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Seven IVIG preparations have been licensed in the U.S.: all seven for
use in primary immunodeficiencies, five for idiopathic
thrombocytopenia, and one for chronic lymphocytic leukemia.
For these disease groups, the limited comparative data
available reveal no differences in efficacy among the
licensed preparations. For the other uses of IVIG, there is
insufficient information to choose one product over another
or to know whether each has comparable activity. Given the
large number of conditions for which IVIG may have potential
value, the prescribing physician should be aware of the
demonstrated efficacy of each IVIG preparation to treat a
specific disorder. The products and their quality are under
the control of commercial firms who must meet general
regulatory guidelines of the Center for Biologics Evaluation
and Research of the Food and Drug Administration. These
include tests for sterility, pyrogenicity, purity, and
safety. It is required also to measure antibody levels
against polio, measles, hepatitis B, and diphtheria. At the
present time, there is no requirement to identify hepatitis
C virus in IVIG preparations. Epidemiologic data support the
quality and safety of current products. However, guidelines
and monitoring methods must be developed as information
about transmission of hepatitis C virus and other infectious
diseases becomes better defined. Consideration should be
given to screening donors for hepatitis C.
Confidence in the capacity of a given preparation to
accomplish the desired end result would be enhanced if a
more rigorous procedure were established for using IVIG to
prevent or treat infections caused by specific
microorganisms. The availability of antibody titers to a
wider range of pathogens would permit a more rational basis
for the choice of a specific product in situations where
immunotherapy is directed to a restricted number of
infectious agents. Because the factor essential for the
effectiveness of IVIG in a number of disorders, such as ITP
and Kawasaki syndrome, is unknown, it is not possible to
predict efficacy of a given preparation of IVIG for any of
these disease processes In conclusion, this shows that IVIG preparations are not all equally well tolerated in patients. The data suggest that, perhaps to a comparable extent to the preparation itself, the infusion rate has a major effect. If a reduction in the infusion rate does not minimize side-effects, one should consider switching the IVIG formulation |
