Immunoglobulin replacement in patients with chronic lymphocytic leukemia (CLL): kinetics of immunoglobulin metabolism.
Chapel HM, Lee M Clin Immunol. 1992 Jan;12(1):17-20..
Department of Immunology, John Radcliffe Hospital, Oxford, UK.
Fifteen
patients with low-grade B-cell tumours were given 3-weekly infusions
for 1 year of intravenous immunoglobulin (IVIg) at a dose of 0.4 g/kg.
Serial measurements of serum IgG levels were made; analysis of eight
samples taken at intervals after the end of the last (17th) infusion
showed that the half-life of IgG in such patients was no shorter than
in normal individuals. To look at the average rates of catabolism of
IgG during the year serum IgG was measured at four time points (pre,
post, day 7, and day 21) after the 5th, 8th, 13th, and 17th infusions;
these data showed that there were no changes in catabolism. Finally,
there was a significant correlation (P less than 0.005) between the
pretreatment serum IgG level and the increase to the mean trough level
achieved after the fifth and subsequent infusions (in each individual).
These data suggest that the catabolic rate of IgG is normal in patients
with low-grade B-cell tumours and that it is not altered by regular
IVIg infusions once a steady state is reached. Significant correlation
of the increment of serum IgG with the endogenous synthesis level
supports the theory that the IgG half-life is proportional to the IgG
level at any given time.
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