title: Intravenous gamma globulin decreases platelet-associated IgG and improves transfusion responses in platelet refractory states.
abstract: In an attempt to improve platelet transfusion responses, intravenous immunoglobulin (IV-IgG) was administered to 19 patients who were refractory to random and best available HLA-matched platelets. A response to IV-IgG was defined as two or more successive transfusions of HLA-matched products that provided recoveries greater than 30%. Thirteen of 19 (68%) patients responded to therapy at a median time of 7 days after initiation of IV-IgG (range = 2-17). Baseline platelet associated IgG levels (PalgG) were elevated in both the responders (61.6 +/- 76.2) (mean +/- SD) and the non-responders (47.0 +/- 46.3 fg/plt). Post-therapy, PalgG levels remained unchanged in the nonresponders but were decreased significantly (p = 0.05) to 11.1 +/- 6.2 fg/plt in the responders. The latter levels were similar to those (11.6 +/- 8.2 fg/plt) measured in a series of 36 transfusion responsive patients. This apparent decline in PalgG was not explained by differences in lymphocytotoxic antibodies (LCT-Ab) after therapy. Moreover, a high degree of alloimmunization was associated with a poorer response to IgG. Only two of eight patients with LCT panel-reactive antibody (PRA) of greater than 85% were responders. By contrast, improved transfusion outcomes were seen uniformly in patients with PRA greater than or equal to 85%. Improved recoveries were obtained using LCT-Ab compatible but not incompatible platelets. The median increment (% predicted) with compatible platelets before therapy was 6.0 +/- 9.9 (SD). Post-IgG, median recoveries were 37.0 +/- 31.2 percent, P less than 0.001. These findings suggest that IV-IgG may alter destructive mechanisms that affect the survival of compatible platelets in refractory patients.
authors.affiliation: Department of Medicine, Montefiore Hospital, Pittsburgh, Pennsylvania.
authors.forename: Z R
authors.initials: ZR
authors.lastname: Zeigler
authors.forename: R K
authors.initials: RK
authors.lastname: Shadduck
authors.forename: C S
authors.initials: CS
authors.lastname: Rosenfeld
authors.forename: A
authors.initials: A
authors.lastname: Winkelstein
authors.forename: D
authors.initials: D
authors.lastname: Przepiorka
authors.forename: J E
authors.initials: JE
authors.lastname: Kiss
authors.forename: R J
authors.initials: RJ
authors.lastname: Duquesnoy
authors.forename: M
authors.initials: M
authors.lastname: Marrari
mesh_terms: D000906:Antibodies / Q000032:analysis; D000961:Antilymphocyte Serum / Q000032:analysis; D001791:Blood Platelet Disorders / Q000628:therapy*; D001792:Blood Platelets / Q000378:metabolism*; D001803:Blood Transfusion; D006680:HLA Antigens / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism*; D007275:Injections, Intravenous; D012016:Reference Values; D005719:gamma-Globulins / Q000627:therapeutic use*
chemical_list: D000906:Antibodies; D000961:Antilymphocyte Serum; D006680:HLA Antigens; D007074:Immunoglobulin G; D005719:gamma-Globulins