Antinuclear antibodies in patients with systemic lupus erythematosus: a comparison of counterimmunoelectrophoresis and immunoblotting.

Abstract

Traditionally, the method used mostly to identify antinuclear antibody (ANA) specificities is the counterimmunoelectrophoresis technique (CIE), in which a salt extract of rabbit thymus powder (so-called extractable nuclear antigen or ENA) serves as the source of antigen. Recently, the immunoblotting technique (IBT) has been introduced in the serology of antinuclear antibodies. A nuclear extract of HeLa cells is generally used as antigen in this method. In this paper, we compared both methods using sera of patients with active systemic lupus erythematosus (SLE). Only anti-Sm, anti-RNP, and Anti-SSB were taken into consideration, as the former technique only allowed the identification of these specificities. Within these restrictions, we found that, of 77 patients with SLE, 21 had CIE-detectable antibodies in their circulation and 29 IBT-detectable antibodies. Anti-RNP and anti-SSB were detected more frequently with the CIE than with the IBT; anti-Sm, on the other hand, was detected more frequently with the IBT than with the CIE. Several significant correlations were found between incidences of measured antibody specificities and disease features. The presence of anti-RNP (both if measured with the IBT or with the CIE) was found to be negatively correlated with nephritis. If measured with the IBT, the presence of anti-Sm correlated negatively with hematological disorders, and the presence of anti-SSB correlated positively with renal involvement.(ABSTRACT TRUNCATED AT 250 WORDS)