- Email: [email protected]
72-P
96
72-P
Abstracts / Human Immunology 73 (2012) 49–167
C1Q BINDING ASSAY: A SUPERIOR TOOL TO MONITORING ANTI-DQ DONOR SPECIFIC ANTIBODY REMOVAL THERAPY? Kamal Abuarquob 1, Timothy Williams 1, Alan Leichtman 2, Chisa Yamada 1, Kevin M. Chan 2, Milagros Samaniego-Picota 2, Randall Sung 3, Daniel Ramon 1. 1 Department of Pathology, University of Michigan Health System, Ann Arbor, USA; 2 Department of Internal Medicine, University of Michigan Health System, Ann Arbor, USA; 3 Department of Surgery, University of Michigan Health System, Ann Arbor, USA. Aim: The association between HLA-DQ Donor Specific Antigen (DSA) and chronic antibody mediated rejection (AMR) has been reported in several cohort studies, and anti-DQ is the most frequent detected DSA after solid organ transplantation. Unlike Class I or HLA-DR DSA, anti-DQ DSA show little improvement with current antibody removal protocols as demonstrated by persistently elevated IgG Mean Fluorescent Intensity (MFI) values (MFI > 7000). Here we compare IgG and C1q single antigen measurements to monitor the response to antibody removal therapy. Methods: Post transplant de novo anti-DQ DSA in one kidney and one lung recipient were tested by single antigen IgG and C1q binding assay (One Lambda). Samples were collected before, during and after antibody removal treatment with plasmapheresis and IVIG. Results were correlated with organ function by creatinine level and FEV1 in the kidney and lung recipients, respectively. Results: Changes in IgG and C1q MFI measurements during treatment are represented in the Table 1 and Fig. 1. Both patients IgG levels remain over MFI > 10,000 after treatment. In contrast, the values of C1q show a decline with treatment that correlates with improving creatinine in the kidney recipient. FEV1appears to stabilize when the C1q MFI is < than 1000 in the lung recipient.
Conclusions: Based on these results, C1q MFI measurements is superior to IgG MFI monitoring during antibody removal therapy to reduce anti–DQ DSA. The combination of these two assays may improve the characterization and the management of AMR due to anti-DQ DSA.
72-P
Abstracts / Human Immunology 73 (2012) 49–167
C1Q BINDING ASSAY: A SUPERIOR TOOL TO MONITORING ANTI-DQ DONOR SPECIFIC ANTIBODY REMOVAL THERAPY? Kamal Abuarquob 1, Timothy Williams 1, Alan Leichtman 2, Chisa Yamada 1, Kevin M. Chan 2, Milagros Samaniego-Picota 2, Randall Sung 3, Daniel Ramon 1. 1 Department of Pathology, University of Michigan Health System, Ann Arbor, USA; 2 Department of Internal Medicine, University of Michigan Health System, Ann Arbor, USA; 3 Department of Surgery, University of Michigan Health System, Ann Arbor, USA. Aim: The association between HLA-DQ Donor Specific Antigen (DSA) and chronic antibody mediated rejection (AMR) has been reported in several cohort studies, and anti-DQ is the most frequent detected DSA after solid organ transplantation. Unlike Class I or HLA-DR DSA, anti-DQ DSA show little improvement with current antibody removal protocols as demonstrated by persistently elevated IgG Mean Fluorescent Intensity (MFI) values (MFI > 7000). Here we compare IgG and C1q single antigen measurements to monitor the response to antibody removal therapy. Methods: Post transplant de novo anti-DQ DSA in one kidney and one lung recipient were tested by single antigen IgG and C1q binding assay (One Lambda). Samples were collected before, during and after antibody removal treatment with plasmapheresis and IVIG. Results were correlated with organ function by creatinine level and FEV1 in the kidney and lung recipients, respectively. Results: Changes in IgG and C1q MFI measurements during treatment are represented in the Table 1 and Fig. 1. Both patients IgG levels remain over MFI > 10,000 after treatment. In contrast, the values of C1q show a decline with treatment that correlates with improving creatinine in the kidney recipient. FEV1appears to stabilize when the C1q MFI is < than 1000 in the lung recipient.
Conclusions: Based on these results, C1q MFI measurements is superior to IgG MFI monitoring during antibody removal therapy to reduce anti–DQ DSA. The combination of these two assays may improve the characterization and the management of AMR due to anti-DQ DSA.