| • | a direct immunofluorescence test (DIF) |
| • | lupus band = confluent granules, bright, continuous (IgG +/- others) at the dermal-epidermal junction in affected skin (also positive in normal appearing skin) |
| • | SLE - involved skin is positive in almost 100 % of cases, while uninvolved skin from sun-exposed areas is positive in about 90% of cases |
| • | the lupus band test may be negative in remissions, very early lesions and some cases of drug-induced LE |
| • | granule ~ immune complex |
| • | linear ~ type II hypersensitivity |
| • | when is lupus band test useful? |
| • | LE vs. clinically and histologically similar lesions (e.g. lymphocytic infiltrate) |
| • | late stage cicatricial alopecia |
| • | when serologic tests are negative and still suspect LE |
|