Infective Endocarditis and Valve Surgery in a Systemic Lupus Erythematosus Patient Following Splenectomy: A Case Report with Immunological Analysis.

Background/aim: Systemic lupus erythematosus (SLE) is an autoimmune disorder that leads to immune dysregulation and increased infection risk, especially with immunosuppressive therapies and surgical interventions like splenectomy. Immune monitoring in these patients is important. This case report aims to describe the immune changes in an SLE patient, who had received splenectomy, with infective endocarditis (IE) undergoing valve replacement surgery, focusing on immune cell dynamics and exhaustion markers.

Case report: A 42-year-old Taiwanese man with SLE and recent splenectomy was diagnosed with IE caused by Staphylococcus aureus, requiring mitral valve replacement surgery. Immune profiling between infection and recover phase showed immune regulation and reconstruction with increased exhaustion markers (killer cell lectin-like receptor subfamily G member 1 (KLRG1), T-cell immunoglobulin and mucin-domain containing-3 (Tim-3), programmed cell death protein 1 (PD-1)) in T cells, expanded regulatory T cells, increased plasmablasts, and decreased regulatory B cells.

Conclusion: SLE leads to significant immune dysregulation, making patients more susceptible to infections, especially when combined with immunosuppressive therapy. This case demonstrates dynamic changes in immune markers, such as KLRG1, Tim-3, and PD-1, following infection and surgery, highlighting the necessary for monitoring of immune function in SLE patients. Changes in T and B cell component emphasize the importance of tailored treatment strategies to keep immune imbalances in these patients. Ongoing research into immune tolerance and exhaustion mechanisms will be crucial for improving therapeutic outcomes in SLE.