Monitoring of early humoral immunity to identify lung recipients at risk for development of serious infections: A multicenter prospective study

Abstract

Background: Infection is still a leading cause of death during the first year after lung transplantation. We performed a multicenter study among teaching hospitals to assess monitoring of early humoral immunity as a means of identifying lung recipients at risk of serious infections.

Methods: We prospectively analyzed 82 adult lung recipients at 5 centers in Spain. Data were collected before transplantation and at 7 and 30 days after transplantation. Biomarkers included IgG, IgM, IgA, complement factors C3 and C4, titers of antibodies to pneumococcal polysaccharide antigens (IgG, IgA, IgM) and antibodies to cytomegalovirus (IgG), and serum B-cell activating factor (BAFF) levels. The clinical follow-up period lasted 6 months. Clinical outcomes were bacterial infections requiring intravenous anti-microbial agents, cytomegalovirus (CMV) disease, and fungal infections requiring therapy.

Results: We found that 33 patients (40.2%) developed at least 1 serious bacterial infection, 8 patients (9.8%) had CMV disease, and 10 patients (12.2%) had fungal infections. Lower IgM antibody levels against pneumococcal polysaccharide antigens at Day 7 (defined as <5 mg/dl) were a risk factor for serious bacterial infection (adjusted odds ratio [OR] 3.96; 95% confidence interval [CI] 1.39 to 11.26; p = 0.0099). At Day 7 after transplantation, IgG hypogammaglobulinemia (defined as IgG <600 mg/dl) was associated with a higher risk of CMV disease (after adjustment for CMV mismatch: OR 8.15; 95% CI 1.27 to 52.55; p = 0.028) and fungal infection (adjusted OR 8.03, 95% CI 1.51 to 42.72; p = 0.015). Higher BAFF levels before transplantation were associated with a higher rate of development of serious bacterial infection and acute cellular rejection.

Conclusion: Early monitoring of specific humoral immunity parameters proved useful for the identification of lung recipients who are at risk of serious infections.

Keywords: BAFF; hypogammaglobulinemia; infection; lung transplantation; risk factors.