Protein A immunoadsorption therapy in HIV-related immune thrombocytopenia: a preliminary report.
Nine homosexual patients with immune thrombocytopenia were treated with autologous plasma that had been perfused over silica-immobilized Staphylococcus aureus protein A (SpA). Pretreatment platelet counts ranged from 10,000 to 98,000 cells/mm3 (mean: 54,000 cells/mm3). Six patients responded to therapy. Platelets increased by a mean of 95,000 cells/mm3 (p less than 0.007) and reached normal levels (greater than 150,000 cells/mm3) in four patients. Increased platelet counts are presently sustained in these four individuals after 5 months of follow-up. Increases in platelet counts significantly correlated with decreases in platelet-associated IgG (PAIgG), platelet-directed IgG (PDIgG), and immune complexes (CIC). PAIgG and PDIgG declined by a mean of 67% (p less than 0.003) and 58% (p less than 0.007), respectively. CIC decreased by a mean of 37% (p = 0.02). Complement was concomitantly activated in all four examined patients. C3a and C5a increased 23-fold and 2.6-fold, respectively, while total hemolytic complement decreased by 50%. Activated complement components and removal of CIC and IgG thus may contribute to the platelet-enhancing activity of SpA immunoadsorption therapy.
Bertram
J H
JH
University of Southern California, Los Angeles.
Snyder
H W
HW
Gill
P S
PS
Shulman
I
I
Henry
D H
DH
Jenkins
D
D
Kiprov
D D
DD
D000163:Acquired Immunodeficiency Syndrome / Q000150:complications*; D000328:Adult; D000936:Antigen-Antibody Complex / Q000032:analysis; D001804:Blood Transfusion, Autologous; D003167:Complement Activation; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D007163:Immunosorbent Techniques; D007167:Immunotherapy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D011696:Purpura, Thrombocytopenic / Q000209:etiology / Q000628:therapy*; D013205:Staphylococcal Protein A
D000936:Antigen-Antibody Complex; D007074:Immunoglobulin G; D013205:Staphylococcal Protein A