Welcome to the Autoimmunity 2021 Congress Calendar

Background and Aims

Pemphigus Vulgaris is an autoimmune disease associated with pathogenic autoantibodies which recognize skin adhesion proteins called desmogleins. Treatment of pemphigus patients with systemic corticosteroids and/or immunosuppressive drugs improve their condition, which is usually associated with a decrease in serum anti-desmoglein autoantibody titers. However, few patients still have persistent serum anti-desmoglein antibodies after treatment, while being in clinical remission (CR).

The aim of this study was to determine whether or not anti-desmoglein autoantibodies detected in the serum from pemphigus patients in CR were pathogenic, and to compare their pathogenic activity with anti-desmoglein autoantibodies (Ab) detected in these patients’sera during the active phase of the disease.

Methods

Pathogenic activity of autoantibodies was measured in vitro on immortalized keratinocytes by immunofluorescence and dissociation assays.

Results

Some patients remained in CR until the end of the study whereas others relapsed. All serum samples, even those collected from patients in CR, had high anti-Dsg3 Ab titers measured by ELISA.

Incubation with the patients’ IgG collected during the active phase of the disease induced a decrease of desmoglein 3 expression on keratinocytes and a disorganization of cytoskeleton revealed by flotilin 2 staining measured by immunofluorescence and a loss of keratinocyte adhesion measured by dissociation assay. The same experiments performed with IgG from patients who further relapsed showed a pathogenic activity. In contrast, the IgG from patient with persistent CR did not induce any pathogenic effect.

Conclusions

Our results showed a differential pathogenic effect of IgG from patients in CR depending on whether patients will further relapse or not.

Background and Aims

Autoimmune blistering dermatoses (ABD) are a heterogeneous group of rare diseases clinically characterized by erosions and/or blisters on the skin and mucous membranes. In ABD the immune system produces autoantibodies (Abs) directed against cell-cell or cell-matrix adhesion molecules. More common ABD entities, pemphigus and bullous pemphigoid (BP), are identified by circulating and tissue-bound Abs against the desmosomal cadherins (mainly desmoglein 1 and 3 – DSG1/3) and dermal-epidermal junction components (BP180 and BP230).Several assays for the serological detection of anti-DSG1/ DSG3/ BP180/ BP230 Abs have been developed, however no gold standard assay exists, so a working set is needed.

Methods

We tested 104 patients suspected or diagnosed for ABD to evaluate the performance of three different assays: traditional IIF on monkey esophagus, innovative IIF BIOCHIP mosaic (an array of six different diagnostic substrates) and ELISA based on recombinant forms of the target antigens (DSG1/DSG3/BP180).

Results

We observed that Specialist Departments (Dermatology and Ophthalmology) and General Medicine Departments required different test profiles: ASA IIF 12% vs 88%, ELISA 68% vs 32% and BIOCHIP 100% vs 0%, respectively. The positive percentages for IIF ASA, ELISA and BIOCHIP were significantly different: 36%, 45% and 75%. The agreement between ASA IIF and Ag-specific test (ELISA-BIOCHIP) was 75%. 7/44 patients (16%) were ASA-/Ag+ and mainly represented by BP180+; instead 4/44 patients (9%) were ASA+/Ag- mainly represented by intercellular substance aspecific pattern.

Conclusions

Our results support the opportunity to perform very sensitive and specific tests, as Ag-specific assay, in order to achieve a definitive diagnosis.

Background and Aims

Frontal fibrosing alopecia (FFA) is a rare type of cicatricial alopecia. The specific mechanisms of development of FFA remain unknown. We previously proposed an autoimmune origin (Med Hypotheses2019;124). Here we describe the clinical and immunohistochemical profile of patients with FFA.

Methods

This was a retrospective cohort of 11 patients with FFA diagnosed by scalp biopsy. To evaluate the expression of immunological markers in 10 available scalp biopsies, we assessed by immunohistochemistry the following markers: B2 microglobulin, HLA class I and II, CD20, CD25, CD3, CD4, and CD8.

Results

All patients were female. Mean age at FFA diagnosis was 55.9 ± 9.51 years. Four (36.36%) patients had SS, and the same number had hypothyroidism. Five (45.45%) patients had positive antinuclear antibodies. In most of the samples, we observed expression of B2 microglobulin, HLA class I and II in the hair follicle. Only one (10%) patient showed CD20+ expression, while four (40%) patients presented infiltrating T lymphocytes (CD3+), including inverted relation among CD4/CD8 in two cases (20%). In 2 patients with SS, infiltrate expression was seen after 2- and 5-years of diagnosis. A patient with a recent diagnosis of SS did not show expression of any marker.

Conclusions

Our findings show a possible immune origin of FFA, represented by lymphocytic infiltration, expression of B2 immunoglobulin, HLA class I, and II causing impairment in the immune privilege of the hair follicle. The association of FFA with SS and hypothyroidism arises the possibility of an autoimmune origin.

Background and Aims

Pyoderma gangrenosum (PG) is an inflammatory disease, which is histologically characterized by an inflammatory infiltrate mediated mainly by granulocytes without evidence of infection. The pathophysiology of this disease is not clear, primarily the uncontrolled production of pro-inflammatory cytokines, which activate neutrophils are the reason why PG is classified as auto-inflammatory. To evaluate the immune profile of the disease, we conducted an RNAseq analysis in skin biopsies of four patients with PG and four healthy controls.

Methods

After total RNA extraction, mRNA was obtained by an Oligo-dT sequence. Afterwards sequenced in an Illumina platform, the readings were mapped against the GRCh38 genome.

Results

We obtained information of 19799 genes, 2798 genes were up-regulated and 2842 down-regulated comparing PG vs. healthy skin. The primary 100 genes were selected in each group. After a functional enrichment analysis, the central up-regulated genes were lytic tissue-destroying genes such as MMPs but also wound healing and angiogenesis genes. Also, pro-inflammatory proteins and neutrophil chemokines, reported in the literature associated with PG, were identified. Besides, an exciting group of genes, S100A genes, were remarkably up-regulated, whose functions of regulating the immune response could trigger the excessive degranulation of neutrophils that damages tissue. Finally, we observed the down-regulation of skin structural support and permeability genes as KRT2 and CLDN10 and the low expression of epidermal growth factors such as ERBB4.

Conclusions

The homeostasis impairment of these molecules in the skin can trigger a PG-type lesion; these findings will be functionally validated in vitro and animal models.

Background and Aims

The progression of vitligo has been the direct effect of auto-immunity mediated destruction of melanocytes. The effect of narrow-band UVB on disease progression in vitiligo has not been evaluated. We evaluated the effect of NB-UVB on progressive versus non-progressive non-segmental vitiligo.

Methods

Adult patients having non-segmental vitiligo >2% BSA were divided into two subsets; patients developing >5 lesions in last 1 month or >15 lesions in last 3 months [Progressive vitiligo, group I] and patients with static disease for last 6 months [Non-progressive vitiligo, group II]; Both groups were treated with NB-UVB for 6 months and its efficacy in halting disease progression, re-pigmentation, side-effects and psychosocial impact were evaluated.

Results

Twenty-four out of 31 patients with progressive vitiligo (group I); and 9 out of 17 with non-progressive vitiligo (group II) completed the study period of 6 months. At the end of 6 months, 19 out of 24 patients had arrest of disease progression while the rest five patients developed lesions at a slower pace. After 6 months, majority of patients; 19 out of 24 (79%) in group I and 6 out of 9 (67%) in group II, had 25-50% re-pigmentation. Pruritus (20/33 patients; 60.6%), blistering (7/33 patients; 21.2%), pain (4/33 patients; 12.1%) and burning sensation (4/33 patients; 12.1%) were the side-effects.

Conclusions

Besides achieving re-pigmentation, NB-UVB has potential to halt disease progression in some patients with progressive vitiligo, with minimal side-effects. Autoimmunity being the definitive factor in progression of vitiligo, these results suggest that NB-UVB may be having an immunomodulator effect in vitiligo.