Ej. Barone et al., INTERLEUKIN-1-ALPHA AND COLLAGENASE ACTIVITY ARE ELEVATED IN CHRONIC WOUNDS, Plastic and reconstructive surgery, 102(4), 1998, pp. 1023-1027
Interleukin-l-alpha (IL-1 alpha) is a member of a family of proinflamm
atory polypeptide mediators that has been shown in vitro to stimulate
collagenase production. Collagenase is a proteolytic enzyme classified
as one of the matrix metalloproteinases (MMP-1) that specifically rec
ognizes and cleaves collagen. Therefore, the objective of this study w
as to compare the levels of these two proteins in chronic wounds as po
ssible factors in the pathogenesis of chronic wounds. Fluids from 10 c
hronic wounds were collected before and after a 1-week treatment with
a hydroactive dressing (Cutinova cavity). In addition, fluids were col
lected from 20 acute wounds for comparison. IL-1 alpha and MMP-1 level
s were quantified using sandwich ELISA. Collagenase activity was measu
red using a radiolabeled collagen as substrate. Clinically, the chroni
c wounds showed decreased area (-21.0 cm(2)) and reduced volume (-134.
5 cm(3)) by 4 weeks after treatment with the hydroactive dressing. The
re were no significant differences in the protein concentrations betwe
en acute wound fluids (21.0 +/- 3.0 mg/ml) and chronic wound fluids be
fore and after treatment with the hydroactive dressing (18.3 +/- 5.5 a
nd 25.2 +/- 7.6 mg/ml, respectively). Levels of IL-1 alpha in the acut
e wound fluids were low (0.019 pg/mg), whereas in the chronic wound fl
uid before treatment they had been significantly elevated (44.9 +/- 21
.8 pg/mg). Following treatment with the hydroactive dressing, the IL-1
alpha levels dropped to 10.3 + 3.3 pg/mg (p < 0.05). Collagenase acti
vity was not detectable in acute wound fluid, elevated in pretreatment
chronic wounds (12.9 + 3.4 units), and decreased in chronic wounds af
ter treatment (11.4 + 3.3 units). This study correlated clinical heali
ng of chronic wounds with biochemical changes in the ulcer microenviro
nment. As the chronic wounds began to heal, there was a significant de
crease in the IL-1 alpha levels and collagenase activity, thus suggest
ing that these two proteins may contribute to the lack of healing char
acteristic of chronic wounds.