A novel IL-18BP ELISA shows elevated serum IL-18BP in sepsis and extensive decrease of free IL-18.
Cytokine
; 14(6): 334-42, 2001 Jun 21.
Article
en En
| MEDLINE
| ID: mdl-11497494
IL-18 binding protein (IL-18BP) is a circulating antagonist of the proinflammatory Th1 cytokine IL-18. It effectively blocks IL-18 by forming a 1:1 high affinity (Kd=400 pM) complex, exhibiting a very low dissociation rate. We have developed a sandwich ELISA for IL-18BPa and determined its limit of detection (62 pg/ml). Interference by IL-18 and related cytokines, as well as cross reactivity with other IL-18BP isoforms (b, c, and d) were determined. Using this ELISA, we measured serum IL-18BPa in large cohorts of healthy individuals and in septic patients. Serum IL-18BPa in healthy individuals was 2.15+/-0.15 ng/ml (range 0.5-7 ng/ml). In sepsis, the level rose to 21.9+/-1.44 ng/ml (range 4-132 ng/ml). Total IL-18 was measured in the same sera by an electrochemiluminescence assay and free IL-18 was calculated based on the mass action law. Total IL-18 was low in healthy individuals (64+/-17 pg/ml) and most of it ( approximately 85%) was in its free form. Total IL-18 and IL-18BPa were both elevated in sepsis patients upon admission (1.5+/-0.4 ng/ml and 28.6+/-4.5 ng/ml, respectively). At these levels, most of the IL-18 is bound to IL-18BPa, however the remaining free IL-18 is still higher than in healthy individuals. We conclude that IL-18BPa considerably inhibits circulating IL-18 in sepsis. Yet, exogenous administration of IL-18BPa may further reduce circulating IL-18 activity.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Ensayo de Inmunoadsorción Enzimática
/
Glicoproteínas
/
Sepsis
/
Interleucina-18
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Cytokine
Asunto de la revista:
ALERGIA E IMUNOLOGIA
Año:
2001
Tipo del documento:
Article
País de afiliación:
Israel
Pais de publicación:
Reino Unido