A Comparison between LTT and CFSE Proliferation Tests in Patients with Inborn Errors of Adaptive Immunity

Abstract

Background: Inborn errors of immunity (IEI) include immunodeficiencies affecting cellular and humoral immunity.

Objectives: We aimed to compare the effectiveness of the LTT and carboxyfluorescein succinimidyl ester (CFSE) assays in assessing lymphocyte proliferation in IEI patients.

Methods: We utilized radioactive [3H]-thymidine and non-radioactive CFSE to measure lymphocyte proliferation in three distinct groups: syndromic CID (SyCID), non-syndromic combined immunodeficiency (N-SyCID), and primary antibody deficiency (PAD).

Results: LTT identified 8 cases of abnormal lymphocyte proliferation among all patients, whereas CFSE detected 23 cases. In the N-SyCID group, LTT identified more abnormalities than CFSE, whereas, in the SyCID and PAD groups, CFSE detected more defects. Two patients with ataxia telangiectasia and CVID had positive results on both LTT and CFSE tests, and a specific ORAI1 gene mutation resulted in differing test outcomes.

Conclusion: It was found that the CFSE method is a reliable and practical choice for measuring mitogenic T-cell responses in unclassified IEI patients for confirmation of immunologic diagnosis.

Keywords: CFSE.; Inborn errors of immunity; LTT; immunodeficiencies; lymphocyte proliferation.