Correlation between Serum IgG, Platelet Membrane IgG, and Platelet Function in Hypergammaglobulinaemic States

Abstract

Platelet membrane IgG levels were measured by the complement lysis inhibition test, and were correlated with serum IgG levels in 29 patients with elevated immunoglobulins due to multiple myeloma, benign monoclonal gammopathy, systemic lupus erythematosis, rheumatoid arthritis, benign hypergammaglobulinaemic purpura and systemic infection. Platelet membrane IgG was increased in proportion to the elevation of serum IgG with a highly significant correlation coefficient (0.561 5 , P I O.OI), irrespective of the underlying disease state. Further

Platelet-Associated IgM Levels in Thrombocytopenia

“…In the present study, the mildly thrombocytopenic patient with macroglobulinemia had an elevated PAIgM and a markedly elevated PBIgM lev el. Whether or not this represents a specific antiplatelet IgM remains to be determined, since our experience as well as that of McGrath et al [8] indicates that platelets in patients with immunoglobulin disorders are readily coated with paraproteins indepen dent of the platelet count. Cheung et al [3] reported elevated levels of both PAIgG and PAIgM in adults and in children with acute and chronic ITP and SLE.…”

Hemorrhagic Diathesis in Multiple Myeloma

“…While several mechanisms may account for the abnormal hemostasis, it has been assumed to be secondary to the interference of the paraprotein on the reactions occurring at the platelet mem brane surface [4]. Abnormalities of bleed ing time, platelet adhesion, platelet factor 3 availability, and platelet aggregation have all been documented [1], There is a correlation between serum and plateletbound IgG, and the most severe abnor malities tend to occur in patients with the highest levels of platelet membrane IgG [5]. Platelet factor 3 availability has been demonstrated to improve with significant decrease in globulin concentration [2], While chemotherapy will often correct the abnormal hemostasis over a period of time, it is of little value in the patient with acute bleeding [6], In some of these cases plasma exchange represents a convenient and rapid way to reverse the bleeding dia thesis [7,8].…”

Detection of Platelet Antibodies: a Comparison of Three Techniques

“…With the QACA, Landolfi et al [9] also found an increased amount of platelet-associated IgG in patients suffering from chronic active hepatitis, and Thomas et al [17] detected immune complexes in the serum of patients with this disease. More over, McGrath et al [10], using the QACA, found an increased amount of surface IgG on the platelets of patients with elevated IgG serum levels due to multiple myeloma and the extent of the increase was related to the IgG level of the serum. This result could be explained by aspecific binding of parapro teins to the non-fixed platelets.…”