Abstract
The lupus band test (LBT) is a direct immunofluorescent technique for demonstrating a band of localized immunoglobulins at the dermal-epidermal junction in the skin of patients with lupus erythematosus (LE). Studies have shown immunoglobulins and complement at the dermal-epidermal junction in systemic (involved and uninvolved skin) and in discoid (involved skin only) LE. It is essential that the appropriate skin site be selected for biopsy, i.e., involved or uninvolved skin, light-exposed or light-protected skin. The proper location of the biopsy site is determined by whether the LBT is intended for diagnostic or prognostic purposes. From a diagnostic standpoint, the LBT is a very sensitive and specific test for LE. This procedure also has considerable value as a prognostic test for a patient with an established diagnosis of LE.