Validity and yield of a two-stage screening procedure for systemic lupus erythematosus

Sixty-six systemic lupus erythematosus (SLE) patients, 375 healthy female controls and 537 young Caucasian females were examined according to a recently suggested two-stage model for population screening for SLE. This model consisted in: a) administration of a 10-item questionnaire based on the ARA preliminary criteria for SLE; b) search of antinuclear antibodies (ANA) in the persons positive during the first stage. Among the SLE patients, the overall sensitivity of the two-stage screening was 90%, while its specificity in the healthy 375 normals reached 96%. 13% of 537 young Caucasian females answered affirmatively to 3 or more questions of the questionnaire. Out of these, 59 were tested for ANA. Two out of these 59 had a positive ANA test, but no one had SLE at a subsequent clinical survey. These data confirm the validity of this two-stage screening procedure for SLE. While the low prevalence of this disorder in the general population hardly justifies its massive application, the screening might be recommended for survey groups at high risk for SLE.