Clinical and humoral response after SARS-CoV-2 breakthrough infection in patients receiving immunosuppressant therapy.

BACKGROUND: Despite impaired humoral response in patients treated with immunosuppressants (ISPs), recent studies found similar severity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) breakthrough infection compared to controls. One potential explanation is the rapid generation of humoral response on infection, but evidence is lacking. OBJECTIVES: We investigated the longitudinal dynamics of the SARS-CoV-2 antibody repertoire after SARS-CoV-2 delta and omicron breakthrough infection in patients with immune-mediated inflammatory diseases (IMIDs) receiving ISP therapy and controls. METHODS: As a prospective substudy of the national Target-to-B! (T2B!) consortium, we included IMID patients receiving ISPs therapy and controls who reported SARS-CoV-2 breakthrough infection between July 1, 2021, and April 1, 2022. To get an impression of the dynamics of the antibody repertoire, 3 antibody titers of wild-type RBD, wild-type S, and omicron RBD were measured at 4 time points after SARS-CoV-2 breakthrough infection. RESULTS: We included 302 IMID patients receiving ISPs and 178 controls. Antibody titers increased up to 28 days after breakthrough infection in both groups. However, in IMID patients receiving therapy with anti-CD20 and sphingosine-1 phosphate receptor modulators, antibody titers were considerably lower compared to controls. In the anti-TNF group, we observed slightly lower antibody titers in the early stages and a faster decline of antibodies after infection compared to controls. Breakthrough infections were mostly mild, and hospitalization was required in less than 1% of cases. CONCLUSIONS: Most ISPs do not influence the dynamics of the SARS-CoV-2 antibody repertoire and exhibit a rapid recall response with cross-reactive antibody clones toward new virus variants. However, in patients treated with anti-CD20 therapy or sphingosine-1 phosphate receptor modulators, the dynamics were greatly impaired, and to a lesser extent in those who received anti-TNF. Nevertheless, only a few severe breakthrough cases were reported.

Low density granulocytes and neutrophil extracellular trap formation are increased in incomplete systemic lupus erythematosus.

OBJECTIVE: To investigate the proportion of low-density granulocytes (LDGs), circulating plasma neutrophil extracellular traps (NETs), and serum-induced NET formation in patients with incomplete systemic lupus erythematosus (iSLE) and systemic lupus erythematosus (SLE). METHODS: LDGs were measured cross-sectionally in 18 iSLE patients, 11 SLE patients and 14 healthy controls (HCs), whereas circulating NETs and serum-induced NET formation were assessed in 35 iSLE patients, 41 SLE patients and 16 HCs. LDGs (CD14lowCD15+) were measured in PBMCs using flow cytometry and circulating plasma NETs were measured using anti-myeloperoxidase-DNA, anti-citrullinated histone H3 and anti-elastase-DNA complex ELISAs. Serum-induced NET formation was assessed by incubating healthy neutrophils with serum from iSLE patients, SLE patients or HCs and visualizing NETs with fluorescence microscopy. RESULTS: Proportions of LDGs and circulating plasma NETs were similarly elevated in iSLE and SLE patients compared with those in HCs. Furthermore, patients under hydroxychloroquine (HCQ) treatment had lower proportions of LDGs than those without. Serum from iSLE and SLE patients similarly induced NET formation in healthy neutrophils. In iSLE patients, myeloperoxidase-DNA complexes were correlated with proportions of age-associated B-cells, memory B-cells and negatively with naïve B-cells, while we did not find associations between measures of NETs or serum-induced NET formation and interferon score or clinical parameters. CONCLUSION: These results show that neutrophil dysfunction, including higher proportions of LDGs, and increased NET formation, already occur in iSLE, similar to SLE, despite differences in disease manifestations. Thereby, neutrophil dysfunction may contribute to sustained exposure to autoantigens and autoreactivity in early stages of SLE.

Suppressed IgG4 class switching in dupilumab- and TNF inhibitor-treated patients after mRNA vaccination.

BACKGROUND: The noninflammatory immunoglobulin G4 (IgG4) is linked to tolerance and is unique to humans. Although poorly understood, prolonged antigenic stimulation and IL-4-signaling along the T helper 2-axis may be instrumental in IgG4 class switching. Recently, repeated SARS-CoV-2 mRNA vaccination has been linked to IgG4 skewing. Although widely used immunosuppressive drugs have been shown to only moderately affect humoral responses to SARS-CoV-2 mRNA vaccination, the effect on IgG4 switching has not been investigated. METHODS: Here we study the impact of such immunosuppressive drugs, including the IL-4 receptor-blocking antibody dupilumab, on IgG4 skewing upon repeated SARS-CoV-2 mRNA vaccination. Receptor-binding domain (RBD) specific antibody responses were longitudinally measured in 600 individuals, including patients with immune-mediated inflammatory diseases treated with a TNF inhibitor (TNFi) and/or methotrexate (MTX), dupilumab, and healthy/untreated controls, after repeated mRNA vaccination. RESULTS: We observed a substantial increase in the proportion of RBD-specific IgG4 antibodies (median 21%) in healthy/untreated controls after third vaccination. This IgG4 skewing was profoundly reduced in dupilumab-treated patients (<1%). Unexpectedly, an equally strong suppression of IgG4 skewing was observed in TNFi-treated patients (<1%), whereas MTX caused a modest reduction (7%). RBD-specific total IgG levels were hardly affected by these immunosuppressive drugs. Minimal skewing was observed, when primary vaccination was adenoviral vector-based. CONCLUSIONS: Our results imply a critical role for IL-4/IL-13 as well as TNF in vivo IgG4 class switching. These novel findings advance our understanding of IgG4 class switch dynamics, and may benefit humoral tolerance induction strategies, treatment of IgG4 pathologies and mRNA vaccine optimization.

Beyond the skin: B cells in pemphigus vulgaris, tolerance and treatment.

Pemphigus vulgaris (PV) is a rare autoimmune bullous disease characterized by blistering of the skin and mucosa owing to the presence of autoantibodies against the desmosome proteins desmoglein 3 and occasionally in conjunction with desmoglein 1. Fundamental research into the pathogenesis of PV has revolutionized its treatment and outcome with rituximab, a B-cell-depleting therapy. The critical contribution of B cells to the pathogenesis of pemphigus is well accepted. However, the exact pathomechanism, mechanisms of onset, disease course and relapse remain unclear. In this narrative review, we provide an overview of the fundamental research progress that has unfolded over the past few centuries to give rise to current and emerging therapies. Furthermore, we summarize the multifaceted roles of B cells in PV, including their development, maturation and antibody activity. Finally, we explored how these various aspects of B-cell function contribute to disease pathogenesis and pave the way for innovative therapeutic interventions.

Pemphigus vulgaris (PV) is a rare autoimmune disease, in which the immune system attacks itself and causes blisters on the skin and inside the mouth. This happens because the body mistakenly attacks specific proteins (called desmosomes) that keep the skin together. Globally, this disease affects anywhere from 0.5 to 16.1 people per million, often older than 50 years. PV is life-threatening when left untreated. From carrying out research as far back as the 1700s, we have made significant strides in understanding PV. For example, research has led to a new treatment with the antibody rituximab, which works by eliminating the cells of the immune system that attack desmosomes (called B cells). However, after therapy is completed, the disease often returns because the same troublesome B cells reappear. There are multiple places that are involved when the body attacks desmosomes. The problems range from the bone marrow where the B cells are made and selected to the ways these cells change as they move around the body. It takes a rare combination of these changes to switch from a normal immune system to one that causes PV. Clinicians and researchers are currently developing new treatment options to better target this skin disease. We want to emphasize that research should continue to uncover how the disease works because a better understanding promotes the development of new therapies, and perhaps even a cure. This is vital, because PV can significantly lower the quality of life of people living with this skin disease.

Global consensus process to establish a core dataset for hidradenitis suppurativa registries.

BACKGROUND: Several registries for hidradenitis suppurativa (HS) already exist in Europe and the USA. There is currently no global consensus on a core dataset (CDS) for these registries. Creating a global HS registry is challenging, owing to logistical and regulatory constraints, which could limit opportunities for global collaboration as a result of differences in the dataset collected. The solution is to encourage all HS registries to collect the same CDS of information, allowing registries to collaborate. OBJECTIVES: To establish a core set of items to be collected by all HS registries globally. The core set will cover demographic details, comorbidities, clinical examination findings, patient-reported outcome measures and treatments. METHODS: Beginning in September 2022, 20 participants - including both clinicians with expertise in HS and patient advocates - from eight countries across three continents participated in a Delphi process consisting of four rounds of voting, with all participants completing each round. A list of potential items for inclusion in the core set was generated from the relevant published literature, including systematic reviews of comorbidities in HS, clinical and examination findings, and epidemiology. For disease severity and progression items, the Hidradenitis SuppuraTiva Core outcome set International Collaboration (HiSTORIC) core set and other relevant instruments were considered for inclusion. This resulted in 47 initial items. Participants were invited to suggest additional items to include during the first round. Anonymous feedback was provided to inform each subsequent round of voting to encourage consensus. RESULTS: The eDelphi process established a CDS of 48 items recommended for inclusion in all HS registries globally. CONCLUSIONS: The routine adoption of this CDS in current and future HS registries should allow registries in different parts of the world to collaborate, enabling research requiring large numbers of participants.

Diet and physical activity as risk-reducing factors for hidradenitis suppurativa.

BACKGROUND: Hidradenitis suppurativa (HS) is a multifactorial inflammatory skin disease that is considered to be an immune-mediated inflammatory disease (IMID). Up till now, the impact of lifestyle on (the development of) HS has not been thoroughly investigated. OBJECTIVES: To investigate the effect of dietary intake and physical activity (PA) on (the development of) HS. MATERIALS AND METHODS: A nested case-control study was performed within the longitudinal Lifelines Cohort Study, that took place in the Northern Netherlands, and identified 1004 adult eligible HS patients and 5000 age-matched controls. Dietary data were collected using a validated food frequency questionnaire, subsequently translated to the Lifelines Diet Score (LLDS), alternate Mediterranean Diet Score (aMED) and Dutch Dietary Guidelines score (DDG), with higher scores reflecting healthier dietary habits. PA was measured by the Short Questionnaire to Assess Health-enhancing PA score. Logistic regression analyses were performed between dietary/PA scores, and the prevalence/development and severity of HS. RESULTS: Compared to controls, HS patients scored lower on the LLDS [OR = 0.98; 95% CI 0.96-0.99], aMED [0.93; 0.89-0.97] and DDG [0.93; 0.88-0.97] with multivariable regression analysis. Overall, this indicates less adherence to dietary recommendations and consumption of a low-quality diet in the HS population. Lower adherence to the LLDS and DDG was also significantly associated with a higher likelihood to HS development in univariable regression analysis [0.96; 0.94-0.99 and 0.91; 0.84-0.99, respectively], and a trend of decreased adherence to the aMED [0.93; 0.85-1.02] was noted. Besides, PA levels were found significantly lower in HS patients (p ≤ 0.001). CONCLUSIONS AND RELEVANCE: Poor diet quality and lower quantities of PA were associated with HS in the general population. Identifying dietary and PA habits of HS patients can contribute to the development of prevention strategies for HS specifically, and for IMIDs in general.

Differences in IgG autoantibody Fab glycosylation across autoimmune diseases.

BACKGROUND: Increased prevalence of autoantibody Fab glycosylation has been demonstrated for several autoimmune diseases. OBJECTIVES: To study whether elevated Fab glycosylation is a common feature of autoimmunity, this study investigated Fab glycosylation levels on serum IgG and its subclasses for autoantibodies associated with a range of different B cell-mediated autoimmune diseases, including rheumatoid arthritis, myasthenia gravis subtypes, pemphigus vulgaris, antineutrophil cytoplasmic antibody-associated vasculitis, systemic lupus erythematosus, anti-glomerular basement membrane glomerulonephritis, thrombotic thrombocytopenic purpura, and Guillain-Barré syndrome. METHODS: The level of Fab glycosylated IgG antibodies was assessed by lectin affinity chromatography and autoantigen-specific immunoassays. RESULTS: In 6 of 10 autoantibody responses, in 5 of 8 diseases, the investigators found increased levels of Fab glycosylation on IgG autoantibodies that varied from 86% in rheumatoid arthritis to 26% in systemic lupus erythematosus. Elevated autoantibody Fab glycosylation was not restricted to IgG4, which is known to be prone to Fab glycosylation, but was also present in IgG1. When autoimmune diseases with a chronic disease course were compared with more acute autoimmune illnesses, increased Fab glycosylation was restricted to the chronic diseases. As a proxy for chronic autoantigen exposure, the investigators determined Fab glycosylation levels on antibodies to common latent herpes viruses, as well as to glycoprotein 120 in individuals who are chronically HIV-1-infected. Immunity to these viral antigens was not associated with increased Fab glycosylation levels, indicating that chronic antigen-stimulation as such does not lead to increased Fab glycosylation levels. CONCLUSIONS: These data indicate that in chronic but not acute B cell-mediated autoimmune diseases, disease-specific autoantibodies are enriched for Fab glycans.

Disease activity in patients with immune-mediated inflammatory diseases after SARS-CoV-2 vaccinations.

For patients with immune-mediated inflammatory diseases (IMIDs), concerns exist about increased disease activity after vaccination. We aimed to assess changes in disease activity after SARS-CoV-2 vaccination in patients with IMIDs, and determine risk factors for increased disease activity. In this substudy of a prospective observational cohort study (Target-to-B!), we included patients with IMIDs who received a SARS-CoV-2 vaccine. Patients reported changes in disease activity on a five-point Likert scale every 60 days for up to twelve months after first vaccination. In case of self-reported increased activity, hospital records were screened whether the treating physician reported increased activity, and for potential intensification of immunosuppressive (ISP) treatment. Mixed models were used to study determinants for self-reported increased disease activity. In total, 2111 patients were included for analysis after primary immunization (mean age 49.7 years [SD 13.7], 1329/2111 (63.0%) female), from which 1266 patients for analysis after first additional vaccination. Increased disease activity at 60 days after start of primary immunization was reported by 223/2111 (10.6%). In 96/223 (43.0%) the increase was confirmed by the treating physician and in 36/223 (16.1%) ISP treatment was intensified. Increased disease activity at seven to 60 days after additional vaccination, was reported by 139/1266 (11.0%). Vaccinations were not temporally associated with self-reported increased disease activity. Conversely, increased disease activity before first vaccination, neuromuscular disease, and multiple sclerosis were associated. Altogether, self-reported increased disease activity after vaccination against SARS-CoV-2 was recorded in a minority of patients and was generally mild. Moreover, multivariate analyses suggest that disease related factors, but not vaccinations are the major determinants for self-reported increased disease activity.

Hidradenitis suppurativa tarda: defining an understudied elderly population.

BACKGROUND: Hidradenitis suppurativa (HS) is a chronic, devastating, multifactorial skin disease. Patients generally develop HS after puberty and the prevalence of the disease is assumed to decrease with higher age. Data outside the usual age range are limited, especially for elderly patients. OBJECTIVES: To investigate the prevalence, clinical characteristics and associated comorbidities among the elderly HS population. METHODS: Data were collected through a population-wide survey-based study within the Lifelines Cohort Study in the Netherlands. The clinical characteristics of elderly patients with HS (≥ 60 years) were compared with an adult population (< 60 years) with HS. The comorbidities in elderly patients with HS were compared with those of a non-HS sex- and age-matched elderly population in a 1 : 4 ratio. HS in the elderly was defined as active HS in patients aged 60 years and older. Within the HS elderly group, two subgroups were defined, late-onset HS (HS developed after 60 years of age) and persistent HS (HS developed from a younger age but continuing after 60 years of age). RESULTS: Within the Lifelines cohort 209 elderly patients with HS were identified as well as an adult (< 60 years) group with HS (n = 793) and a non-HS sex- and age-matched control elderly group (n = 810). The prevalence of HS among the elderly bootstrap analysis population was 0.8% [95% confidence interval (CI) 0.4-1.2]. A significantly higher age of HS symptom onset was found compared with the adult HS group: respectively, 40 vs. 23 years (odds ratio 1.056, 95% CI 1.05-1.07). Among the elderly HS cohort (in the Discussion, the HS tarda cohort) a female : male ratio of 1.7 : 1.0 and a higher family history for HS were found. Moreover, elderly patients with HS had a significantly higher risk of having HS-associated comorbidities compared with the sex- and age-matched controls. CONCLUSIONS: The prevalence of HS in the elderly is not rare. Among the elderly a shift from female predominance towards a lower female : male ratio in HS is observed. In addition, HS in the elderly showed significant variation in age of onset and involved body areas. Moreover, elderly patients with HS were more susceptible to multimorbidity. Finally, we propose defining HS in the elderly as 'HS tarda' and subdividing it as late-onset and persistent HS tarda.

Heterogeneity of reported outcomes in epidermolysis bullosa clinical research: a scoping review as a first step towards outcome harmonization.

BACKGROUND: Epidermolysis bullosa (EB) is a rare, genetically and clinically heterogeneous group of skin fragility disorders. No cure is currently available, but many novel and repurposed treatments are upcoming. For adequate evaluation and comparison of clinical studies in EB, well-defined and consistent consensus-endorsed outcomes and outcome measurement instruments are necessary. OBJECTIVES: To identify previously reported outcomes in EB clinical research, group these outcomes by outcome domains and areas and summarize respective outcome measurement instruments. METHODS: A systematic literature search was performed in the databases MEDLINE, Embase, Scopus, Cochrane CENTRAL, CINAHL, PsycINFO and trial registries covering the period between January 1991 and September 2021. Studies were included if they evaluated a treatment in a minimum of three patients with EB. Two reviewers independently performed the study selection and data extraction. All identified outcomes and their respective instruments were mapped onto overarching outcome domains. The outcome domains were stratified according to subgroups of EB type, age group, intervention, decade and phase of clinical trial. RESULTS: The included studies (n = 207) covered a range of study designs and geographical settings. A total of 1280 outcomes were extracted verbatim and inductively mapped onto 80 outcome domains and 14 outcome areas. We found a steady increase in the number of published clinical trials and outcomes reported over the past 30 years. The included studies mainly focused on recessive dystrophic EB (43%). Wound healing was reported most frequently across all studies and referred to as a primary outcome in 31% of trials. Great heterogeneity of reported outcomes was observed within all stratified subgroups. Moreover, a diverse range of outcome measurement instruments (n = 200) was identified. CONCLUSIONS: We show substantial heterogeneity in reported outcomes and outcome measurement instruments in EB clinical research over the past 30 years. This review is the first step towards harmonization of outcomes in EB, which is necessary to expedite the clinical translation of novel treatments for patients with EB.

Guselkumab for hidradenitis suppurativa: a phase II, open-label, mode-of-action study.

BACKGROUND: The effectiveness of available biologics for the treatment of hidradenitis suppurativa (HS) is limited. Additional therapeutic options are needed. OBJECTIVES: To investigate the efficacy and mode of action of guselkumab [an anti-interleukin (IL)-23p19 monoclonal antibody] 200 mg subcutaneously every 4 weeks for 16 weeks in patients with HS. METHODS: An open-label, multicentre, phase IIa trial in patients with moderate-to-severe HS was carried out (NCT04061395). The pharmacodynamic response in skin and blood was measured after 16 weeks of treatment. Clinical efficacy was assessed using the Hidradenitis Suppurativa Clinical Response (HiSCR), the International Hidradenitis Suppurativa Severity Score System (IHS4), and the abscess and inflammatory nodule (AN) count. The protocol was reviewed and approved by the local institutional review board (METC 2018/694), and the study was conducted in accordance with good clinical practice guidelines and applicable regulatory requirements. RESULTS: Thirteen of 20 patients (65%) achieved HiSCR with a statistically significant decrease in median IHS4 score (from 8.5 to 5.0; P = 0.002) and median AN count (from 6.5 to 4.0; P = 0.002). The overall patient-reported outcomes did not show a similar trend. One serious adverse event, likely to be unrelated to guselkumab treatment, was observed. In lesional skin, transcriptomic analysis revealed the upregulation of various genes associated with inflammation, including immunoglobulins, S100, matrix metalloproteinases, keratin, B-cell and complement genes, which decreased in clinical responders after treatment. Immunohistochemistry revealed a marked decrease in inflammatory markers in clinical responders at week 16. CONCLUSIONS: Sixty-five per cent of patients with moderate-to-severe HS achieved HiSCR after 16 weeks of treatment with guselkumab. We could not demonstrate a consistent correlation between gene and protein expression and clinical responses. The main limitations of this study were the small sample size and absence of a placebo arm. The large placebo-controlled phase IIb NOVA trial for guselkumab in patients with HS reported a lower HiSCR response of 45.0-50.8% in the treatment group and 38.7% in the placebo group. Guselkumab seems only to be of benefit in a subgroup of patients with HS, indicating that the IL-23/T helper 17 axis is not central to the pathophysiology of HS.

Primary SARS-CoV-2 infection in patients with immune-mediated inflammatory diseases: long-term humoral immune responses and effects on disease activity.

BACKGROUND: Patients with immune-mediated inflammatory diseases (IMIDs) on immunosuppressants (ISPs) may have impaired long-term humoral immune responses and increased disease activity after SARS-CoV-2 infection. We aimed to investigate long-term humoral immune responses against SARS-CoV-2 and increased disease activity after a primary SARS-CoV-2 infection in unvaccinated IMID patients on ISPs. METHODS: IMID patients on active treatment with ISPs and controls (i.e. IMID patients not on ISP and healthy controls) with a confirmed SARS-CoV-2 infection before first vaccination were included from an ongoing prospective cohort study (T2B! study). Clinical data on infections and increased disease activity were registered using electronic surveys and health records. A serum sample was collected before first vaccination to measure SARS-CoV-2 anti-receptor-binding domain (RBD) antibodies. RESULTS: In total, 193 IMID patients on ISP and 113 controls were included. Serum samples from 185 participants were available, with a median time of 173 days between infection and sample collection. The rate of seropositive IMID patients on ISPs was 78% compared to 100% in controls (p < 0.001). Seropositivity rates were lowest in patients on anti-CD20 (40.0%) and anti-tumor necrosis factor (TNF) agents (60.5%), as compared to other ISPs (p < 0.001 and p < 0.001, respectively). Increased disease activity after infection was reported by 68 of 260 patients (26.2%; 95% CI 21.2-31.8%), leading to ISP intensification in 6 out of these 68 patients (8.8%). CONCLUSION: IMID patients using ISPs showed reduced long-term humoral immune responses after primary SARS-CoV-2 infection, which was mainly attributed to treatment with anti-CD20 and anti-TNF agents. Increased disease activity after SARS-CoV-2 infection was reported commonly, but was mostly mild. TRIAL REGISTRATION: NL74974.018.20, Trial ID: NL8900. Registered on 9 September 2020.

Chronic Use of Hydrochlorothiazide and Risk of Skin Cancer in Caucasian Adults: A PharmLines Initiative Inception Cohort Study.

Photosensitizing properties of hydrochlorothiazide may increase skin cancer risk. To date, study findings on the association between hydrochlorothiazide use and skin cancer risk are inconsistent, notably regarding confounding and dose-response. The aim of this study was to investigate the association between hydrochlorothiazide use and incidence of skin cancer in a cohort of unselected Caucasian adults, taking dosing into account. As part of the PharmLines Initiative, which links data from the Lifelines Cohort Study and prescription database IADB.nl, patients aged ≥ 40 years were included from Lifelines, a prospective population-based cohort study in the north of the Netherlands. Skin cancer incidence was compared between subjects starting hydrochlorothiazide treatment (n = 608), subjects starting treatment with other antihypertensives (n = 508), and non-antihypertensive long-term medication users (n = 1,710). Cox regression analyses were performed to obtain hazard ratios, adjusted for potential confounders. The risk of any skin cancer, keratinocyte carcinoma, basal cell carcinoma and squamous cell carcinoma was not significantly increased in general hydrochlorothiazide users. A clear association was observed between high cumulative hydrochlorothiazide use (≥ 5,000 defined daily dose; ≥ 125,000 mg) and the risk of any skin cancer (adjusted hazard ratio 5.32, 95% confidence interval (95% CI) 2.40-11.81), keratinocyte carcinoma (adjusted hazard ratio 7.31, 95% CI 3.12-17.13), basal cell carcinoma (adjusted hazard ratio 7.72, 95% CI 3.11-19.16) and squamous cell carcinoma (adjusted hazard ratio 19.63, 95% CI 3.12-123.56). These findings should lead to awareness with high use of hydrochlorothiazide in Caucasian adults.

Paraneoplastic pemphigus: A detailed case series from the Netherlands revealing atypical cases.

BACKGROUND: Paraneoplastic pemphigus (PNP) is an extremely rare life-threatening blistering autoimmune disease that is associated with an underlying neoplasm. There is a set diagnostic criterion for PNP, which is primarily based on a severe stomatitis and the detection of specific antibodies against envoplakin, periplakin and alpha-2-macroglobulin-like protein 1. However, it has become increasingly evident that there are patients with PNP that do not meet all the diagnostic criteria requirements. OBJECTIVES: The aim of this study was to analyse our cohort of Dutch patients and to define the atypical cases that did not meet the diagnostic criteria. METHODS: A retrospective case study of all known Dutch PNP patients of the past 25 years. Patients' clinical and immunological variables were thoroughly analysed and described. RESULTS: Twenty-four patients were included in this study. The results revealed several atypical patient cases that did not completely meet the set diagnostic criteria. Of the 24 patients, two patients presented without stomatitis, in three patients an underlying neoplasm could not be detected, and in two patients the presence of specific autoantibodies could not be demonstrated, although all other criteria for PNP were met. Finally, three of the 24 patients survived the disease. CONCLUSION: Although our findings showed similarities to previous studies and most of the patients met the criteria, there were a few atypical patient cases; highlighting the importance of not strictly adhering to the set criteria when making a diagnosis, as this can lead to a missed or late diagnosis. Thus, it is of crucial importance to combine clinical and elaborate laboratory results to confirm the diagnosis of PNP in suspected patients. Although PNP harbours an unfavourable prognosis in most cases, it might be resolved by timely treatment of the underlying cause.

S2k guidelines on the management of paraneoplastic pemphigus/paraneoplastic autoimmune multiorgan syndrome initiated by the European Academy of Dermatology and Venereology (EADV).

BACKGROUND: Paraneoplastic pemphigus (PNP), also called paraneoplastic autoimmune multiorgan syndrome (PAMS), is a rare autoimmune disease with mucocutaneous and multi-organ involvement. PNP/PAMS is typically associated with lymphoproliferative or haematological malignancies, and less frequently with solid malignancies. The mortality rate of PNP/PAMS is elevated owing to the increased risk of severe infections and disease-associated complications, such as bronchiolitis obliterans. OBJECTIVES: These guidelines summarize evidence-based and expert-based recommendations (S2k level) for the clinical characterization, diagnosis and management of PNP/PAMS. They have been initiated by the Task Force Autoimmune Blistering Diseases of the European Academy of Dermatology and Venereology with the contribution of physicians from all relevant disciplines. The degree of consent among all task force members was included. RESULTS: Chronic severe mucositis and polymorphic skin lesions are clue clinical characteristics of PNP/PAMS. A complete assessment of the patient with suspected PNP/PAMS, requiring histopathological study and immunopathological investigations, including direct and indirect immunofluorescence, ELISA and, where available, immunoblotting/immunoprecipitation, is recommended to achieve a diagnosis of PNP/PAMS. Detection of anti-envoplakin antibodies and/or circulating antibodies binding to the rat bladder epithelium at indirect immunofluorescence is the most specific tool for the diagnosis of PNP/PAMS in a patient with compatible clinical and anamnestic features. Treatment of PNP/PAMS is highly challenging. Systemic steroids up to 1.5 mg/kg/day are recommended as first-line option. Rituximab is also recommended in patients with PNP/PAMS secondary to lymphoproliferative conditions but might also be considered in cases of PNP/PAMS associated with solid tumours. A multidisciplinary approach involving pneumologists, ophthalmologists and onco-haematologists is recommended for optimal management of the patients. CONCLUSIONS: These are the first European guidelines for the diagnosis and management of PNP/PAMS. Diagnostic criteria and therapeutic recommendations will require further validation by prospective studies.

Risk factors associated with short-term adverse events after SARS-CoV-2 vaccination in patients with immune-mediated inflammatory diseases.

BACKGROUND: Studies have suggested incremental short-term adverse events (AE) after repeated vaccination. In this report, we assessed occurrence and risk factors for short-term AEs following repeated SARS-CoV-2 vaccination in patients with various immune-mediated inflammatory diseases (IMIDs). METHODS: Self-reported daily questionnaires on AEs during the first 7 days after vaccination were obtained of 2259 individuals (2081 patients and 178 controls) participating in an ongoing prospective multicenter cohort study on SARS-CoV-2 vaccination in patients with various IMIDs in the Netherlands (T2B-COVID). Relative risks were calculated for potential risk factors associated with clinically relevant AE (rAE), defined as AE lasting longer than 2 days or impacting daily life. RESULTS: In total, 5454 vaccinations were recorded (1737 first, 1992 second and 1478 third vaccinations). Multiple sclerosis, Crohn's disease and rheumatoid arthritis were the largest disease groups. rAEs were reported by 57.3% (95% CI 54.8-59.8) of patients after the first vaccination, 61.5% (95% CI 59.2-63.7) after the second vaccination and 58% (95% CI 55.3-60.6) after the third vaccination. At day 7 after the first, second and third vaccination, respectively, 7.6% (95% CI 6.3-9.1), 7.4% (95% CI 6.2-8.7) and 6.8% (95% CI 5.4-8.3) of patients still reported AEs impacting daily life. Hospital admissions and allergic reactions were uncommon (<0.7%). Female sex (aRR 1.43, 95% CI 1.32-1.56), age below 50 (aRR 1.14, 95% CI 1.06-1.23), a preceding SARS-CoV-2 infection (aRR 1.14, 95% CI 1.01-1.29) and having an IMID (aRR 1.16, 95% CI 1.01-1.34) were associated with increased risk of rAEs following a vaccination. Compared to the second vaccination, the first vaccination was associated with a lower risk of rAEs (aRR 0.92, 95% CI 0.84-0.99) while a third vaccination was not associated with increased risk on rAEs (aRR 0.93, 95% CI 0.84-1.02). BNT162b2 vaccines were associated with lower risk on rAEs compared to CX-024414 (aRR 0.86, 95% CI 0.80-0.93). CONCLUSIONS: A third SARS-CoV-2 vaccination was not associated with increased risk of rAEs in IMID patients compared to the second vaccination. Patients with an IMID have a modestly increased risk of rAEs after vaccination when compared to controls. Most AEs are resolved within 7 days; hospital admissions and allergic reactions were uncommon. TRIAL REGISTRATION: NL74974.018.20 , Trial ID: NL8900. Registered on 9 September 2020.

Breakthrough infections with the SARS-CoV-2 omicron (B.1.1.529) variant in patients with immune-mediated inflammatory diseases.

OBJECTIVES: To compare the cumulative incidence and disease severity of reported SARS-CoV-2 omicron breakthrough infections between patients with immune-mediated inflammatory diseases (IMID) on immunosuppressants and controls, and to investigate determinants for breakthrough infections. METHODS: Data were used from an ongoing national prospective multicentre cohort study on SARS-CoV-2 vaccination responses in patients with IMID in the Netherlands (Target-to-B! (T2B!) study). Patients wih IMID on immunosuppressants and controls (patients with IMID not on immunosuppressants and healthy controls) who completed primary immunisation were included. The observation period was between 1 January 2022 and 1 April 2022, during which the SARS-CoV-2 omicron (BA.1 and BA.2 subvariant) was dominant. A SARS-CoV-2 breakthrough infection was defined as a reported positive PCR and/or antigen test at least 14 days after primary immunisation. A multivariate logistic regression model was used to investigate determinants. RESULTS: 1593 patients with IMID on immunosuppressants and 579 controls were included. The cumulative incidence of breakthrough infections was 472/1593 (29.6%; 95% CI 27% to 32%) in patients with IMID on immunosuppressants and 181/579 (31.3%; 95% CI 28% to 35%) in controls (p=0.42). Three (0.5%) participants had severe disease. Seroconversion after primary immunisation (relative risk, RR 0.71; 95% CI 0.52 to 0.96), additional vaccinations (RR 0.61; 95% CI 0.49 to 0.76) and a prior SARS-CoV-2 infection (RR 0.60; 95% CI 0.48 to 0.75) were associated with decreased risk of breakthrough infection. CONCLUSIONS: The cumulative incidence of reported SARS-CoV-2 omicron breakthrough infections was high, but similar between patients with IMID on immunosuppressants and controls, and disease severity was mostly mild. Additional vaccinations and prior SARS-CoV-2 infections may reduce the incidence of breakthrough infections.

New insights in hidradenitis suppurativa from a population-based Dutch cohort: prevalence, smoking behaviour, socioeconomic status and comorbidities.

BACKGROUND: Hidradenitis suppurativa (HS) is a chronic autoinflammatory skin condition and is associated with several comorbidities. Previous studies report variable prevalence rates of HS, depending on the methodology. However, the exact prevalence remains unknown. OBJECTIVES: To estimate the prevalence of HS in a large population-based cohort in the Northern Netherlands, and to compare patients with HS to the general population, investigate characteristics and identify potential associated comorbidities. METHODS: Data were collected through a cross-sectional survey-based study within the Lifelines Cohort Study (n = 167 729), based on the general population located in the Northern Netherlands. A digital self-reported questionnaire was developed consisting of validated questions for determining HS. RESULTS: Among 56 084 respondents, the overall prevalence of HS was 2.1% [95% confidence interval (CI) 2.0-2.2]. The respondents with HS had lower socioeconomic status than the controls (P < 0.001) and more frequently currently smoked (P < 0.001). Several new significant associations in patients with HS were revealed, such as fibromyalgia (OR 2.26, 95% CI 1.64-3.11), irritable bowel syndrome (OR 1.63, 95% CI 1.18-2.26), chronic fatigue syndrome (OR 1.72, 95% CI 1.06-2.78) and migraine (OR 1.48, 95% CI 1.11-1.96). Fibromyalgia and chronic fatigue syndrome remained significantly associated with HS in the multivariate analysis after adjusting for age, sex, body mass index, smoking status and socioeconomic status. CONCLUSIONS: Our study showed a higher prevalence of HS in the Northern Netherlands compared with the overall estimated prevalence of 1% and identified several new associated comorbidities.

Insights into clinical and diagnostic findings as well as treatment responses in patients with mucous membrane pemphigoid: A retrospective cohort study.

BACKGROUND: The variable clinical severity of mucous membrane pemphigoid (MMP) often leads to diagnostic and therapeutic delays. OBJECTIVE: To describe the characteristics of a large cohort of patients with MMP. METHODS: A retrospective review of clinical and diagnostic characteristics as well as treatment responses in 145 patients with MMP. RESULTS: Monosite involvement was seen in 41.4% and multisite involvement in 58.6% of the patients. The oral mucosa was affected in 86.9% of the patients, followed by the ocular mucosa (30.3%), skin (26.2%), genital mucosa (25.5%), nasal mucosa (23.4%), and pharyngeal and/or laryngeal mucosa (17.2%). Ocular disease developed during the disease course in 41.7% of patients with initially other mucosal site involvement. The malignancy rate was significantly higher in patients with autoantibodies against laminin-332 than in patients with MMP without laminin-332 autoantibodies (35.3% vs 10.9%, respectively; P = .007). Systemic immunosuppressive or immunomodulatory therapy was administered to 77.1% of the patients, mainly to patients with multisite (P < .001), ocular (P < .001), and pharyngeal and laryngeal involvement (P = .002). The remaining patients (22.9%) received topical therapy. Adverse events were frequently reported. LIMITATIONS: Retrospective design. CONCLUSION: Patients with MMP present with a heterogeneous clinical presentation, and new symptoms may develop during the disease course. Cancer screening should be considered for patients with MMP and, in particular, for those with autoantibodies against laminin-332.

Diagnostic Utility of C4d by Direct Immunofluorescence in Bullous Pemphigoid.

ABSTRACT: Bullous pemphigoid (BP) is an autoimmune blistering disease that commonly affects elderly patients. Direct immunofluorescence (DIF) for immunoglobulin G (IgG) and C3c on frozen skin biopsies is the gold standard for the diagnosis of BP. In a minority of cases, IgG and/or C3c are found negative, and in these situations, there is a need for a more stable diagnostic marker of BP. C4d is biologically inactive, but has a long half-life, rendering it a long-lived marker for antibody-mediated complement activation. Previous studies already demonstrated that C4d was diagnostically useful in formalin-fixed paraffin-embedded skin biopsies of patients with BP. We hypothesized that C4d detected by DIF could also be a promising diagnostic marker for BP, particularly in IgG and/or C3c DIF-negative cases. In this single-center retrospective study, 69 cases of BP were analyzed for linear deposition of C4d; of the 69 cases, n = 26 were IgG+/C3c-, n = 10 IgG+/C3c+, and n = 33 IgG-/C3c-. Results were compared with n = 39 negative controls. Seven of the 26 (27%) IgG+/C3c- and 3 of the 33 (9%) IgG-/C3c- BP cases were positive for C4d. All 10 IgG+/C3c+ cases were also C4d positive. In the negative control group, 2 of the 39 (5%) were found positive for C4d. In conclusion, the current study shows that C4d is a more sensitive but not a 100% specific marker of BP. We conclude that C4d by DIF could be an interesting diagnostic adjunct for BP, particularly in IgG-/C3c- double negative cases.