Lupus band test in systemic lupus erythematosus.

The usefulness of the direct immunofluorescent antibody technique--lupus band test--for the diagnosis of systemic lupus erythematosus (SLE) has been well established. The aims of the study were to determine the prevalence of the LBT at various sites of the skin in a cross section of patients with SLE and its correlation with disease activity. The LBT was demonstrated in 64% of skin lesions, 63% in non-lesional sun-exposed (NLSE) skin and 25% in non-lesional sun-protected (NLSP) skin. The prevalence of the LBT in lesional and NLSE groups was significantly different from the NLSP group (p = 0.03 and 0.005 respectively). There was a significant correlation between the presence of a positive LBT in NLSE skin with the presence of the LE cell phenomenon (p = 0.04) and anti - ds DNA antibody (0.02). In addition, there was a significant correlation between IgG LBT in the NLSE skin with serum hypocomplementaemia (p = 0.03) and anti - ds DNA antibody (p = 0.04). Other than these, no significant correlation was detected between the LBT from the 3 sites with overall clinical activity, renal disease, active skin lesions, or other laboratory indices of activity. These findings suggest that the LBT is mainly indicated as a diagnostic tool and has little role in assessing disease activity.