ORIGINAL�ARTICLE ABSTRACT Objective: To determine the association of pro-inflammatory markers with suicidality in patients suffering from major depressive episode. Study Design: Descriptive cross sectional study. Place and Duration of Study: The study was conducted at department of pathology in collaboration with the department of psychiatry, Pakistan Railway Hospital, Islamic International Medical College, Rawalpindi from th th 18 April, 2017 to 17 March, 2018. Materials and Methods: Seventy five subjects recruited through convenient non-probability sampling technique were divided into three groups i.e. Group 1 (patients of major depressive episode with suicidality), Group 2 (patients of major depressive episode without suicidality) and Group 3 included healthy controls. Patients of major depressive episode and suicidality were diagnosed through Hamilton rating scale for depression and beck scale for suicidal intention successively. Pro-inflammatory markers i.e. Interleukin-1ß, Interleukin-6 and C-reactive protein were measured in the serum of all participants. Data was analyzed through statistical package for social sciences version 21. Simple descriptive statistics (frequencies, percentages) were computed for each categorical variable. Mean and standard deviation were calculated for the numerical data. Independent t test and one way ANOVA was applied to determine the statistical significance. P value of < 0.05 was considered significant. Results: Out of 75 enrolled patients, Pro-inflammatory markers i.e. Interleukin-1ß, Interleukin-6 and C-reactive protein were raised in patients of major depressive episode with suicidality. Conclusion: Pro-inflammatory markers i.e. CRP, IL-1ß and IL-6 are markedly raised in patients of major depressive episode with suicidality. So, from the results it is concluded that pro-inflammatory markers have an association with suicidality in patients of major depressive episode and treating inflammation in them can improve their symptoms and reduce suicidal rate. Key Words: CRP, IL-1ß, IL-6, Inflammation, Major Depressive Episode, Pro-inflammatory Markers and Suicidality die of suicide per year in the United States and the global death rate was nearly 800000 in the year 2014 1 calculated by World Health Organization (WHO). It was predicted by WHO in 2011 that one million people would die by the year 2030 due to suicide, 1 that will contribute to 1.4% of all the deaths globally. The real number of deaths may be higher because suicidal deaths are normally not reported due to societal issues and criminalization of suicide in many 1 societies. Suicidal attempts are also insufficiently reported. Almost twenty or more than that suicide attempts occur for every completed suicide, so suicide attempts are more frequent than completed 1 suicide. There is emerging evidence that this behavioral phenotype is independently associated with a pro-inflammatory state in the body, and that it 2 is not linked to the severity of depression per se. Introduction Suicide is the second major cause behind the death of youngsters among the 15–29 age group in the 1 world. According to one estimation, 40,000 people The Association of Pro-inflammatory Markers with Suicidality in Patients Suffering from Major Depressive Episode 1 2 3 4 5 Aqsa Liaqat , Muhammad Nadim Akbar Khan , Athar Muneer , Ama tul Naval , Fakhra Noureen Correspondence: Dr. Aqsa Liaqat Senior Lecturer Department of Pathology HBS Medical and Dental College Islamabad E-mail:aqsach@gmail.com 1 Department of Pathology HBS Medical and Dental College Islamabad 2,3,5 Department of Pathology/Psychiatry Islamic International Medical College Riphah International University, Islamabad 4 Department of Pathology Watim Medical and Dental College, Islamabad Funding Source: NIL; Conflict of Interest: NIL Received: May 24, 2018; Revised: January 09, 2019 Accepted: February 19, 2019 Pro-inflammation Markers and SuicidalityJIIMC 2019 Vol. 14, No.1 13 of pro-inflammatory markers with suicidality in patients of major depressive episode (MDE) patients. The objective of our study is to find the association of pro-inflammatory markers (IL-1β, IL-6 & CRP) with suicidality in patients suffering from major depressive episode (MDE). Materials and Methods This observational cross sectional study was conducted at Chemical Pathology department in collaboration with psychiatry department of Pakistan Railway Hospital, Islamic International th Medical College, Rawalpindi from 18 April, 2017 to th 17 April, 2018 after getting permission from ethical review committee of Riphah International University. Sample size was decided based on the data from similar previous studies. Participants from both genders were enrolled through non-probability convenient sampling after taking informed consent. Seventy-five participants were inducted in the study between the ages of 18 to 65 years and divided into three groups each having twenty-five participants. Group 1 had twenty-five patients of major depressive episode (MDE) with suicidality, Group 2 had twenty-five patients of MDE without suicidality and Group 3 had twenty-five healthy adults. Participants having any acute or chronic infection or inflammation, obesity, allergies, pregnancy and lactating mothers were excluded. Participants of MDE and suicidality were diagnosed based on Hamilton rating scale for depression (HRSD) and Beck Scale for suicidal intent respectively by a qualified Psychiatrist in OPD of psychiatry department. After filling demographic data, patients were directed towards Pathology lab and 5 ml of venous blood was withdrawn in plain vacutainers considering all necessary measures to avoid pre-analytical errors. Samples were transported in crushed ice to CREAM lab of Army Medical College, Rawalpindi for refrigerated centrifuge at 4° C. Serum was extracted and stored at -80 ̊ C. CRP levels of all samples were analyzed through visual agglutination semi quantitative method. IL-1ß and IL-6 were analyzed by ELISA method. Data was analyzed through statistical package for social sciences (SPSS) version 21. Simple descriptive statistics (frequencies, percentages) were computed for each categorical variable. Mean and standard deviation were calculated for numerical data. Independent t test and one way Many studies have shown that suicide is associated with an increase in inflammatory markers in the 2 body. “Cytokine-induced sickness behavior” (i.e., lethargy, fatigue, depression, failure to concentrate, anorexia, sleep problems, reduced sense of personal hygiene and social withdrawal) has been shown to be linked and mediated by pro-inflammatory cytokines 3 i.e. IL-1 and IL-6. Another important mechanism underlying suicidality is the activation of kynurenine pathway for the catabolism of tryptophan. Abnormalities in this pathway lead to certain b i o l o g i c a l m e c h a n i s m w h i c h a s s o c i a t e s 4 inflammation with suicidality and depression. Tryptophan catabolism through kynurenine pathway produces certain neuroactive substances especially 5 quinolinic acid (QUIN) and kynurenic acid (KYNA). The inflammatory cytokines especially IL-1ß, IL-6 and IFN-γ are potent activators of indole amine 2, 3 d i o x y g e n a s e ( I D O - 1 ) a n d t r y p t o p h a n 2 . 3 dioxygenase (TDO2). These two enzymes regulate 6,7 the initial steps in kynurenine pathway. Tryptophan is the precursor of serotonin neurotransmitter, so catabolism of tryptophan through this pathway down regulates the amount of serotonin in the 8 body. This mechanism can directly lead to lower levels of monoamines in the CSF and serum of 1 suicidal victims. A meta-analysis by Black & Miller published in 2015 has shown that levels of IL-1 β, IL-6 & TNF-α are elevated in the body fluids of those psychiatric patients who attempted suicide or have 2 strong suicidal ideation. Identification of specific inflammatory markers and important co-existing biological factors can inform us regarding the risk of suicidal behavior. Further, treatments targeting the constituents of the inflammatory pathway are nowadays undergoing trials for a variety of psychiatric conditions, and this approach can lead to the development of novel therapeutic tools for the 9 prevention of suicide. Our proposition is that patients who contemplate or attempt suicide have an inflammatory state in their bodies which can be detected by measuring pro-inflammatory markers like interleukin-1 β, interleukin 6 and C-reactive 10,2 protein (CRP) in the serum. In the extant literature review, no single study has documented the association of IL-1 β, IL-6 & C-reactive protein 2 together with the existence of suicidality. Further, no local studies are available to relate the association 14 JIIMC 2019 Vol. 14, No.1 Pro-inflammation Markers and Suicidality Discussion The results of present study show that in healthy adults, levels of cytokines are undetectable. In 2013, Kleiner et al. also published a study in which it was concluded that in normal healthy people levels of cytokines were undetectable due to the absence of 9 any inflammatory stimulus. Due to the absence of inflammation in healthy adults, CRP levels are also undetectable or within normal range in them. In patients of major depressive episode without suicidality, the levels of pro-inflammatory markers like interleukin-1ß, interleukin-6 were high as compared to healthy adults. This shows that some degree of inflammation is also present in patients of major depressive episode irrespective of absence of ANOVA were applied to determine the statistical significance. P value of < 0.05 was considered significant. Results Total 75 patients were divided into three equal group i.e. group 1 consisted of patients of MDE with suicidality, group 2 consisted of MDE patients without suicidality and group 3 consisted of healthy adults with no history of somatic or psychiatric illness. Descriptive statistics of age (years) was calculated in terms of mean and standard deviation. Mean age (years) of participants was overall 33.32+8.93 whereas mean age (years) of MDE patients with suicidality was 28.44±6.70 and of MDE patients without suicidality was 37.8±8.10. The mean age (years) of healthy adults was 33.72+8.93. Distribution of gender was calculated in terms of frequency and percentage of male and female patients. There were 39 (52.0%) male participants, of these 11 (44.0%) were present in group 1 (MDE with suicidality), 13 (52.0%) male patients were included in group 2 (MDE without suicidality) and 15 (60.0%) male participants were present in group 3 (Healthy adults). There were 36 (48.0%) female participants included in the study, of these 14 (56.0%) were present in group 1 (MDE with suicidality), 12 (48.0%) female patients were included in group 2 (MDE without suicidality) and 10 (40.0%) were present in group 3 (Healthy adults). The association of pro- inflammatory markers (IL-1 β, IL-6 and CRP) with suicidality in patients suffering from major depressive episode (MDE) was assessed using Table I: Comparison of Pro-inflammatory Markers between Groups 1 and Group 2 P<0.05 was taken as level of significant G r o u p 1 : M D E w i t h s u i c i d a l i t y Group 2: MDE without suicidality Table II: Comparison of Pro-inflammatory Markers between Groups 1 and Group 3 independent t test. The results came out to be statistically significant for all the three markers i.e. P- value < 0.05 as shown in Table I and Table II. Pro-inflammatory markers (CRP, IL-1ß and IL-6) were compared among three groups using one way ANOVA. The results showed statistically significant difference for all pro-inflammatory markers (p value<0.001) as shown in Table III. P<0.05 was taken as level of significance Group 1: MDE with suicidality Group 3: Healthy Adults Table III: Comparison of Pro-inflammatory Markers among Three Groups (n=75) P<0.05 was taken as level of significant 15 JIIMC 2019 Vol. 14, No.1 Pro-inflammation Markers and Suicidality low or high risk for suicidality, CRP levels were raised 16 in acute cases. In another recent study, Gibbs et al. did research work on indoor psychiatric patients with and without suicidal behavior. They found out that MDE patients with high degree of suicidality had greater inflammation and increased levels of CRP when compared to MDE patients without suicidality 17 and healthy adults. In 2015, Black and Miller in their m e t a - a n a l y s i s o f m a ny s t u d i e s b a s e d o n inflammation and suicidality also concluded that inflammation was strongly associated with 2 suicidality in MDE patients. Conclusion It is concluded that pro-inflammatory markers are significantly high in MDE patients with suicidality. This also throws light on the association of pro- inflammatory markers with suicidality and importance of treating patients with anti- inflammatory drugs in medicine resistant depression with suicidality. Limitations This study was conducted in a single outdoor patient department. Due to financial constraints and limited time duration availability, a small group of patients was included. There are some other pro- inflammatory markers and anti-inflammatory markers mentioned in literature like TNF-ɑ, IL-2 etc. They can be considered for further studies. A longitudinal study can be conducted in future to observe the effect of anti-inflammatory drugs in these patients. REFERENCES 1. Brundin L, Bryleva EY, Thirtamara Rajamani K. Role of Inflammation in Suicide: From Mechanisms to Treatment. Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology. 2017;42(1):271-83. 2. Black C, Miller BJ. Meta-Analysis of Cytokines and Chemokines in Suicidality: Distinguishing Suicidal Versus Nonsuicidal Patients. Biological psychiatry. 2015;78(1):28- 37. 3. Courtet P, Giner L, Seneque M, Guillaume S, Olie E, Ducasse D. Neuroinflammation in suicide: Toward a comprehensive model. The World Journal of Biological Psychiatry. 2016;17(8):564-86. 4. Lotrich FE, Ferrell RE, Rabinovitz M, Pollock BG. 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