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Early thymectomy leads to premature immunologic ageing: An 18-year follow-up

2016; Elsevier BV; Volume: 138; Issue: 5 Linguagem: Inglês

10.1016/j.jaci.2016.05.014

1097-6825

Judith Gudmundsdottir, Sólveig Óskarsdóttir, Gabriel Skogberg, Susanne Lindgrén, Vanja Lundberg, Martin Berglund, Anna‐Carin Lundell, Håkan Berggren, Anders Fasth, Esbjörn Telemo, Olov Ekwall,

Neonatal Respiratory Health Research

Early thymectomy is routinely performed in infants undergoing cardiac surgery as the thymus lies anterior to the heart in the mediastinum obstructing the surgeon's access. Early cardiac surgery has become more common in the last decades and in Sweden, with close to 10 million inhabitants, approximately 250 infants are thymectomized (Tx) annually. The population of Tx individuals is thus increasing both in numbers and in age. The ultimate effect of early thymectomy is still obscure although immunologic alterations have been described. Lymphocyte subsets are affected with a T-cell lymphopenia, characterized by a decrease in naive T cells with a concomitant increase in the memory T-cell population.1van den Broek T. Delemarre E.M. Janssen W.J. Nievelstein R.A. Broen J.C. Tesselaar K. et al.Neonatal thymectomy reveals differentiation and plasticity within human naive T cells.J Clin Invest. 2016; 126: 1126-1136Crossref PubMed Scopus (62) Google Scholar, 2van Gent R. Schadenberg A.W. Otto S.A. Nievelstein R.A. Sieswerda G.T. Haas F. et al.Long-term restoration of the human T-cell compartment after thymectomy during infancy: a role for thymic regeneration?.Blood. 2011; 118: 627-634Crossref PubMed Scopus (42) Google Scholar, 3Prelog M. Keller M. Geiger R. Brandstatter A. Wurzner R. Schweigmann U. et al.Thymectomy in early childhood: significant alterations of the CD4(+)CD45RA(+)CD62L(+) T cell compartment in later life.Clin Immunol. 2009; 130: 123-132Crossref PubMed Scopus (85) Google Scholar The effects of thymectomy on the regulatory T (Treg)-cell population differ between studies. One study showed that although the absolute Treg-cell number was lower, the Treg-cell proportion was increased, albeit with a decrease in naive Treg cells.4Schadenberg A.W. van den Broek T. Siemelink M.A. Algra S.O. de Jong P.R. Jansen N.J. et al.Differential homeostatic dynamics of human regulatory T-cell subsets following neonatal thymectomy.J Allergy Clin Immunol. 2014; 133 (e1-6): 277-280Abstract Full Text Full Text PDF PubMed Scopus (15) Google Scholar T-cell receptor excision circles (TRECs) have consistently been found to decrease after thymectomy although to varying degrees.2van Gent R. Schadenberg A.W. Otto S.A. Nievelstein R.A. Sieswerda G.T. Haas F. et al.Long-term restoration of the human T-cell compartment after thymectomy during infancy: a role for thymic regeneration?.Blood. 2011; 118: 627-634Crossref PubMed Scopus (42) Google Scholar, 3Prelog M. Keller M. Geiger R. Brandstatter A. Wurzner R. Schweigmann U. et al.Thymectomy in early childhood: significant alterations of the CD4(+)CD45RA(+)CD62L(+) T cell compartment in later life.Clin Immunol. 2009; 130: 123-132Crossref PubMed Scopus (85) Google Scholar Studies published to date have not shown any alteration in overall disease risk, but generally the groups are small and often heterogeneous, with a lack of information on the amount of thymic tissue that was removed and with a short follow-up time. Here, we present results from a prospective study of the immunologic impact of early thymectomy (age, 90% thymic removal, n = 11) with blood samples collected preoperatively, at 18 months, and 18 years later. Group characteristics and clinical data are presented in Table E1, Table E2 (see this article's Online Repository at www.jacionline.org). Multivariate factor analysis (orthogonal projection to latent structures discriminant analysis) reveals a clear distinction between Tx individuals and healthy controls (Fig 1, A and B). A decrease in T-cell number was apparent and consistent over time in the Tx group (see Table E3 in this article's Online Repository at www.jacionline.org; Fig 1, C-G). Of interest is that the Tx group had a decreased number of lymphocytes, particularly T cells (Table E3; Fig 1, H), even preoperatively. At the 18-year follow-up, the number of naive helper T cells (CD45RA+) was lower in the Tx group than in controls (0.15 vs 0.49 × 109/L; P < .0001) whereas the memory helper T cells (CD45RO+) were unaffected (0.34 vs 0.30 × 109/L; P = .48), thereby showing a proportional increase in relation to the already low CD4+ T-cell number (Fig 1, I and J). In cytotoxic T cells, the same was true: absolute CD8+CD45RA+ naive T-cell number was lower in cases (0.11 vs 0.35 × 109/L; P = .0002) but the CD8+CD45RO+ memory T-cell number was unaffected (0.11 vs 0.13 × 109/L; P = .27) (Fig 1, K and L). The cell surface marker CD31 has been defined as a marker of recent thymic emigrants.5Kimmig S. Przybylski G.K. Schmidt C.A. Laurisch K. Mowes B. Radbruch A. et al.Two subsets of naive T helper cells with distinct T cell receptor excision circle content in human adult peripheral blood.J Exp Med. 2002; 195: 789-794Crossref PubMed Scopus (379) Google Scholar Tx individuals showed a lower proportion of CD31+ helper T cells (55% vs 81%; P = .034), but with a wide range (25% to 89%), whereas the results for the control group were higher and not as wide-ranging (76% to 90%) (Fig 1, M). There was a linear correlation between naive CD4+ and CD8+ cells, indicating that Tx individuals were similarly affected in both subsets (Fig 1, N). Also, the Tx group (black circles) is clearly distinct from the control group (open circles) with a lower number of both CD4+ and CD8+ naive T cells. The total number of Treg cells was lower in the Tx group than in controls (0.035 vs 0.053 × 109/L; P = .0417) (Fig 2, A). The proportions, however, were unaffected (6.5% vs 6.1%; P = .54) (Fig 2, B). Further analysis of the Treg-cell subset reveals that the Tx group showed a decreased number of naive Treg cells but no effect on the memory subset number, resulting in a higher percentage of memory Treg cells in the Tx group (Fig 2, C-F). However, the Treg-cell subset CD4+CD45RA−CD25++ that has been shown to have the greatest suppressive potential6Miyara M. Yoshioka Y. Kitoh A. Shima T. Wing K. Niwa A. et al.Functional delineation and differentiation dynamics of human CD4+ T cells expressing the FoxP3 transcription factor.Immunity. 2009; 30: 899-911Abstract Full Text Full Text PDF PubMed Scopus (1654) Google Scholar did not differ between the groups (Fig 2, G and H). Flow cytometry gating strategies are shown in Fig E1 in this article's Online Repository at www.jacionline.org. Analysis of T-cell receptor variable chain β (TCR Vβ) usage in CD4+ and CD8+ cells showed that Tx individuals had signs of oligoclonality, which was particularly striking for the CD8+ cells (Fig 2, I). Perturbations in Tx individuals defined as a TCR Vβ chain usage deviating more than ±3 SD from the mean value was noted in 8 out of 10 individuals regarding CD8+ cells and in 6 out of 11 regarding CD4+ cells, whereas only a single chain in 1 control was affected (see Table E4 in this article's Online Repository at www.jacionline.org). Individual TCR Vβ family usage is provided in Fig E2 and flow cytometry gating strategy in Fig E3 in this article's Online Repository at www.jacionline.org. TREC PCR analysis showed nondetectable values in 10 out of 11 Tx individuals (Fig 2, J), whereas the controls had a wide distribution of TREC content. The Tx individuals had shorter telomere length in their CD8+ T-cell population compared with the controls, 2.66 versus 3.32, P = .036 (Fig 2, K), as measured by a telomere/single gene ratio according to a method originally described by Cawthon in 2002.7Cawthon R.M. Telomere measurement by quantitative PCR.Nucleic Acids Res. 2002; 30: e47Crossref PubMed Google Scholar The Tx CD4+ T-cell population also had shorter telomeres, 2.73 versus 3.32, but this difference did not reach statistical significance with a P value of .068. The telomere length in CD19+ B cells was unaffected by thymectomy (3.03 vs 3.45; P = .2335).Fig 2Treg-cell number (A) and proportion (B). Naive Treg-cell (CD4+CD25+CD127lowCD45RA+) number (C) and proportion (D). Memory Treg-cell (CD4+CD25+CD127lowCD45RO+) number (E) and proportion (F). Highly suppressive Treg-cell (CD4+CD45RA-CD25++) number (G) and proportion (H). Results shown as individual values with mean and SD; P value summary indicated on each graph. I, TCR Vβ chain usage in CD8+ cells and CD4+ cells presented as a scatter graph. Thymectomized (Tx) = red dots, controls = blue dots. Difference in usage of chains Vβ3 and Vβ14 in CD8+ cells statistically significant, indicated by arrows (Holm-Sidak method for multiple t-test comparison, α = 0.05). Nomenclature according to Wei et al.9Wei S. Charmley P. Robinson M.A. Concannon P. The extent of the human germline T-cell receptor V beta gene segment repertoire.Immunogenetics. 1994; 40: 27-36Crossref PubMed Scopus (146) Google Scholar J, TRECs per 106 cells. K, Telomere/single gene ratio in CD4+, CD8+ T cells, and CD19+ B cells. Fig 2, all data from 18 years follow-up. Data shown as individual values with mean and SD; P value summary indicated on graph. ns, Not significant. *P ≤ .05 and **P ≤ .01.View Large Image Figure ViewerDownload Hi-res image Download (PPT) This prospective study of the immunologic impact of early thymectomy shows a quantitative defect in the T-cell compartment primarily affecting the naive T-cell population with a probable peripheral T-cell proliferation of seeded clones leading to increased proportions of memory T cells. Treg cells seem to be affected to the same extent as other T cells with diminished numbers. The T-cell receptor repertoire is skewed with signs of oligoclonality, the thymic output severely affected with a near-absence of TRECs, and the replicative potential presumably decreased as indicated by a shorter T-cell telomere length. In general, these results are indicative of a persistent and severe immunologic dysfunction even 18 years after thymectomy. To investigate whether thymectomy has any clinical consequences, a future large-scale epidemiologic study would be of value. We gratefully acknowledge all assistance provided by staff at the Queen Silvia Children's Hospital and the Department of Clinical Immunology, Sahlgrenska University Hospital. Individuals born between 1993 and 1995 with a cardiac malformation demanding surgical correction at age less than 6 months (n = 19) were identified preoperatively at the Queen Silvia Children's Hospital, Sahlgrenska University Hospital in Gothenburg, Sweden. The operating surgeon assessed that more than 90% of the thymic tissue was removed during the operation. Patients with syndromic cardiac malformation or a known genetic disorder were excluded from the study. Blood samples were drawn preoperatively and at age 18 months; at the time of blood collection, participants had no signs of infection. For comparison at age 18 months, 10 otherwise healthy children undergoing minor surgery (mainly urological) at the same hospital were recruited. At age 18 months, lymphocyte subset analysis on fresh samples was done. The participants were contacted again 18 years later (median age, 18.7 years; range, 17.2-19.9 years) and asked to participate in a follow-up study. Eleven agreed to take part and answered a questionnaire regarding their general health, vaccinations, infections, allergies, autoimmune diseases, and cancer. An equal number of healthy age-matched controls were recruited (median age, 18.4 years; range, 17.1-19.9 years). Blood was drawn from a peripheral vein at Sahlgrenska University Hospital or the nearest health care center with express delivery to the research center within 24 hours. The blood samples were analyzed for lymphocyte subsets, TCR Vβ usage, TRECs, and telomere length. Participants showed no signs of infection at the time of blood collection. Informed consent was obtained, and the Regional Ethical Review Board at University of Gothenburg, Gothenburg, Sweden, approved the study. PBMCs were isolated with Ficoll-Paque density gradient centrifugation (GE Healthcare Life Sciences, Little Chalfont, Buckinghamshire, United Kingdom), and fresh cells were analyzed directly for CD3+, CD4+, CD8+, CD16/56+, CD19+, and CD45+ cell markers (Multitest 6-Color TBNK Reagent), recent thymic emigrants CD4+CD45RA+CD31+, and TCR Vβ chain usage. The remaining cells were viably frozen using 15% dimethyl sulphoxide in FCS and stored in a −80°C freezer. Analyses of naive (CD3+CD4+CD45RA+ and CD3+CD8+CD45RA+), memory (CD3+CD4+CD45RO+ and CD3+CD8+CD45RO+), and regulatory (CD3+CD4+CD25+CD127low) T cells were performed on thawed cryopreserved PBMCs incubated with a panel of mAbs to CD3-APC-H7, CD4-PerCP-Cy5.5, CD8-PE-Cy7, CD45RO-FITC, CD45RA-APC, CD25-BV421, and CD127-PE. Analysis of recent thymic emigrants was done on fresh samples using a panel of mAbs to CD4-APC, CD45RO-FITC, CD45RA-APC-H7, and CD31-PE. All antibodies were from BD Biosciences, Franklin Lakes, NJ. The multicolor analyses were performed on a FACS Canto II flow cytometer and results analyzed using FlowJo Data analysis software version 10.0.7 (FlowJo LLC, Ashland, Ore). Further information on gating strategy is provided in Fig E1 in this article's Online Repository at www.jacionline.org. To ensure optimal flow cytometer performance, setup, and reproducibility of results, CS&T research beads (BD Biosciences) were used daily and CD-Chex Plus (Streck, Omaha, Neb) weekly according to manufacturer's instructions. TCR Vβ repertoire was analyzed using IOTest Beta Mark (Beckman Coulter Inc, Brea, Calif) according to manufacturer's instructions on fresh cells directly after isolation. Cells were also stained with CD4-PE-Cy5 (Beckman Coulter Inc) and CD8-Pacific Blue (BD Biosciences). Approximately 200,000 cells were incubated in each well, giving a minimum of 10,000 CD4+ or CD8+ cell count for all but 2 cases of suboptimal CD8+ cell count thus excluded from further analysis. The samples were processed on a FACS Canto II flow cytometer and the data processed with FlowJo Data analysis software version 10.0.7 (FlowJo LLC). Genomic DNA was isolated using the Q1Amp Blood Mini Kit (Qiagen, Venlo, The Netherlands) according to instructions. Before the PCR reaction, the purified DNA concentration was determined by ultraviolet spectrophotometry and adjusted to a concentration of 30 ng/μL with dH2O. The real-time PCR analysis was performed on a Roche LightCycler instrument. The signal joint TREC primer sequences were forward (5′-CAT CCC TTT CAA CCA TGC TGA CAC CTC T-3′) and reverse (5′-CGT GAG AAC GGT GAA TGA AGA GCA GAC A-3′) (Scandinavian Gene Synthesis AB, Köping, Sweden).E1Hochberg E.P. Chillemi A.C. Wu C.J. Neuberg D. Canning C. Hartman K. et al.Quantitation of T-cell neogenesis in vivo after allogeneic bone marrow transplantation in adults.Blood. 2001; 98: 1116-1121Crossref PubMed Scopus (103) Google Scholar PCR reactions were done in triplicates with a final reaction volume of 20 μL containing 2 μL LightCycler FastStart DNA Master SYBR Green I, 2 μL sample DNA (30 ng/μL), 2 × 0.5 μL primer solution (forward and reverse; 0.5 μM), 2.4 μL MgCl2 (4 μM), and 12.6 μL dH2O. Amplification of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) reference gene was done in the same plate with GAPDH primer sequences forward (5′-CAG CCC CTT CAT ACC CTC A 3′) and reverse (5′-GGA CCA TAT TGA GGG ACA CA 3′). The reaction setup was composed of step 1: 95°C for 10 minutes, step 2: 45 cycles of 10 seconds at 95°C (denaturation), 5 seconds at 62°C to 72°C "touch down" (annealing), and finally step 3: 6 seconds at 72°C (elongation), followed by 1 cycle of melting (95°C for 0 second, 72°C for 10 seconds, 95°C for 0 seconds) and a cooling step to 40°C for 30 seconds. The TREC number was estimated by extrapolating sample quantities from a standard curve acquired by serial dilutions (108, 107, 106, 105, 104, 103, 102, and 101) of a pCR2.1-human TREC and pCR2.1-GAPDH gene plasmids (Eurofins MWG Operon).E2Sottini A. Ghidini C. Zanotti C. Chiarini M. Caimi L. Lanfranchi A. et al.Simultaneous quantification of recent thymic T-cell and bone marrow B-cell emigrants in patients with primary immunodeficiency undergone to stem cell transplantation.Clin Immunol. 2010; 136: 217-227Crossref PubMed Scopus (86) Google Scholar In every PCR reaction, the plasmids were included in 1 concentration as standards as well as a positive control consisting of human cord blood DNA (30 ng/μL, rich in TRECs) and a negative control (dH2O). The number of TRECs was estimated according to the following formula: (Mean of TRECs quantity/(Mean of GAPDH quantity/2)) × 106 = number of TREC molecules per 106 cells. The mean quantity of GAPDH was divided by 2 because of the biallelic occurrence of this gene. Frozen PBMCs (−80°C) were thawed; the cells were pelleted, resuspended, and stained with CD4-FITC, CD8-BV421, CD19-PE, CD14-APC, and CD56-APC (BD Biosciences). CD4, CD8, and CD19 cell populations were then sorted (i-Cyt Synergi cell sorter, Sony Biotechnology Inc, San Jose, Calif) with purity of more than 95% after sorting. DNA was isolated from CD4, CD8, and CD19 cell subsets (QIAamp DNA mini kit, QIAcube, Qiagen, Venlo, the Netherlands) according to manufacturer's instructions. Telomere length was estimated using a quantitative PCR method described by CawthonE3Cawthon R.M. Telomere measurement by quantitative PCR.Nucleic Acids Res. 2002; 30: e47Crossref PubMed Scopus (2535) Google Scholar that allows an estimation of the relative telomere length from a ratio of the telomere (T) repeat copy number to a single (S) gene copy number (RPLP0). The telomere primer sequences were (5′-GGT TTT TGA GGG TGA GGG TGA GGG TGA GGG TGA GGG T-3′) and (5′-TCC CGA CTA TCC CTA TCC CTA TCC CTA TCC CTA TCC CTA-3′) with a final reaction concentration of 270 and 900 nM, respectively. The RPLP0 primer sequences were (5′-CAG CAA GTG GGA AGG TGT AAT CC-3′) and (5′-CCC ATT CTA TCA TCA ACG GGT ACA A-3′) with a final reaction concentration of 400 nM. The genomic DNA amount was 5 ng per reaction for all samples. Two samples were excluded from analysis because of limited yield; in those samples, the DNA concentration was 4.64 (from CD8 cells, thymectomy) and 3.16 (CD19, control) ng per reaction. The quantitative PCR reaction was performed with TATAA SYBR GrandMaster Mix # TA01 (TATAA Biocenter, Gothenburg, Sweden) in a final 10 μL reaction volume in duplicate on a LightCycler 480 instrument (Roche, Basel, Switzerland). Detection was performed in the SYBR channel. All pipetting was performed by robot (EpMotion 5070, Eppendorf, Germany). The quantitative PCR temperature protocol began with an initiation step at 95°C for 180 seconds followed by an amplification step consisting of 40 cycles of (1) 95°C for 5 seconds (denaturation), (2) 54°C for 15 seconds (anneal), and (3) 72°C for 20 seconds (elongation and fluorescent measurement). Finally, gradual heating from 60°C to 95°C for 10 seconds gave a postreaction melting curve. Assay evaluation was done on a pool of DNA samples from CD4+ and CD8+ cells. An 8-point standard curve was generated with 4 replicates in each point and run in 4-fold dilution steps. The dilution series covered a template concentration between 50 ng/μL and 0.003 ng/μL. The reaction volume and components were prepared and thermal cycling and analysis were done as described above. Linear polyacrylamide carriers were added to the dilution series to avoid unspecific interactions of the target. The telomere assay receives high efficiency and linearity when excluding the 3 lowest STD (50-0.195 ng/μL used in the calculation of efficiency), whereas the RPLP0 assay receives high efficiency and linearity when excluding the lowest STD (50-0.012 ng/μL used in the calculation of efficiency). For every thymectomized individual (Tx), a healthy age- and sex-matched control was recruited. All statistical analyses were done with Graphpad Prism version 6.0b (Graphpad Software Inc, San Diego, Calif). To assess quantitative differences in cell populations between Tx and controls, the t test for unpaired data was used for all variables with a Gaussian distribution whereas the Mann-Whitney test was used for a few variables (CD8+, CD19+ at 18 m and CD56+; Treg cells and CD8+CD45RO+ absolute numbers) that differed from normality when tested using the D'Agostino and Pearson omnibus normality test. The unpaired t test was also used comparing TRECs and relative telomere lengths between groups. TCR Vβ was analyzed by defining whether each individual's Vβ-chain usage deviated more or less than 3 SD from the mean of the controls using Fisher exact test. The comparison of TCR Vβ chain usage between the 2 groups was done using the Holm Sidak multiple comparison test. Multivariate orthogonal projection to latent structures discriminant analysis was implemented to examine whether Tx individuals and healthy controls could be discriminated on the basis of various immune variables assessed (SIMCA-P+ software, Umetrics, Umeå, Sweden). All data were scaled to unit variance so that all the variables were given equal weight regardless of their absolute value. The quality of the latent structures discriminant analysis model was based on the variable R2 (ie, the goodness of fit of the model) and Q2 (ie, how well a variable can be predicted by a model).Fig E2Individual CD4+ (above) and CD8+ (below) T-cell TCR Vβ clonograms. Thymectomized (A) and controls (B); CD4+. Thymectomized (C) and controls (D); CD8+. Shown as the percentage of CD4+ or CD8+ T cells expressing each TCR Vβ family. Nomenclature of TCR Vβ families according to Wei et al.E4Wei S. Charmley P. Robinson M.A. Concannon P. The extent of the human germline T-cell receptor V beta gene segment repertoire.Immunogenetics. 1994; 40: 27-36Crossref PubMed Scopus (162) Google ScholarView Large Image Figure ViewerDownload Hi-res image Download (PPT)Fig E2Individual CD4+ (above) and CD8+ (below) T-cell TCR Vβ clonograms. Thymectomized (A) and controls (B); CD4+. Thymectomized (C) and controls (D); CD8+. Shown as the percentage of CD4+ or CD8+ T cells expressing each TCR Vβ family. Nomenclature of TCR Vβ families according to Wei et al.E4Wei S. Charmley P. Robinson M.A. Concannon P. The extent of the human germline T-cell receptor V beta gene segment repertoire.Immunogenetics. 1994; 40: 27-36Crossref PubMed Scopus (162) Google ScholarView Large Image Figure ViewerDownload Hi-res image Download (PPT)Fig E3Flow cytometry analysis of TCR Vβ for both CD4+ and CD8+ T cells. A representative plot from 1 individual is shown. Each vial of antibodies contains 3 mAbs, 1 PE, 1 FITC, and 1 a combination of the 2, giving a total of 24 different specificities toward the different TCR Vβ families.View Large Image Figure ViewerDownload Hi-res image Download (PPT)Table E1Sex, type of congenital heart defect, and age at operationPatientSexType of heart defectAge at thymectomy (d)1FAS1072FCoA103FTGA644MFallot1385MVSD616MTGA67FVSD508FTGA1489FVSD13310MTGA611MTGA48AS, Aorta stenosis; CoA, coarctation of the aorta; F, female; Fallot, Fallots tetralogy; M, male; TGA, transposition of the great arteries; VSD, ventricular septal defect. Open table in a new tab Table E2Reported clinical data from a questionnaire answered by participants and parents at 18-year follow-upClinical dataThymectomized (no. 11)Controls (no. 10)Acute otitis media97 <10 per individual in total64 ≥10 per individual in total33Surgery related to recurrent otitis media13Pneumonia52Frequent respiratory infections71Severe infection (hospital admission)61Autoimmune disease (any)11Allergy (any)52 Open table in a new tab Table E3Number of lymphocytes, CD4+ and CD8+ T cells, CD19+ B cells, and CD16+/56+ natural killer cells analyzed preoperatively, at age 18 months, and at 18-year follow-up shown as mean cell number × 109/L with 95% CI and P value using either the unpaired t test or the Mann-Whitney test as appropriateStageCellThymectomized (×109/L)95% CIControls(×109/L)95% CIP valuePreopLymphocytes3.672.75-4.60NACD4+1.721.24-2.21—CD8+0.620.43-0.80—CD19+0.850.33-1.37—CD16+/56+0.400.12-0.69—18 moLymphocytes2.991.80-4.184.253.15-5.35.0925CD4+0.790.43-1.151.901.39-2.41.0014CD8+0.520.27-0.771.000.67-1.33.0144CD19+0.940.52-1.360.980.65-1.31.5870CD16+/56+0.370.08-0.660.200.11-0.30.371718 yLymphocytes1.411.10-1.731.871.62-2.13.0202CD4+0.550.45-0.660.830.67-1.00.0050CD8+0.290.18-0.400.530.40-0.67.0038CD19+0.270.16-0.380.220.17-0.27.3157CD16+/56+0.260.10-0.430.190.15-0.24.9099NA, Not analyzed. Open table in a new tab Table E4TCR Vβ usage in CD8+ and CD4+ cells in thymectomized and controlsThymectomyOligoclonality CD8+Vβ chainOligoclonality CD4+Vβ chain1YesVβ21.3No2YesVβ2,3,5.1,5.3,12,14YesVβ7.23YesVβ3,5.1,12,14No4YesVβ13.2No5NoNo6YesVβ1,12,14,23YesVβ17YesVβ5.1YesVβ13.68YesVβ1,3,5.1,5.3,8,11,13.6,23YesVβ89NoNo10YesVβ1YesVβ2211NAYesVβ5.1,17ControlsOligoclonality CD8+Vβ chainOligoclonality CD4+Vβ chain1NoNo2NANo3NoNo4NoNo5NoNo6YesVβ13.2No7NoNo8NoNo9NoNo10NoNo11NoNoNA, Not analyzed.Nomenclature according to Wei et al.E4Wei S. Charmley P. Robinson M.A. Concannon P. The extent of the human germline T-cell receptor V beta gene segment repertoire.Immunogenetics. 1994; 40: 27-36Crossref PubMed Scopus (162) Google Scholar Oligoclonality is defined as Vβ usage exceeding ±3SD from the mean of the controls. Open table in a new tab AS, Aorta stenosis; CoA, coarctation of the aorta; F, female; Fallot, Fallots tetralogy; M, male; TGA, transposition of the great arteries; VSD, ventricular septal defect. NA, Not analyzed. NA, Not analyzed. Nomenclature according to Wei et al.E4Wei S. Charmley P. Robinson M.A. Concannon P. The extent of the human germline T-cell receptor V beta gene segment repertoire.Immunogenetics. 1994; 40: 27-36Crossref PubMed Scopus (162) Google Scholar Oligoclonality is defined as Vβ usage exceeding ±3SD from the mean of the controls.