. Author manuscript; available in PMC: 2012 Dec 1.

Published in final edited form as: Nat Rev Rheumatol. 2011 Nov 1;7(12):708–717. doi: 10.1038/nrrheum.2011.157

Table 4.

Studies of erythrocyte-bound or reticulocyte-bound C4d as biomarkers for disease activity assessment in SLE

Study	Number of cases	Findings	Matching or adjustments	Controls for treatment effect	Validated disease-activity measures used	Study design	Included patients with a wide range of DAS?
Singh et al. (2008)⁴⁸	111	Erythrocyte-bound C4d levels associated with disease activity but with low correlation	None	None	SELENA-SLEDAI	Cross-sectional	Not stated
Yang et al. (2009)⁴⁹	63	Erythrocyte-bound C4d levels correlated with disease activity	None	None	SLEDAI	Cross-sectional	No (SLEDAI score 6 ± 0.52)
Kao et al. (2010)⁵⁰	157	Erythrocyte-bound C4d levels correlated with disease activity	None	None	SLAM SELENA-SLEDAI	Longitudinal (5 years)	Yes
Liu et al. (2005)⁵¹	156	Erythrocyte-bound C4d and reticulocyte-bound C4d levels correlated with disease activity	None	None	SLAM SELENA-SLEDAI	Cross-sectional Longitudinal	Yes

Abbreviations: SELENA-SLEDAI, Safety of Estrogens in Lupus Erythematosus: National Assessment (SELENA)-Systemic Lupus Erythematosus (SLE) Disease Activity Index (SLEDAI); SLAM, Systemic Lupus Activity Measure.