Secondary antibody deficiency is associated with development of infection in kidney transplantation: results of a multicenter study.

BACKGROUND We performed a multicenter study to assess the association between secondary antibody deficiency (IgG hypogammaglobulinemia combined with low levels of specific antibodies) and development of infection in kidney transplantation. METHODS We prospectively analyzed 250 adult kidney recipients at 4 centers. The assessment points were before transplantation and 7 and 30 days after transplantation. The immune parameters were as follows: IgG, IgA, and IgM and complement factors C3 and C4 tested by nephelometry; specific IgG antibodies to cytomegalovirus (CMV) and IgG and IgG2 antibodies to pneumococcal polysaccharide (anti-PPS) determined by ELISA. The clinical follow-up period lasted 6 months. The clinical outcomes were CMV disease and recurrent bacterial infections requiring antimicrobial therapy. STATISTICS Multivariate logistic regression. RESULTS At day 7, IgG hypogammaglobulinemia (IgG levels < 700 mg/dL) combined with low IgG anti-CMV antibody titers (defined as levels < 10000 units) was present in 12% of kidney recipients. IgG hypogammaglobulinemia combined with low IgG anti-PPS antibody titers (defined as levels < 10 mg/dL) at one month after kidney transplantation were recorded in 16% of patients. At day 7 the combination of IgG hypogammaglobulinemia and low anti-CMV titers was independently associated with development of CMV disease (odds ratio [OR], 6.95; 95% confidence interval, 1.17-41.31; p=0.033). At day 30 after transplantation, the combination of IgG < 700 mg/dL and IgG anti-PPS < 10 mg/dL, was independently associated with recurrent bacterial infection (OR, 5.942; 95% CI, 1.943-18.172; p=0.002). CONCLUSION In a prospective multicenter study, early immunologic monitoring of secondary antibody deficiency proved useful for the identification of kidney recipients who developed severe infection.