Freisetzung von Interleukin-1 aus Blutmonozyten bei septischen Frühgeborenen

Abstract

This study examined lipopolysaccharide (LPS) induced in vitro secretion of interleukin-1 (IL-1) by peripheral blood monocytes from pre-term infants with and without sepsis. Thirteen pre-term babies were tested; eight were completely healthy and five suffered from six episodes of sepsis. The latter group was tested both in the acute septic phase and in the convalescent period. IL-1 secretion by monocytes derived from septic pre-term infants was lower, but not significantly different from healthy pre-term infants (7.1 +/- 1.0 U/ml versus 8.1 +/- 0.9 U/ml, respectively). IL-1 secretion by monocytes of eight control full-term babies was in the same range (8.4 +/- 0.6 U/ml). In the convalescent period IL-1 secretion by monocytes from septic pre-term babies increased (9.0 +/- 0.3 U/ml) and was significantly higher than values measured during acute infection (p less than 0.05). Septic premature babies were also found to have higher absolute blood neutrophil concentration (p less than 0.001), but their body temperature did not increase along the infectious stage. The decreased secretion of IL-1 by monocytes from pre-term babies in the acute phase of infection compared to the convalescent period may have contributed to their inability to mount appropriate immunological as well as inflammatory responses. Sepsis promoting IL-1 production in vivo may have limited the monocytes' capacity for LPS stimulated IL-1 synthesis in vitro.

Patterns of Proinflammatory Cytokines and Inhibitors during Typhoid Fever

“…such as severe postoperative infection [31). sepsis [32][33][34], and attacks of familial Mediterranean fever [35. 36).…”

“…Many investigators [31][32][33][34][35][36] have interpreted the finding of low cytokine production capacity as exhaustion of cytokineproducing cells, which could be a consequence of exposure in vivo to stimuli such as endotoxin. Our finding that IL-IRA is produced in high concentrations argues against such a hypothesis and also rules out the possibility that the decreased production of proinflammatory cytokines is due to an enhanced lysis of producing cells or to increased inactivation of LPS by lipids in the acute phase .…”

Plasmatic levels of interleukin-1ß and interleukin-6 in newborn infants with fever

“…Nossos achados foram superponíveis aos da literatura 12,15,21 . Os níveis plasmáticos de IL-1ß foram mais elevados no grupo 3, constituído de RNs não infectados e com febre.…”

“…O mesmo ocorreu quando comparamos os grupos 2 e 4, ou seja, para IL-1ß, é a variável febre que, basicamente, diferencia os grupos, a presença de infecção é coadjuvante. Além disso, encontramos níveis plasmáticos de IL-1ß muito baixos, especialmente quando comparados com os encontrados em adultos [23][24][25] , possivelmente porque os monócitos de RNs secretam IL-1ß em concentrações menores do que os de adultos 12,15 . Ao utilizarmos o teste de Correção de Bonferroni para a comparação entre dois grupos, devemos ser rigorosos e aceitarmos como significativos somente valores de p < 0,01.…”

“…A IL-1ß é considerada um pirogênio endógeno, produzindo febre pela ativação de receptores especializados, localizados no hipotálamo anterior, que estimulam a sín-tese local de PGE2 e metabólitos [13][14][15] . Influencia também na resposta imunológica e na gênese de células produtoras de anticorpos e células T citotóxicas 7 , podendo ocorrer hipotensão sistêmica -em função da capacidade da IL-1ß em induzir febre-, síntese de proteínas hepáticas de fase aguda e aumento de neutrófilos [16][17][18] .…”