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.