BRAF V600E is associated with higher incidence of second cancers in adults with Langerhans cell histiocytosis

In this retrospective study, BRAF mutation status did not correlate with disease extent or (event-free) survival in 156 adults with Langerhans cell histiocytosis. BRAFV600E was associated with an increased incidence of second malignancies, often comprising hematological cancers, which may be clonally related.

Long-Term Follow-Up of Patients with Scleritis After Rituximab Treatment Including B Cell Monitoring

PURPOSE

We report the long-term effect of rituximab (RTX) in scleritis and determine the value of B-cell monitoring for the prediction of relapses.

METHODS

We retrospectively studied 10 patients with scleritis, who were treated with RTX. Clinical characteristics were collected, and blood B-cell counts were measured before the start of RTX, and at various time points after treatment.

RESULTS

Clinical activity of scleritis decreased after RTX treatment in all patients within a median time of 8 weeks (range 3-13), and all reached remission. The median follow-up was 101 months (range 9-138). Relapses occurred in 6 out of 10 patients. All relapses, where B-cell counts were measured (11 out of 19), were heralded by returning B cells. However, B cells also returned in patients with long-term remissions.

CONCLUSIONS

RTX is a promising therapeutic option for scleritis. Recurrence of B cells after initial depletion does not always predict relapse of scleritis.

Digital Outcome Measurement to Improve Care for Patients With Immune-Mediated Inflammatory Diseases: Protocol for the IMID Registry

BACKGROUND

Despite enormous clinical improvements, due to better management strategies and the availability of biologicals, immune-mediated inflammatory diseases (IMIDs) still have a significant impact on patients' lives. To further reduce disease burden, provider- as well as patient-reported outcomes (PROs) should be taken into account during treatment and follow-up. Web-based collection of these outcomes generates valuable repeated measurements, which could be used (1) in daily clinical practice for patient-centered care, including shared decision-making; (2) for research purposes; and (3) as an essential step toward the implementation of value-based health care (VBHC). Our ultimate goal is that our health care delivery system is completely aligned with the principles of VBHC. For aforementioned reasons, we implemented the IMID registry.

OBJECTIVE

The IMID registry is a digital system for routine outcome measurement that mainly includes PROs to improve care for patients with IMIDs.

METHODS

The IMID registry is a longitudinal observational prospective cohort study within the departments of rheumatology, gastroenterology, dermatology, immunology, clinical pharmacy, and outpatient pharmacy of the Erasmus MC, the Netherlands. Patients with the following diseases are eligible for inclusion: inflammatory arthritis, inflammatory bowel disease, atopic dermatitis, psoriasis, uveitis, Behçet disease, sarcoidosis, and systemic vasculitis. Generic and disease-specific (patient-reported) outcomes, including adherence to medication, side effects, quality of life, work productivity, disease damage, and activity, are collected from patients and providers at fixed intervals before and during outpatient clinic visits. Data are collected and visualized through a data capture system, which is linked directly to the patients' electronic health record, which not only facilitates a more holistic care approach, but also helps with shared decision-making.

RESULTS

The IMID registry is an ongoing cohort with no end date. Inclusion started in April 2018. From start until September 2022, a total of 1417 patients have been included from the participating departments. The mean age at inclusion was 46 (SD 16) years, and 56% of the patient population is female. The average percentage of filled out questionnaires at baseline is 84%, which drops to 72% after 1 year of follow-up. This decline may be due to the fact that the outcomes are not always discussed during the outpatient clinic visit or because the questionnaires were sometimes forgotten to set out. The registry is also used for research purposes and 92% of the patients with IMIDs gave informed consent to use their data for that.

CONCLUSIONS

The IMID registry is a web-based digital system that collects provider- and PROs. The collected outcomes are used to improve care for the individual patient with an IMID and facilitate shared decision-making, and they are also used for research purposes. The measurement of these outcomes is an essential step toward the implementation of VBHC.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/43230.

The role of etoposide in the treatment of adult patients with hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a potentially fatal inflammatory clinical condition, in which an exaggerated immune response is ineffectively regulated. Although etoposide-containing regimens are generally recommended for children with HLH, the exact role of etoposide in the adult setting remains unclear. We performed a systematic review of the literature on the use of etoposide in adults with HLH. All articles written in English on the use of etoposide in adults with HLH available from seven databases and published on or before July 2021 were analyzed. Thirteen studies were found to be relevant to the search results. Ten of these studies report a statistical analysis on the effect of etoposide, of which five found etoposide-containing regimens superior to non-etoposide-containing regimens. Seven studies provided sufficient data to be included in the meta-analysis. For these data, the estimated logit relative risk of etoposide on survival was 1.06 (95% confidence interval: 0.92-1.21, standard error: 2.06). The pooled data of the meta-analysis did thus not support a beneficial effect of etoposide. It should be taken into account that the presented results are highly susceptible to bias and that the effect of etoposide differs between HLH-triggers. Although the meta-analysis does not support the effect of etoposide, we do not recommend abandoning etoposide as treatment modality. The limitations of the meta-analysis, together with several individual articles confirming the benefit of etoposide, justify etoposide for select cases in adults with HLH such as refractory or severe disease with (threatening) multiorgan failure.

Impact of the First SARS-CoV-2 Lockdown on Adherence to Biological Treatment in Patients with Immune-Mediated Inflammatory Diseases in the Netherlands

PURPOSE

During the SARS-CoV-2 pandemic, national and international societies have recommended continuing biological agents in patients with immune-mediated inflammatory diseases (IMID) in the absence of SARS-CoV-2 symptoms. However, adherence to biological treatment might decrease, because these recommendations contradict patients' beliefs. Especially an increased concern about side effects could have influenced the adherence to biological treatment during the first lockdown. The primary objective was to investigate the impact of the first SARS-CoV-2 lockdown on adherence to biological treatment in IMID patients.

PATIENTS AND METHODS

In this prospective cohort study, IMID patients who received a biological agent before and during the first SARS-CoV-2 lockdown (March 2020- June 2020) were included. Patients were excluded if they did not complete the medication adherence report scale-5 (MARS-5) questionnaire at ≥1 visit before the lockdown and ≥1 visit during the lockdown. Adherence to biological treatment was measured with the MARS-5 and Medication Possession Ratio (MPR).

RESULTS

We included 157 IMID patients. The percentage of adherent patients, defined as MARS-5 score >21, was significantly lower during the lockdown compared to the period before the lockdown (88.5% vs 84.1%, p<0.001). Additionally, the overall percentage of adherent patients during the lockdown based on the MPR ≥90% was significantly lower compared to adherence based upon the MARS-5 (65.1% vs 84.1%, p<0.001).

CONCLUSION

This study showed that the first SARS-CoV-2 lockdown negatively impacts adherence to biological treatment in IMID patients. Therefore, treating physicians should be aware of this problem to minimize the potential harmful effects of non-adherence.

A pilot study into bosentan (Tracleer®) as an immunomodulating agent in patients with Behçet's disease

BACKGROUND

Behçet's disease (BD) is an auto-inflammatory vasculitis characterized by aphthous oro-genital ulcers, inflammatory skin changes and uveitis. Treatment is mainly immunosuppressive. Interestingly, elevated endotheline-1 (ET-1) levels suggest a possible beneficial effect of treatment with an ET-1 receptor antagonist.

OBJECTIVE

The aim of our study was to investigate the possible beneficial effect of the ET-1 inhibitor bosentan.

METHODS

We performed a prospective double-blind placebo controlled pilot study into the effect and safety of bosentan in BD patients. Disease activity was measured using the Behçet Disease Current Activity Form. The primary objective of the study was to determine whether bosentan is therapeutically effective in patients with BD. Secondary endpoints were safety, tapering of medication and the effect of bosentan on possible disease activity markers such as ET-1, circulating endothelial cells (CECs), soluble interleukin-2 receptor (sIL2R) and cytokine levels.

RESULTS

Ten patients were randomized to either bosentan or placebo. Overall, no effect on disease activity was observed, although one patient responded clinically and continued treatment after the study period. Despite one SAE, bosentan seems safe to use. No effect on tapering of medication, CECs, sIL2R and cytokine levels was found. In the bosentan group, ET-1 levels were elevated during the treatment period, with no correlation with disease activity.

CONCLUSIONS

Although this is a small pilot study, bosentan appears to be safe in BD patients. One patient had a durable and significant clinical response. Our observations should be confirmed and extended in a larger patient cohort to be of significant impact in the treatment options for BD.

Tissue IgG2/IgG4 Ratio as an Additional Tool to Distinguish IgG4-Related Disease From Other Fibroinflammatory Disorders

Interpretation of biopsies taken on suspicion of immunoglobulin (Ig)G4-related disease (IgG4-RD) may be hampered by uninterpretable immunohistochemical stains for IgG because of strong background signals. This study aims to determine the significance of tissue IgG2 positive plasma cell counts in IgG4-RD in comparison with non-IgG4-related inflammatory disorders. Descriptive, retrospective case-control study of 16 patients with IgG4-related orbital disease (IgG4-ROD) and 24 with extraorbital IgG4-RD. Histopathology and serology of this group was compared with 16 patients with orbital non-IgG4-related disorders and 22 patients with extraorbital non-IgG4-related disorders. The mean tissue IgG2/IgG4 ratio was 0.16 in IgG4-ROD and 0.27 in extraorbital IgG4-RD and far below 1 in 98% of patients. This was significantly lower compared with the non-IgG4-related disorders that showed a mean tissue IgG2/IgG4 ratio of 1.98 in the orbital and 2.20 in the extraorbital group (range: 0.20 to 10, P <0.05). In 74% of tissue samples an IgG2/IgG4 ratio >1 was seen. The tissue IgG2/IgG ratio was significantly lower in IgG4-RD compared with non-IgG4-related inflammatory disorders. Serum IgG2 concentration was not abnormal in patients with IgG4-RD. A significantly lower tissue IgG2/IgG4 and IgG2/IgG ratio was observed in IgG4-RD, compared with non-IgG4-related inflammatory disorders. Additional immunohistochemical staining for IgG2 positive plasma cells can be helpful in the diagnosis of IgG4-RD. Especially in cases with uninterpretable IgG staining, a well-recognized problem that may give rise to a failed interpretation of the biopsy.

Aggressive unifocal bone Langerhans cell histiocytosis with soft tissue extension both responsive to radiotherapy: a case report

BACKGROUND

Langerhans cell histiocytosis (LCH) is a rare haematological neoplasm characterized by the accumulation of CD1a⁺, CD207/Langerin⁺ histiocytes within inflammatory lesions. LCH can involve any organ, but osteolytic bone lesions are most often encountered. Unifocal bone lesions may regress spontaneously after a thick needle biopsy has been taken.

CASE PRESENTATION

In this case report, we describe the initial presentation of a single BRAF^V600E mutated osteolytic LCH lesion in the left proximal humerus of a 46-year-old previously healthy woman. Despite multiple surgical interventions, she unexpectedly experienced progressive disease manifestation with significant soft tissue extension to the surrounding musculature, subcutis and epidermis. Because the disease manifestation remained loco-regional, radiotherapy (RT) (total dose of 20 Gy in 10 fractions) was initiated.

CONCLUSION

The patient achieved a complete remission without any side effects. This case highlights that RT is a rational and relative mild local treatment option for patients with aggressive LCH affecting the bone and surrounding soft tissue.

Vision loss caused by immunoglobulin G4-related disease of the skull base complicated by a mucocele of the sphenoid sinus

BACKGROUND

Immunoglobulin G4-related disease (IgG4-RD) is a fibro-inflammatory disorder and manifestation in de paranasal and sphenoid sinus is well recognized. In this patient, IgG4-RD presented in an unusual manner with vision loss due to mucocele formation in the sphenoid sinus.

CASE DESCRIPTION

A 19-year-old man, with an unremarkable medical history, was referred with decreased vision in the left eye, headaches, and a sharp pain in the left orbit and ear. Compression of the left optic nerve due to a large mucocele caused papillary edema and emergency endoscopic marsupialization of the mucocele was performed. When the vision decreased again, a more extensive decompressing sphenoidotomy was performed. Histopathology showed IgG4-RD. Despite dexamethasone, the lesion expanded to the anterior skull base and the patient required repeat endoscopic surgery. After 3 months, a decrease in smell and vision warranted for a fourth extensive endoscopic decompressing surgery, complicated by a cerebrospinal fluid leak. Prednisone and later rituximab were commenced. Unfortunately, the patient reported a complete loss of vision after 4 months of rituximab due to increased mass effect on the optic nerve. An extensive combined craniofacial-endoscopic surgery was performed to remove the entire mucocele and to prevent further contralateral and intracranial progression. Methylprednisolone monthly was commenced to prevent further complications.

DISCUSSION

This case illustrates that in therapy-resistant sino-orbital IgG4-RD, extensive surgery might be necessary at an earlier stage. It may even be the only option to prevent irreversible damage to the surrounding tissues. A multidisciplinary approach in the management of sino-orbital IgG4-RD is therefore warranted.

ALK-positive histiocytosis: a new clinicopathologic spectrum highlighting neurologic involvement and responses to ALK inhibition

ALK-positive histiocytosis is a rare subtype of histiocytic neoplasm first described in 2008 in 3 infants with multisystemic disease involving the liver and hematopoietic system. This entity has subsequently been documented in case reports and series to occupy a wider clinicopathologic spectrum with recurrent KIF5B-ALK fusions. The full clinicopathologic and molecular spectra of ALK-positive histiocytosis remain, however, poorly characterized. Here, we describe the largest study of ALK-positive histiocytosis to date, with detailed clinicopathologic data of 39 cases, including 37 cases with confirmed ALK rearrangements. The clinical spectrum comprised distinct clinical phenotypic groups: infants with multisystemic disease with liver and hematopoietic involvement, as originally described (Group 1A: 6/39), other patients with multisystemic disease (Group 1B: 10/39), and patients with single-system disease (Group 2: 23/39). Nineteen patients of the entire cohort (49%) had neurologic involvement (7 and 12 from Groups 1B and 2, respectively). Histology included classic xanthogranuloma features in almost one-third of cases, whereas the majority displayed a more densely cellular, monomorphic appearance without lipidized histiocytes but sometimes more spindled or epithelioid morphology. Neoplastic histiocytes were positive for macrophage markers and often conferred strong expression of phosphorylated extracellular signal-regulated kinase, confirming MAPK pathway activation. KIF5B-ALK fusions were detected in 27 patients, whereas CLTC-ALK, TPM3-ALK, TFG-ALK, EML4-ALK, and DCTN1-ALK fusions were identified in single cases. Robust and durable responses were observed in 11/11 patients treated with ALK inhibition, 10 with neurologic involvement. This study presents the existing clinicopathologic and molecular landscape of ALK-positive histiocytosis and provides guidance for the clinical management of this emerging histiocytic entity.

Parafoveal Microvascular Alterations in Ocular and Non-Ocular Behҫet's Disease Evaluated With Optical Coherence Tomography Angiography

Purpose

To compare quantitative optical coherence tomography angiography (OCT-A) measurements of the parafoveal microvasculature in retinal capillary plexuses among Behҫet uveitis (BU) patients, non-ocular Behҫet's disease (NOBD) patients, and healthy volunteers (HVs).

Methods

Sixty-eight subjects were enrolled in this prospective observational cross-sectional study. OCT-A imaging was performed using the Heidelberg Engineering Spectralis OCT. A custom algorithm was developed to calculate the vessel density (VD) in three retinal vascular layers: deep capillary plexus, intermediate capillary plexus, and superficial vascular plexus. The foveal avascular zone (FAZ) and acircularity index were calculated for the whole retinal vascular complex.

Results

We analyzed one eye from 21 BU patients (age, 51 ± 10 years), 23 NOBD patients (age, 48 ± 14 years), and 22 HVs (age, 44 ± 13 years). One-way multivariate analysis of covariance showed a statistically significant difference in VD among the three groups when combining the layers after controlling for scan quality (P < 0.001). The VD was lowest in the BU group and highest in the HV group in all layers. The FAZ area was also statistically significant different among the groups (P < 0.005), with the largest FAZ areas in BU patients and smallest FAZ areas in the HV group. However, no statistically significant difference was found for the acircularity index.

Conclusions

The parafoveal microvasculature is affected not only in BU patients but also in NOBD patients. Most deviations in the retinal microcirculation in Behҫet patients were found in the deeper layers of the retina by using the quantitative VD measurement.

Human TBK1 deficiency leads to autoinflammation driven by TNF-induced cell death

TANK binding kinase 1 (TBK1) regulates IFN-I, NF-κB, and TNF-induced RIPK1-dependent cell death (RCD). In mice, biallelic loss of TBK1 is embryonically lethal. We discovered four humans, ages 32, 26, 7, and 8 from three unrelated consanguineous families with homozygous loss-of-function mutations in TBK1. All four patients suffer from chronic and systemic autoinflammation, but not severe viral infections. We demonstrate that TBK1 loss results in hypomorphic but sufficient IFN-I induction via RIG-I/MDA5, while the system retains near intact IL-6 induction through NF-κB. Autoinflammation is driven by TNF-induced RCD as patient-derived fibroblasts experienced higher rates of necroptosis in vitro, and CC3 was elevated in peripheral blood ex vivo. Treatment with anti-TNF dampened the baseline circulating inflammatory profile and ameliorated the clinical condition in vivo. These findings highlight the plasticity of the IFN-I response and underscore a cardinal role for TBK1 in the regulation of RCD.

Characteristics of COVID-19 infection and antibody formation in patients known at a tertiary immunology department

Background

Knowledge about COVID-19 infections is expanding, although knowledge about the disease course and antibody formation in patients with an auto-immune disease or immunodeficiency is not fully unraveled yet. It could be hypothesized that immunodeficient patients, due to immunosuppressive drugs or their disease, have a more severe disease course due to their immunocompromised state. However, it could also be hypothesized that some of the immunosuppressive drugs protect against a hyperinflammatory state.

Methods

We collected data on the incidence of COVID-19, disease course and SARS-CoV-2 antibody formation in COVID-19 positive patients in a cohort of patients (n ​= ​4497) known at the Clinical Immunology outpatient clinic in a tertiary care hospital in the Netherlands.

Results

In the first six months of the pandemic, 16 patients were identified with COVID-19, 14 by nasal swab PCR, and 2 patients by SARS-CoV-2 antibodies. Eight patients were admitted to the hospital. SARS-CoV-2 antibodies were measured in 8 patients and were detectable in all, including one patient on B-cell ablative therapy and one patient with Common Variable Immunodeficiency Disorder.

Conclusion

This study indicates that the disease course differs among immunocompromised patients, independently of (dis)continuation of immunosuppressive drugs. Antibody production for SARS-CoV-2 in immunocompromised patients was shown. More research needs to be conducted to confirm these observations and guidelines regarding (dis)continuation of immunosuppressive drugs in COVID-19 positive immunocompromised patients should be developed.

•

The disease course of COVID-19 largely differs among immunocompromised individuals.

•

Antibody production against SARS-CoV-2 is noticed in immunocompromised patients.

•

Further recommendations on (dis)continuation on immunosuppressive drugs during a COVID-19 infection are needed.

Leukocyte toll-like receptor expression in pathergy positive and negative Behçet's disease patients

Objectives

To investigate whether the auto-inflammatory nature and the pathergic reaction in Behçet’s disease (BD) are driven by a disturbed toll-like receptor (TLR) response.

Methods

We compared both TLR expression by flow-cytometry and TLR response by stimulation assay in 18 BD patients (both pathergy positive and pathergy negative) with 15 healthy controls.

Results

Expression of TLR1 and 2 was significantly elevated in B-lymphocytes of BD patients compared with healthy controls. TLR1, 2 and 4 were significantly more highly expressed in both CD4⁺ and CD8⁺ T-lymphocytes of BD patients. Granulocytes of BD patients displayed significantly higher expression of TLR1, 2, 4 and 6. TLR2, 4 and 5 expression was significantly increased on classical monocytes of BD patients. Intermediate monocytes of BD patients showed an increase in expression of TLR2. Furthermore, TLR2 and 5 were significantly more highly expressed in non-classical monocytes of BD patients. In pathergy positive patients, TLR5 was even more highly expressed compared with pathergy negative patients on B- and T-lymphocytes and granulocytes. Furthermore, TLR2 and 5 showed an elevated TNF-α response to stimulation with their cognate ligands.

Conclusion

Immune cells of BD patients overexpress TLR1, 2, 4, 5 and 6. Furthermore, after stimulation of TLR2 and 5, BD patients demonstrate a more potent TNF-α response. Although this is a small cohort, in the pathergy positive patients, TLR5 expression is even further augmented, suggesting that a microbial (flagellin) or damage (HMGB1) associated signal may trigger the exaggerated immune response that is characteristic for the pathergy phenomenon in BD. In conclusion, these results point to an exaggerated TLR response in the auto-inflammatory nature of BD.

Infliximab treatment in pathology-confirmed neurosarcoidosis

Objective

To assess the efficacy and risks of treatment with infliximab (anti–tumor necrosis factor alpha) in pathology-confirmed neurosarcoidosis.

Methods

In a retrospective study in 2 tertiary referral centers in the Netherlands, we analyzed clinical characteristics, complications, and outcome of patients with neurosarcoidosis treated with infliximab.

Results

Twenty-eight patients were identified with a mean age of 42 years. Neurosarcoidosis presented with a cerebral parenchymal localization in 16 (59%), pituitary gland/hypothalamic sarcoidosis in 15 (54%), peripheral nerve involvement in 12 (43%), and chronic meningitis in 11 patients (41%). Initial treatment response after the start of infliximab was complete remission in 6 (21%) and improvement in 14 (50%), whereas 7 patients had stable disease (25%), and 1 (4%) deteriorated and died. At the end of follow-up, with a median of 32 months, 5 patients (18%) had died, and 2 (40%) were using infliximab at the time of death. Tapering or discontinuation of corticosteroids without a relapse was achieved in 19 of 28 patients (68%). In patients with decreasing dosing or discontinuation of infliximab, a relapse occurred in 5 of 19 patients (26%). Complications of infliximab were reported in 10 of 28 patients (36%) and mainly consisted of infections in 8 (29%).

Conclusion

Infliximab is an effective treatment in neurosarcoidosis leading to remission or improvement in 70%. The mortality rate in infliximab-treated patients was substantial, indicating the severity of disease and treatment-associated complications.

Classification of evidence

This study provides Class IV evidence that in people with pathology-confirmed neurosarcoidosis, infliximab is beneficial.

Behçet's Disease Under Microbiotic Surveillance? A Combined Analysis of Two Cohorts of Behçet's Disease Patients

Background: In Behçet's disease (BD), an auto-inflammatory vasculitis, an unbalanced gut microbiota can contribute to pro-inflammatory reactions. In separate studies, distinct pro- and anti-inflammatory bacteria associated with BD have been identified.

Methods: To establish disease-associated determinants, we performed gut microbiome profiling in BD patients from the Netherlands (n = 19) and Italy (n = 13), matched healthy controls (HC) from the Netherlands (n = 17) and Italy (n = 15) and oral microbiome profiling in Dutch BD patients (n = 18) and HC (n = 15) by 16S rRNA gene sequencing. In addition, we used fecal IgA-SEQ analysis to identify specific IgA coated bacterial taxa in Dutch BD patients (n = 13) and HC (n = 8).

Results: In BD stool samples alpha-diversity was conserved, whereas beta-diversity analysis showed no clustering based on disease, but a significant segregation by country of origin. Yet, a significant decrease of unclassified Barnesiellaceae and Lachnospira genera was associated with BD patients compared to HC. Subdivided by country, the Italian cohort displays a significant decrease of unclassified Barnesiellaceae and Lachnospira genera, in the Dutch cohort this decrease is only a trend. Increased IgA-coating of Bifidobacterium spp., Dorea spp. and Ruminococcus bromii species was found in stool from BD patients. Moreover, oral Dutch BD microbiome displayed increased abundance of Spirochaetaceae and Dethiosulfovibrionaceae families.

Conclusions: BD patients show decreased fecal abundance of Barnesiellaceae and Lachnospira and increased oral abundance of Spirochaetaceae and Dethiosulfovibrionaceae. In addition, increased fecal IgA coating of Bifidobacterium, Ruminococcus bromii and Dorea may reflect retention of anti-inflammatory species and neutralization of pathosymbionts in BD, respectively. Additional studies are warranted to relate intestinal microbes with the significance of ethnicity, diet, medication and response with distinct pro- and inflammatory pathways in BD patients.

Apparent Lack of BRAF V600E Derived HLA Class I Presented Neoantigens Hampers Neoplastic Cell Targeting by CD8+ T Cells in Langerhans Cell Histiocytosis

Langerhans Cell Histiocytosis (LCH) is a neoplastic disorder of hematopoietic origin characterized by inflammatory lesions containing clonal histiocytes (LCH-cells) intermixed with various immune cells, including T cells. In 50-60% of LCH-patients, the somatic BRAF ^V600E driver mutation, which is common in many cancers, is detected in these LCH-cells in an otherwise quiet genomic landscape. Non-synonymous mutations like BRAF ^V600E can be a source of neoantigens capable of eliciting effective antitumor CD8⁺ T cell responses. This requires neopeptides to be stably presented by Human Leukocyte Antigen (HLA) class I molecules and sufficient numbers of CD8⁺ T cells at tumor sites. Here, we demonstrate substantial heterogeneity in CD8⁺ T cell density in n = 101 LCH-lesions, with BRAF ^V600E mutated lesions displaying significantly lower CD8⁺ T cell:CD1a⁺ LCH-cell ratios (p = 0.01) than BRAF wildtype lesions. Because LCH-lesional CD8⁺ T cell density had no significant impact on event-free survival, we investigated whether the intracellularly expressed BRAF ^V600E protein is degraded into neopeptides that are naturally processed and presented by cell surface HLA class I molecules. Epitope prediction tools revealed a single HLA class I binding BRAF ^V600E derived neopeptide (KIGDFGLATEK), which indeed displayed strong to intermediate binding capacity to HLA-A^*03:01 and HLA-A^*11:01 in an in vitro peptide-HLA binding assay. Mass spectrometry-based targeted peptidomics was used to investigate the presence of this neopeptide in HLA class I presented peptides isolated from several BRAF ^V600E expressing cell lines with various HLA genotypes. While the HLA-A^*02:01 binding BRAF wildtype peptide KIGDFGLATV was traced in peptides isolated from all five cell lines expressing this HLA subtype, KIGDFGLATEK was not detected in the HLA class I peptidomes of two distinct BRAF ^V600E transduced cell lines with confirmed expression of HLA-A^*03:01 or HLA-A^*11:01. These data indicate that the in silico predicted HLA class I binding and proteasome-generated neopeptides derived from the BRAF ^V600E protein are not presented by HLA class I molecules. Given that the BRAF ^V600E mutation is highly prevalent in chemotherapy refractory LCH-patients who may qualify for immunotherapy, this study therefore questions the efficacy of immune checkpoint inhibitor therapy in LCH.

Adalimumab provides long-lasting clinical improvement in refractory mucocutaneous Behçet's disease without formation of antidrug antibodies

OBJECTIVES

The TNF-blocker adalimumab can be effective in Behçet's disease (BD), a multisystem auto-inflammatory disorder. Unfortunately, the therapeutic efficacy of TNF-blockers can be hampered by the formation of anti-drug antibodies. We present an observational study of adalimumab in refractory BD with measurement of anti-drug antibodies.

METHODS

The effect of fortnightly 40mg adalimumab in nine patients with therapy refractory mucocutaneous, non-ocular or organ threatening BD was studied up to 60 months. Primary endpoint was a decrease in disease activity, measured by the BD Current Activity Form (BDCAF) within 6 months. Secondary endpoints included serum cytokines and the long-term formation of anti-adalimumab antibodies.

RESULTS

BDCAF improved significantly in all nine patients from 5.4 (SD=1.4) to 2.4 (SD=1.4) (p=0.007) within one month up to 6 months and after prolonged follow up of 5 years. All patients could either taper or stop concomitant therapy. Symptoms of mucocutaneous lesions, erythema nodosum and joint involvement decreased or disappeared. Serum TNF-alpha levels were elevates in five patients and decreased upon treatment (p=0.017). Adalimumab was save and none of the patients experienced therapy failure or antibodies against adalimumab.

CONCLUSIONS

We present an observational study on patients with BD treated with adalimumab and provide a basis for long-term use in refractory mucocutaneous BD. These findings show that adalimumab can safely be administered yielding sustainable clinical effects in refractory BD patients with mucocutaneous disease without formation of anti-adalimumab antibodies, even after long follow up.

The treatment outcomes in IgG4-related orbital disease: a systematic review of the literature

IgG4-related disease (IgG4-RD) is an immune-mediated systemic fibro inflammatory disease. Treatment of IgG4-related orbital disease (IgG4-ROD) is often indicated to relieve the symptoms and to prevent complications. For IgG4-ROD, no international formal treatment guidelines are available and the optimal treatment strategy is uncertain. In this systematic review, we describe the efficacy of conventional and biologic disease-modifying antirheumatic drugs (DMARDs) in IgG4-ROD. A systematic search of Embase, Medline, Web-of-Science, PubMed publisher, Cochrane and Google Scholar was performed for treatment outcomes in IgG4-ROD. Relevant articles on treatment of IgG4-ROD were retrieved to last date of inclusion 3 January 2018. The following inclusion criteria were used: articles in English or English translation, studies evaluating the use of DMARDs (conventional and biologic) in the treatment of IgG4-ROD. Meta-analysis and review articles were excluded. A final selection after full-text evaluation was made by independent reviewers, based on treatment of IgG4-ROD with DMARDs and the availability of treatment outcomes. With this systematic review, we identified 35 studies and case reports/series on IgG4-ROD, describing 95 patients, treated with conventional and/or biologic DMARDs. The success of conventional DMARDs varies between 36% and 75% in patients with IgG4-ROD, while rituximab is successful in the majority (93%) of the patients. Based on this systematic review, rituximab is the most effective DMARD in IgG4-ROD, while the efficacy of conventional DMARDs is limited. We propose early initiation of rituximab in case of refractory and organ- or life-threatening disease.

A rare infection in the tropics that is not uncommon in cases of chronic granulomatous disease

Chromobacterium violaceum is a rare cause of infection in immunocompromised patients in the tropics with a spectrum of disease manifestations, including severe disease. Early identification of this micro-organism is essential for appropriate management. We present a case of C. violaceum septicaemia in a patient with chronic granulomatous disease.

Decreased quality of life and societal impact of cryopyrin-associated periodic syndrome treated with canakinumab: a questionnaire based cohort study

Background

Cryopyrin-associated periodic syndrome (CAPS) is a rare disease. Knowledge on the quality of life (QoL) and the disease’s societal impact is limited. Canakinumab is used in increasing frequency for the treatment of CAPS.

Methods

Observational study in Dutch CAPS patients. Patients completed questionnaires regarding treatment with canakinumab at baseline and retrospectively. Quality of life was assessed using the EQ-5D-5L in adults and CHQ-PF50 in children. Impact on work and school was assessed. Caregivers' quality of life was assessed using the CarerQol.

Results

Mean quality of life scores during treatment with canakinumab were 0.769 (EQ-5D-5L), 51.1 (CHQ-P) and 57–1 (CHQ-M). Most patients experienced problems on the pain/discomfort dimension. Higher disease activity and the presence of complications negatively influenced QoL. Half of the patients with a paid job reported absenteeism from work due to CAPS, for an average of 8.7 days in a 4-week period. All schoolgoing patients (N = 5) reported absence from school due to CAPS, for an average of 2.9 days. Caregivers reported gaining a lot fulfillment from providing care for their family members.

Conclusion

QoL during treatment is lower than in the general Dutch population. CAPS leads to productivity loss and absenteeism from school, and impacts the quality of life in informal caregivers.

Electronic supplementary material

The online version of this article (10.1186/s13023-018-0799-1) contains supplementary material, which is available to authorized users.

Expansion of blood IgG4+ B, TH2, and regulatory T cells in patients with IgG4-related disease

BACKGROUND

IgG₄-related disease (IgG₄-RD) is a systemic fibroinflammatory condition affecting various organs and has a diverse clinical presentation. Fibrosis and accumulation of IgG₄⁺ plasma cells in tissue are hallmarks of the disease, and IgG₄-RD is associated with increased IgG₄ serum levels. However, disease pathogenesis is still unclear, and these cellular and molecular parameters are neither sensitive nor specific for the diagnosis of IgG₄-RD.

OBJECTIVE

Here we sought to develop a flow cytometric gating strategy to reliably identify blood IgG₄⁺ B cells to study their cellular and molecular characteristics and investigate their contribution in disease pathogenesis.

METHODS

Sixteen patients with histologically confirmed IgG₄-RD, 11 patients with sarcoidosis, and 30 healthy subjects were included for 11-color flow cytometric analysis of peripheral blood for IgG₄-expressing B cells and T_H subsets. In addition, detailed analysis of activation markers and chemokine receptors was performed on IgG₄-expressing B cells, and IgG₄ transcripts were analyzed for somatic hypermutations.

RESULTS

Cellular and molecular analyses revealed increased numbers of blood IgG₄⁺ memory B cells in patients with IgG₄-RD. These cells showed reduced expression of CD27 and CXCR5 and increased signs of antibody maturation. Furthermore, patients with IgG₄-RD, but not patients with sarcoidosis, had increased numbers of circulating plasmablasts and CD21^low B cells, as well as T_H2 and regulatory T cells, indicating a common disease pathogenesis in patients with IgG₄-RD.

CONCLUSION

These results provide new insights into the dysregulated IgG₄ response in patients with IgG₄-RD. A specific "peripheral lymphocyte signature" observed in patients with IgG₄-RD, could support diagnosis and treatment monitoring.

Chronic signs of memory B cell activation in patients with Behçet's disease are partially restored by anti-tumour necrosis factor treatment

OBJECTIVES

Behçet's disease (BD), an auto-inflammatory vasculitis with oro-genital ulcerations, skin lesions and uveitis, is regarded as T cell mediated. A successful trial with rituximab suggests an additive role for B cells in the pathogenesis. Therefore, we studied B cell abnormalities in BD patients and the effect of TNF-blocking therapy.

METHODS

B cells in blood (n = 36) and tissue (n = 6) of BD patients were analysed with flow cytometry and/or immunohistochemistry and compared with healthy controls (n = 22). BD current activity form (BDCAF) in relation to B cell somatic hypermutations (SHMs) and immunoglobulin class-switching were studied.

RESULTS

Thirty-six patients (17 males) were included, mean age 44 years, average disease duration 10 years and mean BDCAF 2.7. Blood B cell numbers were significantly lower in patients than in controls (P = 0.0061), mostly due to decreased CD27⁺ memory B cells expressing IgM (P = 0.0001), IgG (P = 0.0002) and IgA (P = 0.0038) B cell subsets. CD27⁺ IgA⁺ B cells showed the highest magnitude of decrease in active disease, measured with BDCAF (P = 0.02). CD27⁺ IgM⁺ IgD⁺ B cells were impaired in replication history (P = 0.0133) and selection of SHM, whereas IgA⁺ B cells carried elevated SHM levels (P = 0.04) and lower IgA2 subclass usage (P = 0.0004) than controls. Immunohistochemistry revealed B cells in tissue of active mucosal ulcers. In adalimumab-treated patients, blood B cells were similar to controls.

CONCLUSION

We show significant deviations in the memory B cell compartment, related to disease activity and therapeutic efficacy. Pronounced molecular impairments were seen in the fast-responding IgM⁺-memory and the mucosal IgA⁺-memory B cells. Because of the demonstrated abundance of B cells in affected tissue, we hypothesize relocation of memory B cells to the site of inflammation could account for the deviations found in blood of BD patients. These peripheral B cells are easily accessible as a marker to monitor therapeutic efficacy.

B-Cell Dysregulation in Crohn's Disease Is Partially Restored with Infliximab Therapy

BACKGROUND

B-cell depletion can improve a variety of chronic inflammatory diseases, but does not appear beneficial for patients with Crohn's disease.

OBJECTIVE

To elucidate the involvement of B cells in Crohn's disease, we here performed an 'in depth' analysis of intestinal and blood B-cells in this chronic inflammatory disease.

METHODS

Patients with Crohn's disease were recruited to study B-cell infiltrates in intestinal biopsies (n = 5), serum immunoglobulin levels and the phenotype and molecular characteristics of blood B-cell subsets (n = 21). The effects of infliximab treatment were studied in 9 patients.

RESULTS

Granulomatous tissue showed infiltrates of B lymphocytes rather than Ig-secreting plasma cells. Circulating transitional B cells and CD21low B cells were elevated. IgM memory B cells were reduced and natural effector cells showed decreased replication histories and somatic hypermutation (SHM) levels. In contrast, IgG and IgA memory B cells were normally present and their Ig gene transcripts carried increased SHM levels. The numbers of transitional and natural effector cells were normal in patients who responded clinically well to infliximab.

CONCLUSIONS

B cells in patients with Crohn's disease showed signs of chronic stimulation with localization to granulomatous tissue and increased molecular maturation of IgA and IgG. Therapy with TNFα-blockers restored the defect in IgM memory B-cell generation and normalized transitional B-cell levels, making these subsets candidate markers for treatment monitoring. Together, these results suggest a chronic, aberrant B-cell response in patients with Crohn's disease, which could be targeted with new therapeutics that specifically regulate B-cell function.

Bone Mineral Density in Sjögren Syndrome Patients with and Without Distal Renal Tubular Acidosis

Primary Sjögren's syndrome (pSS) can be complicated by distal renal tubular acidosis (dRTA), which may contribute to low bone mineral density (BMD). Our objective was to evaluate BMD in pSS patients with and without dRTA as compared with healthy controls. BMD of lumbar spine (LS) and femoral neck (FN) was measured in 54 pSS patients and 162 healthy age- and sex-matched controls by dual-energy X-ray absorptiometry (DXA). dRTA was defined as inability to reach urinary pH <5.3 after an ammonium chloride (NH4Cl) test. LS- and FN-BMD were significantly higher in pSS patients compared with controls (1.18 ± 0.21 g/cm(2) for patients vs. 1.10 ± 0.18 g/cm(2) for controls, P = 0.008 and 0.9 ± 0.16 g/cm(2) for patients vs. 0.85 ± 0.13 g/cm(2) for controls, P = 0.009, respectively). After adjustment for BMI and smoking, the LS- and FN-BMD remained significantly higher. Patients with dRTA (N = 15) did not have a significantly different LS- and FN-BMD compared with those without dRTA (N = 39) after adjustment for BMI, age, and gender. Thirty-seven (69 %) pSS patients were using hydroxychloroquine (HCQ). Unexpectedly, pSS patients had a significantly higher LS- and FN-BMD compared with healthy controls. Patients with dRTA had similar BMD compared with patients without dRTA. We postulate that an explanation for the higher BMD in pSS patients may be the frequent use of HCQ.

Systemic mastocytosis: A cohort study on clinical characteristics of 136 patients in a large tertiary centre

BACKGROUND

Systemic mastocytosis (SM) is a rare heterogeneous disease which is characterized by the aberrant proliferation of mast cells. It can be divided into various subtypes with different phenotypes and prognoses. Here, we report on the clinical characteristics of 136 SM patients.

METHODS

A retrospective cohort study was conducted from January 2009 to September 2014 in a large tertiary centre in The Netherlands. We included all patients who fulfilled WHO criteria for SM. Data were collected from electronic patient files.

RESULTS

A total of 124 patients had indolent SM (ISM) (91.2%), 7 had aggressive SM (ASM) (5.1%) and 5 had SM with associated hematological non-mast cell lineage disease (SM-AHNMD) (3.7%). There was no progression from ISM to advanced SM subtypes, but 1 patient with ASM developed chronic myelocytic leukemia 2years after diagnosis. The average time to diagnosis for the whole population was 8.1years (range, 0-49years). The most frequent triggers for work-up-skin involvement, anaphylaxis and osteoporosis-were characterized by an interval to diagnosis of 10.9, 2.9 and 7.5years, respectively. A total of 32 patients (23.5%) had a serum tryptase levels below the cutoff value of 20ng/mL at the time of diagnosis, but these patients did not have significant differences in clinical phenotype.

CONCLUSIONS

SM comprises a wide spectrum of signs and symptoms and its often atypical presentation can delay the establishment of the diagnosis substantially. Skin involvement, anaphylaxis and unexplained osteoporosis should trigger analysis for mastocytosis. A normal serum tryptase does not exclude the diagnosis of SM.

Diagnosis and treatment of uveitis; not restricted to the ophthalmologist

Uveitis is associated with a wide range of underlying causes. Familiarity with its clinical manifestations, referral indications, and treatment strategies are required for the optimal use of current therapeutic options. Uveitis can be caused by infectious and non-infectious factors, resulting in differing prognoses and treatments. The treatment of chronic, non-infectious uveitis has profoundly changed in the last years due to the advent of biologicals, but also of intraocular therapies. In severe uveitis, treatment of the underlying cause, whether ocular or systemic, is required to prevent severe loss of vision. For these purposes, a multidisciplinary clinical approach is important, which is addressed in this review. Relevance for patients: A broad understanding of the different causes of uveitis and the implementation of disease-tailored, multidisciplinary management of uveitis is expected to improve treatment outcomes for patients with different types of uveitis.

Prevalence of distal renal tubular acidosis in primary Sjögren's syndrome

OBJECTIVES

Our objectives were to analyse the prevalence of distal renal tubular acidosis (dRTA) in primary SS (pSS) and to compare a novel urinary acidification test with furosemide and fludrocortisone (FF) with the gold standard ammonium chloride (NH4Cl) to detect dRTA.

METHODS

Urinary acidification was assessed in 57 pSS patients using NH4Cl and FF. A urinary acidification defect was defined as an inability to reach a urinary pH of <5.3 after NH4Cl.

RESULTS

The prevalence of complete dRTA (urinary acidification defect with acidosis) was 5% (3/57). All three patients had positive SSA/Ro and SSB/La autoantibodies and impaired kidney function. The prevalence of incomplete dRTA (urinary acidification defect without acidosis) was 25% (14/57). Compared with patients without dRTA, patients with incomplete dRTA had significantly lower venous pH and serum bicarbonate and higher urinary pH. SSB/La antibodies were more prevalent in the dRTA groups (P < 0.05). Compared with NH4Cl, the positive and negative predictive values of FF were 46% and 82%, respectively. Vomiting occurred more often during the urinary acidification test with NH4Cl than with FF (9 vs 0, P < 0.05).

CONCLUSION

Incomplete dRTA is common in pSS and causes mild acidaemia and higher urinary pH, which may contribute to bone demineralization and kidney stone formation. FF cannot replace NH4Cl in testing urinary acidification in pSS, but may be considered as a screening tool, given its reasonable negative predictive value and better tolerability.

Utility of contrast-enhanced ultrasound for the assessment of the carotid artery wall in patients with Takayasu or giant cell arteritis

AIMS

Carotid contrast-enhanced ultrasound (CEUS) was recently proposed for the evaluation of large-vessel vasculitides (LVV), particularly to assess vascularization within the vessel wall. The aim of this pilot study was to evaluate the potential of carotid colour Doppler ultrasound (CDUS) and CEUS in patients with LVV.

METHODS AND RESULTS

This prospective study included seven patients (mean age 48 ± 14 years, all females) with established LVV (Takayasu arteritis or giant cell arteritis). All patients underwent CDUS and CEUS (14 carotid arteries). Intima-media thickness, lumen diameter, Doppler velocities, vessel wall thickening, and lesion thickness were assessed. CEUS was used to improve visualization of the lumen-to-vessel wall border, and to visualize carotid wall vascularization. Four (57%) patients [7 (50%) carotid arteries] exhibited lesions, and the average lesion thickness was 2.0 ± 0.5 mm. According to the Doppler peak systolic velocity, 5 (35%) carotid arteries had a <50% stenosis, 1 (7%) had a 50-70% stenosis, and 1 (7%) had a ≥70% stenosis. The contrast agent improved the image quality and the definition of the lumen-to-vascular wall border. Carotid wall vascularization was observed in 5 (71%) patients [9 (64%) carotid arteries]. Five (36%) carotid arteries had mild-to-moderate vascularization, and 4 (29%) had severe wall vascularization.

CONCLUSION

Carotid CDUS allows the assessment of anatomical features of LVV, including vessel wall thickening and degree of stenosis. Carotid CEUS improves the visualization of the lumen border, and allows dynamic assessment of carotid wall vascularization, which is a potential marker of disease activity in patients with LVV.

[Diagnosis and treatment of uveitis; not restricted to the ophthalmologist]

Visual symptoms due to uveitis involve a wide range of possible causes. Familiarity with its clinical manifestations, referral indications and treatment strategies is required for the optimal use of current therapeutic options. Uveitis can be caused by infectious and non-infectious factors, resulting in differing prognoses and treatments. The treatment of chronic, non-infectious uveitis has profoundly changed in the last years due to the advent of biological therapies. In severe uveitis, treatment of the underlying cause is required for the prevention of the loss of vision; multidisciplinary team collaboration is therefore important.

[Colchicine has no negative effect on fertility and pregnancy]

OBJECTIVE

To inventorise the possible development of infertility and pregnancy complications in patients with Familial Mediterranean Fever (FMF), on treatment with colchicine.

DESIGN

Systematic review.

METHOD

PubMed was searched for articles in English, describing the effects of colchicine on fertility and pregnancy in animals or humans.

RESULTS

We found 73 articles, 13 of which matched the inclusion criteria. We selected another 12 articles via cross references and after evaluation by the co-authors. From these articles it appeared that colchicine inhibits the clinical symptoms of FMF and the development of amyloid deposits. No statistically significant effect was found of colchicine treatment on semen quality or hormone levels. Treatment with colchicine during pregnancy did not lead to severe complications. Both male and female patients who were treated with colchicine had a better prospect of maintaining fertility, compared with patients without this treatment.

CONCLUSION

According to the literature selected, colchicine use has no demonstrable negative effect on fertility. If untreated, FMF itself can lead to amyloid deposits in the testis and ovary, resulting in infertility. Patients with FMF may safely continue to use colchicine throughout the reproductive phase of their life.

[Sarcoidosis: changing insights in therapy]

Sarcoidosis is a granulomatous disease of unknown etiology. Standard treatment with immune suppressants such as glucocorticoids is started when vital organ function is threatened. Biotechnology has resulted in new treatments ('biologicals'), in particular monoclonal antibodies, that may be effective in the treatment of sarcoidosis. In patients with sarcoidosis, only the use of monoclonal antibodies that block tumour necrosis factor (TNF) has been studied scientifically, other biologicals hardly at all. TNF-blockers are used at present in patients with therapy refractory sarcoidosis.

Do synovial biopsies help to support evidence for involvement of innate immunity in the immunopathology of Behçet's disease?

Behçet's disease is a complex vasculitis of unknown etiology. Abundant neutrophils suggest the involvement of innate immunity. Cytokines are skewed to the T-helper-1 pattern. Few sterile organs are easily accessible for analysis in Behçet's disease. Cañete and coworkers identify inflamed joints as a feasible model and suggest the involvement of innate immunity in Behçet's disease.

Octreotide long-acting repeatable for the treatment of chronic macular edema in uveitis

PURPOSE

To report on the efficacy of the somatostatin analog octreotide long-acting repeatable (LAR), in the treatment of uveitic chronic macular edema (CME).

DESIGN

Case series, retrospective analysis.

METHODS

In 20 patients, 20 episodes of recurrent CME during otherwise quiescent uveitis were treated with intramuscular octreotide LAR injections. Patients were included if CME control with acetazolamide or systemic and periocular steroids had failed during previous CME episodes or if contraindications existed for persistent use of these therapies. Mean outcome points were CME and visual acuity changes. Correlation of prognostic factors with these outcomes was analyzed.

RESULTS

The included CME episodes occurred 7.6 +/- 1.4 years after onset of uveitis. Octreotide LAR treatment started 7.0 +/- 7.3 months after diagnosis of CME. CME decreased in 70% of episodes, after 2.7 +/- 1.3 months of treatment. After arrest of successful treatment, CME recurred instantly (27.2%) or within six months (36.4%). In 36.4% of successfully treated episodes, CME was absent for more than one year. A probable prognostic factor for success was the duration of CME before treatment.

CONCLUSIONS

Octreotide LAR had an edema-reducing effect in 70% of treated CME episodes. Successful response was related to duration of CME before start of treatment. The early recurrence of CME (63.6%) after arrest of octreotide LAR advocates a long-term treatment in recent episodes of macular edema in otherwise quiescent uveitis.

Epstein-Barr viral load assessment in immunocompetent patients with fulminant infectious mononucleosis

We describe 2 immunocompetent adolescents with fulminant infectious mononucleosis and virus-associated hemophagocytosis. A new quantitative polymerase chain reaction revealed high serum Epstein-Barr virus DNA levels in these patients. One patient died with an increasing viral load not responding to corticosteroids followed by antiviral and intensified immunomodulatory treatment. The other patient received corticosteroids and acyclovir at diagnosis; her rapid recovery was heralded by a steep decline of viral load. We propose monitoring the clinical course of fulminant infectious mononucleosis in immunocompetent patients by Epstein-Barr virus DNA quantification and prompt corticosteroid and antiviral therapy when viral load is high.