Kinetics of anti-CMV antibodies after administration of intravenous immunoglobulins to bone marrow transplant recipients.

Polyspecific iv immunoglobulins (IVIG) are routinely used to prevent cytomegalovirus (CMV) infections in bone marrow transplant recipients; however, the plasma disappearance pattern of CMV-specific antibodies after administration of this product remains unclear because conflicting kinetic data have been reported previously. We studied the half-life of CMV-specific antibodies in 9 patients undergoing bone marrow transplantation after administration of 500 mg/kg of a conventional polyspecific IVIG preparation (Sandoglobulin, Sandoz Pharmaceuticals). Eight serial blood samples were drawn for kinetic evaluation after the dose. The titer of CMV-specific antibodies in the sample was determined by the FIAX method, and the decay curves of CMV-specific antibodies were analyzed kinetically using model-independent method. The 9 kinetic curves showed that a titer above 20 Fiax units was maintained for only 7 days after dosing. The mean half-life of CMV-specific antibodies was 5.6 days (range 3.5 to 12.5 days), indicating that their elimination rate was much faster than that found in several other studies. Our results suggest that the optimal dosing interval for these products is around 1 week in bone marrow transplant recipients.