Table 2

Positivity rate of ANA, anti-dsDNA and anti-Sm antibodies, reduced C3, reduced C4 or combination of reduced C3 and/or C4 (reduced C3/C4), EC4d and BC4d in a population of 794 subjects14 14

SLE (n=304)Rheumatoid arthritis (n=161)Sjogren’s syndrome (n=33)Scleroderma (n=35)Polymyositis/dermatomyositis (n=27)Others (n=29)NHV (n=205)
Positivity rate (%) in each group
ANA≥20 units (%)89328966743110
Anti-dsDNA>301 units (%)33406070
Anti-Sm>10 units (%)14000000
Reduced C3 (%)334612006
Reduced C4 (%)32730444
Reduced C3/C4 (%)4510912448
EC4d>14 net MFI (%)46512911101
BC4d>60 net MFI (%)539964101
Net MFI (mean±SEM) in each group
EC4d net MFI21±37±110±27±18±18±15±1
BC4d net MFI106±632±226±432±527±446±1923±1
  • EC4d and BC4d are also expressed as average±SEM of net MFI. The group of subjects with other diseases included granulomatosis with polyangiitis (n=5), fibromyalgia (n=13), vasculitis (n=10) and antiphospholipid syndrome (n=1).14

  • Modified from Putterman et al.14

  • anti-SM, Smith antigen; dsDNA, double-stranded DNA; MFI, mean fluorescence intensity; NHV, normal healthy volunteers.