Denatured hemoglobin increases human blood mononuclear cell procoagulant effect.
OBJECTIVE
To study the effects of the common contaminants of hemoglobin solutions, red cell stroma, bacterial endotoxin, and denatured hemoglobin on the causes of the thrombotic lesions which have been reported in animal experiments after hemoglobin administration.


METHODS
Human blood mononuclear cells were isolated on Ficoll-Hypaque gradients and incubated with hemoglobin from the LAIR production facility, red cell stroma, bacterial endotoxin (E. coli, Wittaker Bioproducts), and hemoglobin denatured by boiling. Incubations were performed separately and in combinations. Mononuclear cells were then lysed and assayed for procoagulant activity in a recalcification time assay.


RESULTS
Only bacterial endotoxin and hemoglobin denatured by boiling increased the procoagulant activity of human blood mononuclear cells. Denatured hemoglobin mixed one part in eight with undenatured hemoglobin increased mononuclear cell procoagulant activity by more than ten-fold that of the undenatured hemoglobin control.


CONCLUSIONS
The study suggests that denatured but not undenatured hemoglobin causes increased blood procoagulant activity which is thought to be a marker of macrophage activation. These findings suggest a possible mechanism of toxicity of cell-free hemoglobins and the need for sensitive measures of hemoglobin denaturation.
Kim
S A
SA
Blood Research Division, Letterman Army Institute of Research, San Francisco, CA 94129-6800.
Villa
V O
VO
Hess
J R
JR
D001779:Blood Coagulation Factors / Q000378:metabolism*; D001802:Blood Substitutes / Q000009:adverse effects* / Q000737:chemistry; D004340:Drug Contamination; D004731:Endotoxins / Q000633:toxicity; D006441:Hemoglobin A / Q000009:adverse effects* / Q000737:chemistry; D006801:Humans; D066298:In Vitro Techniques; D007963:Leukocytes, Mononuclear / Q000187:drug effects* / Q000378:metabolism; D008262:Macrophage Activation / Q000187:drug effects; D011489:Protein Denaturation; D012449:Safety
D001779:Blood Coagulation Factors; D001802:Blood Substitutes; D004731:Endotoxins; C045071:leukocyte procoagulant activity; C028881:hemoglobin A(0); C044101:endotoxin, Escherichia coli; D006441:Hemoglobin A