Novel Diagnostic and Therapeutic Approach to Antibody-Mediated Rejections in Heart Transplantation

Despite the improvement of immunosuppressive therapy in heart transplantation (HTx), antibody-mediated rejection (AMR) is still a great obstacle to prolong cardiac graft survival. Anti-donor-specific antibodies (DSAs), especially anti-donor human leukocyte antigen (HLA) antibody, lead to heart graft failure resulting in hemodynamic consequence and often in the recipient death. To prevent hyperacute rejection, prospective complement-dependent cytotoxicity test has been performed in every cardiac donor in Japan. But in other solid organ transplantations, flow cytometry crossmatch has been recently recommended to crossmatch to select the recipient in Japan as well as the world. However, flow cytometry is too sensitive to select the recipient, because not all DSAs determined by flow cytometry are cytotoxic to the cardiac graft. On the first complement classical pathway, alloantibodies bind to HLA antigens on cells of the graft and then recruit C1q, which is essential to make membrane attack complex and kill the cell. We review a role of the novel monitoring method of complement pathway regarding C1q in occurrence of AMR and its diagnostic and therapeutic significance in managing AMR in HTx.

Immunosuppression and Viral Infections

Immunosuppression is commonly used for prevention of graft rejection in solid organ transplantation (SOT) and prevention of graft versus host disease in hematopoietic allogeneic stem cell transplant (ASCT). In ASCT, immunosuppression is used to control GVHD and can be tapered off within 6–12 months after transplantation. SOT recipients require lifelong immunosuppression to prevent graft rejection, making them susceptible to serious viral infections including EBV PTLD. EBV PTLD occurs within the first 6 months following ASCT prior to effective reconstitution of cytotoxic T lymphocytes (CTL). Our understanding on EBV-related PTLD is mostly extrapolated from SOT-associated PTLD. Features of conditioning and use of serotherapy remain important in development of EBV PTLD. Other viral infections that occur early post-transplant include CMV, HHV6, BK, and adenovirus, and usually correspond to degree of immunosuppression post-transplant. These infections are associated with significant morbidity and mortality. However, the current literature lacks information on outcomes of viral infections related to immunosuppression. Alternative donor ASCT are now more common, and patients are more susceptible to multiple viral infectious complications at the peak of immunosuppression and require monitoring for viral infections in these immunosuppressed patients.

Role of Hybrid Operating Room: Present and Future

With the dramatic progress of medical imaging modalities and growing needs for high-resolution intraoperative imaging in minimally invasive surgery, hybrid operative room (OR) has been developed as a powerful tool for different surgical scenarios. Under the guidance of high-definition cone beam CT (CBCT), an electromagnetic navigation bronchoscopy (ENB)-based marker implantation and subsequent localization of the pulmonary nodules can be implemented within a hybrid OR. Furthermore, the unparalleled real-time imaging capabilities and the ability to perform multiple tasks within the hybrid OR can facilitate image-guided single-port video-assisted thoracic surgery (iSPVATS), increasing the precision and improving outcomes of the procedure. With the help of a hybrid theatre, catheter-based thermal ablation can provide a safer and less invasive treatment option for select patient groups with early-stage non-small cell lung carcinomas (NSCLC) or metastases. In the future, the combination of hybrid operating room and other inspiring innovative techniques, such as robotic bronchoscopy, 3D-printing, natural orifice transluminal endoscopic surgery (NOTES) lung surgery could lead to a paradigm shift in the way thoracic surgery is conducted.

Biological Modulation of the Treg:Teff Ratio: From Immunosuppression to Immunoactivation

T cell-mediated immunomodulation can be, in simple terms, defined as altering the normal Treg:Teff ratio. Immunosuppression skews the net Treg:Teff ratio toward the ‘tolerogenic’ Treg component, while immunoactivation skews the response toward the ‘proinflammatory’ Teff component. In the treatment of autoimmune diseases, achieving an immunosuppressive state is a desirable goal in order to prevent ongoing injury by activated Teff cells. In contrast, an innate, or induced, immunosuppressive state can be deleterious and prevent pathogen-induced disease while allow for the progression of cancer. Indeed, a current goal of cancer therapy is attenuating an existing endogenous immunosuppressive state that prevents effective T cell-mediated immunorecognition of cancer cells. Thus, the biological modulation of the Treg:Teff ratio provides a unique approach for treating both autoimmune diseases and cancers. Using a biomanufacturing system, miRNA-enriched immunotherapeutic has been generated that either induce (TA1) or overcome (IA1) an immunosuppressive state. As will be shown, these therapeutics show efficacy both in vitro and in vivo in the prevention of autoimmune Type 1 diabetes and in enhancing the ability of resting immune cells to recognize and inhibit cancer cell growth. The successful development of these cost-effective, and easily biomanufactured, secretome-based therapeutics may prove useful in treating both autoimmune diseases and cancer.

The New Era of Immunotherapy in Bile Duct Cancer Management

Bile duct carcinoma or well known as cholangiocarcinoma (CCA) is the second most common of primary liver malignancy after hepatocellular carcinoma (HCC). Although cholangiocarcinoma is a rare cancer, it has an aggressive feature with very poor prognosis. The epidemiological profile of cholangiocarcinoma varies widely across the world, which is reflecting the exposure of different risk factors, such as chronic inflammatory disease of the biliary tract, specific infectious disease, and congenital malformation. Diagnosis of CCA is quite challenging. CCA is generally asymptomatic in the early stages. Therefore, the management of this malignancy is often delayed due to late diagnosed, where the metastasis has already present or even when it is causing bile duct obstruction. Treatment for CCA is often difficult and should be managed in the tertiary referral hospital with a multidisciplinary team approach. Surgical treatment with complete resection could be benefit only for patient with early stage of the disease. Other treatment modalities as adjuvant therapy are also have been developed to improve survival of the patient, such as chemotherapy, radiotherapy, molecular targeted therapy, targeting angiogenesis and EGFR, and immunotherapy. Recently, immunotherapy has also been developed as a new cancer treatment option and showed a promising result. Whether immunotherapy can be useful for treatment biliary malignancy is still controversial. Hence, a lot of studies is still required to confirm the preliminary findings.

Induced Immunosuppression in Critical Care

The maladaptive nature of the systemic inflammatory response syndrome, which may be caused by sepsis, trauma, or ischemia-reperfusion injury, is characterized by a shift towards the distant effects of pro- and anti-inflammatory mediators. Shock, blood loss, and metabolic disorders may cause the onset of multiple organ dysfunction syndrome. The final phase of critical illness is generally associated with induced immunosuppression and dysfunctions of neutrophils, monocytes and macrophages, dendritic cells, release of myeloid-derived suppressor cells, damage to glycocalyx and endothelium, and impaired metabolic conjugation. This review is aimed at providing novel evidences on the roles of various immune components, either innate or acquired, in the induction of immunosuppression from the standpoint of the rapid diagnosis of immune disorders in the intensive care unit using flow cytometry as a commonly accepted option.