Comparison of De Novo Donor-Specific Anti-HLA Antibodies (DSAs) Between Living-Donor Lobar Lung Transplantation and Cadaveric Lung Transplantation

Recently, the importance of donor-specific anti-HLA antibodies (DSAs) has been pointed out in lung transplantation. We investigated various characteristics of DSAs, such as timing of initial DSA detection and its type of HLA classes, in living-donor lobar lung transplantation (LDLLT) and cadaveric lung transplantation (CLT) at a single lung transplant center in Japan. Since July 2010, anti-HLA antibodies have been prospectively screened periodically in 92 patients undergoing lung transplantation, using LABScreen Mixed (One Lambda, CA, USA). In addition, they were also investigated when recipients presented symptoms or abnormal findings. When anti-HLA antibodies were detected, their specificities were identified using LABScreen Single Antigen (One Lambda, CA, USA). HLA mismatches (A, B, and DR) were also investigated. Anti-HLA antibodies were screened in 47 patients with LDLLT and 45 patients with CLT before and after lung transplantation. DSA was detected in 2 patients (4%) preoperatively in LDLLT (class II, low MFI, negative flow cytometry crossmatch), but DSA diminished soon after lung transplantation. In contrast, DSA was detected in 2 patients (4%) preoperatively in CLT (class I, negative flow cytometry crossmatch), and DSA diminished after lung transplantation in 1 patient. Postoperatively, 10 patients (11%) had de novo DSAs. There were 2 patients in LDLLT (4%) and 8 patients in CLT (18%, p=0.037). In LDLLT, DSAs were initially detected more than 10 months postoperatively and were persistently detected in all patients. Class II DSAs were seen in all patients. On the other hand, in CLT, DSAs were detected within 5 months postoperatively in all patients (7 of 8 were within 2 months). Class I DSAs were seen in 7 patients and class II were seen in 4 patients (both class I and II in 3 patients). DSAs vanished in 5 out of 8 patients. HLA mismatches were 4.2±1.3 in patients with de novo DSA and 2.9±1.4 in patients without de novo DSA (p=0.002). Both in LDLLT and CLT, there were no differences in HLA mismatches between patients with and without de novo DSA (p=0.12 and 0.46). We confirmed that de novo DSAs were detected in LDLLT as well as CLT; however, we also found that timing of initial detection of de novo DSA and its type of HLA classes in LDLLT were different from those in CLT.