Detection of endotoxin-like interleukin-1-inducing activity during in vitro dialysis.
In order to study the integrity of dialysis membranes to pyrogens, the dialysate side of a closed loop hemodialysis (HD) circuit was challenged with E. coli microfiltrate containing 500 ng/ml endotoxin. Three solutions, a) tissue culture medium/saline, b) 5% human serum albumin, and c) 10% fresh human plasma, were circulated in the blood loop for five hours. Samples drawn from the blood side were assayed for interleukin-1 (IL-1)-inducing activity on human mononuclear cells (MNC) in vitro. No IL-1-inducing substances were detected when saline or culture medium was circulated in the blood loop. Circulating 5% human serum albumin revealed IL-1-inducing activity in the samples drawn only after five hours of HD. However, the addition of 10% fresh human plasma to the blood side resulted in the appearance of an IL-1-inducing substance(s) after 15 minutes of HD. After 30 minutes, maximum IL-1-inducing activity was observed (control stimulation index, 3.30 +/- 0.67 SEM vs. 7.59 +/- 1.50, P less than 0.02). The IL-1-inducing activity of the samples was completely inhibited by polymyxin B, a cationic antibiotic which blocks the IL-1-inducing activity of endotoxin. Additional experiments demonstrated that in vitro MNC IL-1-production induced by the same E. coli microfiltrate is enhanced in the presence of 10% plasma. These studies demonstrate that: (a) in the presence of plasma, IL-1-inducing factors pass into the blood compartment of a dialysis system challenged with bacterial pyrogen; and (b) MNC production of IL-1 is enhanced in the presence of plasma.(ABSTRACT TRUNCATED AT 250 WORDS)
Lonnemann
G
G
Department of Medicine, Tufts University School of Medicine, Boston, Massachusetts.
Bingel
M
M
Floege
J
J
Koch
K M
KM
Shaldon
S
S
Dinarello
C A
CA
D004731:Endotoxins / Q000302:isolation & purification*; D004926:Escherichia coli; D006801:Humans; D066298:In Vitro Techniques; D007375:Interleukin-1 / Q000096:biosynthesis*; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008033:Limulus Test; D011749:Pyrogens / Q000302:isolation & purification; D006435:Renal Dialysis / Q000009:adverse effects*; D012709:Serum Albumin / Q000378:metabolism
D004731:Endotoxins; D007375:Interleukin-1; D011749:Pyrogens; D012709:Serum Albumin