IgG Hypogammaglobulinemia One Year After Heart Transplantation: A Persistent Risk Factor for Severe Infection.

Abstract

Objective. We have previously described that IgG hypogammaglobulinemia (HGG: IgG<600 mg/dL) during the first month after transplantation is a risk factor for severe infection during the first year after heart transplantation. Our group remains concerned, however, about the persistence of this problem in a subgroup of patients long-term after transplantation and regarding its potential impact on infection risk. Hypothesis: HGG is a risk factor of severe infection long-term after transplantation. Objective: To characterize the prevalence of HGG and its impact on the prevalence of severe infections in heart recipients after the first year of transplantation. Methods. Design. Retrospective study. 122 heart recipients. IgG monitoring was performed at month 12 after transplantation by nephelometry. Clinical follow-up from one-year after transplantation to development of infection or latest visit: 24-111 months. Clinical outcomes: Severe infection defined as all infections that required antimicrobial therapy in hospital after the first year of transplantation. Statistics: Logistic regression. Results. The prevalence of HGG after transplantation was as follows: day 7 (35.4%), day 30 (50%), day 90 (33%), day 180 (23.7%), 1 year (18%). During the follow-up period after the first year of transplantation, 26 patients (21.3%) developed at least one episode of severe infection. Distribution of infection: Bacterial meningitis (n=1), bacterial pneumonia (n=10), other bacterial infections (n=6), CMV disease (n=5), other viral infection (n=1), systemic aspergillosis (n=1), intestinal strongyloidiasis (n=1), severe influenza A (n=1). HGG at month 12 was a risk factor of severe infection (Odds-ratio [OR] 24, p<0.001) and of deadly infections (OR 9.5, p=0.0037). Clinical variables that were associated with infection risk were: receptor negative for CMV serology and patients who had CMV or bacterial infections during the first year. In multivariate logistic regression analysis long-term HGG was an independent predictor of infection (OR 21, p<0.001) after adjustment by clinical variables. Conclusion: HGG at one year of heart transplantation is a risk factor of infection. IgG monitoring must be performed up to the first year after transplantation.