, and culture supernatants were collected at 48 hr and analyzed by ELISA for IL-1&bgr;, sIL-1RII, TNF-&agr;, sTNFRI, sTNFRII, and LIF. Serum levels for sIL-1RII, sTNFRI, and sTNFRII were also measured. Results. FNAB cultures from groups 1 and 4 synthesized significantly lower amounts of sTNFRI and sTNFRII than those from either groups 2 or 3. Both sTNFRI and sTNFRII reached high positive and negative predictive values for acute rejection. IL-1&bgr; and sIL-1RII were synthesized by all groups but without differences. No trace of LIF and TNF-&agr; was found. sTNFRII was significantly higher in serum from group 3. Conclusions. Both TNF receptors were positively associated with acute rejection and were good predictors of impending acute rejection. The ratio of sIL-1RII over IL-1 (together with IL-1ra that we previously measured in FNAB cultures) suggests that IL-1 actions may be inhibited with current immunosuppression early after transplantation.

Periodontal inflammation in renal transplant recipients receiving Everolimus or Tacrolimus – preliminary results

OBJECTIVE To compare oral health status between renal transplant recipients (RTRs) receiving tacrolimus (Tac) or everolimus (ERL) as immunosuppressive therapy. DESIGN This study is a cross-sectional study. METHODS Thirty-six RTRs receiving Tac and 22 RTRs receiving ERL were included in the study. Age, gender, time since transplant and pharmacological data were recorded for both groups. Oral health status was assessed through the evaluation of teeth, periodontal parameters as well as saliva flow rate and pH. RESULTS RTRs receiving ERL were older than those receiving Tac. No differences were found between groups concerning oral hygiene habits, oral symptoms, smoking habits, unstimulated and stimulated saliva flow rate and pH, clinical attachment level or the number of decayed, missing and filled teeth. However, RTRs receiving ERL presented lower visible plaque index and lower values for bleeding on probing when compared to RTRs receiving Tac. In addition, RTRs receiving ERL presented a gingival index varying from normal to moderate inflammation whereas RTRs receiving Tac presented a gingival index varying from mild to severe inflammation. CONCLUSIONS RTRs receiving ERL have lower periodontal inflammation when compared to RTRs receiving Tac.

Relationship between everolimus blood concentration assessed using the Innofluor Certican Fluorescence Polarization Immunoassay and the Architect i System sirolimus chemiluminescent microparticle immunoassay.

Everolimus, an immunosuppressive macrolide derivative of sirolimus, has a narrow therapeutic index and variable bioavailability. Assessment of blood concentration of everolimus is necessary to improve immunosuppressive efficacy without increasing potential adverse effects. Recently, Seradyn, Inc (Indianapolis, Indiana) introduced a fluorescence polarization immunoassay (Innofluor Certican Fluorescent Polarization Immunoassay [FPIA]) for quantitation of everolimus blood concentration. This immunoassay has concentration-dependent cross-reactivity with sirolimus, which must be considered in patients recently treated with that drug. In this short-term study, treatment in 53 renal transplant recipients was converted from a sirolimus-based regimen to an everolimus-based regimen. Patients were followed up for 3 months. We investigated whether cross-reactivity with everolimus also occurred with the Abbott Laboratories (Abbott Park, Illinois) Architect i System, a sirolimus chemiluminescent microparticle immunoassay (CMIA) used to quantify sirolimus blood concentration. Quantification of everolimus blood concentration using both the CMIA and the FPIA demonstrated a linear regression: CMIA = 0.73 FPIA +/- 0.77 (r(2) = 0.80; P < .001). A high degree of correlation between the CMIA and FPIA methods (r = 0.90) was confirmed using the Bland-Altman test. We conclude that the Abbott Architect i System sirolimus CMIA should be considered an alternative method for everolimus drug monitoring. The cross-reactions of both the FPIA and CMIA techniques with both sirolimus and everolimus must be considered when converting therapy from one drug to the other. In these conditions, use of an equivalent dosage is of particular importance.

Anti-troponin I antibodies in renal transplant patients

OBJECTIVE To characterize the prevalence and clinical correlates of anti-troponin I antibodies in renal transplant patients. METHODS A group of 48 consecutive renal transplant patients under immunosuppressive therapy were studied. Anti-troponin I antibodies were measured and clinical data were retrieved. RESULTS An anti-troponin I antibody titer <1:40 was seen in most patients (30). IgG antibody titers ≥1:80 were seen in eight patients, with a single value of 1:160. Regarding IgM antibodies, in six cases titers ≥1:80 were seen, with one value of 1:320. In only one patient were both anti-troponin I antibody IgG and IgM titers 1:80 or higher. Clinical cardiac disease was seen in nine patients. The presence of an anti-troponin I antibody titer ≥1:80 was not associated with the presence of clinical cardiac disease (p=0.232), but was associated with statin therapy status (p=0.008), being less frequent in patients under statin therapy. CONCLUSIONS Anti-troponin I antibodies are seen in a minority of renal transplant patients, and are not associated with the presence of clinical heart disease, but are associated with lack of statin therapy.

Partially Reversible Cardiomyopathy after Renal Transplant Associated with Anti-Troponin I Antibodies

Cardiomyopathy associated with dialysis has been shown to be reversible in some cases. A 58-year-old female patient with polycystic renal disease and end-stage renal disease had a renal transplant after 9 years on hemodialysis. Dilated cardiomyopathy with depressed left ventricular ejection fraction markedly improved after transplantation, with normalization of the ejection fraction. High titers for anti-troponin I antibodies were measured: IgG 1:640, IgM 1:80. In our case, the presence of anticardiac (anti-troponin I) antibodies may suggest that the syndrome of reversible cardiomyopathy seen after renal transplantation is associated with immunosuppression therapy acting on immunological mechanisms previously at play.

Body composition assessed by impedance changes very early with declining renal graft function.

Background: Kidney transplant (Tx) restores renal filtration, although it does not achieve the function of two native kidneys, and with time it may variably involute back to chronic renal failure. We hypothesized that bioelectrical impedance analysis (BIA) might highlight differences for body compartments among Tx with different filtration rates, and we compared them with healthy controls. Methods: 38 Tx patients (25 males, 13 females) were studied at 75.9 ± 37.8 months postsurgery and divided into three groups: good creatinine clearance (CrCl, ml/min/1.73 m2; > 65.0), borderline (35.0 < CrCl < 60.0) and bad (CrCl < 35.0). BIA was assessed three times in a year. Total body water, extracellular water (ECW), intracellular water (ICW), Na:K exchange rate (Nae:Ke) and phase angle were studied. Healthy (n = 11) and hemodialysis (n = 11) groups were also studied. Results: BIA showed no differences between healthy controls and good Tx while both borderline and bad Tx presented a significantly higher ECW and lower ICW than either good Tx or normal controls. Only good CrCl was different from predialysis. Conclusions: A good kidney graft manages to restore and maintain normal body composition, even with potential disturbances brought about by steroids and cyclosporine. With mild renal dysfunction a change in body compartments was observed, moving towards the composition of that with chronic renal failure patients.