- Letter to the Editor
- Open Access
HLA-DR expression in neonates after cardiac surgery under cardiopulmonary bypass: a pilot study
© The Author(s). 2018
- Received: 13 October 2017
- Accepted: 14 December 2017
- Published: 11 January 2018
Monocyte HLA-DR expression has been reported as a marker of immunosuppression and a predictor of sepsis development. However, to date, there is no report on monocyte HLA-DR monitoring exclusively in neonates (< 28 days of life) who underwent cardiac surgery under cardiopulmonary bypass (CPB), which have a high risk of nosocomial infection. In this pilot study, we studied nine neonates with a diagnosis of congenital heart disease requiring surgery under CPB. There was a significant reduction in monocyte HLA-DR expression for the first two postoperative days, as compared to preoperatively (p = 0.004). Moreover, neonates who displayed an episode of NI had a dramatically lower HLA-DR expression at day 4, as compared to neonates without NI (4257 AB/c [2220–5895] vs 14,947 AB/c [9858–16,960]; p = 0.04). Our preliminary results could indicate that HLA-DR expression may be a useful biomarker of immunosuppression-induced secondary infection after CPB in neonates.
The pro-inflammatory response that accompanies the onset of critical illness often occurs concurrently with a compensatory anti-inflammatory response. When severe and persistent, this anti-inflammatory response has been termed immunoparalysis. The diminished monocyte human leukocyte antigen-DR (HLA-DR) expression on cell surface is proposed to reflect immunoparalysis in critically ill patients [1, 2]. To date, HLA-DR expression has been assessed in adults as a predictor of septic complications after various injuries [3–6]. In pediatric cardiac surgery, HLA-DR expression has been examined in two studies [7, 8]. However, the results were principally limited by concern related to age of patient with a large heterogeneity  or non-inclusion of children younger than 3 months . To our knowledge, no study has specifically focused on HLA-DR expression on circulating monocytes among neonates who underwent cardiac surgery under cardiopulmonary bypass (CPB), which have a high risk of nosocomial infection (NI) . In this pilot study, we investigated the kinetic of monocyte HLA-DR expression in this population and described the relationship between monocyte HLA-DR expression and the subsequent development of NI.
Blood samples were collected from neonates preoperatively at line insertion, and 1, 2, 3, and 4 days after the end of CPB on immunology laboratory working days (Monday to Friday). The number of HLA-DR molecules per monocyte (AB/c) was determined immediately after sample collection (i.e., within 90 min) by flow cytometry on whole blood using a standardized method with a Quantibrite phycoerythrin fluorescence quantitation kit (Quantibrite anti HLA-DR/Anti Monocytes CD14, BD Biosciences, Le Pont de Claix, France), as previously described [10, 11]. Blood samples for cytokine assays were immediately centrifuged, and the plasma was stored at − 80 °C. Cytokine concentrations in the plasma (IL-6, IL-8, and IL-10) were measured by multiplex immunoassay according to the manufacturer’s protocol (Merck Millipore, Molsheim, France). Immunological analysis was conducted blind, and clinical data were not available to the immunology staff before the end of the study.
NI including catheter-related bloodstream infections, ventilator-associated pneumonia, and sternal wound infections were defined based on the Center of Disease Control (CDC) and National Nosocomial Infections Surveillance criteria  and were prospectively recorded during the PICU stay or within 30 days after surgery. All parents were informed of the project and written consent was waived. The study was approved by the local ethics committee of the University Hospital of Nantes.
Statistical analyses were performed using GraphPad Prism software (GraphPad, La Jolla, CA). The Kruskal–Wallis test was used for comparisons of multiple groups (preoperatively, 1, 2, 3, and 4 days after CPB). Dunn’s multiple comparisons test was used as a post hoc test for intergroup comparisons. Continuous nonparametric variables were expressed as medians (extremes values). The Mann–Whitney test was used to compare two independent groups on day 4 (infected versus non-infected patients). Significance was defined as p-value less than 0.05.
Characteristics of patients (n = 9)
Male, n (%)
Gestational age < 36 weeks, n (%)
Genetic abnormality, n (%)
Cyanotic congenital heart defects, n (%)
Lymphocyte cell count preoperatively (/mm3)
Characteristics of surgery
RACHS-1 score a
Time on cardiopulmonary bypass (min)
Aortic cross-clamp time (min)
Hypothermia (20–28 °C), n (%)
Characteristics during the PICU stay after surgery
Use of corticoids during the first 48 h, n (%)
Extracorporeal membrane oxygenation support, n (%)
Delayed closure of sternum, n (%)
Peak Vasoactive-Inotropic score during the first 48 h b
Positive fluid balance at day 2, n (%)
Acute kidney injury at day 2 c, n (%)
Lymphocyte cell count at day 2 (/mm3)
Time on mechanical ventilation (days)
Nosocomial infection, n (%)
PICU length of stay (days)
Death, n (%)
In this pilot study, we report that neonates had a dramatic reduction in HLA-DR expression on circulating monocytes during the first two postoperative days after CPB, and those with prolonged decreased HLA-DR in the early postoperative period (day 4) could represent a subpopulation at greatly increased risk of later NI. Moreover, immunoparalysis described here after neonatal CPB accompanies a pro-inflammatory response, illustrated by high circulating levels of IL-6 and IL-8. This increase in pro-inflammatory cytokines IL-6 and IL-8 24 h after CPB is consistent with previous studies in pediatric cardiac surgery .
The main limitation of this preliminary study concerns the fact that HLA-DR values were not censored after NI diagnosis given the small number of patients included. These promising findings warrant thus a larger confirmatory trial (NCT03309839) before HLA-DR expression can be introduced in the clinical practice as a useful biomarker of immunosuppression-induced after CPB in neonates.
AC designed the study, performed the statistical analysis, and drafted the manuscript. CB and NS performed the immunological analysis. AC, NC, PB, and NJ collected the clinical data. NC, PB, NJ, RJ, AR, and KA revised it for important intellectual content. All authors approved the final version of the manuscript.
Ethics approval and consent to participate
All parents were informed of the project which was approved by the local ethics committee of the University Hospital of Nantes.
Consent for publication
Written parental consent to publish has been obtained from all children included in the study.
The authors declare that they have no competing interests.
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- Bronicki RA, Hall M (2016) Cardiopulmonary bypass-induced inflammatory response: pathophysiology and treatment. Pediatr Crit Care Med 17(8 Suppl 1):S272–S278View ArticlePubMedGoogle Scholar
- Hall MW, Greathouse KC, Thakkar RK, Sribnick EA, Muszynski JA (2017) Immunoparalysis in pediatric critical care. Pediatr Clin N Am 64(5):1089–1102View ArticleGoogle Scholar
- Lukaszewicz AC, Grienay M, Resche-Rigon M, Pirracchio R, Faivre V, Boval B, Payen D (2009) Monocytic HLA-DR expression in intensive care patients: interest for prognosis and secondary infection prediction. Crit Care Med 37(10):2746–2752PubMedGoogle Scholar
- Monneret G, Lepape A, Voirin N, Bohe J, Venet F, Debard AL, Thizy H, Bienvenu J, Gueyffier F, Vanhems P (2006) Persisting low monocyte human leukocyte antigen-DR expression predicts mortality in septic shock. Intensive Care Med 32(8):1175–1183View ArticlePubMedGoogle Scholar
- Landelle C, Lepape A, Voirin N, Tognet E, Venet F, Bohe J, Vanhems P, Monneret G (2010) Low monocyte human leukocyte antigen-DR is independently associated with nosocomial infections after septic shock. Intensive Care Med 36(11):1859–1866View ArticlePubMedGoogle Scholar
- Strohmeyer JC, Blume C, Meisel C, Doecke WD, Hummel M, Hoeflich C, Thiele K, Unbehaun A, Hetzer R, Volk HD (2003) Standardized immune monitoring for the prediction of infections after cardiopulmonary bypass surgery in risk patients. Cytometry B Clin Cytom 53(1):54–62View ArticlePubMedGoogle Scholar
- Gessler P, Pretre R, Burki C, Rousson V, Frey B, Nadal D (2005) Monocyte function-associated antigen expression during and after pediatric cardiac surgery. J Thorac Cardiovasc Surg 130(1):54–60View ArticlePubMedGoogle Scholar
- Allen ML, Peters MJ, Goldman A, Elliott M, James I, Callard R, Klein NJ (2002) Early postoperative monocyte deactivation predicts systemic inflammation and prolonged stay in pediatric cardiac intensive care. Crit Care Med 30(5):1140–1145View ArticlePubMedGoogle Scholar
- Grisaru-Soen G, Paret G, Yahav D, Boyko V, Lerner-Geva L (2009) Nosocomial infections in pediatric cardiovascular surgery patients: a 4-year survey. Pediatr Crit Care Med 10(2):202–206View ArticlePubMedGoogle Scholar
- Docke WD, Hoflich C, Davis KA, Rottgers K, Meisel C, Kiefer P, Weber SU, Hedwig-Geissing M, Kreuzfelder E, Tschentscher P et al (2005) Monitoring temporary immunodepression by flow cytometric measurement of monocytic HLA-DR expression: a multicenter standardized study. Clin Chem 51(12):2341–2347View ArticlePubMedGoogle Scholar
- Demaret J, Walencik A, Jacob MC, Timsit JF, Venet F, Lepape A, Monneret G (2012) Inter-laboratory assessment of flow cytometric monocyte HLA-DR expression in clinical samples. Cytometry B Clin Cytom 84(1):59–62PubMedGoogle Scholar
- Horan TC, Andrus M, Dudeck MA (2008) CDC/NHSN surveillance definition of health care-associated infection and criteria for specific types of infections in the acute care setting. Am J Infect Control 36(5):309–332View ArticlePubMedGoogle Scholar
- Schefold JC, Porz L, Uebe B, Poehlmann H, von Haehling S, Jung A, Unterwalder N, Meisel C: Diminished HLA-DR expression on monocyte and dendritic cell subsets indicating impairment of cellular immunity in pre-term neonates: a prospective observational analysis. J Perinat Med 2014, 43(5):609-618Google Scholar
- Liu KD, Altmann C, Smits G, Krawczeski CD, Edelstein CL, Devarajan P, Faubel S (2009) Serum interleukin-6 and interleukin-8 are early biomarkers of acute kidney injury and predict prolonged mechanical ventilation in children undergoing cardiac surgery: a case-control study. Crit Care 13(4):R104View ArticlePubMedPubMed CentralGoogle Scholar
- Jenkins KJ, Gauvreau K, Newburger JW, Spray TL, Moller JH, Iezzoni LI (2002) Consensus-based method for risk adjustment for surgery for congenital heart disease. J Thorac Cardiovasc Surg 123(1):110–118View ArticlePubMedGoogle Scholar
- Gaies MG, Gurney JG, Yen AH, Napoli ML, Gajarski RJ, Ohye RG, Charpie JR, Hirsch JC (2010) Vasoactive-inotropic score as a predictor of morbidity and mortality in infants after cardiopulmonary bypass. Pediatr Crit Care Med 11(2):234–238View ArticlePubMedGoogle Scholar
- Akcan-Arikan A, Zappitelli M, Loftis LL, Washburn KK, Jefferson LS, Goldstein SL (2007) Modified RIFLE criteria in critically ill children with acute kidney injury. Kidney Int 71(10):1028–1035View ArticlePubMedGoogle Scholar