Effects of extracorporeal photoimmunotherapy on soluble IL-2Ralpha, TNF-RI, and CD8 in patients with steroid-resistant acute graft-versus-host disease

Prediction of graft-versus-host disease: a biomarker panel based on lymphocytes and cytokines

Graft-versus-host disease (GvHD) still belongs to the major challenges after allogeneic hematopoietic stem cell transplantation (HSCT). Immune-suppressive therapy against GvHD is a double-edged sword due to risk of infections and relapse. The ability to adapt prophylactic treatment according to the probability of severe GvHD would be an essential advantage for the patients. We analyzed different biomarkers for their potential to predict the development of GvHD in 28 patients who underwent allogeneic HSCT. Blood was taken once directly after hematopoietic engraftment. In this study, patients were monitored for 12 months after HSCT for the occurrence of acute GvHD or acute/chronic GvHD overlap syndrome. Soluble IL-2 receptor and CD4/CD8 T cell ratio were independently associated with the occurrence of GvHD in the observation period. However, the largest area under the receiver operating characteristic curve with 0.90 was observed when a 5-parameter biomarker score based on CD4⁺ T cells, CD8⁺ T cells, CD19^- CD21⁺ precursor B cells, CD4/CD8 T cell ratio, and soluble IL-2 receptor was used to predict GvHD. In addition, CD8⁺ T cell levels above 2.3% of all mononuclear cells after engraftment may predict relapse-free survival at least for 12 months. In summary, we found a new biomarker panel for prediction of GvHD which is featured by established laboratory assays and high statistical significance. In order to introduce the biomarker panel into routine clinical protocols, we suggest performing a larger multi-center study.

Life-threatening graft-vs-host disease

Hematopoietic stem cell transplant (SCT) is considered standard therapy for a variety of malignant and nonmalignant diseases. Graft-versus-host disease (GVHD) still represents today a major complication of hematopoietic SCT. Two types of GVHD have traditionally been recognized on the basis of the time of onset following transplantation, distinct pathobiological pathways, and different clinical presentations. The acute form commonly breaks out 2 to 6 weeks after transplantation, affecting up to 60% of patients receiving allogeneic transplants from HLA identical donors. Transfer of immunocompetent donor T cells contained in the graft may undergo alloreactivity against recipient cells because of major or minor histocompatibility antigens disparities between the donor and the immunosuppressed host. Target specificity in acute GVHD involves preferential injury to epithelial surfaces of the skin and mucous membranes, biliary ducts of the liver, and crypts of the intestinal tract. Chronic GVHD affects approximately 30% to 80% of patients surviving 6 months or longer after stem cell transplantation and is the leading cause of nonrelapse deaths occurring more than 2 years after transplantation. Chronic GVHD is a multiorgan syndrome with clinical features suggesting some autoimmune diseases, and possibly both alloreactive and autoreactive T cell clones are involved in its pathophysiology. Although GVHD may convey beneficial graft-versus-leukemia/lymphoma effects, it also entails a significant risk of morbidity and mortality. Patients with mild GVHD need only minimal, if any, immunosuppressive treatment, whereas prognosis of patients with extensive disease or resistant to standard immunosuppressive treatment may be dismal. Early recognition of GVHD followed by prompt therapeutic intervention may prevent the progression to higher-grade disease and improve the outcome for patients receiving hematopoietic SCT.

Establishment of an ELISA system for determining soluble LAIR-1 levels in sera of patients with HFRS and kidney transplant

LAIR-1, the leukocyte-associated Ig-like receptor-1, is a trans-membrane molecule that functions as an inhibitory receptor on natural killer cells, T lymphocytes and monocytes. It has been well known that many trans-membrane receptors can shed from the cell surface and be released into the circulation in soluble form when lymphocytes, endothelials and other immune cells are activated. In many cases, the levels of soluble receptors in the circulation can be used as markers of lymphocyte activation in transplant patients and virus infection patients. To investigate whether LAIR-1 is able to be released into the sera, we developed a sandwich enzyme-linked immunosorbent assay (ELISA) system based on two anti-LAIR-1 monoclonal antibodies (MAb) with different epitope specificities. Using this ELISA, we found that sLAIR-1 existed in the supernatants collected from PMA, PHA or CD3 MAb-stimulated lymphocytes cultures in vitro for the first time. Moreover, we found that LAIR-1 level in serum samples from healthy individuals was 6.2 +/- 3.3 ng/ml, whereas the levels in sera of patients with hemorrhagic fever with renal syndrome (HFRS) and patients 3-7 days after kidney transplant increased to 47.2 +/- 35.9 and 24.4 +/- 16.0 ng/ml, respectively. Furthermore, HFRS patients in oliguric phase showed higher serum sLAIR-1 levels than those in other phases, and transplant patients with rejection showed higher serum sLAIR-1 level than those without rejection. These findings demonstrated that LAIR-1 can be released when lymphocytes are activated, suggesting sLAIR-1 may be used as a predictor for monitoring immune reaction in some virus infections and organ transplants which may be useful in clinical treatment of these diseases.

Mechanism of action of extracorporeal photochemotherapy in chronic graft-versus-host disease

Chronic graft-versus-host disease (GvHD) affects 50% of long-term bone marrow transplant survivors and remains a cause of major long-term morbidity in these patients despite aggressive therapy. Extracorporeal photochemotherapy (ECP), considered as an effective treatment for patients with erythrodermic cutaneous T-cell lymphoma (CTCL), has recently been used successfully in the treatment of GvHD. One of the most intriguing aspects of ECP is its ability to induce two apparently opposite effects: activation of the immune system against neoplastic cells (as in CTCL) and downregulation of the activity of T-cell clones in autoimmune diseases (as in systemic sclerosis, systemic lupus erythematosus and pemphigus vulgaris) and autoallogeneic immune responses (as in GvHD and allograft rejection). Only a better and more complete understanding of the various mechanisms involved will enable this interesting new therapy to be made more effective and selective.