TABLE 2.

Anti-ENA antibodies most commonly detected by different methods and their performance characteristicsa

ENAMajor clinical associationsCIEPELISAIBComments
SeSpSeSpSeSp
SS-ASjogren’s syndrome85-9550-6090-9745-5070-8540-50Conformational epitopes on 52- and 60-kDa SS-A antigen best detected by CIEP; IB is unreliable because of denaturation of epitopes by SDS-PAGE
SLE25-3050-6035-6045-5010-1540-50
SS-BSjogren’s syndrome70-8060-7075-8550-6090-9555-65Linear epitopes on 48-kDa SS-B antigen best detected by IB; CIEP is less sensitive but more specific
SLE10-1550-5520-3045-5030-3540-50
SmSLE30-3598-10035-5055-9930-3595-99ELISA specificity may be improved by use of highly purified or recombinant antigens; IB is more specific than ELISA
U1 RNPMixed CTD90-9560-7595-9850-6080-8565-75ELISA specificity may be improved by use of highly purified or recombinant antigens; IB is more specific than ELISA
SLE15-3555-7550-6050-5530-4055-70
Scl-70Scleroderma25-3595-9930-4580-9030-4590-95CIEP is less sensitive because of the low negative charge on Scl-70 antigen at pH 8.0; this factor can be improved by running gel electrophoresis at pH 8.4
SLE0-50-520-2515-2510-205-10Anti-Scl-70 antibodies detected by ELISA in SLE may not be “false positives”; rather, they may identify a subgroup of patients at high risk of pulmonary hypertension and renal disease
Jo-1PM/DMb25-4095-9935-4590-9560-9095-99Anti-Jo-1 antibodies stain the cytoplasm of HEp-2 cells and may be reported as“ANA negative”
  • a Sensitivities (Se) and specificities (Sp) for the associated clinical conditions are given as percentages and are estimates based on interpretation of the available literature.

  • b PM/DM, polymyositis and dermatomyositis.