Bloods
FBC (pancytopenia), CRP (normal), ESR (raised), U+E, GFR, Cr
(renal disease), LFTs (low Alb), clotting
Immune screen: ANA [sensitive, not specific], dsDNA [not sensitive, specific], C3/C4 [low], anti-Sm, anti-RNP, anti-histone [drug induced], anti-phospholipids; also check ANCA, RF, CCP, Anti ENA [Ro, La])