Investigation of type II phospholipase A₂ values and eicosanoid values during polymyxin-B-immobilized fiber direct hemoperfusion of septic shock patients

Introduction

Type II phospholipase A₂ (type II PLA₂) is a rate-limiting enzyme in the eicosanoid cascade. We investigated type II PLA₂ and eicosanoids during polymyxin-B-immobilized fiber direct hemoperfusion (PMX-DHP) of septic shock patients.

Methods

A highly sensitive nephelometry method was used to measure endotoxin. The 11 patients all had positive endotoxin levels (>1.1 ng/ml). Their mean age was 69 years (range: 43 to 85 years). The mean APACHE II score was 32 points, and the mean SOFA score was 14 points. PMX-DHP was performed twice in every patient.

Results

The endotoxin level of every patient converted to negative after two PMX-DHP sessions, and they rapidly recovered from shock. The patient's TNFα values decreased significantly (from 296 to 133 pg/ml) in response to the two PMX-DHP sessions, and their LBT4 values (from 114 to 77 pg/ml), PGF1α values (from 32 to 19 pg/ml), and TXB2 values (from 79 to 57 pg/ml) also all decreased significantly. The 28-day mortality rate was 9%, and the 180-day mortality rate was 18%.

Conclusion

The results suggested that type II PLA₂ produced in response to stimulation (for example, endotoxins or proinflammatory cytokines) may further activate the arachidonic acid cascade, induce the production of various lipid mediators, and be involved in the formation of various pathological conditions. It seemed that production of these humoral factors decreased as a result of suppression of the inflammatory response by performing PMX-DHP and that their suppression was linked to the improvement in pathology.