Lupus band test in untreated SLE patients: correlation of immunoglobulin deposition in the skin of the extensor forearm with clinical renal disease and serological abnormalities.

This study demonstrated that 88% of untreated systemic lupus erythematosus patients with clinical renal disease displayed the deposition of immunoglobulin and complement at the dermal epidermal junction of the noninvolved light exposed extensor surface of the upper 1/3 of the forearm (P less than 0.005) (positive lupus band test). Eighty-five percent of these untreated systemic lupus erythematosus patients with anti-deoxyribonucleic acid antibodies (native and/or single stranded) (P less than 0.001) and 96% of systemic lupus erythematosus patients with hypocomplementemia had a positive lupus band test (P less than 0.001). Those systemic lupus erythematosus patients with a negative lupus band test or a positive lupus band test composed of pure IgM had a decreased incidence of renal disease, serum hypocomplementemia and anti-DNA antibodies. Their sera, however, frequently contained antibodies directed against nuclear ribonuclear protein or against the cytoplasmic non-nucleic acid glycoprotein termed Ro. On the contrary, 85% of systemic lupus erythematosus patients with a positive lupus band test composed solely or in part of IgG, had anti-DNA antibodies (P less than 0.001). Their sera also frequently contained anti-Sm antibodies. The lupus band test was found to be dynamic. In general, the appearance as well as the disappearance or the marked decrease in intensity and complexity of a positive lupus band test was found to correlate with disease exacerbation, remission and the appearance and disappearance of DNA antibodies and serum hypocomplementemia.