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Advances in surgical techniques and immunosuppression (IS) have led to an appreciable reduction in postoperative complications following transplantation. However, wound complications as probably the most common type of post-transplantation surgical complication can still limit these improved outcomes and result in prolonged hospitalization, hospital readmission, and reoperation, consequently increasing overall transplant cost. Our aim was to review the literature to delineate the evidence-based risk factors for wound complications following kidney and liver transplantation (KTx, LTx), and to present the preventive and therapeutic modalities for this bothersome morbidity. Generally, wound complications are categorized as superficial and deep wound dehiscences, perigraft fluid collections and seroma, superficial and deep wound infections, cellulitis, lymphocele and wound drainage. The results of several studies showed that the most important risk factors for wound complications are IS and obesity. Additionally, there are surgical and/or technical factors, including type of incision, reoperation, and surgeon's expertise, as well as comorbidities such as advanced age, diabetes mellitus, malnutrition, and uremia. Preventive management of wound complications necessitates defining their etiological factors so that their detrimental effects on healing processes can be addressed and reduced. IS modalities and agents, especially sirolimus (SRL), and steroids (ST) should be adjusted according to the patient's co-existing risk factors. SRL should be administered three months after transplantation and ST should be tapered as soon as possible. A body mass index (BMI) lower than 30 kg/m2 is advisable for inclusion in a transplantation program, but higher BMIs do not exclude recipients. Surgical risk factors can be prevented by applying precise surgical techniques. Therapeutic modalities must focus on the most efficient and cost-effective medications and/or interventions to facilitate and improve wound healing.

Summary The proteasome constitutes the central proteolytic component of the highly conserved ubiquitin–proteasome system, which is required for the maintenance and regulation of basic cellular processes, including differentiation, proliferation, cell cycling, gene transcription and apoptosis. Here we show that inhibition of proteasomal proteolytic activity by the proteasome inhibitors bortezomib and lactacystin suppresses essential immune functions of human CD4+ T cells activated by allogeneic dendritic cells (DCs). In activated CD4+ T cells, proteasome inhibition induces apoptosis accompanied by rapid accumulation and stabilization of the tumour suppressor protein p53. Activated CD4+ T cells surviving proteasome inhibition undergo inhibition of proliferation by induction of G1 phase cell‐cycle arrest. Induction of G1 arrest is accompanied by the accumulation of cyclin‐dependent kinase inhibitors p21WAF1/CIP1 and p27KIP1 and the disappearance of cyclin A, cyclin D2 and proliferating cell nuclear antigen, proteins known to regulate G1 to S phase cell‐cycle transitions. Expression of the activation‐associated cell surface receptors CD25, CD28, CD120b and CD134 as well as production of interferon‐γ (IFN‐γ), tumour necrosis factor‐α (TNF‐α), interleukin‐4 (IL‐4) and IL‐5 is suppressed in response to proteasome inhibition in CD4+ T cells activated by DCs. Expression of CD25, IFN‐γ, TNF‐α, IL‐4 and IL‐5 is known to be mediated by the transcriptional activity of nuclear factor of activated T cells (NFAT), and we show here that proteasome inhibition suppresses activation and nuclear translocation of NFATc2 in activated CD4+ T cells. Thus, the proteasome is required for essential immune functions of activated CD4+ T cells and can be defined as a molecular target for the suppression of deregulated and unwanted T‐cell‐mediated immune responses.

Summary There is evidence that interferon‐gamma (IFN‐γ)‐dependent interactions of dendritic cell (DC), T regulatory (Treg), and T suppressor (Ts) subpopulations contribute to allograft acceptance. We measured DC subsets, CD3+CD4+CD25+ (Treg phenotype) and CD3+CD8+CD28− (Ts phenotype) peripheral blood lymphocytes (PBL) expressing Foxp3, Th1 or Th2 cytokines, peripheral T‐ and B‐cell counts, and plasma cytokines in 33 kidney transplant recipients with a serum creatinine of ≤1.8 mg/dl and 32 recipients with a serum creatinine of ≥2.0 mg/dl more than 100 days post‐transplant. Cell subsets were measured in whole blood using four‐color flow cytometry. Patients with increased creatinine had less frequently detectable CD3+CD4+CD25+IFN‐γ+ PBL than patients with good graft function (P = 0.017). In patients with good graft function, CD3+CD4+CD25+IFN‐γ+ PBL were associated with high Foxp3+, IL‐2+, IL‐12+, IL‐4+, and IL‐10+ CD3+CD4+CD25+ T PBL (P < 0.001), low CD3+CD8+CD28−Foxp3+ (P = 0.002), CD3+CD4+DR+ (P = 0.002), CD3+CD8+DR+ T (P = 0.005) and CD19+ B PBL (P = 0.005), and low lineage−HLA‐DR+CD11c+CD123− DC1 (P = 0.006). Patients with impaired graft function did not show these associations. Additional flow cytometric analysis confirmed strong co‐expression of IFN‐γ and Foxp3 by CD4+CD25+ PBL particularly in patients with good graft function. Our data support an immunoregulatory role of CD3+CD4+CD25+Foxp3+IFN‐γ+ cells in a subgroup of transplant recipients with good graft acceptance.