Long-term immunological changes after corrective cardiac surgery.

Area of Science:

• Pediatric Immunology
• Cardiothoracic Surgery
• Immunosenescence

Background:

• Congenital heart disease (CHD) often necessitates thymectomy during corrective cardiac surgery (CCS).
• The long-term immunological consequences of early thymectomy, including infection susceptibility and impaired immune tolerance, are not fully understood.

Purpose of the Study:

• To investigate the long-term immunological effects of thymectomy performed in infancy.
• To assess immune tolerance mechanisms, susceptibility to infections, allergies, and autoimmunity in patients with a history of early thymectomy.

Main Methods:

• Prospective follow-up of 22 infants undergoing thymectomy for CHD.
• Comprehensive immunological evaluation including immunoglobulins, vaccine responses, T-cell subsets (CD4+ naive, recent thymic emigrants, memory), T-cell proliferation, and T-cell receptor excision circles (TRECs).

Main Results:

• 27% of patients exhibited lymphopenia, with decreased naive and recent thymic emigrant T cells and increased memory T cells, indicating early immunosenescence.
• Low IgG, IgA, and IgM levels were observed in 36%, 40%, and 22% of patients, respectively.
• While 90% had positive vaccine responses, 22% developed allergic diseases; autoimmunity was not detected.

Conclusions:

• Infancy thymectomy leads to permanent immunological alterations, characterized by early immunosenescence and potential defects in immune tolerance.
• Recommendations include preserving thymic tissue during surgery and long-term monitoring for infections, allergies, and autoimmunity.