E. J. ter Borg, G. Horst, E. J. Hummel, P. C. Limburg and C. G. M. Kallenberg, “Predictive Value of Rises in Anti Double Strand DNA Antibody Levels for Disease Exacerbations in Systemic Lupus Erythematosus,” Ar thritis and Rheumatism, Vol. 33, No. 5, 1990, pp. 634 643. doi:10.1002/art.1780330505

has been cited by the following article:

• TITLE: Low Levels of Complement Factor C4 Not Always Implicate Disease Activity in Systemic Lupus Erythematosus

  AUTHORS: E. J. ter Borg, H. van Velzen-Blad, D. Hamann

  KEYWORDS: Complement; Homozygous C4A Isotype Deficiency; Systemic Lupus Erythematosus

  JOURNAL NAME: International Journal of Clinical Medicine, Vol.4 No.2, February 26, 2013

  ABSTRACT: A lupus patient with a clinically quiescent disease stage will be described who had severely depressed C4 levels while levels of C3 en CH50 were normal. Additional testing revealed a homozygous C4Aisotype deficiency as the cause of the very low C4 levels. It should be emphasized that in SLE, a (very) low C4 level does not always means (subclinical) disease activity.