Are Salivary Immunoglobulin A and Lysozyme Biomarkers of Stress Among Nurses?

Abstract

Salivary immunoglobulin A (IgA) and lysozyme have been studied as possible biomarkers of stress. This study examined the stress levels among female nurses in various units and the relationship between these stress levels and salivary IgA and lysozyme secretion. One hundred ninety-five (43%) of 457 eligible female nurses from surgical wards/operating theaters (SURG), medical wards (MED), and outpatient clinics/day-surgery theaters (OPD) completed a self-administered questionnaire. From this group of 195 nurses, 124 provided a salivary sample accumulated over 5 minutes. Stress levels were assessed with a ten-point Stress Assessment Score (SAS) for Asians and a direct question on perceived life stress. Enzyme-linked immunosorbent assay and lyso-plate methods were used to determine salivary IgA and lysozyme levels. Forty-five percent of SURG, 35% of MED, and 17% of OPD nurses scored at least four points on the SAS. SURG nurses had the lowest IgA secretion (geometric mean; 95% confidence interval [CI]) rates (43 micrograms/min; 36 to 51 micrograms/min). The other groups had significantly higher salivary IgA secretion rates: MED (96 micrograms/min; 80 to 116 micrograms/min) and OPD (77 micrograms/min; 60 to 98 micrograms/min) Findings for salivary lysozyme (microgram/min) were similar; SURG (9 micrograms/min; 6 to 13 micrograms/min) MED (19 micrograms/min; 12 to 28 micrograms/min) and OPD (16 micrograms/min; 9 to 28 micrograms/min). The salivary IgA (Spearman's r = -0.22, P = 0.01) but not the lysozyme (Spearman's r = -0.01, P = 0.9) secretion rate correlated negatively with SAS. Nurses working in various units under different conditions experienced dissimilar levels of stress. Salivary IgA, but not lysozyme, correlated inversely with self-reported levels of stress. It may thus be a potential biomarker in future studies on stress.

A pilot study on the association between job stress and repeated measures of immunological biomarkers in female nurses

“…For example, the associations reported between role-stress and nonparticipation in decision making among nurses and increased level of IgA and IgG, respectively (Endresen et al 1987), was not replicated in the following studies that reported inverse association between self-reported levels of stress and the level of both salivary IgA (Ng et al 1999;Yang et al 2002) or lysozyme (Yang et al 2002). Although the relationship between stress level (i.e., quantitative work load and a conflict with physicians) and decreased natural killer (NK) cell activity among nurses has been reported by Morikawa et al (2005), another study could not find strong association (Ng et al 1999). A recent longitudinal study conducted for nurses (Amati et al 2010) has suggested the association between job satisfaction and decreased low cell numbers of CD8(?)…”

“…In addition to commonplace stress, work-related stress has also been reported to alter immunological parameters in nurses (Endresen et al 1987;Henningsen et al 1992;De Gucht et al 1999;Ng et al 1999;Yang et al 2002;Morikawa et al 2005;Amati et al 2010), male shift workers (Meijiman et al 1995), blue-collar workers (Kawakami et al 1997;Bosch et al 2009), electric power plant workers (Nakata et al 2000;Nakata et al 2002), athletes (Gleeson 2000), police officers (Piercecchi-Marti et al 1999), and air traffic controllers (Zeier et al 1996).…”

Secretory Ig a in Saliva and Academic Stress

“…Secretory immunoglobulin (lg) A (S-IgA), which has been measured in saliva, and is an index of mucosal immunity (1,2), has been reported to be sensitive to psychological variables (3)(4)(5)(6)(7)(8)(9)(10)(11)(12). Several studies have demonstrated that S-IgA is down-regulated by chronic stress, whereas an acute psychological challenge induces mobilization (5,6,10,11).…”

Perturbation of Secretory Ig A in Saliva and Its Daily Variation by Academic Stress.

“…Several studies have shown that S-IgA in saliva may be an indicator of psychological stresses, such as academic examination stress 1,4,7,10) and work-related stress 2,3,6) , and that it may be influenced by personality characteristics [7][8][9][10] . Chronic stress has been reported to down-regulate S-IgA, whereas an acute psychological challenge induces mobilization.…”

“…Secretory immunoglobulin (Ig) A (S-IgA) measured in saliva, which is an index of mucosal immunity, has been reported to be sensitive to psychological variables [1][2][3][4][5][6][7][8][9][10] . Several studies have demonstrated that chronic stress down-regulates S-IgA, whereas an acute psychological challenge induces mobilization 3,4,8,9) .…”