The influence of daily psychosocial stressors and associated emotions on the dynamic course of urine cortisol and urine neopterin in systemic lupus erythematosus: Experience taken from two "integrative single-case studies"

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characte rized by flare-ups, the cause of which is unknown. According to new stress concepts, two "integrative single-case studies" have been conducted in orde r to gather evidence about whether daily stressful incidents and associated emotions interfere with the dynamics of urine cortisol and urine neopterin in SLE. Patients under study collected their urine at home, for a period of at leas t 50 days, on a daily basis, divided into day and night urine. Additionally , patients filled out questionnaires twice a day to determine their emotion al state, life style and disease activity. Each week, patients were examine d clinically and interviewed to identify the past week's stressors using th e Incidents and Hassles Inventory (IHI, Brown and Harris). Statistical anal ysis of the serial data was performed using time-series analysis according to Box and Jenkins. In both "integrative single-case studies" we were able to demonstrate that stressful incidents predicted an increase in urine neopterin 36 hours (Case 1) to 60 hours (Case 2) later (p < 0.05). Additionally, in Case 1 the neop terin levels were highly associated with stress resulting from the weekly e xaminations and interviews. Furthermore, in Case 2 it turned out that depen ding on their predictability stressful incidents were preceded by a decreas e in urine cortisol 12 hours earlier or were followed by a decrease in urin e cortisol 36 hours later. And finally, emotional irritation was highly cor related with the course of urine-neopterin. In Case 2 irritation led to an increase in urine neopterin 84 hours later. There were no clinical signs;of SLE during both prospective studies. In conclusion, our results validate the idea of "integrative single-case st udies" as a new "bio-psycho-social" approach in psychoneuroimmunology. Furt her studies with SLE patients as well as with healthy probands will be nece ssary in order to both strengthen and generalize these results.