Hypogammaglobulinemia in liver transplant recipients: incidence, timing, risk factors, and outcomes.

Background: Recent studies suggest a substantial incidence of posttransplant hypogammaglobulinemia and an association with infection.

Methods: We conducted a retrospective analysis of immunoglobulin (Ig) G levels from blood prospectively collected during a randomized double-blind placebo-controlled trial of cytomegalovirus (CMV) immune globulin that included 146 patients who underwent liver transplantation between December 1987 and June 1990. Serum samples collected at baseline and approximately weeks 4, 8, 12, 16, 24, and 32 posttransplant were analyzed. Hypogammaglobulinemia was defined as having at least one IgG level below 560 mg/dl. A variety of variables were analyzed as potential risk factors and outcomes of hypogammaglobulinemia.

Results: A total of 613 samples from 112 patients were analyzed. Twenty-nine (26%) patients had posttransplant hypogammaglobulinemia. Fourteen (12.5%) had hypogammaglobulinemia at the time of their baseline measurement. There was a strong association between hypogammaglobulinemia and both one-year (P=0.0490) and five-year mortality (P=0.0187), even when adjusted for variables known to be associated with mortality (HR for one-year mortality 3.08, confidence interval 1.20, 7.91). Risk factors for hypogammaglobulinemia included only non A/non B hepatitis and "other diagnosis" (a category made up of rare causes of liver disease). None of the infectious outcomes examined, including CMV infection, CMV disease, bacteremia or invasive fungal disease, or rejection were significantly associated with hypogammaglobulinemia.

Conclusions: In orthotopic liver transplant recipients we found a 26% incidence of posttransplant hypogammaglobulinemia. Approximately half of these patients were hypogammaglobulinemic at baseline. A strong association between hypogammaglobulinemia and mortality was seen. Prospective studies are needed to further elucidate the risk factors and outcomes of posttransplant hypogammaglobulinemia.