scholarly journals Sticking Up for the Immune System Integrity: Should the Thymus Be Preserved During Cardiac Surgery?

10.5772/27479 ◽  
2012 ◽  
Author(s):  
Sara Ferrando-Martnez ◽  
M. ngeles ◽  
Manuel Leal
Keyword(s):  
Cardiac Surgery ◽  
Immune System ◽  
System Integrity

scholarly journals The Effect of Remote Ischaemic Preconditioning on the Immune Response

2021 ◽  
Author(s):  
◽  
Jennifer Mae Williams-Spence
Keyword(s):  
Immune Response ◽  
Cardiac Surgery ◽  
Immune System ◽  
Inflammatory Response ◽  
Direct Effect ◽  
Peripheral Blood ◽  
Serum Levels ◽  
Ischaemic Preconditioning ◽  
Significant Difference ◽  
Remote Ischaemic Preconditioning

<p>Remote ischaemic preconditioning (RIPC) describes the phenomenon where brief intermittent periods of limb ischaemia are used to protect the heart and other organs from subsequent prolonged ischaemic insults. RIPC has been identified as a promising intervention for use during cardiac surgery and has consistently shown a beneficial effect in animal models; however, the results of early clinical trials have not been as successful. The exact mechanisms involved in mediating RIPC have not yet been characterised and a better understanding of the pathways through which RIPC exerts its protective effects will be essential in order to progress the translation of this intervention into the clinical setting. There is increasing evidence that RIPC modifies the inflammatory response, therefore the central aim of the research presented in this thesis was to investigate how RIPC affects the human immune system.  We performed a double-blind randomised controlled trial of RIPC in 96 high-risk cardiac surgery patients and found no evidence that the intervention reduced myocardial injury or altered peri-operative expression levels of the key inflammatory cytokines, interleukin (IL)-6, IL-8, and IL-10, during simple or more complex procedures. There was a trend towards higher levels of IL-6 and IL-8 in the preconditioned patients; however, confounding variables in the trial design and the heterogeneous patient population limited our ability to interpret the results.  We next conducted a paired-analysis trial with 10 healthy male volunteers to assess the direct effect of preconditioning on the early immune response, away from any form of ischaemic injury or comorbidities. We found that RIPC directly and significantly decreased serum levels of the chemokines MIP-1α and MIP-1β, but did not increase the serum concentrations of a range of key cytokines or alter the cytokine producing potential of peripheral blood leukocytes. These findings strongly suggest that a cytokine is not likely to be the humoral mediator associated with transmitting the RIPC protective signal.  RIPC did not alter the immunophenotype or extravasation of peripheral leukocyte populations, or the proliferative and cytokine responses of peripheral blood mononuclear cells (PBMC) to pharmacological, physiological, and antigen-specific stimuli. However, preconditioning did appear to reduce the ability of monocytes and neutrophils to respond to activation signals, as indicated by lower levels of CD11b expression in stimulated cultures, and a significant increase in the basal production of IL-22 was also detected in PBMC cultured for 6 days following preconditioning. These alterations may reduce neutrophil and monocyte tissue infiltration and limit the inflammatory response during the early window of RIPC-induced protection and enhance tissue and wound repair several days later. A multivariate analysis confirmed that there was a significant difference in the response between the control and RIPC treatments and the main contributing factors were identified as changes in neutrophil and T cell activation, serum levels of MIP-1α and β, and production of IL-10 and IL-22 from PBMC cultured for 6 days.  Overall, our results suggest that RIPC has a subtle but direct effect on the systemic innate immune response during the early window of protection in healthy volunteers, whereas the effects on the adaptive immune system seem to be considerably delayed. The changes detected following RIPC are likely to contribute to protection against ischaemia-reperfusion injury but not solely account for the extent of the beneficial effects of RIPC detected in animals. Our findings reinforce the safety profile of this intervention and have defined a number of immune parameters that are altered by preconditioning for focusing future research.</p>

scholarly journals Tranexamic acid modulates the immune response and reduces postsurgical infection rates

2019 ◽  
Vol 3 (10) ◽  
pp. 1598-1609 ◽  
Author(s):  
Dominik F. Draxler ◽  
Kah Yep ◽  
Gryselda Hanafi ◽  
Anoushka Winton ◽  
Maria Daglas ◽  
...  
Keyword(s):  
Cardiac Surgery ◽  
Immune System ◽  
Tranexamic Acid ◽  
Postoperative Infection ◽  
Immune Cell ◽  
Innate Immune ◽  
Innate Immune Cell ◽  
Independent Effect ◽  
Surgical Trauma ◽  
Infection Rates

Abstract Tranexamic acid (TXA) is an antifibrinolytic agent that blocks plasmin formation. Because plasmin is known to promote inflammatory and immunosuppressive responses, we explored the possibility that plasmin-mediated immunosuppression in patients undergoing cardiac surgery can be directly reversed by TXA and decrease postoperative infection rates. The modulatory effect of TXA on inflammatory cytokine levels and on innate immune cell activation were evaluated with multiplex enzyme-linked immunosorbent assay and flow cytometry, respectively. Postoperative infection rates were determined in patients undergoing cardiac surgery and randomized to TXA (ACTRN12605000557639; http://www.anzca.edu.au). We demonstrate that TXA-mediated plasmin blockade modulates the immune system and reduces surgery-induced immunosuppression in patients following cardiac surgery. TXA enhanced the expression of immune-activating markers while reducing the expression of immunosuppressive markers on multiple myeloid and lymphoid cell populations in peripheral blood. TXA administration significantly reduced postoperative infection rates, despite the fact that patients were being administered prophylactic antibiotics. This effect was independent of the effect of TXA at reducing blood loss. TXA was also shown to exert an immune-modulatory effect in healthy volunteers, further supporting the fibrin-independent effect of TXA on immune function and indicating that baseline plasmin levels contribute to the regulation of the immune system in the absence of any comorbidity or surgical trauma. Finally, the capacity of TXA to reduce infection rates, modulate the innate immune cell profile, and generate an antifibrinolytic effect overall was markedly reduced in patients with diabetes, demonstrating for the first time that the diabetic condition renders patients partially refractory to TXA.

scholarly journals The Effect of Remote Ischaemic Preconditioning on the Immune Response

2021 ◽  
Author(s):  
◽  
Jennifer Mae Williams-Spence
Keyword(s):  
Immune Response ◽  
Cardiac Surgery ◽  
Immune System ◽  
Inflammatory Response ◽  
Direct Effect ◽  
Peripheral Blood ◽  
Serum Levels ◽  
Ischaemic Preconditioning ◽  
Significant Difference ◽  
Remote Ischaemic Preconditioning

<p>Remote ischaemic preconditioning (RIPC) describes the phenomenon where brief intermittent periods of limb ischaemia are used to protect the heart and other organs from subsequent prolonged ischaemic insults. RIPC has been identified as a promising intervention for use during cardiac surgery and has consistently shown a beneficial effect in animal models; however, the results of early clinical trials have not been as successful. The exact mechanisms involved in mediating RIPC have not yet been characterised and a better understanding of the pathways through which RIPC exerts its protective effects will be essential in order to progress the translation of this intervention into the clinical setting. There is increasing evidence that RIPC modifies the inflammatory response, therefore the central aim of the research presented in this thesis was to investigate how RIPC affects the human immune system.  We performed a double-blind randomised controlled trial of RIPC in 96 high-risk cardiac surgery patients and found no evidence that the intervention reduced myocardial injury or altered peri-operative expression levels of the key inflammatory cytokines, interleukin (IL)-6, IL-8, and IL-10, during simple or more complex procedures. There was a trend towards higher levels of IL-6 and IL-8 in the preconditioned patients; however, confounding variables in the trial design and the heterogeneous patient population limited our ability to interpret the results.  We next conducted a paired-analysis trial with 10 healthy male volunteers to assess the direct effect of preconditioning on the early immune response, away from any form of ischaemic injury or comorbidities. We found that RIPC directly and significantly decreased serum levels of the chemokines MIP-1α and MIP-1β, but did not increase the serum concentrations of a range of key cytokines or alter the cytokine producing potential of peripheral blood leukocytes. These findings strongly suggest that a cytokine is not likely to be the humoral mediator associated with transmitting the RIPC protective signal.  RIPC did not alter the immunophenotype or extravasation of peripheral leukocyte populations, or the proliferative and cytokine responses of peripheral blood mononuclear cells (PBMC) to pharmacological, physiological, and antigen-specific stimuli. However, preconditioning did appear to reduce the ability of monocytes and neutrophils to respond to activation signals, as indicated by lower levels of CD11b expression in stimulated cultures, and a significant increase in the basal production of IL-22 was also detected in PBMC cultured for 6 days following preconditioning. These alterations may reduce neutrophil and monocyte tissue infiltration and limit the inflammatory response during the early window of RIPC-induced protection and enhance tissue and wound repair several days later. A multivariate analysis confirmed that there was a significant difference in the response between the control and RIPC treatments and the main contributing factors were identified as changes in neutrophil and T cell activation, serum levels of MIP-1α and β, and production of IL-10 and IL-22 from PBMC cultured for 6 days.  Overall, our results suggest that RIPC has a subtle but direct effect on the systemic innate immune response during the early window of protection in healthy volunteers, whereas the effects on the adaptive immune system seem to be considerably delayed. The changes detected following RIPC are likely to contribute to protection against ischaemia-reperfusion injury but not solely account for the extent of the beneficial effects of RIPC detected in animals. Our findings reinforce the safety profile of this intervention and have defined a number of immune parameters that are altered by preconditioning for focusing future research.</p>

scholarly journals Relationship between vitamin D deficiency and atopy in children

2018 ◽  
Vol 5 (5) ◽  
pp. 1705
Author(s):  
Kulthum Al Mahdi ◽  
Mariyah Albrahim ◽  
Fatimah Alkhars ◽  
Ola Alkhalifah ◽  
Rabab Alaithan ◽  
...  
Keyword(s):  
Vitamin D ◽  
Immune System ◽  
Vitamin D Deficiency ◽  
Immunoglobulin E ◽  
Serum Levels ◽  
Inhibitory Effect ◽  
Vitamin D Receptors ◽  
System Integrity ◽  
Randomized Controlled Studies ◽  
Vitamin D Levels

Along with its role in regulation of calcium metabolism and bone health, vitamin D is essential for immune system integrity. Vitamin D is an essential immunomodulatory vitamin that interact with the immune system in response to foreign antigens. This interaction is mediated by the vitamin D receptors (VDR) expressed on the surface of various immune cells. Vitamin D has an inhibitory effect on synthesis and release of immunoglobulin E and thus is closely related to atopic disorders. Vitamin D deficiency is a risk factor for bronchial asthma, and it increased asthma-related exacerbation. Low vitamin D levels are encountered in patients with allergic rhinitis and increase the severity of the disease. Other allergic conditions such as atopic dermatitis, contact dermatitis, and food allergy were reported to be significantly correlated with vitamin D serum levels. Despite the established correlation between vitamin D and atopic disorders, double-blinded randomized controlled studies are still lacking to approve this relationship and to provide clear guidelines for the recommended supplementary doses of vitamin D to prevent or treat these conditions. This article aims to review the relationship between vitamin D deficiency and atopy in children.

IMPACT OF LEUKOCYTE ACTIVATION ON THE INNATE IMMUNE SYSTEM FOLLOWING CARDIAC SURGERY

Shock ◽  
1997 ◽  
Vol 7 (Supplement) ◽  
pp. 107
Author(s):  
A. Markewitz ◽  
G. Rudolph ◽  
M. Rothenburger ◽  
W. D. Kuhlmann ◽  
C. Weinhold
Keyword(s):  
Cardiac Surgery ◽  
Immune System ◽  
Innate Immune System ◽  
Innate Immune ◽  
Leukocyte Activation

Blood-volume studies in cardiac-surgery patients

JAMA ◽  
1966 ◽  
Vol 195 (5) ◽  
pp. 356-361 ◽  
Author(s):  
J. B. McClenahan
Keyword(s):  
Cardiac Surgery ◽  
Blood Volume
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