Perioperative ABO Blood Group Isoagglutinin Titer and the Risk of Acute Kidney Injury after ABO-Incompatible Living Donor Liver Transplantation

Abstract

For ABO-incompatible liver transplantation (ABO-i LT), therapeutic plasma exchange (TPE) is performed preoperatively to reduce the isoagglutinin titer of anti-ABO blood type antibodies. We evaluated whether perioperative high isoagglutinin titer is associated with postoperative risk of acute kidney injury (AKI). In 130 cases of ABO-i LT, we collected immunoglobulin (Ig) G and Ig M isoagglutinin titers of baseline, pre-LT, and postoperative peak values. These values were compared between the patients with and without postoperative AKI. Multivariable logistic regression analysis was used to evaluate the association between perioperative isoagglutinin titers and postoperative AKI. Clinical and graft-related outcomes were compared between high and low baseline and postoperative peak isoagglutinin groups. The incidence of AKI was 42.3%. Preoperative baseline and postoperative peak isoagglutinin titers of both Ig M and Ig G were significantly higher in the patients with AKI than those without AKI. Multivariable logistic regression analysis showed that preoperative baseline and postoperative peak Ig M isoagglutinin titers were significantly associated with the risk of AKI (baseline: odds ratio 1.06, 95% confidence interval 1.02 to 1.09; postoperative peak: odds ratio 1.08, 95% confidence interval 1.04 to 1.13). Cubic spline function curves show a positive relationship between the baseline and postoperative peak isoagglutinin titers and the risk of AKI. Clinical outcomes other than AKI were not significantly different according to the baseline and postoperative peak isoagglutinin titers. Preoperative high initial and postoperative peak Ig M isoagglutinin titers were significantly associated with the development of AKI. As the causal relationship between high isoagglutinin titers and risk of AKI is unclear, the high baseline and postoperative isoagglutinin titers could be used simply as a warning sign for the risk of AKI after liver transplantation.

Keywords: ABO blood-group system; acute kidney injury; anti-ABO blood type antibody; isoagglutinin; liver transplantation; living donor; therapeutic plasma exchange.

Figure 1

Distribution of the initial baseline (A) and postoperative peak (B) Ig G and Ig M isoagglutinin titers of the patients (n = 130). Ig = immunoglobulin. Data symbol is depicted where there is a case with each specific Ig G and Ig M titer.

Figure 2

Anti-ABO blood type Ig G (A) and Ig M (B) isoagglutinin titers at baseline, pre-liver transplantation, and postoperative peak between patients with and without postoperative acute kidney injury. Pre-liver transplantation refers to the titer measured before the day of transplantation and postoperative peak titer was determined as the highest value during the postoperative two weeks. * Significant difference between groups (p < 0.05). Ig = immunoglobulin. The top edge of each box shows the mean value and the error bar shows standard deviation.

Figure 3

Cubic spline function curve relating initial baseline isoagglutinin titers of Ig M (A) and Ig G (B) and postoperative peak titers of Ig M (C) and Ig G (D) to the risk of acute kidney injury in ABO-incompatible liver transplantation. Ig = immunoglobulin. Shaded area represents 95% confidence interval of each estimated probability.

Figure 4

Laboratory results after liver transplantation between the high and low postoperative peak Ig M isoagglutinin titer groups (high group: peak Ig M titer ≥ 32; low group: peak Ig M titer ≤ 16). Laboratory values, including total bilirubin (A), aspartate aminotransferase (B), alanine aminotransferase (C), prothrombin time: international normalized ratio (D), serum creatinine (E), and estimated glomerular filtration rate (F) are depicted during postoperative day 1 to 14. * = significant difference between groups (p < 0.05); Ig = immunoglobulin; eGFR = estimated glomerular filtration rate. The top edge of each box shows the mean value, and the error bar shows standard deviation.