title: Analysis of the concentrations of interleukin 18 in amniotic fluid in the second and the third trimesters of pregnancy.
abstract: BACKGROUND
  Interleukin 18 (IL-18) is a glycoprotein produced by macrophages. IL-18 influences different populations of T lymphocytes and NK cells and stimulates the production of INF-gamma by these cells. IL-18 induces both Th1 and Th2 response. That is why IL-18 is a unique cytokine.
  
  
  OBJECTIVE
  The aim of work was to examine the concentration of interleukin 18 in amniotic fluid in the 2nd and the 3rd trimesters of physiological pregnancies.
  
  
  METHODS
  74 pregnant women were qualified to take part in the studies. The amniotic fluid samples by amniocentesis were taken from the patients. Two groups were distinguished among the examined patients: group I - 45 pregnant women qualified for genetic amniocentesis between the 15th and 19th week of pregnancy. All findings of the cytogenetic tests were normal. Group II: 29 pregnant women in their 3rd trimester were qualified for diagnostic amniocentesis in order to determine the biological maturity of the fetuses. The concentration of IL-18 was marked with the immunoenzymatic method ELISA with the use of the kit produced by the MBL company. Method sensitivity was < 12.5 pg/mL.
  
  
  RESULTS
  In the 2nd trimester of pregnancy the average concentration of IL-18 in the amniotic fluid was 454.69 pg/mL and in the 3rd trimester was 71.73 pg/mL. The obtained data proved that the average concentration of IL-18 in the 2nd trimester was significantly higher than in the 3rd trimester. The obtained differences in the findings were statistically significant (p < 0.05).
  
  
  CONCLUSIONS
  The presence and high levels of IL-18 in the amniotic fluid in the 2nd trimester of pregnancy indicate an early process of initiation of immunological mechanisms by the fetus. An average concentration of IL-18 in the amniotic fluid was significantly higher in the 2nd trimester of pregnancy than in the 3rd trimester, which may indicate the influential role of IL-18 on the development of the immune response in the fetus in this period of gestation.
authors.affiliation: Second Department of Gynecology and Obstetrics, Wroclaw Medical University, Poland.
authors.forename: Dominika
authors.initials: D
authors.lastname: Klimkiewicz-Blok
authors.forename: Jerzy
authors.initials: J
authors.lastname: Florjański
authors.forename: Jerzy
authors.initials: J
authors.lastname: Zalewski
authors.forename: Radosław
authors.initials: R
authors.lastname: Blok
mesh_terms: D000328:Adult; D000653:Amniotic Fluid / Q000276:immunology*; D005260:Female; D006801:Humans; D020382:Interleukin-18 / Q000032:analysis* / Q000502:physiology; D008875:Middle Aged; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D011263:Pregnancy Trimester, Third
chemical_list: D020382:Interleukin-18