RESUMEN
Recent data suggest that the nucleosome plays a key role in the pathogenesis of systemic lupus erythematosus [SLE]. To determine the prevalence, sensitivity and specificity of antinucleosome antibodies [AnuA] in SLE patients and their association with disease activity, clinical and laboratory data. This study included three groups of 20 subjects each: group I [SLE patients], group II [rheumatoid arthritis [RA] patients], and group III [apparently healthy controls]. Serum AnuA, antinuclear antibodies [ANA], and anti-double stranded DNA [Anti-dsDNA] were measured with ELISA. Clinical activity of the disease was assessed with SLE Disease Activity Index [SLEDAI]. The highest prevalence of AnuA was found in group I [90%], significantly higher than that for group II [10%], and group HI [0%] [p<0.0001]. In group I, 55% were positive for AnuA, but not for anti-dsDNA. There was significantly higher prevalence of dermatological, joint, and renal disease in SLE patients with positive AnuA [p<0.01, p<0.001, p<0.01, respectively]. Moreover, AnuA correlated with disease activity [p<0.05] and had significantly higher sensitivity [90%] for the diagnosis of SLE. AnuA are of particular importance in the diagnosis of SLE, when anti-dsDNA is absent, AnuA correlates with disease activity, and most of the dermatological, joint, and renal disease manifestations, in patients with SLE. Moreover, AnuA are the most sensitive antibody marker, with an equal specificity, in the diagnosis of SLE, as compared with anti-dsDNA and ANA