Correlation between erythrocyte CR1 reduction and other blood proteinase
markers in patients with malignant and inflammatory disorders
MS Currie, M Vala, DS Pisetsky, CS Greenberg, J Crawford and HJ Cohen
Geriatric Research, Education and Clinical Center, Veterans Administration,
Medical Center, Durham, NC.
Erythrocyte CR1, a C3b/C4b-binding complement-regulatory protein, is
sensitive to proteolysis in vitro. To test the hypothesis that in vivo
erythrocyte CR1 reduction results from intravascular proteinase activities,
we used enzyme-linked immunosorbent assays to measure gamma- crosslinked
fibrin degradation products (D-dimers) as indicators of
coagulation/fibrinolytic activity, and complexes of neutrophil elastase
with alpha 1 proteinase inhibitor (E/A) as indicators of neutrophil enzyme
release in malignant and inflammatory disorders. Erythrocyte CR1, measured
by monoclonal anti-CR1 antibody binding, was inversely related to disease
activity and blood proteinase markers. Levels of erythrocyte CR1 were
significantly lower for patients with active versus remittent squamous and
small cell lung cancers, Hodgkin's and diffuse large cell lymphomas, and
acute myelogenous leukemias. In patients with active thoracic cancers,
elevated D-dimer levels correlated with reduction of CR1. In patients with
rheumatoid arthritis, CR1 reduction was correlated with elevated levels of
elastase complexes. Our findings substantiate the relationship of acquired
CR1 reduction to the activity of certain diseases and provide
circumstantial support for the hypothesis that erythrocyte CR1 is lost to
proteolysis in vivo. Although heritable differences in CR1 expression
reduce the interpretability of single measurements of erythrocyte CR1
levels, disease-associated CR1 reduction may be a useful indicator of
disorders with chronically increased blood proteinase activity.
Volume 75,
Issue 8,
pp. 1699-1704,
04/15/1990
Copyright © 1990 by The American Society of Hematology
