Plasma C3d/C3 quotient as a parameter for in vivo complement activation

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Abstract

Plasma levels of C3 and C3d in 30 healthy donors and 58 patients with systemic lupus eryththematosus were determined by rocket immunoelectrophoresis and Con-A affinoimmunoelectrophoresis. Significantly decreased levels of C3 were found in approximately 50% of the SLE sera. Slight increases of free C3d were found in 55%, and marked increases in 9% of the SLE sera; the remaining SLE sera did not show increased C3d levels. When results were expressed as quotients of plasma C3d/C3, a significant pattern emerged and 70% of the SLE sera clearly fell outside the normal range. 10% of the SLE sera had normal C3d/C3 indices but had markedly depressed C3 levels. We conclude that in cases where total serum C3 is not markedly reduced (less than 60% of normal), the C3d/C3 quotient may be a more sensitive parameter for assessing in vivo complement activation than C3 of C3d determinations alone.

References (8)

  • S. Bhakdi et al.

    J. Immunol. Methods

    (1984)
  • I. Brandslund et al.

    J. Immunol. Methods

    (1981)
  • J.A. Charlesworth et al.

    J. Clin. Invest.

    (1974)
  • J.J. Miller et al.

    Arthritis Rheum.

    (1979)
There are more references available in the full text version of this article.

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This work forms part of a doctoral dissertation by W. Nürnberger to be presented to the Fachbereich Humanmedizin, University of Giessen.

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