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

BACKGROUND

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

OBJECTIVES

We aimed to compare the effectiveness of the lymphocyte transformation test (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.