The usefulness of immunofluorescent tests in pemphigus patients in clinical remission.

Direct and indirect immunofluorescent studies (DIF, IIF) were performed on 24 pemphigus vulgaris patients who were in a state of clinical remission. The tests were repeated after an interval of 6 months. All the patients were on maintenance therapy with oral prednisone. The DIF in eight patients showed negative results among whom seven remained negative. Six patients out of 24 showed weakly positive fluorescence and ten patients showed strong positive fluorescence. The IIF was negative in 17 patients and positive in seven patients who also showed positive DIF. During a follow-up period of 20 months, one of eight patients with negative DIF relapsed compared with two of six patients with weak positive DIF and five of 10 patients with strong DIF. Five patients with strong DIF for IgG also had C3, of whom three relapsed, compared with five of 19 patients who were negative for C3. Four of seven patients with positive IIF relapsed compared with four of 17 with negative IIF. It is suggested that repeated DIF tests in pemphigus patients, who are in clinical remission, may serve as an indicator for the immunological activity and be of help in the management of these cases.