Alterations in lymphocyte phenotype of infected preterm newborns.

The cord blood lymphocytes from 44 premature newborns were analyzed using two-color monoclonal antibodies and flow cytometry. Depending on whether or not there was an infection at birth, the newborns were divided into two groups and the immunophenotypes of infected and uninfected newborns were compared. The percentage of T lymphocytes (CD3+) was significantly lower in the infected prematures. The percentage of both helper and cytotoxic T lymphocytes was lower. The proportion of activated T lymphocytes, cytotoxic non-MHC-restricted T lymphocytes, NK cells and B lymphocytes did not differ between the group of infected and the group of uninfected prematures. The percentage of memory helper T lymphocytes (CD45RO+CD4+) was very low in premature newborns regardless of whether or not they were infected and could not be used as a marker of bacterial infection at this age. Copyright 2001 S. Karger AG, Basel