Table 1.

Immunological abnormalities in first-degree relatives of SLE patients

Biomarkers	Abnormality*	Comments
Plasma IgG	Raised2,4	Inverse correlation with blood NKT cells
Plasma IgM	Reduced (females)4	Inverse correlation with blood NK cells
Pokeweed mitogen-induced IgG	Raised2	High capacity for IgG production
B lymphocytes	Increased frequency in lymphocyte pool (females)3
T lymphocytes	Activated state (females)17	Indirect evidence of T cell activation
Miscellaneous	Variable frequency of abnormalities among different relative types5,12	Suggestive of environmental or epigenetic influences in their inheritance
Autoantibodies	Presence of anti-DNA and other autoantibodies1,12,13,15
Pro-inflammatory and regulatory cytokines/mediators	High or altered levels of IFN-α, IFN-induced and other proteins13,16

^*Abnormality observed in both male and female relatives unless specified.