Intermediate monocytes exhibit higher levels of TLR2, TLR4 and CD64 early after congenital heart surgery.

INTRODUCTION: Congenital heart surgery with cardiopulmonary bypass (CPB) initiates an immune response which frequently leads to organ dysfunction and a systemic inflammatory response. Complications associated with exacerbated immune responses may severely impact the postoperative recovery. The objective was to describe the characteristics of monocyte subpopulations and neutrophils at the level of pattern recognition receptors (PRR) and the cytokine response after CPB in infants. METHODS: An observational cohort study was conducted between June 2016 and June 2017 of infants < 2 years of age, electively admitted for surgical correction of acyanotic congenital heart defects using CPB. Fourteen blood samples were collected sequentially and processed immediately during and up to 48 h following cardiac surgery for each patient. Flow cytometry analysis comprised monocytic and granulocytic surface expression of CD14, CD16, CD64, TLR2, TLR4 and Dectin-1 (CLEC7A). Monocyte subpopulations were further defined as classical (CD14++/CD16-), intermediate (CD14++/CD16+) and nonclassical (CD14+/CD16++) monocytes. Plasma concentrations of 14 cytokines, including G-CSF, GM-CSF, IL-1ß, IL-1RA, IL-4, IL-6, IL-8, IL-10, IL-12p40, IL-12p70, TNF-α, IFN-γ, MIP-1ß (CCL4) and TGF-ß1, were measured using multiplex immunoassay for seven points in time. RESULTS: Samples from 21 infants (median age 7.4 months) were analyzed by flow cytometry and from 11 infants, cytokine concentrations were measured. Classical and intermediate monocytes showed first receptor upregulation with an increase in CD64 expression four hours post CPB. CD64-expression on intermediate monocytes almost tripled 48 h post CPB (p < 0.0001). TLR4 was only increased on intermediate monocytes, occurring 12 h post CPB (p = 0.0406) along with elevated TLR2 levels (p = 0.0002). TLR4 expression on intermediate monocytes correlated with vasoactive-inotropic score (rs = 0.642, p = 0.0017), duration of ventilation (rs = 0.485, p = 0.0259), highest serum creatinine (rs = 0.547, p = 0.0102), postsurgical transfusion (total volume per kg bodyweight) (rs = 0.469, p = 0.0321) and lowest mean arterial pressure (rs = -0.530, p = 0.0135). Concentrations of IL-10, MIP-1ß, IL-8, G-CSF and IL-6 increased one hour post CPB. Methylprednisolone administration in six patients had no significant influence on the studied surface receptors but led to lower IL-8 and higher IL-10 plasma concentrations. CONCLUSIONS: Congenital heart surgery with CPB induces a systemic inflammatory process including cytokine response and changes in PRR expression. Intermediate monocytes feature specific inflammatory characteristics in the 48 h after pediatric CPB and TLR4 correlates with poorer clinical course, which might provide a potential diagnostic or even therapeutic target.

Analysis of malignancies in patients after heart transplantation with subsequent immunosuppressive therapy.

OBJECTIVE: The aim of this study was to analyze the distribution of malignancies in patients after heart transplantation (HTX) and to evaluate the risk factors including immunosuppressive therapy with regard to the development of malignancies and survival. Special emphasis was placed on the effects of a mammalian target of rapamycin (mTOR) containing immunosuppressive regimen. METHODS: A total of 381 patients (age ≥18 years) receiving HTX were included in the present analysis. All patients were followed-up at the University of Heidelberg Heart Center, Heidelberg, Germany. Data were retrieved from the Heidelberg Registry for Heart Transplantation being collected between 1989 and 2014. According to center standard, all patients received induction therapy with anti-thymocyte globulin guided by T-cell monitoring since 1994. The initial immunosuppressive regimen consisting of cyclosporine A (CsA) and azathioprine (AZA) was replaced by CsA and mycophenolate mofetil (MMF) in 2001 and by tacrolimus (TAC) and MMF in 2006. Additionally, mTOR inhibitors (everolimus/sirolimus) were applied since 2003. RESULTS: Mean recipient age at HTX was 51.2±10.5 years and the mean follow-up period after HTX was 9.7±5.9 years. During follow-up, 130 patients developed a neoplasm (34.1% of total). Subgroup analysis revealed 58 patients with cutaneous malignancy only (15.2%), 56 patients with noncutaneous malignancy only (14.7%), and 16 patients with both cutaneous and noncutaneous malignancy (4.2%). Statistically significant risk factors associated with an increased risk of malignancy after HTX were older age (P<0.0001), male recipients (P=0.0008), dyslipidemia (P=0.0263), diabetes mellitus (P=0.0003), renal insufficiency (P=0.0247), and >1 treated rejection episode (TRE) in the first year after HTX (P=0.0091). Administration of CsA (P=0.0195), AZA (P=0.0008), or steroids (P=0.0018) for >1 year after HTX was associated with increased development of malignancy, whereas administration of MMF (P<0.0001) or mTOR inhibitors (P<0.0001) was associated with a lower risk for development of malignancy. Additionally, 5-year follow-up of cutaneous malignancy recurrence (P=0.0065) and noncutaneous malignancy mortality (P=0.0011) was significantly lower in patients receiving an mTOR inhibitor containing therapy after the development of a malignancy. CONCLUSION: This study highlights the complexity of risk factors including immunosuppression with regard to the development of malignancies after HTX. mTOR-inhibitor-based immunosuppression is associated with a better outcome after HTX, particularly in cases with noncutaneous malignancy.

Perioperative management of a child with glutaric aciduria type I undergoing cardiac surgery.

Patients with glutaric aciduria type I are at risk for acute striatal injury precipitated by catabolic stress. Here, we report the successful interdisciplinary anesthetic and perioperative management of a child with glutaric aciduria type I undergoing cardiac surgery with extracorporeal circulation. Given the central focus on prevention of acute striatal injury, our anesthetic strategy emphasized avoiding a high protein load, high-dose inotropics, especially epinephrine (associated with impaired glucose utilization), deliberate hyperventilation, and other interventions associated with systemic inflammatory response.