Comparison of ethylenediaminetetraacetic acid-treated desmoglein ELISA and conventional desmoglein ELISA in the evaluation of pemphigus vulgaris in remission

Factors associated with the healing time of pemphigus vulgaris oral lesions: a prospective study

OBJECTIVES

This study determines the healing time of lesions on different locations and the contributing factors to the healing time in patients with pemphigus.

METHODS

In this prospective study, newly diagnosed patients with mucosal lesions were included. A dermatologist evaluated the lesions, disease status, side effects and assigned the PDAI. Follow-up visits were conducted monthly until the patient reached complete remission and every three months thereafter. A Tzanck smear was performed on lesions clinically suspected to be herpetic in origin.

RESULTS

Sixty patients enrolled in the study with a mean age of 45.9 ± 11.7 years. The buccal lesions took the longest to resolve(73[33.5-105.5] days). However, the posterior pharynx lesions showed the shortest healing time(20[13.0-25.5] days). The likelihood of improvement in buccal and soft palate lesions decreased by 5% and 3% with each additional year of age, respectively. Also, the resolution duration of soft palate lesions was significantly shorter in female patients than males(median of 24.0 days vs. 38.5 days). In contrast, lower gingival lesions resolve significantly faster in male patients by a median of 9 days. HSV infection increases the healing time of lesions by 26 days(median of 55 days vs. 29 days, hazard ratio 2.62, 95%CI:1.04-5.92).

CONCLUSIONS

Buccal and lower gingival lesions are more recalcitrant to treatment, while posterior pharynx lesions heal most rapidly. Furthermore, older age was also associated with a lower rate of lesion improvement.

Current status and prospects for the diagnosis of pemphigus vulgaris

Introduction: Pemphigus vulgaris (PV) is an intraepidermal autoimmune bullous disease (AIBD) characterized by autoantibodies against desmosomal adhesion proteins, most commonly desmoglein (Dsg)3, leading to the suprabasal cleft formation and acantholysis.Areas covered: Direct immunofluorescence (DIF) and indirect immunofluorescence (IIF) studies display the intercellular deposition of IgG/C3 throughout the epidermis and presence of circulating autoantibodies respectively, as a net-like pattern. However, the target antigen remains unknown using immunofluorescence techniques. Thanks to the development of Dsg ELISA, using recombinant technology, circulating antibodies against Dsg1 and 3 could be detected sensitively. It is possible to differentiate PV from pemphigus foliaceus (PF) using this assay. BIOCHIP mosaic and multivariant ELISA are two novel serologic methods with the added value of the ability to screen several AIBDs simultaneously.Non-Dsg1/3 antigens are also involved in the pathogenesis of PV and investigated more deeply thanks to the protein microarrays technique. Additionally, patients with high values of anti-Dsg1/3 may be lesion-free, suggesting the presence of nonpathogenic autoantibodies.Expert opinion: Newer diagnostic methods to replace traditional techniques should possess high sensitivity and specificity and be widely available, noninvasive, and relatively cheap. The newly developed methods need to be further evaluated before being recommended for routine use.

Estimated cut-off values for pemphigus severity classification according to pemphigus disease area index (PDAI), autoimmune bullous skin disorder intensity score (ABSIS), and anti-desmoglein 1 autoantibodies

BACKGROUND

Pemphigus is a potentially fatal disease if left untreated. Valid scoring systems and defined cut-off values for classification of patients would help with better management through specified pharmaceutical and non-pharmaceutical treatments.

METHODS

In this study, pemphigus patients who were receiving immunosuppressive treatments and had recent disease relapse were recruited for examination of pemphigus disease area index(PDAI), autoimmune bullous skin disorder intensity score (ABSIS), physician global assessment (PGA), autoimmune bullous disease quality of life (ABQoL), anti-desmoglein 1 (anti-Dsg1), and anti-Dsg3 autoantibody titers from December-2017 to February-2018. Cut-off values were estimated using model-based clustering classification and the 25th and 75th percentiles approach, performed separately for the exclusive cutaneous, exclusive mucosal, and mucocutaneous groups.

RESULTS

In the 109 included patients, the 25th and 75th percentiles cut-offs were 6.2 and 27 for PDAI score, and 4 and 29.5 for ABSIS score. The model-based analysis resulted in two groups (cut-point:15) for PDAI score, and three groups (cut-points:6.4 and 31.5) for ABSIS score. The groups were significantly different for the PDAI, ABSIS, PGA, and ABQoL values. Based on anti-Dsg1 autoantibody values, the model-based analysis cut-point was 128 and the 25th and 75th percentiles cut-offs were 98 and 182. Anti-Dsg3 autoantibody values did not differentiate between pemphigus severity classes.

CONCLUSIONS

Estimated cut-off values based on the anti-Dsg1 level, PDAI, and ABSIS scoring systems could be used to classify patients into different severity grades for better management and prognosis.

Short-term clinical and serological follow-up with conventional and conformational anti-desmoglein antibodies in treatment-naïve and previously treated patients with pemphigus vulgaris after receiving rituximab

Background

Pemphigus vulgaris (PV) is a blistering, life-threatening autoimmune disease. Ethylenediaminetetraacetic acid (EDTA)-treated desmoglein (Dsg) enzyme-linked immunosorbent assay (ELISA) has recently been suggested to detect nonpathogenic antibodies. Rituximab (RTX) is now considered a first-line treatment for PV.

Objective

The primary and secondary aims were to evaluate anti-Dsg and EDTA-treated anti-Dsg ELISA and clinical response before and 3 months after RTX in treatment-naïve and previously treated patients, respectively. In addition, we compared the short-term efficacy of RTX between these groups.

Methods

Seventy-five patients with PV who received RTX (500 mg weekly for 4 weeks or 1000 mg 2 weeks apart) and prednisolone were followed for 3 months. Thirty-seven treatment-naïve newly diagnosed (group A) and 38 relapsed patients (group B) were included. Disease activity was scored with the Pemphigus Disease Area Index (PDAI). Clinical response was also assessed. Serum samples were collected at two points and examined for anti-Dsg1/3 and EDTA-treated anti-Dsg1/3. Conformational anti-Dsg values were calculated by subtracting EDTA-treated from conventional anti-Dsg values.

Results

The correlation of conventional and conformational anti-Dsg values was perfect (correlation coefficient > 0.98; p < .001) at every time point for both anti-Dsgs. There was no difference with regard to PDAI and anti-Dsg values between the two groups at baseline. The frequency of responders was significantly higher in group A (100%) than in group B (89%; p = .006). Three patients relapsed, and five patients had persistent disease activity in group B. After 3 months, conventional and conformational anti-Dsg values were significantly higher in group B compared with group A (anti-Dsg3: p = .017 and .021, respectively; anti-Dsg1: p = .014 and .016, respectively). Total and scalp PDAI were significantly lower in group A than in group B (p = .042 and .016, respectively).

Conclusion

EDTA-treated anti-Dsg ELISA had no added value. Using RTX as first-line treatment in patients with PV appears to be associated with better clinical response and immunologic profile than delayed treatment in the short term.