Blood transfusions with high levels of contaminating soluble HLA-I correlate with levels of soluble CD8 in recipients' plasma; a new control factor in soluble HLA-I-mediated transfusion-modulated immunomodulation?

Implications of perioperative allogeneic red blood cell transfusion on the immune-inflammatory response

Background

The allogeneic transfusion-related immunomodulation (TRIM) may be responsible for an increase in survival of renal transplants but in contrast it could increase the rate of bacterial infections or the recurrence rate of tumors post-operatively.

Objective

This review focuses in the implications of perioperative allogeneic transfusions on the immune-inflammatory response of surgical transfused patients.

Results

ABTs modify immune functions in recipients including decrease of the number of lymphocytes; decrease the CD4 cells; decrease the CD4/CD8 T-cell ratio; decrease NK cells; and decrease the lymphocyte response to mitogens. TRIM effects may be mediated by allogeneic white cells present in blood products; soluble peptides present in transfused plasma; and/or biologic mediators released into the supernatant of blood units. A recent systematic review and meta-analysis including 36 clinical observational studies (n = 174,036) concluded that perioperative ABTs not only decreased overall survival and reduced colorectal cancer-specific survival. Furthermore ABTs increased the rate of infectious, cardiac, pulmonary and anastomotic complications in colorectal cancer patients undergoing surgery.

Conclusions

It has been demonstrated by laboratory tests that TRIM is associated with transfusion recipient immune alterations but its influence in colorectal cancer recurrence after resection remains controversial though may exist. Surgical techniques reducing intraoperative blood loss have limited the number of ABTs perioperatively, however increase in mortality continues to be reported in literature after ABT in colorectal cancer surgery. Poor survival associated to TRIM in colorectal cancer might be due to higher number of allogeneic transfused units and/or prolonged length of blood storage.

Effect of storage period of red blood cell suspensions on helper T-cell subpopulations

BACKGROUND

The aim of this study was to investigate the immunological alterations that occur during the storage of erythrocyte suspensions which may lead to transfusion-related immunomodulation following allogeneic blood transfusion.

MATERIALS AND METHODS

One part of the erythrocyte suspensions obtained from donors was leucoreduced while the other part was not. The leucoreduced (LR) and non-leucoreduced (NL) erythrocyte suspensions were then further divided into three equal amounts which were stored for 0, 21 or 42 days prior to measurements, by enzyme-linked immunosorbent assays, of cytokine levels in their supernatants. T-helper (Th) lymphocyte subgroups and gene expression were analysed in the NL erythrocyte suspensions by flow cytometry and real-time polymerase chain reaction, respectively. Results were compared to those of storage day 0.

RESULTS

By day 21, the number of Th2 cells had increased significantly and the numbers of Th1, Th22 and Treg cells had decreased significantly in the NL erythrocyte suspensions. On day 42 the numbers of Th2 and Treg cells in the NL suspensions were significantly increased while the number of Th1 cells was significantly decreased. The levels of transcription factors (TBX21, GATA3, and SPI.1) were significantly decreased on days 21 and 42, and AHR, FOXP3 and RORC2 levels were significantly increased on day 42 in NL erythrocyte suspensions. The decrease in interleukin-22 and increase in transforming growth factor-β levels found in NL erythrocyte suspensions on day 21 were statistically significant. Elevated levels of interleukin-17A were found in both LR and NL erythrocyte suspensions on day 42.

DISCUSSION

Our results suggest that allogeneic leucocytes and cytokines may play significant roles in the development of transfusion-related immunomodulation.

Mechanisms of red blood cell transfusion-related immunomodulation

Red blood cell (RBC) transfusion is common in critically ill, postsurgical, and posttrauma patients in whom both systemic inflammation and immune suppression are associated with adverse outcomes. RBC products contain a multitude of immunomodulatory mediators that interact with and alter immune cell function. These interactions can lead to both proinflammatory and immunosuppressive effects. Defining clinical outcomes related to immunomodulatory effects of RBCs in transfused patients remains a challenge, likely due to complex interactions between individual blood product characteristics and patient-specific risk factors. Unpacking these complexities requires an in-depth understanding of the mechanisms of immunomodulatory effects of RBC products. In this review, we outline and classify potential mediators of RBC transfusion-related immunomodulation and provide suggestions for future research directions.

Potential molecular characteristics in situ in response to repetitive UVB irradiation

Background

To identify molecular characteristics in situ in response to repetitive UVB (ultraviolet-B) irradiation.

Methods

Microarray data from the Gene Expression Omnibus were re-analyzed to identify DEGs (differentially expressed genes) between UVB-irradiated and non-irradiated skin biopsies. Enrichment and annotation analyses were performed respectively using DAVID, and TSGene and TAG databases. PPIs (protein-protein interactions) were analyzed using STRING, and miRNAs (microRNAs) and TFs (transcription factors) were predicted separately by miRNA-related databases and ENCODE. Accordingly, the PPI network and regulatory networks were visualized using Cytoscape, and they were merged together to obtain an integrated network for mining densely connected modules.

Results

Altogether, 151 up- and 64 down-regulated genes were identified between UVB-irradiated and non-irradiated skin biopsies, among which down-regulated DNAJB4 and SLIT2 were annotated as tumor-suppressors and up-regulated KIT was annotated as an oncogene. The up-regulated DEGs were significantly enriched in biological processes related to pigmentation (DCT, SOX10, TYRP1, TYR, MLPH, KIT and GPR143), while the down-regulated DEGs were dramatically related to haemopoiesis and the immune system (GPR183, INHBA, PTPRC, PLEK, CD8A and IKZF1). Furthermore, many miRNAs were screened for the DEGs, including miR-206 and miR-496 targeting KIT, miR-184 targeting DCT, and highly significant miR-337-5p, miR-21 and miR-16. Additionally, TFs were identified for the DEGs, among which PAX5 and HNF4A targeted MLPH and GPR143, respectively, while BATF, SPI1 and EP300 jointly target GPR183, PTPRC and PLEK.

Conclusions

The pigmentation and immune system implicated by DEGs, miRNAs and TFs might be important molecular mechanisms in response to UVB irradiation.