Photobiomodulation in acute rejection of fetal intestinal grafts: morphological aspects and lymphocyte activation.

Early reduction of regulatory T cells is associated with acute rejection in liver transplantation under tacrolimus-based immunosuppression with basiliximab induction.

Transplant: immunology and treatment of rejection

CD25 (the α-subunit of the IL-2-receptor, IL-2Rα) is only expressed on activated T cells and is crucial to the clonal expansion of anti-allograft host lymphocytes that mediate acute rejection. Specific anti-CD25 monoclonal antibodies, such as daclizumab (Zenapax, Hoffman LaRoche, Mississauga, Ontario, Canada) bind to but do not stimulate IL-2Rα, thereby inhibiting the host immune response against the allograft (1). A two-dose daclizumab-induction regimen has been shown to be effective in preventing acute rejection in solid organ transplantation (1–4). To our knowledge, CD25 saturation has not been studied in heart transplant recipients receiving daclizumab-induction. We report the results of a prospective pilot study of the CD25 saturation rate of peripheral blood lymphocytes in heart transplant patients receiving two-dose daclizumab-induction. Written informed consent was obtained for three women and two men (range 43–66 years). Patients received daclizumab-induction consisting of 2 mg/kg at the time of transplant and 1 mg/kg on postoperative day 14. Maintenance immunosuppression therapy consisted of corticosteroids, mycophenolate mofetil (Cell-Cept Hoffman LaRoche), and a calcineurin inhibitor (cyclosporine in three patients and tacrolimus in two). CD25 expression was measured by flow cytometry (Beckman-Colter XL/MCL) with saturation defined as a percent expression of CD25 ≤2%. Acute rejection was defined as grade ≥3A, according to the International Society of Heart and Lung Transplantation classification (5). Primary endpoints were the CD25 percent expression and the incidence of acute rejection. The mean CD25 percent expression (±SD) pretransplant was 23%±14% and subsequently 1%±2%, 2%±3%, 7%±9%, 1%±1%, 3%±4%, and 3%±2% on postoperative days 14, 28, 42, 56, 70, and 84, respectively. The CD25 saturation rate of peripheral blood CD4 lymphocytes in each of the five patients is shown in Figure 1.FIGURE 1. CD25 percent-expression in five heart transplant patients receiving daclizumab-induction.One patient (20%) experienced an acute rejection episode (grade 3A) on day 84 posttransplant that reversed on high-dose methylprednisolone. This patient (Patient 4) had a 0% CD25 expression by flow cytometry on all measures except on the last measurement at 84 days when the CD25 percent expression was 4%. Both patients 2 and 3 had unpredictable CD25 saturation rates throughout follow-up; patient 2 having had multiple CD25 percent expression measurements >2% but without experiencing an acute rejection episode during the 3-month follow-up period. Two-dose daclizumab-induction in kidney transplant recipients has been found to result in effective CD25 saturation for up to 70 days (1). However, in our heart transplant patients receiving the same daclizumab-induction regimen, CD25 saturation occurred unpredictably. Nevertheless, several studies have shown support for two-dose daclizumab-induction for the prophylaxis of acute graft rejection in solid organ transplantation (1–3), including in heart transplant patients in our own experience (4). To our knowledge, the direct correlation of the CD25 saturation rate to the incidence of acute rejection has not been reported. Despite the attractive theoretical basis for the assumption of a link, prospective studies are needed to determine what level of CD25 blockade is required for adequate acute rejection prophylaxis. In addition, the value of CD25 percent expression measurements in solid organ transplant patients receiving two-dose daclizumab-induction and its usefulness as a predictor of acute graft rejection remain to be evaluated prospectively. Brian J. Potter Nadia Giannetti Jean-Pierre Routy Renzo Cecere Marcelo Cantarovich Departments of Medicine and Cardiovascular and Thoracic Surgery, Multi-Organ Transplant Program, Royal Victoria Hospital, McGill University Health Center, McGill University, Montréal, Québec, Canada

Allogeneic acute rejection on fetal small‐bowel graft: role of gangliosides

Fetal intestinal transplantation: A new therapeutic approach in short-bowel syndrome

De novo development of circulating anti-endothelial cell antibodies rather than pre-existing antibodies is associated with post-transplant allograft rejection

The remote ischemic preconditioning (R-IPC) has shown protective effect by reducing the activation of lymphocytes and the production of inflammatory cytokines in a model of ischemia and reperfusion of lower limb. In experimental intestinal transplantation, N-acetylcysteine (NAC) reduced plasma levels of TNF-α and IL-8. The aim was to evaluate the role of the remote ischemic preconditioning or N-acetylcysteine on inflammatory response after fetal intestinal transplantation. Methods: It was used pregnant mice from BALB/c strain to obtain fetal intestine graft to transplant in BALB/c (ISO) and C57BL/6 (ALO) adult mice, without immunosuppression. Pregnant were submitted to remote ischemic preconditioning 10x10 or to N-acetylcysteine (150mg/kg) administration. At the 7th post-operative day, the intestinal graft was harvested to seek the cytokines expression. The mRNA expressions of IFN-γ, IL-10 and IL-6 of the lymph nodes were evaluated by real-time PCR. Expression levels were standardized for GAPDH (housekeeping) gene expression. Results: We observed that endogenous IFN-γ mRNA expression were significantly lowered by both strategies on iso and allogeneic transplant. The endogenous IL-10 mRNA expression and the treatment increased IL-10 expression on ISO/R-IPC (˜3,0 folds) and ISO/NAC (˜2,3 folds) compared with control group (ISO). We also noted that R-PCI induced a high level of interleukin-6 mRNA only on ISO group when compared to others groups (˜3,5 folds). Conclusion: Remote as well as N-acetylcysteine reduced inflammatory response in fetal intestinal graft.

Extracellular matrix proteins in organ transplantation.

Low-Level Laser and Light Therapy After Total Knee Arthroplasty Improves Postoperative Pain and Functional Outcomes: A Three-Arm Randomized Clinical Trial

This study aimed to evaluate the efficacy of low-level laser therapy (LLLT) and light-emitting diodes (LEDs) for reducing pain in hyperglycemic and normoglycemic patients who underwent coronary artery bypass surgery with internal mammary artery grafts. This study was conducted on 120 volunteers who underwent elective coronary artery bypass graft (CABG) surgery. The volunteers were randomly allocated to four different groups of equal size (n = 30): control, placebo, LLLT [λ = 640 nm and spatial average energy fluence (SAEF) = 1.06 J/cm(2)], and LED (λ = 660 ± 20 nm and SAEF = 0.24 J/cm(2)). Participants were also divided into hyperglycemic and normoglycemic subgroups, according to their fasting blood glucose test result before surgery. The outcome assessed was pain during coughing by a visual analog scale (VAS) and the McGill Pain Questionnaire. The patients were followed for 1 month after the surgery. The LLLT and LED groups showed a greater decrease in pain, with similar results, as indicated by both the VAS and the McGill questionnaire (p ≤ 0.05), on the 6th and 8th postoperative day compared with the placebo and control groups. The outcomes were also similar between hyperglycemic and normoglycemic patients. One month after the surgery, almost no individual reported pain during coughing. LLLT and LED had similar analgesic effects in hyperglycemic and normoglycemic patients, better than placebo and control groups.

Fetal tissue transplantation has gathered considerable interest among researchers dealing with organ transplantation. A large number of studies concerning fetal intestinal transplantation have been published in the past 2 decades, almost all of them aiming to determine the feasibility of a properly functioning fetal transplant in continuity with the host's own enteral system. This study was designed to determine the absorptive capacity of the neogut in vivo, without anastomosing the transplant to the host's intestine, and to evaluate its use as an accessory enteral segment. Intestinal segments taken from Wistar albino fetuses were transplanted subcutaneously into the abdominal wall of 20 Sprague-Dawley rats. Immunosuppression was maintained by daily cyclosporin A (Cy A) 10 mg/kg injections s.c. and evaluated by determination of serum Cy A level and T-helper/T-suppressor cell ratio. The neogut was converted into a Thiry-Vella loop 2 weeks after transplantation. A test solution composed of 20% glucose and Trophamine was perfused via the stomas; glucose and amino acid absorption gradients were calculated. The gamma-glutamyl transferase (GGT) activity and mitotic index of the neogut were determined. Results were compared to those obtained from the host. There was no significant difference (P > 0.05) in glucose absorption between the neogut and the host tissue. Amino acid absorption and specific GGT activity were significantly less (P < 0.01) in the neogut. There was no significant difference (P > 0.05) between neogut and host intestine in mitotic index. Our data support the idea of using a transplanted fetal intestinal segment as an accessory feeding route.

Fetal intestinal transplant model for mucosal immune responses

Techniques of intestinal transplantation in rat.

Allogeneic fetal intestinal transplantation with FK506 immunosuppression

Background: A great variety of natural products have been evaluated for the skin wound healing due to anti-inflammatory, antioxidant and antibacterial activities, and procollagen synthesis, of which may be mentioned the honey and propolis. In turn, low-level laser therapy (LLLT) is considered an important tool in the treatment of skin wounds, because of ability to raise the ATP production, to stimulate the microcirculation, and formation of new blood vessels. Therefore,this study aimed to assess the influence of LLLT, alone or combined with natural products, in the healing of excisional skin wounds in rats. Materials, Methods &amp; Results: One hundred twenty-six male Wistar rats, aged 14 weeks, were randomly divided into seven groups (n = 18 per group) according to wound treatments: G1 (negative control): 0.9% saline solution; G2 (positive control): allantoin + zinc oxide ointment; G3: LLLT; G4: mixture of honey + 5% propolis hydroalcoholic solution; G5: LLLT + honey + hydroalcoholic solution of 5% propolis; G6: LLLT + honey in natura; G7: LLLT + 5% propolis hydroalcoholic solution. Six rats from each group were euthanized on the 7th, 14th, and 21th postoperative days. Macroscopic and histological evaluations of wound healing were performed. A decrease in wound area occurred in all groups, but in general G4 had the higher reduction and G1 and G3 had the lower reductions. These findings corresponded to the percentage of wound contraction, since the largest contraction was G4 and the lowest contractions were G1 and G3. Histological analysis showed no significant difference among groups on the 7th postoperative day. On postoperative day 14, a significant decrease in hemorrhage occurred between G1xG4, G1xG5 and G1xG7, and a significant decrease in congestion between G1xG7 and G2xG5. In addition, intensity of the inflammatory infiltrate showed a significant reduction between G1xG7, G2xG7 and G3xG7. On postoperative day 21, a significant changed from mixed to mononuclear inflammatory infiltrate was observed between G1xG3, G1xG4, G1xG6, G1xG7, G2xG3, and G2xG6. Regarding organization of fibroblasts, there were differences between G1xG6 and G1xG7. Discussion: Spite the red laser has been associated to in increase fibroblast proliferation, G3 showed inadequate decrease in wound area and percentage of contraction. Histological examination showed no differences among groups in the inflammatory phase. However, in the proliferative and remodeling phases around days 14 and 21 were found some differences among groups, which may be related to the actions of the natural products, or laser. Studies have shown that honey acts as a repair and anti-inflammatory agent in skin woundthat may be associated to lower hemorrhage in G4 and G4 compared to G1 on day 14. Propolis is related to reduction of free radicals and increasing the amount of collagen, which may have contributed for quality improvement of the inflammatory infiltrate in G4 and G7 compared to G1, and fibroblast organization in G7 at postoperative day 21. In conclusion, macroscopically the mixture of honey + 5% propolis hydroalcoholic solution was the most effective in reducing wound area and increasing wound contraction. However, based on the parameters evaluated histologically, may be highlighted the evolution of the treatments with LLLT + honey, as well as LLLT + 5% propolis hydroalcoholic solution. Keywords: honey, propolis, biomodulation, wound, healing.