title: Polyclonal, newly derived T cells with low expression of inhibitory molecule PD-1 in tonsils define the phenotype of lymphocytes in children with Periodic Fever, Aphtous Stomatitis, Pharyngitis and Adenitis (PFAPA) syndrome.
abstract: OBJECTIVE
  PFAPA syndrome is a benign, recurrent inflammatory disease of childhood. Tonsillectomy is one of the therapeutic options with a yet unexplained biological mechanism. We tested whether specific lymphocyte subsets recruited from blood to human tonsils participate in PFAPA pathogenesis.
  
  
  METHODS
  Paired tonsils/peripheral blood (PB) samples were investigated (a) from children with PFAPA that successfully resolved after tonsillectomy (n=10) (b) from children with obstructive sleep apnoea syndrome as controls (n=10). The lymphocyte profiles were analysed using 8-colour flow cytometry, immunoglobulin (IGH) and T-cell receptor (TCR) gene rearrangements via PCR and next generation sequencing; a TREC/KREC analysis was performed using qPCR.
  
  
  RESULTS
  The PFAPA tonsils in the asymptomatic phase had a lower percentage of B-lymphocytes than controls; T-lymphocyte counts were significantly higher in PB. The percentages of cytotoxic CD8pos T-lymphocytes were approximately 2-fold higher in PFAPA tonsils; the transitional B cells and naïve stages of both the CD4pos and CD8pos T-lymphocytes with a low expression of PD-1 molecule and high numbers of TREC were also increased. With the exception of elevated plasmablasts, no other differences were significant in PB. The expression levels of CXCL10, CXCL9 and CCL19 genes were significantly higher in PFAPA tonsils. The IGH/TCR pattern showed no clonal/oligoclonal expansion. DNA from the Epstein-Barr virus, Human Herpervirus-6 or adenovirus was detected in 7 of 10 PFAPA tonsils but also in 7 of 9 controls.
  
  
  CONCLUSIONS
  Our findings suggest that the uninhibited, polyclonal response of newly derived lymphocytes participate in the pathogenesis of PFAPA. Because most of the observed changes were restricted to tonsils and were not present in PB, they partly explain the therapeutic success of tonsillectomy in PFAPA syndrome.
authors: Department of ENT, Charles University, 2nd Faculty of Medicine, Charles University Prague and University Hospital Motol, Czech Republic.
authors: Petra
authors: P
authors: Dytrych
authors: Petra
authors: P
authors: Krol
authors: Department of ENT, Charles University, 2nd Faculty of Medicine, Charles University Prague and University Hospital Motol, Czech Republic.
authors: Dytrych
authors: D
authors: Petra
authors: Pediatric Rheumatology Unit, Department of Pediatrics and Adolescent Medicine, Charles University Prague, and General University Hospital in Prague, 1st Faculty of Medicine, Czech Republic.
authors: Krol
authors: K
authors: Petra
authors: Michaela
authors: M
authors: Kotrova
authors: Daniela
authors: D
authors: Kuzilkova
authors: CLIP, Department of Paediatric Haematology/Oncology, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, Czech Republic.
authors: Kotrova
authors: K
authors: Michaela
authors: CLIP, Department of Paediatric Haematology/Oncology, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, Czech Republic.
authors: Kuzilkova
authors: K
authors: Daniela
authors: Petr
authors: P
authors: Hubacek
authors: Ladislav
authors: L
authors: Krol
authors: CLIP, Department of Paediatric Haematology/Oncology, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, Czech Republic; Department of Medical Microbiology, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, Czech Republic.
authors: Hubacek
authors: H
authors: Petr
authors: CLIP, Department of Paediatric Haematology/Oncology, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, Czech Republic.
authors: Krol
authors: K
authors: Ladislav
authors: Rami
authors: R
authors: Katra
authors: Ondrej
authors: O
authors: Hrusak
authors: Department of ENT, Charles University, 2nd Faculty of Medicine, Charles University Prague and University Hospital Motol, Czech Republic.
authors: Katra
authors: K
authors: Rami
authors: CLIP, Department of Paediatric Haematology/Oncology, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, Czech Republic.
authors: Hrusak
authors: H
authors: Ondrej
authors: Zdenek
authors: Z
authors: Kabelka
authors: Pavla
authors: P
authors: Dolezalova
authors: Department of ENT, Charles University, 2nd Faculty of Medicine, Charles University Prague and University Hospital Motol, Czech Republic.
authors: Kabelka
authors: K
authors: Zdenek
authors: Pediatric Rheumatology Unit, Department of Pediatrics and Adolescent Medicine, Charles University Prague, and General University Hospital in Prague, 1st Faculty of Medicine, Czech Republic.
authors: Dolezalova
authors: D
authors: Pavla
authors: Tomas
authors: T
authors: Kalina
authors: Eva
authors: E
authors: Fronkova
authors: CLIP, Department of Paediatric Haematology/Oncology, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, Czech Republic.
authors: Kalina
authors: K
authors: Tomas
authors: CLIP, Department of Paediatric Haematology/Oncology, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, Czech Republic. Electronic address: eva.fronkova@lfmotol.cuni.cz.
authors: Fronkova
authors: F
authors: Eva
mesh_terms: D000256:Adenoviridae / Q000235:genetics / Q000302:isolation & purification; D001402:B-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D054415:Chemokine CCL19 / Q000096:biosynthesis; D054357:Chemokine CXCL10 / Q000096:biosynthesis; D054370:Chemokine CXCL9 / Q000096:biosynthesis; D002648:Child; D002675:Child, Preschool; D005260:Female; D005335:Fever of Unknown Origin / Q000150:complications / Q000276:immunology* / Q000601:surgery; D004854:Herpesvirus 4, Human / Q000235:genetics / Q000302:isolation & purification; D015654:Herpesvirus 6, Human / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D007223:Infant; D008199:Lymphadenitis / Q000150:complications / Q000276:immunology / Q000601:surgery; D018655:Lymphocyte Count; D008297:Male; D014066:Palatine Tonsil / Q000166:cytology / Q000276:immunology* / Q000601:surgery; D010612:Pharyngitis / Q000150:complications / Q000276:immunology / Q000601:surgery; D061026:Programmed Cell Death 1 Receptor / Q000096:biosynthesis*; D011948:Receptors, Antigen, T-Cell / Q000235:genetics; D020181:Sleep Apnea, Obstructive / Q000276:immunology / Q000601:surgery; D013281:Stomatitis, Aphthous / Q000150:complications / Q000276:immunology / Q000601:surgery; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D014068:Tonsillectomy
chemical_list: C515460:CCL19 protein, human; C114753:CXCL10 protein, human; C080810:CXCL9 protein, human; D054415:Chemokine CCL19; D054357:Chemokine CXCL10; D054370:Chemokine CXCL9; C105992:PDCD1 protein, human; D061026:Programmed Cell Death 1 Receptor; D011948:Receptors, Antigen, T-Cell
keywords: Autoinflammatory disease; Chemokine; Flow cytometry; KREC; PD-1; PFAPA; T lymphocyte; T-cell receptor gene rearrangement; TREC; Tonsillectomy