Differentiation between major and milder acute mental stress by means of the leukocyte adhesiveness/aggregation test.

Following previous observations that the adhesive state of white blood cells in the peripheral blood increases during stress, we examined 645 volunteers in various conditions of anticipatory anxiety. The volunteer subjects included 465 controls in whom stress was related solely to impending venipuncture, 149 persons under moderate stress (students before delivering a graded lecture, patients before dental treatment, etc), as well as 31 individuals under major stress (eg, before induction of anesthesia in the operating room). The respective values of aggregated leukocytes in the peripheral blood were 5.2 +/- 3.8, 6 +/- 4.2, and 19.3 +/- 9.3% of aggregated cells, with a significant difference (p < .0001) between the third and the other two groups. In both discriminant analysis and multiple regression, the leukocyte adhesiveness/aggregation test (LAAT) was shown to be superior to the white blood cell count for the detection of major stress. The LAAT had a sensitivity of 0.8, compared with only 0.35 for leukocyte count for that purpose. We concluded that the LAAT could be a powerful tool for the diagnosis of major acute mental stress and for discrimination between conditions causing major stress and those conditions that are less stressful.