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A Protein Microarray Assay for Serological Determination of Antigen-specific Antibody Responses Following Clostridium difficile Infection
Published on: June 15, 2018
Quantitation of alloantibody concentration can predict patient sensitivity to intravenous immunoglobulin
Pamela M Kimball1, Angela Owens, Eric Gibney
1Department of Transplant Surgery, Virginia Commonwealth University Hospital, Richmond, VA, USA. pkimball@gems.vcu.edu
Despite the success of intravenous immunoglobulin (IVIg) desensitization to reduce anti-human leukocyte antigen antibodies, its high failure rate and expense limit its usefulness. We speculated that quantitation of alloantibody concentration could allow early identification of IVIg resistant patients. Patients were described as nonresponders (n=3) or responders (n=8). Panel reactive antibodies (PRA) were determined using Flowbeads and concentration calculated as molecules of equivalent soluble fluorochrome (MESF). PRA was equivalent between nonresponders and responders before (97+/-3% vs. 76+/-20%, P=NS) and after 3 IVIg/plasmapheresis (PP) treatments but lower among responders at end-of-treatment (76+/-20% vs. 44+/-15%, P<0.01). In contrast, pretreatment MESFs were higher (333,640+/-241,352 vs. 38,741+/-5,133, P=0.006) among nonresponders than responders. During treatment, MESFs decreased (P<0.05) in 0 of 3 nonresponders vs. 8 of 8 responders. Final MESFs were higher among nonresponders than responders. We report that quantitation of MESFs allows early identification of IVIg/PP resistant patients. This sensitive and inexpensive technique should allow more effective patient selection and reduce the costs associated with desensitization.
Despite the success of intravenous immunoglobulin (IVIg) desensitization to reduce anti-human leukocyte antigen antibodies, its high failure rate and expense limit its usefulness. We speculated that quantitation of alloantibody concentration could allow early identification of IVIg resistant patients. Patients were described as nonresponders (n=3) or responders (n=8). Panel reactive antibodies (PRA) were determined using Flowbeads and concentration calculated as molecules of equivalent soluble fluorochrome (MESF). PRA was equivalent between nonresponders and responders before (97+/-3% vs. 76+/-20%, P=NS) and after 3 IVIg/plasmapheresis (PP) treatments but lower among responders at end-of-treatment (76+/-20% vs. 44+/-15%, P<0.01). In contrast, pretreatment MESFs were higher (333,640+/-241,352 vs. 38,741+/-5,133, P=0.006) among nonresponders than responders. During treatment, MESFs decreased (P<0.05) in 0 of 3 nonresponders vs. 8 of 8 responders. Final MESFs were higher among nonresponders than responders. We report that quantitation of MESFs allows early identification of IVIg/PP resistant patients. This sensitive and inexpensive technique should allow more effective patient selection and reduce the costs associated with desensitization.

