Direct and indirect immunofluorescence (IF) testing was performed on 63 patients with active or inactive pemphigus in order to determine the reliability of these tests for diagnosis and for monitoring disease severity. Direct IF was positive in 58 of 63 patients with pemphigus. The five patients with negative direct IF had been free of lesions for more than a year. Thus, the direct IF test is a reliable diagnostic procedure that shows positive findings early in the disease. Indirect IF is inferior to direct IF as a diagnostic test because it may be negative in early cases, as observed in four patients. Furthermore, indirect IF, contrary to claims, is not reliable for evaluating the status of the disease. Thus, in patients with lesions and receiving treatment, 41% of the determinations showed a negative titer; whereas in patients free of lesions, 45% of the determinations showed a positive titer. In particular, seven patients without lesions and without treatment for more than a year had a positive titer.
(Arch Dermatol 115:428-432, 1979)
Judd KP, Lever WF. Correlation of Antibodies in Skin and Serum With Disease Severity in Pemphigus. Arch Dermatol. 1979;115(4):428-432. doi:10.1001/archderm.1979.04010040006002