POS0495 CYTOKINE SYNERGY ENHANCES SYNOVIAL FIBROBLAST ACTIVATION IN CHILDREN WITH DOWN’S SYNDROME-ASSOCIATED ARTHRITIS

Background

We have previously shown that children with Down’s syndrome-associated arthritis (DA) display a more aggressive form of inflammatory arthritis compared to that of Juvenile Idiopathic Arthritis (Shih et al., 2019). DA is associated with an increase in polyfunctional T-cells coexpressing TNF-α DA is associated with an increase in polyfunctional T-cells coexpressing TNF-fibroblasts (FLS) (Foley et al., 2019).

Objectives

In this study we examine the effect of cytokine synergy on primary DA FLS function.

Methods

Primary DA FLS were cultured and stimulated with TNF-α (0.1 and 1ng/ml), IL-17A (20 and 50ng/ml), IFN-ɣ (10 and 50ng/ml) and GM-CSF (20 and 100ng/ml) or a combination of these cytokines and the following functional experiments performed. Chemokine and adhesion molecule cell surface expression were quantified by flow cytometry, in addition to quantification of leukocyte-DA-FLS adhesion assays. Gene and protein expression of proinflammatory and metabolic mediators were quantified by ELISA and RT-PCR. Furthermore, real-time metabolic activity in response to cytokine stimulation was assessed by measuring the two major energy pathways: glycolysis (ECAR) and oxidative phosphorylation (OCR), by the Seahorse XFe96 Analyser.

Results

We examined the effects of T cell derived cytokines, TNF-α, IL-17A, IFN-γ and GM-CSF, alone and in combination on DA FLS function. TNF-α, IL-17A and IFN-γ induced IL-6, RANTES and MCP-1 production, with no effect observed for GM-CSF. Furthermore, TNF-α, IFN-ɣ and IL-17A increased leukocyte adhesion to DA FLS. TNF-α and IFN-ɣ induced cell surface expression of CXCR3, CXCR4, ICAM-1 and VCAM-1 on DA FLS. Next, we investigated the potential synergistic relationship that these cytokines could have on proinflammatory mediators. IL-17A and IFN-ɣ potentiated the effects TNF-α on IL-6 and MCP-1 secretion compared to stimulation alone. Furthermore, cytokine synergy significantly induced IL-6, IL-8, RANTES and LDHA mRNA expression compared to basal. IL-17A and IFN-αL-17A and IFN- eeased ts TNF-α on IL-6 and MCP-1 secretion compared to stimulation alone. Additionally, IFN the ECAR:OCR ratio demonstrating a shift in the metabolic profile of DA FLS to glycolysis. Overall DA FLS are transformed from a quiescent metabolic state to an energetic phenotype.

Conclusion

TNF-αNF-lusion:OCR ratio demonstrating a shift in the metabolhe aggressive phenotype of DA FLS through increased cytokine, adhesion molecule and chemokine expression, which is pathways for the treatment of DA.

References

[1]Foley, C. et al. (2019) ‘Increased T cell plasticity with dysregulation of T follicular helper, T peripheral helper and T regulatory cell responses in children with JIA and Down syndrome-associated arthritis’, Arthritis & Rheumatology, pp. 0–1. doi: 10.1002/art.41150.

[2]Shih, Y. J. et al. (2019) ‘Enthesitis-related arthritis is the most common category of juvenile idiopathic arthritis in Taiwan and presents persistent active disease’, Pediatric Rheumatology. Pediatric Rheumatology. doi: 10.1186/s12969-019-0363-0.

Disclosure of Interests

None declared.

POS0069 INCREASED T CELL RESPONSES, METABOLIC ACTIVITY AND FIBROBLAST INVASIVE CAPACITY IN CHILDREN WITH DOWN’S SYNDROME-ASSOCIATED ARTHRITIS COMPARED TO JUVENILE IDIOPATHIC ARTHRITIS

Background:

Juvenile idiopathic arthritis (JIA) was thought to be the most common inflammatory arthritis in children (Shih et al., 2019). However an aggressive, erosive arthritis of little-known immunologic mechanism occurs 20 times more frequently in children with Down’s syndrome (Foley et al., 2019).

Objectives:

This study was undertaken to characterize immune cell responses and synovial fibroblast invasiveness in children with Down’s syndrome-associated arthritis (DA).

Methods:

Multiparametric flow cytometric analysis was used to examine peripheral blood T cell, B cell and monocyte populations. In addition, T cell cytokine responses and their metabolic profile in children with DA, JIA, Down’s Syndrome (trisomy 21 [T21]), and in healthy controls were assessed. The function of DA primary synovial fibroblasts (FLS) was assessed in response to stimulation with pro-inflammatory mediators alone and in combination (TNF-α, IL-17a, IFN-γ, GM-CSF). The two major energy pathways glycolysis (ECAR) and oxidative phosphorylation (OCR) were quantified by the Seahorse XFe96 Analyser. Migration, adhesion, invasion and cytokine/chemokine secretion were quantified by wound repair scratch assays, Transwell collagen invasion chambers, adhesion binding assays, and ELISAs.

Results:

T cell frequencies were higher in DA compared to JIA and T21 in contrast to B cell frequencies which were decreased. T cell responses in DA were characterized by increased frequencies of CD4+ and CD8+ TNF- α, IFN- γ and GM-CSF producing T cells. The frequency of T peripheral helper (Tph) cells were elevated in children with DA compared to all other groups. In parallel, an increase in their metabolic profile evident by higher phosphorylation of mTOR pathway components AKT, mTOR and S6. Comparison of DA and JIA FLS demonstrated that DA FLS display a more invasive/migratory capacity and are more metabolically active. Based on the increased cytokine responses in DA T cells, we next examined the effect T cell derived cytokines TNF-α, IL-17A, IFN-γ and GM-CSF alone and in combination on DA FLS function. TNF-α, IL-17a and IFN-γ induced IL-6, RANTES and MCP-1 secretion, with no effect observed for GM-CSF. Furthermore, TNF-α and IL-17A induced DA FLS migration and PBMC adhesion to DA FLS. Finally IL17A and IFN-γ potentiated the effect of TNF-α on IL-6 and MCP-1 secretion compared to stimulations alone.

Conclusion:

DA is a more common and aggressive form of arthritis compared to JIA. It is characterized by increased T cell responses and a more invasive FLS phenotype compared to that of JIA, with T cell derived cytokine alone and in combination further inducing DA FLS pathogenic mechanisms. These effects mirror the increased erosive disease observed clinically.

References:

[1]Foley, C. et al. (2019) ‘Increased T cell plasticity with dysregulation of T follicular helper, T peripheral helper and T regulatory cell responses in children with JIA and Down syndrome-associated arthritis’, Arthritis & Rheumatology, pp. 0–1. doi: 10.1002/art.41150.

[2]Shih, Y. J. et al. (2019) ‘Enthesitis-related arthritis is the most common category of juvenile idiopathic arthritis in Taiwan and presents persistent active disease’, Pediatric Rheumatology. Pediatric Rheumatology. doi: 10.1186/s12969-019-0363-0.

Disclosure of Interests:

None declared.

Vulval acne: a case series describing clinical features and management

Intermittent inflammation of the vulval pilosebaceous units is common and usually self-limiting, but some patients experience recurrent and more troublesome symptoms. There is a scarcity of information on this problem. We describe the clinical and histological features in these patients and the response to treatment. A retrospective, observational study of 16 patients with this phenomenon of recurrent, protracted folliculocentric inflammation of the vulval pilosebaceous unit was performed. Details on the clinical features, histology and response to treatment were collected. Mean age at presentation was 32 years (range 21-45). All patients reported recurrent painful papules and pustules on the labia majora and labia minora. Nine patients reported a cyclical pattern to the development of lesions, with premenstrual exacerbation being most common. Histological examination of these lesions showed a folliculocentric microabscess formation surrounded by an acute and chronic inflammatory cell infiltrate, with a focal foreign-body granulomatous reaction. All our patients responded well to tetracycline, antiandrogenic or retinoid therapy. We propose the term 'vulval acne' for this condition and propose a stepwise approach to its management. We hope to highlight this as a common but underreported entity.

Impaired calcineurin signaling in myeloid cells results in downregulation of pentraxin-3 and increased susceptibility to aspergillosis

Treatment of post-transplant patients with immunosuppressive drugs targeting the calcineurin-nuclear factor of activated T cells (NFAT) pathway, including cyclosporine A or tacrolimus, is commonly associated with a higher incidence of opportunistic infections, such as Aspergillus fumigatus, which can lead to severe life-threatening conditions. A component of the A. fumigatus cell wall, β-glucan, is recognized by dendritic cells (DCs) via the Dectin-1 receptor, triggering downstream signaling that leads to calcineurin-NFAT binding, NFAT translocation, and transcription of NFAT-regulated genes. Here, we address the question of whether calcineurin signaling in CD11c-expressing cells, such as DCs, has a specific role in the innate control of A. fumigatus. Impairment of calcineurin in CD11c-expressing cells (CD11c^crecnb1^loxP) significantly increased susceptibility to systemic A. fumigatus infection and to intranasal infection in irradiated mice undergoing bone marrow transplant. Global expression profiling of bone marrow-derived DCs identified calcineurin-regulated processes in the immune response to infection, including expression of pentraxin-3, an important antifungal defense protein. These results suggest that calcineurin inhibition directly impairs important immunoprotective functions of myeloid cells, as shown by the higher susceptibility of CD11c^crecnb^loxP mice in models of systemic and invasive pulmonary aspergillosis, including after allogeneic bone marrow transplantation. These findings are relevant to the clinical management of transplant patients with severe Aspergillus infections.

'It's effective but should I bother?' A study of personal protection measures against Malaria in urban India

OBJECTIVES

Malaria affects millions of people in urban and rural India every year. This study addresses two main gaps in current research: 1) attitudes towards personal protective strategies against Malaria among urban populations; and 2) understanding of the extent to which urban health information seeking preferences shape preventive behaviours.

STUDY DESIGN

Cross-sectional face-to-face surveys using stratified sampling design.

METHODS

A 60-min survey was carried out to 1000 middle-of-pyramid (MOP) population in five main cities in India by trained interviewers. Variables assessed included perceived effectiveness and actual practice of 14 scientific and indigenous personal protection methods, Malaria-related attitudes (susceptibility, severity and response efficacy) and health information seeking preferences.

RESULTS

Actual practice of Malaria preventive behaviours was found to be significantly lower than the perceived effectiveness of each of the fourteen scientific and indigenous methods. Television, newspapers, and mobile phones were reported as the top three preferred media for seeking public health information. Lastly, perceived susceptibility, response efficacy, and health-related media use were found to play significant roles in predicting actual practice behaviours.

CONCLUSIONS

Our study highlights a need for health authorities to focus on translating positive attitudes to actual practice of preventive behaviours. Communication efforts may focus on the use of TV, newspapers and mobile phones for greater reach and efficacy. Other implications for Malaria prevention programs are discussed.

Sequestrated meningocoele within a naevus sebaceous of Jadassohn on the scalp of a child

Sequestrated meningocoele is an uncommon developmental anomaly in which meningothelial elements are found in the skin or subcutaneous tissue without underlying bony defect. By contrast, naevus sebaceous of Jadassohn (NSJ) is a circumscribed hamartomatous lesion occurring in about 0.3% of newborns. We report a child with a histologically confirmed sequestrated meningocoele within an NSJ on his scalp vertex. Such an occurrence has not been reported previously.

Acute stroke patients with high BMI are less likely to have severe disability at initial presentation

This is a prospective study to determine the severity of disability and prognosis of acute stroke patients related to their Body Mass index (BMI). A total of 79 consecutive CT-scan-proven acute stroke patients who were admitted to Hospital Tuanku Ja'afar, Seremban between November 2006 and April 2007 were recruited (male:female 49:30; mean age 62.7 years; ischemic stroke 70, intracerebral bleed 9). The patients were divided according to BMI less than 25 (Group A) and equal or greater than 25 (Group B). Severity of disability was measured between 24-48 hours by modified Rankin's score. Patients were followed up after one month. Thirty-seven patients had severe disability (Rankin Score 5). Twenty-nine patients had adverse outcomes including 11 deaths and 18 rehospitalizations or prolonged hospital/nursing home stay. 34.3% of Group B had severe disability compared to 56.8% of Group A (chi2 P = 0.046). Conversely 42.9% of Group B had adverse events at one month compared to 31.8% of Group A (chi2 P = 0.312). There were no statistical differences between high- and low-BMI groups for gender ratio, smoking, hypertension, diabetes, prior cardiovascular disease, mean age, mean lipid profile and blood pressure. When comparing patients with Rankin Score 1-4 versus 5, age and BMI were statistically significant between the two groups. By multivariate analysis only age is independent predictor for severe disability (P < 0.05). The results of this pilot study should be confirmed in larger prospective multicentre trial.

Complex partial seizures in young children

We retrospectively analyzed the clinical manifestations of complex partial seizures (CPS) in children aged < or = 10 years using video and EEG telemetry and evaluated their course, investigations, management, and seizure status at follow-up. Seventeen patients with CPS were studied at the Prince of Wales Children's Hospital (POWCH) and Prince Henry Hospital (PHH) between 1987 and 1992. Because 15 of the 17 patients had intractable seizures, the population was selective. Mean age was 6.5 years; 4 patients were aged < or = 2 years. Clinical features were normal or mild intellectual handicap (13); hemiplegia (5); and infantile spasms preceding CPS (4); of these, 2 also had simple partial motor seizures. Structural abnormalities were noted on scanning in 9 patients. Eighty-seven seizures were reviewed. Mean duration of each clinical seizure was 59.7 s (total population), 108 s (subgroup 1, aged < or = 2 years), and 48.5 s (subgroup 2, aged > 2 years). Major ictal manifestations were auras (9), staring (9), autonomic changes (6), and automatisms (17). In subgroup 1, automatisms were simple and mainly oroalimentary and gestural. Two patients had no change in surface ictal recordings, and 2 had normal interictal EEGs. At follow-up, 8 patients were seizure-free for 6 months, 1 was partially controlled (more than two seizures a month), and 8 had intractable seizures (two or more seizures a month). Seven patients underwent operation for intractable epilepsy, and 4 achieved a class 1A outcome (Engel classification).

Simplified pressure method for respirator fit testing

A simplified pressure method has been developed for fit testing air-purifying respirators. In this method, the air-purifying cartridges are replaced by a pressure-sensing attachment and a valve. While wearers hold their breath, a small pump extracts air from the respirator cavity until a steady-state pressure is reached in 1 to 2 sec. The flow rate through the face seal leak is a unique function of this pressure, which is determined once for all respirators, regardless of the respirator's cavity volume or deformation because of pliability. The contaminant concentration inside the respirator depends on the degree of dilution by the flow through the cartridges. The cartridge flow varies among different brands and is measured once for each brand. The ratio of cartridge to leakflow is a measure of fit. This flow ratio has been measured on human subjects and has been compared to fit factors determined on the same subjects by means of photometric and particle count tests. The aerosol tests gave higher values of fit.