title: Paneth cells in the developing gut: when do they arise and when are they immune competent?
abstract: Little is known about the perinatal development of Paneth cells (PCs) during gestation and the relation with necrotizing enterocolitis (NEC). We aimed to investigate when PCs arise and when they become immune competent during gestation.
  
  
  
  We included 57 samples of ileum tissue of fetuses/infants with a gestional age (GA) between 9 and 40 wk taken as part of a standard autopsy procedure. Hematoxylin-eosin staining and anti-human defensin 5 immunohistochemistry were performed. We performed a semi-quantitative assessment of (immune-competent) PC numbers per 10 crypts per tissue section per GA.
  
  
  
  The number of PCs and the number of immune-competent PCs increased with increasing GA (Spearman's ρ = 0.41, P = 0.002 and ρ = 0.61, P < 0.001, respectively). Whereas significantly higher PC numbers were observed after 37 wk gestation (median 7, range 0-12) compared to preterm infants (median 0, range 0-15; P = 0.002), we counted higher numbers of immune-competent PCs already in infants with GA above 29 wk (median 6, range 0-18) compared to infants with GA under 29 wk (median 2, range 0-9; P < 0.001).
  
  
  
  The significant increase of immune-competent PCs starting from a GA of 29 wk mimics the rise in incidence of NEC during a similar postmenstrual age in preterm infants.
authors.affiliation: Department of Pediatric Surgery, Beatrix Children's Hospital, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.|Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Fardou H
authors.initials: FH
authors.lastname: Heida
authors.affiliation: Department of Pediatric Surgery, Beatrix Children's Hospital, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.|Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Gaia
authors.initials: G
authors.lastname: Beyduz
authors.affiliation: Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Marian L C
authors.initials: ML
authors.lastname: Bulthuis
authors.affiliation: Department of Neonatology, Beatrix Children's Hospital, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Elisabeth M W
authors.initials: EM
authors.lastname: Kooi
authors.affiliation: Department of Neonatology, Beatrix Children's Hospital, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Arend F
authors.initials: AF
authors.lastname: Bos
authors.affiliation: Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Albertus
authors.initials: A
authors.lastname: Timmer
authors.affiliation: Department of Pediatric Surgery, Beatrix Children's Hospital, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Jan B F
authors.initials: JB
authors.lastname: Hulscher
mesh_terms: D020345:Enterocolitis, Necrotizing / Q000196:embryology* / Q000276:immunology*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007082:Ileum / Q000196:embryology / Q000276:immunology; D007107:Immune System; D015994:Incidence; D007231:Infant, Newborn; D007234:Infant, Premature; D007422:Intestines / Q000196:embryology* / Q000276:immunology*; D008297:Male; D015588:Observer Variation; D019879:Paneth Cells / Q000166:cytology* / Q000276:immunology*; D013997:Time Factors; D023084:alpha-Defensins / Q000378:metabolism
chemical_list: D023084:alpha-Defensins