The assessment of phagocytic and bactericidal activity of platelets and plasma bactericidal activity in late preterm newborns*
Abstract
Background
The aim of the study was to compare the phagocytic and bactericidal properties of blood platelets and the plasma bactericidal activity in 66 late preterm (LPN) and 74 full-term newborns (FTN).
Materials/Methods
Blood samples were collected from the umbilical artery. Bacteria of the Staphylococcus aureus ATCC 6538P were used for the tests.
Results
Platelet counts in LPN vs FTN were the following: 225 vs 258.5 (×103/μL), p = 0.003. The percentage of phagocytic platelets was the following: Me = 1.1 in LTN vs Me = 1.1 in FTN. The phagocytic index was the following: Me = 1 for both LPN and FTN. The phagocytic properties of platelets increased as the birth weight increased. The bactericidal activity of platelets was the following: Me = 0; (average = 0.7) in LPN vs Me = 0; (average = 0.8) in FTN. The median plasma bactericidal activity in LPN was 41.6 vs 43.8, in FTN, p = 0.027. The bactericidal capacity of plasma increased with increasing fetal age and birth weight of newborns. sP-selectin was: 63.9 ng/ml in LPN vs 71 ng/ml in FTN, p = 0.026. IL-6 in LPN was 3.6 vs 3.9 (pg/ml) in FTN, p = 0.02.
Conclusion
Late preterm newborns have lower defensive capacity against infection than full-term newborns, due to lower platelets count, lower plasma bactericidal activity and lower sP-selectin concentration, which cooperates with neutrophils, monocytes in fighting against infection. All newborns had similar phagocytic and bactericidal properties of platelets.
© 2021 Alicja Wasiluk, Barbara Kicel-Wesolowska, Robert Milewski, Joanna Matowicka-Karna, published by Hirszfeld Institute of Immunology and Experimental Therapy
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.