Psychosocial factors and T lymphocyte counts in Brazilian peacekeepers

Abstract

OBJECTIVE:To investigate the associations between psychosocial factors and peripheral blood CD4 and CD8 T lymphocyte numbers in Brazilian peacekeepers.METHODS:Venous blood was collected from 759 peacekeepers who had just returned from a peace mission in Haiti. Among the 759 soldiers, 642 individuals completed the psychosocial measures. CD4 and CD8 T lymphocyte counts were measured by flow cytometry using a commercially available kit. Psychosocial factors, including military peace force stressors, clinical stress, anxiety and depression, were recorded. As a reference for T lymphocyte numbers, we measured T lymphocyte counts in 75 blood donors from the Instituto de Biologia do Exército, Rio de Janeiro.RESULTS:The median numbers of CD4 and CD8 T lymphocytes in the blood donors were 819 cells/µl and 496 cells/µl, respectively, with a CD4:CD8 ratio of 1.6. Significantly (p<0.05) lower CD4 T cell counts (759 cells/µl) were recorded for peacekeepers, with similar CD8 levels (548 cells/µl) and smaller CD4:CD8 ratios (1.3, p<0.001) compared to blood donors. These differences were due to a group of 14 military personnel with CD4 and CD8 medians of 308 and 266 cells/µl, respectively. Only one (7.1%) of these 14 individuals was diagnosed with clinical stress compared with 13.5% of the individuals with normal levels of CD4 T lymphocytes. One individual out of 628 (0.16%) had a Lipp's Stress Symptom Inventory score of 3, indicating near exhaustion.CONCLUSION:The prevalence of psychological disorders was low and there were no associations with CD4 or CD8 T cell numbers.

UN peacekeeper health and risk factors --- a systematic scoping review

“…One study mentioned that when peacekeepers’ hardiness were high, their psychological distress became low [ 128 ]. One study found no association between psychosocial factors (military peace force stressors, clinical stress, anxiety and depression) and blood T lymphocyte among Brazilian peacekeepers in Haiti [ 129 ].…”

“…A number of troop-contributing countries such as Australia and Netherland also explored psychological factors as health risk factors of UN peacekeepers in host countries such as Lebanon and Haiti. Due to missing hometown, disharmony in interpersonal relationships, and personal barriers to disclose experiences could lead to peacekeepers’ psychological distress such as anxiety and depression during and after deployment [ 49 , 104 , 124 , 129 ]. Natural environmental factors and behavioral lifestyle factors were also seemed to be important health risk factors of UN peacekeepers multiple troop-contributing such as Finland and China, and host countries such as the Democratic Republic of Congo and Somalia.…”

“… Region of the Americas: Brazil, U.S. Haiti, Kosovo, Bosnia Questionnaire, Cohort study Social environmental factors (work-to-family enrichment support, family stressors and financial difficulties, differences in support structures). Psychological factors Bramsen et al 2000 [ 15 ], Dirkzwager et al 2005 [ 124 ], Ippolito et al 2005 [ 47 ], Maguen et al 2006 [ 121 ], Souza et al 2008 [ 24 ], Jia et al 2009 [ 49 ], Proctor et al 2009 [ 125 ], Shao et al 2011 [ 53 ], Britt et al 2011 [ 42 ], Orme et al 2014 [ 128 ], Silva et al 2015 [ 129 ], Zhou et al 2016 [ 104 ], Lamb et al 2018 [ 126 ], Zhao et al 2019 [ 62 ], Gjerstad et al 2020 [ 37 ] Western Pacific Region: China, Australia Timor-Leste or the Solomon Islands, The Democratic Republic of the Congo, Lebanon, Multination Questionnaire, Retrospective study Psychological factors (higher hardiness scores are associated with lower levels of reported psychological distress and physical ill-health, resilience, life stress events and emotional experiences, lack of patience, loss of emotional control, longing for family members, instability state of mind). European Region: Netherlands, Norway, U.K. Lebanon, Yugosla, Multination Cross-sectional study, Questionnaire, Interview Psychological factors (personal barriers to disclose experiences and current unemployment, vulnerabilities and exposure to traumatic events, confidence and team cohesiveness to build personnel’s resilience).…”