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.
Cancer Research Center, Safra Children's Hospital, Chaim Sheba Medical Center, Tel Hashomer 52621, Israel.
Ninette
N
Amariglio
Atar
A
Lev
Amos
A
Simon
Ester
E
Rosenthal
Zvi
Z
Spirer
Ori
O
Efrati
Arnon
A
Broides
Gideon
G
Rechavi
Raz
R
Somech
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