title: Reference ranges of lymphocyte subsets in healthy adults and adolescents with special mention of T cell maturation subsets in adults of South Florida.
abstract: BACKGROUND
  Analysis of peripheral blood lymphocyte subsets has become an essential tool in the evaluation of outcome of diagnostic and research related questions in immunological and pathological conditions. Periodic evaluation and establishment of normal lymphocyte reference ranges are required in clinical and research settings of various immunodeficiency disorders for evaluation of the significance of observations. It is also important that age and gender specific lymphocyte subset reference ranges should be locally established for meaningful comparison and accurate result interpretation as age plays a significant role in the development of immune system.
  
  
  METHODS
  We performed dual platform flow cytometry to determine reference ranges for lymphocyte subsets (CD3, CD4, CD8, CD19 [B cells] and CD16+CD56+ [Natural Killer - NK cells]) in 50 adolescents (age range: 12-18) and 100 adults (age range: 21-67) along with T cell maturation, activation and co-stimulatory molecules in healthy multiracial adult population of South Florida.
  
  
  RESULTS
  The lymphocyte reference ranges percentages [absolute counts - Abs, cells/μl] unadjusted for gender differences for adolescents are: CD3: 49-83 [939-2959]; CD4: 27-53 [467-1563]; CD8: 16-40 [259-1262]; CD19+ B cells: 8-31 [169-1297] and CD16+CD56+ NK cells: 3-30 [59-1178] and for adults are: CD3: 65-88 [983-3572]; CD4: 26-62 [491-2000]; CD8: 14-44 [314-2,087]; CD19+ B cells: 2-27 [64-800] and CD16+CD56+ NK cells: 2-27 [27-693]. The ranges for CD4:CD8 ratio for adolescents and adults are 0.7-2.6 and 0.6-4.4, respectively. Gender based analysis of relative percentages of lymphocyte subsets showed no significant differences between adult and adolescent males and females. The mean CD4:CD8 ratio was significantly higher in adult females than males (P=0.04) and in adolescents this difference was not significant between genders. The mean CD3 and CD4 T cell percentages were higher and CD19 cell percentages were lower in adults compared to adolescents (P<0.0001). Absolute lymphocyte counts showed a positive correlation with the absolute counts of CD3+, CD4+, CD8+, CD19+, CD16+CD56+, CD45RO+ and CD45RA+ cells (all correlations with P<0.0001 except CD45RO [P=0.01] and CD45RA [P=0.03]).
  
  
  CONCLUSIONS
  The reference values of peripheral blood lymphocyte subsets were analyzed in healthy adolescent and adult population of South Florida. This study indicates the need for periodic evaluation and establishment of lymphocyte reference ranges for patient population served based on gender and age since these could influence immune status and treatment outcome.
authors.affiliation: University of Miami - Miller School of Medicine, Miami, FL, USA. Electronic address: RValiathan@med.miami.edu.
authors.forename: Ranjini
authors.initials: R
authors.lastname: Valiathan
authors.affiliation: University of Miami - Miller School of Medicine, Miami, FL, USA.
authors.forename: Khaled
authors.initials: K
authors.lastname: Deeb
authors.affiliation: University of Miami - Miller School of Medicine, Miami, FL, USA.
authors.forename: Marc
authors.initials: M
authors.lastname: Diamante
authors.affiliation: University of Miami - Miller School of Medicine, Miami, FL, USA.
authors.forename: Margarita
authors.initials: M
authors.lastname: Ashman
authors.affiliation: University of Miami - Miller School of Medicine, Miami, FL, USA.
authors.forename: Naresh
authors.initials: N
authors.lastname: Sachdeva
authors.affiliation: University of Miami - Miller School of Medicine, Miami, FL, USA. Electronic address: DAsthan@med.miami.edu.
authors.forename: Deshratn
authors.initials: D
authors.lastname: Asthana
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D018941:Antigens, CD19 / Q000276:immunology / Q000378:metabolism; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D017252:CD3 Complex / Q000276:immunology / Q000378:metabolism; D016516:CD4-CD8 Ratio; D019002:CD56 Antigen / Q000276:immunology / Q000378:metabolism; D002648:Child; D005260:Female; D005431:Florida; D005434:Flow Cytometry; D006801:Humans; D007694:Killer Cells, Natural / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D018655:Lymphocyte Count; D016131:Lymphocyte Subsets / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D017452:Receptors, IgG / Q000276:immunology / Q000378:metabolism; D012016:Reference Values; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D055815:Young Adult
chemical_list: D018941:Antigens, CD19; D017252:CD3 Complex; D019002:CD56 Antigen; D017452:Receptors, IgG
keywords: Adolescents; Adults; Lymphocytes; Maturation subsets; Reference ranges