Suppression of allo-human leucocyte antigen (HLA) antibodies secreted by B memory cellsin vitro: intravenous immunoglobulin (IVIg) versusa monoclonal anti-HLA-E IgG that mimics HLA-I reactivities of IVIg

Immunoglobulin (Ig)G purified from human sera mirrors intravenous Ig human leucocyte antigen (HLA) reactivity and recognizes one's own HLA types, but may be masked by Fab complementarity-determining region peptide in the native sera

“…Besides the questionable immunosuppressive effect of IVIg [34,35], as used routinely in transplant patients, there is the imminent danger of HLA-reactive IVIg preparations producing transfusion-related acute lung injury (TRALI). Variations in the IVIg preparation can make it more toxic.…”

Characterization of the Anti-HLA Class I and II IgG Antibodies in Moroccan IVIg Using Regular Beads and Ibeads in Luminex Multiplex Single Antigen Immunoassay

“…In addition to the above structural variants, a pool of β2m-free HLA as β2-free HC (β2fHC) was observed in proliferating human lymphoid cells [45], and in activated human T and B cells [46,47]. Binding of IVIg to activated T and B cells may bring about immunomodulation such as suppression of antibody production, which may be beneficial for patients with autoimmune diseases and organ transplants [48].…”

Immunobiology of HLA Class-Ib Molecules in Transplantation

“…Routinely, only HLA-Ia and -II antibodies are tested in transplant recipients, and HLA-Ib antibodies are never considered. However, various investigations [23,24,39,[104][105][106][107] of HLA-Ib antibodies showed that one molecule of HLA-Ib (with or without β2m) can elicit different kinds of mAbs, some recognizing strictly the HLA immunogen used in immunization. Alternatively, these antibodies (e.g., HLA-E mAb TFL-033) [23,39] can be considered monospecific since they react to only one HLA-Ib molecule.…”

“…Alternatively, these antibodies (e.g., HLA-E mAb TFL-033) [23,39] can be considered monospecific since they react to only one HLA-Ib molecule. The other antibodies generated by an HLA-Ib molecule (e.g., HLA-E mAbs TFL-006 and TFL-007) [24,106,107] can react to other HLA-I molecules at various levels. Such polyreactive binding (reacting with more than one HLA-Ib and/or -Ia molecule) can be a consequence of the antibodies recognizing the amino acid sequences common to the HLA molecules [23][24][25]104].…”