Autoantibodies before the clinical onset of systemic lupus erythematosus

Dual role of autoantibodies to heat shock proteins in autoimmune diseases

Autoimmune diseases are characterized by the recognition of self-antigens (autoantigens) by immune system cells. Loss of immunological tolerance may lead to the generation of autoantibodies and, consequently, tissue damage. It has already been proven that highly immunogenic bacterial and autologous extracellular heat shock proteins (eHsps) interact with immune cells of the innate and adaptive arms of the immune system. The latter interactions may stimulate a humoral (auto)immune response and lead to the generation of anti-Hsps (auto)antibodies. Although circulating levels of anti-Hsps autoantibodies are often elevated in patients suffering from multiple inflammatory and autoimmune diseases, their role in the development of pathological conditions is not fully established. This mini-review presents the dual role of anti-Hsps autoantibodies - protective or pathogenic - in the context of the development of selected autoimmune diseases.

Proton pump inhibitors-related subacute cutaneous lupus erythematosus: Clinical characteristics, management, and outcome

PURPOSE

Previous knowledge about the association between proton pump inhibitors (PPIs) exposure and subacute cutaneous lupus erythematosus (SCLE) was mainly based on limited case reports or few review studies. We aim to evaluate the clinical characteristics, management, and outcome in patients with PPIs-induced SCLE.

METHODS

Case reports and case series from 2000 to December 31, 2021, on SCLE induced by PPIs were collected and retrospectively analyzed.

RESULTS

A total of 29 patients (6 male and 23 female) were included from 19 studies, the median age was 61 years (range 19-85), and 65.5% of patients were ≥60 years old. 37.9% of patients had the history of autoimmune diseases. The incubation period of PPIs intro to SCLE was 6 weeks for PPI-naive patients and 2 weeks for those re-administration of PPIs. The most common symptoms were annular and polycyclic erythematous (74.1%), rash or maculopapular (48.1%), and scaly plaques (40.7%). Trunk (69.2%), extremities (69.2%), face (26.9%), chest (26.9%), and back (26.9%) were common involved locations. Antinuclear antibodies, anti-Ro/SSA antibodies, and anti-La/SSB antibodies were positive in 24 patients (82.8%), 24 patients (82.8%), and 6 patients (20.7%), respectively. Direct immunofluorescence was positive in 50% of cases. Complete clinical remission (92.6%) was observed (median time: 4 weeks) with discontinuation of PPIs and treatment of oral corticosteroids (61.1%), hydroxychloroquine (44.4%), or topical steroids (16.7%).

CONCLUSION

PPIs-related SCLE is a rare adverse reaction based on clinical manifestations associated with immunological abnormalities and suggestive histological findings. PPIs should be suspected when considering possible culprits for drug-related SCLE.

MHC haplotype and B cell autoimmunity: Correlation with pathogenic IgG autoantibody subclasses and Fc glycosylation patterns

Genome-wide association studies (GWAS) have identified many genes that are associated with the development of certain autoimmune disorders, but the MHC haplotypes still represent the most prevalent genetic risk factor for many autoimmune diseases. The mechanisms by which MHC-associated genetic susceptibility translates into B cell autoimmunity and the development of autoimmune diseases are complex. There is increasing evidence that the MHC haplotype modulates autoreactive B cell responses in multiple ways. Instead of merely inhibiting the production of IgG autoantibodies and mediating complete immunological tolerance, the non-permitting MHC haplotypes seem to facilitate the production of IgG autoantibodies exhibiting Fc glycosylation patterns that are associated with reduced pathogenicity and a protective cytokine profile of T follicular helper (Tfh) cells. Here, we discuss mechanisms linking MHC haplotypes to the production of pathogenic IgG autoantibodies, which could be relevant for the development of improved diagnosis, particularly in the context of individual medicine.