Abatacept as a Long-Term Targeted Therapy for LRBA Deficiency

Area of Science:

• Immunology
• Genetics
• Pediatric Medicine

Background:

• LPS-responsive beige-like anchor (LRBA) deficiency is characterized by recurrent infections, autoimmunity, and lymphoproliferation.
• The long-term efficacy of abatacept for immune dysregulation in LRBA deficiency requires further investigation.

Purpose of the Study:

• To characterize the clinical and immunological features of LRBA deficiency.
• To evaluate the long-term effectiveness of abatacept in managing LRBA deficiency manifestations.

Main Methods:

• Prospective follow-up of 22 LRBA-deficient patients.
• Clinical and immunological assessments every 3 months for 18 patients on abatacept.
• Flow cytometry analysis of LRBA expression, lymphocyte subsets, and T follicular helper cells.

Main Results:

• Common features include recurrent infections (86.4%), immune dysregulation (81.8%), and lymphoproliferation (72.7%).
• Abatacept demonstrated long-term control of lymphoproliferation, diarrhea, and autoimmune cytopenias.
• More frequent abatacept administration (weekly/bi-weekly) improved disease control; T follicular helper cells correlated with disease activity.

Conclusions:

• Long-term abatacept therapy is effective for the majority of patients with LRBA deficiency.
• Abatacept successfully manages immune dysregulatory features and lymphoproliferation.
• T follicular helper cell counts can serve as a biomarker for treatment efficacy in LRBA deficiency.