PROTON MAGNETIC-RESONANCE SPECTROSCOPY OF POLYMORPHONUCLEAR LEUKOCYTES FROM PATIENTS WITH SERIOUS BACTERIAL-INFECTIONS

Triacylglycerols in human neutrophils exposed to proinflammatory stimu li generate a high-resolution proton magnetic resonance (H-1 MR) spect rum. Lipid cross-peak F volumes in neutrophils from patients with infl ammatory conditions were measured. Values in patients hospitalized wit h localized infections (14.4 +/- 9.0; mean +/- SD) or bacteremia (19.3 +/- 9.7) were significantly higher than in patients with noninflammat ory conditions (6.2 +/- 5.3) and healthy controls (2.0 +/- 3.0; P < .0 01). The positive predictive value of F volumes >10 was 93% for all in fection; the negative predictive value of volumes less-than-or-equal-t o 10 was 68% for all infection and 92% for bacteremia. Plasma lipopoly saccharide (LPS) concentrations were highest in bacteremic patients bu t did not correlate with levels of tumor necrosis factor-alpha (TNFalp ha) or interleukin-6. In vitro, LPS increased F volumes of control neu trophils from 2.0 +/- 3.0 to 37.2 +/- 6.7 (P < .001); TNFalpha had no effect. F volumes in H-1 MR spectra may be useful clinically to discri minate between serious bacterial infection and other inflammatory cond itions. TNFalpha is not the stimulus for generation of lipid spectra i n vivo.