Archives of Academic Emergency Medicine. 2019; 7 (1): e14 BR I E F RE P O RT Association of Lymphopenia with Short Term Outcomes of Sepsis Patients; a Brief Report Hojat Sheikh Motahar Vahedi1,2, Aida Bagheri2, Amirhosein Jahanshir1,2, Javad Seyedhosseini1,2, Elnaz Vahidi1,2∗ 1. Prehospital Research Center, Tehran University of Medical Sciences, Tehran, Iran. 2. Department of Emergency Medicine, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran. Received: October 2018; Accepted: December 2018; Published online: 20 January 2019 Abstract: Introduction: Studies have claimed that low lymphocyte count is independently correlated with 28-day survival of sepsis patients. Therefore, this study aimed to evaluate the value of lymphopenia in predicting the short-term outcome of sepsis patients. Methods: This cross-sectional study was performed on sepsis patients referred to the emergency department during an 8-month period and relationship of lymphopenia with 28-day mortal- ity and probability of septic shock and readmission due to sepsis was assessed. Results: 124 cases with the mean age of 66.12 ± 15.82 (21-90) years were studied (54.8% male). 81 (65.3%) cases had lymphopenia (59.3% male). Lymphopenic patients had a significantly higher mean age (p = 0.003), higher need for ICU admission (p < 0.001), higher prevalence of 28-day septic shock (p < 0.001), higher 28-day mortality (p < 0.001), higher probability of readmission due to sepsis (p = 0.048), and higher SOFA score (p < 0.001). During 28 days of fol- low up, 57 (46%) patients were expired. They had a higher prevalence of septic shock (p < 0.001) and higher SOFA score (p < 0.001). Multivariate analysis showed that septic shock (OR=364.6; 95% CI: 26.3 to 5051.7; p = 0.001) and lymphopenia (OR=19.2; 95% CI: 1.7 to 211.3; p = 0.016) were the independent predictors of 28-day mortality. Conclusion: Based on the findings, lymphopenia was independently associated with higher 28-day mortality and lymphopenic patients were older than the control group and had a significantly higher need for ICU admission, higher probability of 28-day septic shock and readmission due to sepsis, and higher SOFA score. Keywords: Lymphopenia; sepsis; prognosis; emergency service, hospital Cite this article as: Sheikh Motahar Vahedi H, Bagheri A, Jahanshir A, Seyedhosseini J, Vahidi E. Pan vs. Association of Lymphopenia with Short Term Outcomes of Sepsis Patients; a Brief Report. Arch acad Emerg Med. 2019; 7(1): e14. 1. Introduction Sepsis is one of the most common causes of emergency de- partment (ED) referral among all different ages, especially el- derlies. It is reported that 571000 severe sepsis cases are an- nually referred to EDs in the US. Its mortality risk is between 20% and 50% and it is among the 10th most common reasons of mortality and morbidity in US (1-3). Currently, it is believed that sepsis triggers a complicated im- munologic response that impairs the balance between pro and anti-inflammatory processes. This results in an immune suppression phase leading to progressive primary and sec- ondary infections, and high morbidity and mortality rates (7). ∗Corresponding Author: Elnaz Vahidi; Department of Emergency Medicine, Shariati Hospital, Tehran, Iran. Tel: +982184902719; Email: evahidi62@yahoo.com One of the immune suppression characteristics in sepsis is apoptosis of immune cells including T-helper and cytotoxic lymphocytes, B lymphocytes and dendritic cells (8). Many studies have shown that lymphocyte count decreases in the early phase of sepsis and follows the same pattern during the first 28 days (8-13). It was reported that neutrophilia and lymphopenia were both related to bacteremia, but the latter had a higher predictive value. It is also found that both neutrophilia and lymphope- nia had more prognostic value than total white blood cell (WBC) count (14). It was also claimed that low lymphocyte count independently correlates with 28-day patient survival rate in sepsis and some special types of organ failure (15). Based on the above-mentioned points, this study aimed to evaluate the value of lymphopenia in predicting the short- term outcome of sepsis patients. This open-access article distributed under the terms of the Creative Commons Attribution NonCommercial 3.0 License (CC BY-NC 3.0). Downloaded from: http://journals.sbmu.ac.ir/aaem H. Sheikh Motahar Vahedi et al. 2 Table 1: Comparing the characteristics of lymphopenic sepsis patients with non-lymphopenic ones Variables Lymphocyte count P value < 1500 (n = 81) ≥ 1500 (n = 43) Sex (%) Male 48 (59.3) 20 (46.5) 0.182 Female 33 (40.7) 22 (51.2) Age (year) 18 - 45 4 (4.9) 8 (18.6) 45 - 60 16 (19.8) 9 (20.9) 0.042 ≥ 60 61 (75.3) 26 (60.5) Duration of admission (day) Mean ± SD 10.90 ± 6.67 9.79 ± 5.81 0.359 Need for ICU admission Yes 42 (51.9) 6 (14.0) <0.001 No 39 (48.1) 37 (86.0) Source of infection Pneumonia 50 (61.7) 23 (53.5) Urinary tract 19 (23.5) 12 (27.9) Soft tissue 4 (4.9) 3 (17.0) 0.914 Central nervous system 1 (1.2) 1 (2.3) Others 7 (8.6) 4 (9.3) SOFA score Mean ± SD 5.74 ± 2.58 3.90 ± 2.22 < 0.001 28-day outcome Mortality 59 (88.1) 8 (11.9) < 0.001 Septic shock 57 (85.1) 10 (14.9) < 0.001 Readmission 20 (52.6) 18 (47.4) 0.048 Data are presented as mean ± standard deviation (SD) or number (%). 2. Methods 2.1. Study design and setting This cross-sectional study was performed on sepsis pa- tients referred to emergency department of Shariati Hos- pital, Tehran, Iran, during the first 8 months of 2017. The study method was approved by the ethics commit- tee of Tehran University of Medical Sciences and the code of IR.TUMS.MEDICINE.REC.1395.1627 has been assigned. Signed informed written consent has been obtained from all patients or their family to participate in our study. 2.2. Participants Sampling was performed prospectively in a continuous man- ner and all patients over 18 years old suspected of having sep- sis who were admitted to the ED were eligible. Concomitant underlying diseases affecting white blood cell (WBC) count like blood dysplasia, history of immune deficiency or being under chemotherapy, death before the 4t h day, and unwill- ingness to participate in our research were considered as ex- clusion criteria. 2.3. Data gathering A predesigned checklist including the demographic informa- tion of patients as well as source of infection, sequential or- gan failure assessment (SOFA) score, length of hospital stay, need for intensive care unit (ICU) admission, lymphocyte count, and 28-day outcome was filled for all patients by a se- nior emergency medicine resident. Peripheral blood samples were taken on the admission day and 4 days later, and complete blood count (CBC) and cell differentiation were performed. Lymphopenia was defined as lymphocyte count <1500 cells/µL and lymphocyte count ≥1500 cells/µL was considered normal. This count should have remained in the same group during the first 4 days of admission, and the cases whose count changed over 4 days were excluded. 28-day mortality, 28-day readmission due to sepsis, and 28-day prevalence of septic shock were consid- ered as outcomes. 2.4. Statistical analysis SPSS v.22 was used for statistical analyses. Descriptive statis- tics, including mean ± standard deviation or frequency (per- centage) were used for reporting the findings. Compar- ison of baseline characteristics between 28-day survivors and expired patients was done using unpaired t-test, Mann- Whitney U test, or chi-square test, as appropriate. To deter- mine the independent effect of absolute lymphocyte count on 28-day mortality, logistic regression analysis was used. P < 0.05 was considered as level of significance. This open-access article distributed under the terms of the Creative Commons Attribution NonCommercial 3.0 License (CC BY-NC 3.0). Downloaded from: http://journals.sbmu.ac.ir/aaem 3 Archives of Academic Emergency Medicine. 2019; 7 (1): e14 Table 2: Comparing the characteristics of expired and survived groups Variables Died (n=67) Survived (n=57) P-value Sex Male 37 (55.4) 31 (54.4) 0.553 Female 30 (44.8) 26 (45.6) Age (year) Mean ± SD 73.10 ± 12.41 57.91 ± 15.54 0.001 Source of infection (%) Pneumonia 44 (65.7) 29 (50.9) Urinary tract 14 (20.9) 17 (29.9) Soft tissue 3 (4.5) 4 (7.1) 0.652 Central nervous system 1 (1.5) 1 (1.5) Others 5 (7.4) 6 (10.6) Septic shock Number (%) 64 (95.5) 3 (5.3) 0.001 Lymphocyte count Mean ± SD 991.7 ± 684.7 1923.8 ± 1167.9 Median (IQR) 847.0 (784.0) 1600.0 (1011.0) 0.001 Lymphopenia<1500 (%) 59 (88.1) 22 (38.6) SOFA score Mean ± SD 6.9 ± 2.0 2.9 ± 0.9 0.001 Median (IQR) 6.0 (4.0) 3.0 (1.0) IQR: Interquartile range; SD: standard deviation; SOFA: sepsis related organ failure assessment. Data are presented as mean ± Data are presented as mean ± standard deviation (SD) or number (%). 3. Results: 143 patients suspected of having sepsis were studied, 124 of whom met the inclusion criteria. The mean age of the par- ticipants was 66.12 ± 15.82 (21-90) years (54.8% male). 81 (65.3%) cases had lymphopenia (59.3% male). Table 1 com- pares the characteristics of lymphopenic patients with oth- ers. Lymphopenic patients had a significantly higher mean age (p = 0.003), higher need for ICU admission (p < 0.001), higher prevalence of 28-day septic shock (p < 0.001), higher 28-day mortality (p < 0.001), higher probability of readmis- sion due to sepsis (p = 0.048), and higher SOFA score (p < 0.001). During 28 days of follow up, 57 (46%) patients were expired. Table 2 compares the characteristics of dead and survived patients. The mean age of the expired patients was significantly higher (p=0.001). They had a significantly higher rate of lymphopenia (p < 0.001), higher prevalence of septic shock (p < 0.001), and higher SOFA score (p < 0.001). Multi- variate analysis showed that septic shock (OR=364.6; 95% CI: 26.3 to 5051.7; p = 0.001) and lymphopenia (OR=19.2; 95% CI: 1.7 to 211.3; p = 0.016) were independent significant predic- tors of 28-day mortality. 4. Discussion Based on the findings, lymphopenia was independently as- sociated with higher 28-day mortality and lymphopenic pa- tients were older than the control group and had a signif- icantly higher need for ICU admission, higher probability of 28-day septic shock and readmission due to sepsis, and higher SOFA score. Some previous studies like those of Chea- dle et al., Felmet et al., Monserrat et al., Hein et al., and In- oue et al. confirmed that B and T cell lymphocyte counts had significantly reduced during the first week of diagnosis in patients who died of sepsis (8-12). In 2014, Drewry et al. studied 335 adult patients with bacteremia and sepsis and re- ported the death of 77 cases within 28 days after admission. They showed that the median lymphocyte count on the 4th day of admission was a good independent predictor in mor- tality prediction (4). In 2015, Chung et al. announced that severe lymphopenia was associated with elevated plasma in- terleukin (IL)-15 levels and increased mortality during severe sepsis (1). They considered severe lymphopenia as lympho- cyte count less than 0.5 ×103 cells/µl and found that it was associated with increased 28-day mortality in severe sepsis. Like in our study, pneumonia and urinary tract infections were the most common sources of sepsis in the population they studied. They reported that septic shock had a higher in- cidence rate in the expired group. Expired group had a higher SOFA score compared to survivors. In 2017, Li et al. performed a study on 63 patients with severe sepsis and they used the ratio of Il-10 to lymphocyte count as a predictor of 28-day mortality and severity. This ratio showed moderate sensitivity and specificity (around 70%) in their study (16). Expired group had significantly lower lym- phocyte count than the survivors. Wyllie in 2004 and Chien et al. in 2012 suggested that both lymphocyte and neutrophil counts should be considered in adults with suspected bac- teremia (13, 14). They showed a quantitative association be- This open-access article distributed under the terms of the Creative Commons Attribution NonCommercial 3.0 License (CC BY-NC 3.0). Downloaded from: http://journals.sbmu.ac.ir/aaem H. Sheikh Motahar Vahedi et al. 4 tween lymphopenia and the risk of bacteremia. Based on the results of the present and the mentioned study, it seems that lymphopenia could be considered as a predictor of 28-day mortality and bad outcome of sepsis patients presenting to emergency department. 5. Conclusion Based on the findings, lymphopenia was independently as- sociated with higher 28-day mortality and lymphopenic pa- tients were older than the control group and had a signif- icantly higher need for ICU admission, higher probability of 28-day septic shock and readmission due to sepsis, and higher SOFA score. 6. Appendix 6.1. Acknowledgements The authors would like to express their special thanks to the Prehospital Research Center for their support in conducting this study. 6.2. Author contribution All the authors of this study met the standard criteria of authorship based on the recommendations of International Committee of Medical Journal Editors. Authors’ ORCIDs Hojat Sheikh Motahar Vahedi: 0000-0002-6796-6403 Amirhosein Jahanshir: 0000-0002-0449-4314 Javad Seyedhosseini: 0000-0002-9131-9732 Elnaz Vahidi: 0000-0002-4580-1456 6.3. Funding No funding was received for this study. 6.4. Conflict of interest None declared. References 1. Chung KP, Chang HT, Lo SC, Chang LY, Lin SY, Cheng A, et al. Severe lymphopenia is associated with elevated plasma interleukin-15 levels and increased mortality during severe sepsis. Shock (Augusta, Ga). 2015;43(6):569-75. 2. Macdonald SP, Williams JM, Shetty A, Bellomo R, Finfer S, Shapiro N, et al. Review article: Sepsis in the emergency department - Part 1: Definitions and outcomes. Emer- gency medicine Australasia : EMA. 2017;29(6):619-25. 3. Mirbaha S, Abushouk AI, Negida A, Rouhipour A, Barat- loo A. The effect of fluid therapy on hemodynamic and venous blood gas parameters in patients with septic shock. Journal of Medical Physiology. 2016;1(2):55-9. 4. Drewry AM, Samra N, Skrupky LP, Fuller BM, Comp- ton SM, Hotchkiss RS. Persistent lymphopenia after di- agnosis of sepsis predicts mortality. Shock (Augusta, Ga). 2014;42(5):383-91. 5. Bloos F. Clinical diagnosis of sepsis and the combined use of biomarkers and culture- and non-culture-based assays. Methods in molecular biology (Clifton, NJ). 2015;1237:247-60. 6. Baratloo A, Rahmati F, Rouhipour A, Motamedi M, Ghey- tanchi E, Amini F, et al. Correlation of Blood Gas Parame- ters with Central Venous Pressure in Patients with Septic Shock; a Pilot Study. Bulletin of emergency and trauma. 2014;2(2):77-81. 7. Hotchkiss RS, Monneret G, Payen D. Sepsis-induced immunosuppression: from cellular dysfunctions to immunotherapy. Nature reviews Immunology. 2013;13(12):862-74. 8. Hattori Y, Hattori K, Suzuki T, Matsuda N. Recent ad- vances in the pathophysiology and molecular basis of sepsis-associated organ dysfunction: Novel therapeutic implications and challenges. Pharmacology & therapeu- tics. 2017;177:56-66. 9. Wesche DE, Lomas-Neira JL, Perl M, Chung CS, Ayala A. Leukocyte apoptosis and its significance in sepsis and shock. Journal of leukocyte biology. 2005;78(2):325-37. 10. Monserrat J, de Pablo R, Reyes E, Diaz D, Barcenilla H, Za- pata MR, et al. Clinical relevance of the severe abnormal- ities of the T cell compartment in septic shock patients. Critical care (London, England). 2009;13(1):R26. 11. Felmet KA, Hall MW, Clark RS, Jaffe R, Carcillo JA. Pro- longed lymphopenia, lymphoid depletion, and hypopro- lactinemia in children with nosocomial sepsis and multi- ple organ failure. Journal of immunology (Baltimore, Md : 1950). 2005;174(6):3765-72. 12. Venet F, Davin F, Guignant C, Larue A, Cazalis MA, Darbon R, et al. Early assessment of leukocyte alter- ations at diagnosis of septic shock. Shock (Augusta, Ga). 2010;34(4):358-63. 13. Wyllie DH, Bowler ICJW, Peto TEA. Relation between lymphopenia and bacteraemia in UK adults with medical emergencies. Journal of clinical pathology. 2004;57(9):950-5. 14. Chien y-c, Chung k-p, Cheng j-s, Chang H-T, Yu c- j. Lymphopenia Is Associated With Worse Outcome In Patients With Severe Sepsis. D57 SEPSIS: OF MICE, METABOLOMICS, AND MAN: American Thoracic Soci- ety; 2012. p. A5992-A. 15. Markwart R, Condotta SA, Requardt RP, Borken F, Schu- This open-access article distributed under the terms of the Creative Commons Attribution NonCommercial 3.0 License (CC BY-NC 3.0). Downloaded from: http://journals.sbmu.ac.ir/aaem 5 Archives of Academic Emergency Medicine. 2019; 7 (1): e14 bert K, Weigel C, et al. Immunosuppression after sepsis: systemic inflammation and sepsis induce a loss of naive T-cells but no enduring cell-autonomous defects in T-cell function. PloS one. 2014;9(12):e115094-e. 16. Li X, Xu Z, Pang X, Huang Y, Yang B, Yang Y, et al. Interleukin-10/lymphocyte ratio predicts mortality in se- vere septic patients. PLoS One. 2017;12(6):e0179050. This open-access article distributed under the terms of the Creative Commons Attribution NonCommercial 3.0 License (CC BY-NC 3.0). Downloaded from: http://journals.sbmu.ac.ir/aaem Introduction Methods Results: Discussion Conclusion Appendix References