Not all antibodies are the same.
C1q is a protein component of the complement system, which is part of the immune system. In kidney transplantation, C1q is used as a biomarker to help identify patients who are at greater risk of developing antibody-mediated rejection (AMR).
AMR is a type of rejection that can occur after kidney transplantation when the recipient's immune system produces antibodies against the transplanted kidney. These antibodies can cause damage to the transplanted kidney and lead to graft loss .
Studies have shown that the presence of C1q-binding DSAs is associated with an increased risk of developing AMR and graft loss. Therefore, monitoring for C1q-binding DSAs can help identify patients who may benefit from more aggressive immunosuppressive therapies or alternative treatment options [1,2,3].
In addition, some centers also use C1q as a part of their pre-transplant screening process to identify which potential kidney donors may be of higher risk for a particular individual . Donors against whom the recipient has C1q-binding DSAs may be excluded from donating to that patient to reduce the risk of developing AMR post-transplant.
Similar to the the One Lambda™ LABScreen™ Single Antigen Bead assay, our C1qScreen™ assay uses a bead-based assay where beads are coated with purified HLA molecules. Human serum and purified C1q molecules are then added. A specific antibody will bind to the HLA molecules, and C1q will bind to any complement-binding antibodies. The beads are then washed, and a secondary anti-C1q antibody labeled with a fluorescent tag is added. This secondary antibody will bind to any C1q-bound onto HLA antibodies present on the beads, and the level of fluorescence is measured. The amount of fluorescence is directly proportional to the level of complement-binding antibodies present in human serum.
The C1qScreen assay is a highly sensitive and specific test for detecting complement-binding antibodies.
C1qScreen (#C1Q) assay is CE-IVD: For In Vitro Diagnostic Use. (European Union Only). Product is CE-IVD marked but not 510(k)-cleared and not available for sale in the U.S. Availability of product in each country depends on local regulatory marketing authorization status.