Abstract
IVIG is occasionally used for preventing and treating severe infections of patients who are to undergo transplantation. Administration of IVIG, which includes high-titer antibodies (Abs) against HLA class I and II, might have a substantial influence on the HLA Ab test results of these patients. However, this issue has remained unreported. METHODS: Anti-HLA Ab titers were determined in 4 types of IVIG preparations, fresh frozen plasma, and the sera of 11 patients with hematological diseases before and after IVIG administration. RESULTS: Although anti-HLA Abs were not detected in any of the fresh frozen plasma products, various anti-HLA class I and II Abs were detected in all 4 IVIG preparations. Six out of 11 patients who had received IVIG showed a low titer of anti-HLA class II Abs, which were not detected before IVIG administration. Conversely, no anti-HLA class I Abs were detected in any of the 11 patients. Furthermore, all 4 (100%) patients who were positive for anti-HLA class II Abs initially and were assessable became negative for anti-HLA Abs after the discontinuation of IVIG treatment (median, d 79; range, d 22-192). CONCLUSIONS: IVIG preparations consist of high-titer anti-HLA class I and II Abs, but the latter can be transiently detected in the sera of patients who had received IVIG. When these patients are screened for the presence of donor-specific Abs, some may be incorrectly deemed positive for HLA class II Abs. Thus, caution is necessary when only donor-specific Abs specific to class II HLAs are detected in patients.