Molecular assessment of thymus capabilities in the evaluation of T-cell immunodeficiency.
T-cell immunodeficiency may pose a diagnostic challenge to clinicians, especially when the basic T-cell immune workup is not sufficiently informative. An intensive assessment of thymus capabilities that involves either measuring the recent thymic emigrant cells or analyzing the T-cell receptor (TCR) repertoire is often required to estimate the severity and nature of the immune disorder. A comprehensive T-cell immune workup, including TCR excision circles (TRECs) and TCR repertoire analyses, was performed in three patients with various degrees of severity of T-cell immunodeficiency. All three patients had normal peripheral CD3+ T lymphocytes. TCR repertoire analysis revealed oligoclonal (patient 1), restricted (patient 2), and near-normal (patient 3) patterns. TREC quantification was significantly reduced in patients 1 and 2 but normal in patient 3. Based on clinical features at presentation and at follow-up, and supported by the results of immunologic studies, patients 1 and 2 were diagnosed as having significant T-cell immunodeficiency and patient 3 as having T-cell immunocompetence. Assessment of thymus capabilities by TRECs and TCR repertoire analyses is helpful in diagnosing patients with T-cell immunodeficiency and should be part of the evaluation of every patient suspected of having that condition.
Amariglio
Ninette
N
Cancer Research Center, Safra Children's Hospital, Chaim Sheba Medical Center, Tel Hashomer 52621, Israel.
Lev
Atar
A
Simon
Amos
A
Rosenthal
Ester
E
Spirer
Zvi
Z
Efrati
Ori
O
Broides
Arnon
A
Rechavi
Gideon
G
Somech
Raz
R
D018941:Antigens, CD19 / Q000032:analysis; D017252:CD3 Complex / Q000032:analysis; D002675:Child, Preschool; D005260:Female; D005434:Flow Cytometry; D015334:Gene Rearrangement, gamma-Chain T-Cell Antigen Receptor; D006801:Humans; D007121:Immunocompetence; D007153:Immunologic Deficiency Syndromes / Q000175:diagnosis* / Q000235:genetics / Q000276:immunology; D016130:Immunophenotyping; D007223:Infant; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D011948:Receptors, Antigen, T-Cell / Q000235:genetics*; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000235:genetics; D012720:Severity of Illness Index; D013601:T-Lymphocytes / Q000276:immunology*; D013950:Thymus Gland / Q000276:immunology*
D018941:Antigens, CD19; D017252:CD3 Complex; D011948:Receptors, Antigen, T-Cell; D016693:Receptors, Antigen, T-Cell, alpha-beta; D016692:Receptors, Antigen, T-Cell, gamma-delta