Immunoglobulin G dynamics and outcomes of hypogammaglobulinemia in liver transplant recipients

Hypogammaglobulinemia (HGG) is a common complication of liver transplantation (LT). However, the impact of underlying liver disease severity on post-LT immunoglobulin dynamics remains unclear. We aimed to evaluate the differences in serum immunoglobulin G (IgG) levels based on the pre-transplantation model for end-stage liver disease (MELD) scores. We collected data from patients who underwent LT between July 2016 and December 2022 at a tertiary hospital. Propensity score matching was performed between the low and high MELD groups and IgG dynamics were evaluated. The significance of peri-LT HGG on clinical outcomes was also evaluated. In a matched population (1:1 propensity score matching), the median serum IgG levels decreased significantly from 1,606.5 mg/dL pre-LT to 1,011.6 mg/dL 1-month post-LT. IgG levels before and after transplantation (1 month, 6 months, and 1 year) did not differ significantly between the groups. Overall, 36.0% of patients developed HGG within 1 year after transplantation. Multivariable Cox regression analysis showed that pre-LT HGG was independently associated with mortality. In conclusion, HGG is frequent complication in peri-LT period and pre-LT HGG is significantly associated with mortality. No significant difference in HGG according to the MELD score was observed.