Very low monocytic HLA-DR expression indicates high risk of infection--immunomonitoring for patients after neurosurgery and patients during high dose steroid therapy

Abstract

In patients with disturbed immunoreactivity caused by trauma or immunosuppressive therapy infections are still a severe problem. To determine whether measurement of monocytic HLA-DR expression is useful for identifying patients with a high risk of infection after elective neurosurgery, blood was obtained from 57 patients during the first 3 days after surgery. HLA-DR expression was lower in 14 patients who developed infection, compared with patients with an uncomplicated postoperative course (p < 0.0001). Out of ten patients with less than 30% HLA-DR positive monocytes, nine developed infection. In 11 neurosurgical patients additional investigations were performed. Measurements in these patients show that HLA-DR expression decreased temporarily within hours after surgery, coinciding with a considerable increase of inflammatory cytokines in CSF, but, surprisingly, not in plasma. High plasma concentrations of ACTH and cortisol hours after surgery indicated a hypothalamus-pituitary axis response, probably involved in the downregulation of monocytic HLA-DR expression. Likewise, monitoring of dermatological patients (n = 10) who received high dose systemic steroids revealed a very low HLA-DR expression in those patients who later developed infection. Our studies show that very low HLA-DR expression indicates high risk of infection. We recommend the measurement of this parameter for immunomonitoring.