Immunofluorescence of the outer root sheath: an aid to diagnosis in pemphigus

Demonstration of direct immunofluorescence on three substrates in a case of pemphigus

Direct immunofluorescence (DIF) on skin is considered as the gold standard in the diagnosis of pemphigus. However, alternate substrates can be used. We demonstrate DIF on three substrates, skin biopsy specimen, anagen hair and scrapings of oral erosions. Collection of alternative substrates can be more acceptable to young patients as it is less invasive. It may also be used to detect relapses in cases of pemphigus.

Plucked Hair as a Substrate for Indirect Immunofluorescence in Cases of Pemphigus Vulgaris

Introduction

Indirect immunofluorescence (IIF) is used to determine the circulating autoantibodies in cases of Pemphigus. For IIF in Pemphigus several substrates had been used. This study was done to determine whether plucked hair can be utilized as a substrate for IIF in cases of Pemphigus. Aim & Objectives: To determine the efficacy of utilizing the plucked hair as a substrate for indirect immunofluorescence among patients with Pemphigus vulgaris.

Methodology

Thirty two consecutive patients with active and fresh diagnosed cases of pemphigus vulgaris (PV) who did not undergo any treatment and those patients who had positive DIF findings of characteristic fish net or chicken wire pattern of intercellular IgG deposits in the epidermis of perilesional skin were included in the study. A total of 32 control subjects without any auto immune disorders were selected and the blood samples were taken from these patients for IIF analysis. Anagen hair were collected from the healthy volunteers without pemphigus in the same way as for trichogram. Telogen hair were obtained by combing the hair and collecting the loose strands of hair on the comb and further confirmed under microscope. Three hairs each of anagen and telogen stage were collected from each subject to be utilized as a substrate for IIF.

Results

Out of 32 samples 20 samples showed positive results for Ig G alone and 5 samples showed positivity for Ig G and C3. One sample showed positivity for C3alone. All these 26 samples were considered to have positive IIF test based on the intercellular pattern of deposit. Positive IIF results were observed in anagen hair samples and were negative in all the telogen hair samples. Six anagen hair samples did not show any positive findings in IIF for the study group. All the 32 control samples showed negative reports in IIF.

Conclusion

In conclusion, IIF microscopy on plucked hair as a substrate is a more sensitive immunoassay for the detection of circulating intercellular autoantibodies in PV and the lower negative predictive value of this substrate is a limitation. Further large scale studies might provide better information regarding the practical utility.

Direct immunofluorescence of the outer root sheath in anagen and telogen hair in pemphigus vulgaris and pemphigus foliaceus

Direct immunofluorescence of peri-lesional skin is the gold standard in the diagnosis of pemphigus. A specific immunofluorescence pattern may also be demonstrated in the outer root sheath of anagen and telogen hair. We demonstrated an intercellular reticular deposition of immunoglobulin G in the outer root sheath of plucked anagen and telogen hair in all pemphigus vulgaris patients with active disease and for the first time in all patients with active pemphigus foliaceus. Moreover, we demonstrated for the first time that plucked hair samples may be kept at -20°C for at least 2 weeks before immunofluorescent staining and analysis.

Direct immunofluorescence on hair follicles--present and future perspectives

Direct immunofluorescence (DIF) is an important tool for evaluating bullous autoimmune and connective tissue disorders. We report 21 cases of pemphigus vulgaris, bullous pemphigoid and lupus erythematosus that were investigated by performing DIF on scalp hair follicles. The study was done using a simplified technique of preparing the hairs for DIF testing. The anagen hairs tested positive in pemphigus vulgaris patients while the telogen hairs were negative. In bullous pemphigoid and lupus erythematosus cases hair DIF presented negative results.Hair DIF has the potential of taking the place of skin or mucosal DIF in pemphigus patients if performed on anagen hair follicles. The technique used to perform hair DIF is important in obtaining reliable results and eliminating the possibility of generating false-negative testing. Larger studies are needed in order to validate this method.