Determination of T-cell subpopulations and intracellular cytokine production (interleukin-2, interleukin-4, and interferon-c) by cord blood T-lymphocytes of neonates from atopic and non-atopic parents Hagendorens MM, Van Bever HP, Schuerwegh AJ, De Clerck LS, Bridts CH, Stevens WJ. Determination of T-cell subpopulations and intracellular cytokine production (interleukin-2, interleukin-4, and interferon-c) by cord blood T-lymphocytes of neonates from atopic and non-atopic parents. Pediatr Allergy Immunol 2000: 11: 12±19. # Munksgaard, 2000 This report describes the results of a prospective study on immunological markers in cord blood for the prediction of allergic diseases in children. First we evaluated methodological aspects of the ¯ow cytometric technique on cord blood cytokine measurements. Subsequently, the T- cell subsets and percentage of cytokine-producing cord blood T-helper (Th) and T-suppressor/cytotoxic lymphocytes of neonates from atopic and non-atopic parents were compared. A group of 33 healthy, full-term newborn infants of whom 23/33 were at risk for atopy (i.e. having at least one parent with one or more atopic symptoms and positive speci®c immunoglobulin E [IgE] to at least one common inhalant allergen) was studied. A ¯ow cytometric technique was used to analyze cord blood T- cell subsets and to determine the percentage of interleukin (IL)-2-, IL-4-, and interferon-c (IFN-c)-producing cord blood Th and T-suppressor/ cytotoxic lymphocytes following stimulation with phorbol 12-myristate 13-acetate (PMA) and ionomycin. The percentage of CD3 (T lymphocytes), CD3 + CD4 + (Th lymphocytes), CD3 + CD8 + (T-suppressor/cytotoxic lymphocytes), CD19 + (B lymphocytes), CD3 + CD4 + CD45RO + (memory Th lymphocytes), and CD3 + CD4 + CD45RA + (naive Th lymphocytes) cells was unrelated to parental atopic status. PMA stimulation augmented the percentage of IL-2- and IFN-c-producing Th and T-suppressor/cytotoxic lymphocytes, whereas the number of IL-4-producing T lymphocytes remained very low or undetectable. No differences in the percentage of IL-2-, IL-4- and IFN-c-producing Th and T-suppressor/cytotoxic lymphocytes were found between neonates from atopic and non-atopic parents. These results will be re-evaluated when the atopic status of the children at the age of 1 and 2 years can be assessed. Margo M. Hagendorens 1 , Hugo P. Van Bever 1 , Annemie J. Schuerwegh 2 , Luc S. De Clerck 2 , Chris H. Bridts 2 and Wim J. Stevens 2 Departments of 1 Paediatrics and 2 Immunology, Allergology and Rheumatology, University of Antwerp, UIA, Antwerp, Belgium Key words: allergy; atopy; cord blood; cytokines; interleukin-2; interleukin-4; interferon-c Professor Dr W. J. Stevens, UIA University of Antwerp, Department of Immunology, Allergology and Rheumatology, Universiteitsplein 1, 2610 Antwerp, Belgium. Tel.: +32 3820 25 95 Fax: +32 3820 26 55 Accepted 19 September 1999 Over the last 25 years, the prevalence of atopic diseases has increased considerably in developed countries, especially in children and young adults (1). Atopy is associated with a T-helper 2 (Th2) cytokine pro®le (interleukin [IL]-4 and IL-5), as opposed to the T-helper 1 (Th1) pro®le (IL-2 and interferon-c [IFN-c]), which is a feature of non- atopics (2±4). It has been accepted that the development of atopic diseases is in¯uenced by the interaction between environmental exposure Pediatr Allergy Immunol 2000: 11: 12±19 Printed in UK. All rights reserved Copyright # Munksgaard 2000 PEDIATRIC ALLERGY AND IMMUNOLOGY ISSN 0905-6157 12