HOW RELIABLE IS THE BASEMENT-MEMBRANE PHENOMENON IN THE DIAGNOSIS OF SYSTEMIC LUPUS-ERYTHEMATOSUS

Background. Although the basement membrane (BM) phenomenon is consider ed a good test to differentiate between systemic (SLE) and discoid lup us erythematosus (DLE), OUT observations question its reliability. Met hods. Direct immunofluorescence stain was done to detect immunoglobuli ns and complement deposits in 10 SLE patients and in 10 healthy contro ls. Specimens were taken from the normal skin of the dorsa of hands. R esults. The group of SLE patients showed deposits of IgG in 4, IgM in 7, IgA in 1, C3 in 7, and C4 in 1 patient. The group of healthy contro ls showed IgM in 2, C3 in 5, C4 in 2 cases, but no IgG or IgA deposits . Conclusion. A positive BM phenomenon test could be found in normal i ndividuals and may be due to the effect of ultraviolet rays. We think that the BM phenomenon has a limited reliability in diagnosing SLE.