Treatment of cryptoglandular fistulas with the fistula tract laser closure (FiLaC™) method in comparison with standard methods: first results of a multicenter retrospective comparative study in the Netherlands

BACKGROUND

Current surgical closure techniques for sphincter-sparing treatment of high cryptoglandular fistulas in the Netherlands include the mucosal advancement flap procedure (MAF) and ligation of the intersphincteric fistula tract (LIFT). A relatively novel treatment is the fistula tract laser closure (FiLaC™) method. The aim of this study was to investigate the differences in healing and recurrence rates between FiLaC™ and current standard practices.

METHODS

This multicenter retrospective cohort study included both primary and recurrent high cryptoglandular anorectal fistulas, treated with either FiLaC™ or standard methods (MAF or LIFT) between September 2015 and July 2020. Patients with extrasphincteric fistulas, Crohn's disease, multiple fistulas, age < 18 years or missing data regarding healing time or recurrence were excluded. The primary outcomes were the clinical primary and secondary healing and recurrence rates. Primary healing was defined as a closed external opening without fluid discharge within 6 months of treatment on examination, while secondary healing was the same endpoint after secondary treatment. Secondary outcomes included healing time and complaints.

RESULTS

A total of 162 high fistulas from 3 Dutch hospitals were included. Ninety-nine high fistulas were treated with FiLaC™ and 63 with either MAF or LIFT. There were no significant differences between FiLaC™ and MAF/LIFT in terms of clinical healing (55.6% versus 58.7%, p = .601), secondary healing (70.0% versus 69.2%, p = .950) or recurrence rates (49.5% versus 54%, p = .420), respectively. Median follow-up duration was 7.1 months in the FiLaC™ group (interquartile range [IQR] 4.1-14.4 months) versus 6 months in the control group (IQR 3.5-8.1 months).

CONCLUSIONS

FiLaC™ treatment of high anorectal fistulas does not appear to be inferior to MAF or LIFT. Based on these preliminary results, FiLaC™ can be considered as a worthwhile treatment option for high cryptoglandular fistulas. Prospective studies with a longer follow-up period and well-determined postoperative parameters such as complication rates, magnetic resonance imaging for confirmation of fistula healing, incontinence and quality of life are warranted.

Insulitis in the pancreas of non-diabetic organ donors under age 25 years with multiple circulating autoantibodies against islet cell antigens

Autoantibodies against islet cell antigens are routinely used to identify subjects at increased risk of symptomatic type 1 diabetes, but their relation to the intra-islet pathogenetic process that leads to positivity for these markers is poorly understood. We screened 556 non-diabetic organ donors (3 months to 24 years) for five different autoantibodies and found positivity in 27 subjects, 25 single- and two double autoantibody-positive donors. Histopathological screening of pancreatic tissue samples showed lesion characteristic for recent-onset type 1 diabetes in the two organ donors with a high-risk profile, due to their positivity for multiple autoantibodies and HLA-inferred risk. Inflammatory infiltrates (insulitis) were found in a small fraction of islets (<5%) and consisted predominantly of CD3+CD8+ T-cells. Islets with insulitis were found in close proximity to islets devoid of insulin-positivity; such pseudo-atrophic islets were present in multiple small foci scattered throughout the pancreatic tissue or were found to be distributed with a lobular pattern. Relative beta cell area in both single and multiple autoantibody-positive donors was comparable to that in autoantibody-negative controls. In conclusion, in organ donors under age 25 years, insulitis and pseudo-atrophic islets were restricted to multiple autoantibody-positive individuals allegedly at high risk of developing symptomatic type 1 diabetes, in line with reports in older age groups. These observations may give further insight into the early pathogenetic events that may culminate in clinically overt disease.

THU0496 APPLICATION OF SYSTEMS BIOLOGY-BASED IN SILICO TOOLS TO OPTIMIZE TREATMENT STRATEGY IN STILL’S DISEASE

Background:

Systemic Juvenile Idiopathic Arthritis (sJIA) and Adult Onset Still’s Disease (AOSD) are manifestations of an autoinflammatory disorder with complex pathophysiology and significant morbidity, together also termed Still’s disease.

Objectives:

To investigate the optimal treat-to-target strategy for Still’s disease by in silico models based on systems biology.

Methods:

Molecular characteristics of Still’s disease and data on biological inhibitors of interleukin (IL)-1 (anakinra, canakinumab), IL-6 (tocilizumab, sarilumab), glucocorticoids as well as conventional disease-modifying anti-rheumatic drugs (DMARDs, methotrexate) were used to construct in silico mechanisms of action (MoA) models by means of Therapeutic Performance Mapping System technology (TPMS). TPMS combines artificial neuronal networks (ANN), sampling-based methods and artificial intelligence. The models were validated with publicly available expression data from sJIA patients (Fig.1).

Figure 1.

Schematic TPMS approach used to evaluate the Still’s disease treatments efficacy and their MoA

Results:

Biologicals demonstrated more pathophysiology-directed efficiency than non-biological drugs. IL-1 blockade mainly acts on the innate immune system, while IL-6 signaling blockade has a weaker activity on the innate immunity and rather affects the adaptive immunity (Table 1). The MoA models showed that the IL-1β inhibitor canakinumab is more efficient than the IL-6 receptor inhibiting antibody tocilizumab in the autoinflammatory/systemic phases of Still’s disease. MoA models reproduced 67% of the information obtained from expression data (Fig.2).

Table 1.

Summary of ANN scores. A) Global Still’s disease evaluation. B) Immune system component. ANN scores mean the probability of the resulted relationship is true positive: +++ correspond to values >78% (p-value<0.05); ++ correspond to values > 59% (p-values<0.15) and; + correspond to values > 38% (p-value<0.25)

A) Still’s disease molecular definitionBiologicsNon-biologicsAnakinraCanakinumabSarilumabTocilizumabMethotrexatePrednisoneStill’s disease+++ (81%)+++ (86%)+++ (85%)+++ (85%)- (5%)++ (70%)Systemic profile+++ (80%)+++ (88%)+++ (85%)+++ (85%)- (4%)++ (70%)Rheumatic profile+++ (87%)+++ (92%)+++ (81%)+++ (81%)- (9%)++ (64%)B) Immune system componentsBiologicsNon-biologicsAnakinraCanakinumabSarilumabTocilizumabMethotrexatePrednisoneInnate immune system deregulation++ (71%)++ (71%)+ (55%)+ (55%)- (10%)++ (65%)Adaptive immune systemT-cell response activation+ (45%)- (37%)++ (71%)++ (71%)- (25%)+ (47%)Defective immune regulation- (19%)- (37%)+ (47%)+ (47%)- (15%)+ (50%)Figure 2.

Systems biology-based MoA models of canakinumab and tocilizumab focused on innate immune system modulation. Canakinumab preferably modulates NF-κB, IL-8 (CXCL8), MyD88, S100A9 and ATG5, which are involved in processes of general innate immune inflammation, neutrophil recruitment, activation and autophagy, whereas tocilizumab preferably modulates FCGR1, which is involved in neutrophil activation

Conclusion:

Systems biology-based modelling supported the preferred use of biologics as immunomodulatory treatment strategy for Still’s disease. This further encourages early IL-1β blockade in initial autoinflammatory/systemic phases of Still’s Disease to prevent the development of disease or drug-related complications. Further studies are needed to determine the optimal timeframe of the window of opportunity for canakinumab treatment.

Disclosure of Interests: :

Mireia Coma Grant/research support from: Novartis, Employee of: Anaxomics, Speakers bureau: Novartis, Cristina Segú-Vergés Grant/research support from: Novartis, Employee of: Anaxomics, Christoph Kessel: None declared, Serge Smeets Employee of: Novartis, Dirk Foell Grant/research support from: Novartis, Sobi, Pfizer, Speakers bureau: Novartis, Sobi, Anna Aldea Employee of: Novartis

Evidence of Tissue Repair in Human Donor Pancreas After Prolonged Duration of Stay in Intensive Care

M2 macrophages play an important role in tissue repair and regeneration. They have also been found to modulate β-cell replication in mouse models of pancreatic injury and disease. We previously reported that β-cell replication is strongly increased in a subgroup of human organ donors characterized by prolonged duration of stay in an intensive care unit (ICU) and increased number of leukocytes in the pancreatic tissue. In the present study we investigated the relationship between duration of stay in the ICU, M2 macrophages, vascularization, and pancreatic cell replication. Pancreatic organs from 50 donors without diabetes with different durations of stay in the ICU were analyzed by immunostaining and digital image analysis. The number of CD68⁺CD206⁺ M2 macrophages increased three- to sixfold from ≥6 days' duration of stay in the ICU onwards. This was accompanied by a threefold increased vascular density and a four- to ninefold increase in pancreatic cells positive for the replication marker Ki67. A strong correlation was observed between the number of M2 macrophages and β-cell replication. These results show that a prolonged duration of stay in the ICU is associated with an increased M2 macrophage number, increased vascular density, and an overall increase in replication of all pancreatic cell types. Our data show evidence of marked levels of tissue repair in the human donor pancreas.

Effects of early life and current housing on sensitivity to reward loss in a successive negative contrast test in pigs

Animals in a negative affective state seem to be more sensitive to reward loss, i.e. an unexpected decrease in reward size. The aim of this study was to investigate whether early-life and current enriched vs. barren housing conditions affect the sensitivity to reward loss in pigs using a successive negative contrast test. Pigs (n = 64 from 32 pens) were housed in barren or enriched conditions from birth onwards, and at 7 weeks of age experienced either a switch in housing conditions (from barren to enriched or vice versa) or not. Allotting pigs to the different treatments was balanced for coping style (proactive vs. reactive). One pig per pen was trained to run for a large reward and one for a small reward. Reward loss was introduced for pigs receiving the large reward after 11 days (reward downshift), i.e. from then onwards, they received the small reward. Pigs housed in barren conditions throughout life generally had a lower probability and higher latency to get the reward than other pigs. Proactive pigs ran overall slower than reactive pigs. After the reward downshift, all pigs ran slower. Nevertheless, reward downshift increased the latency and reduced the probability to get to the reward, but only in pigs exposed to barren conditions in early life, which thus were more sensitive to reward loss than pigs from enriched early life housing. In conclusion, barren housed pigs seemed overall less motivated for the reward, and early life housing conditions had long-term effects on the sensitivity to reward loss.

[Use of therapeutic hypothermia in sudden unexpected postnatal collapse]

Sudden postnatal collapse of a full-term newborn is uncommon but may result in severe consequences: these include death; epilepsy; and motor, cognitive, or sensory impairment. Most authors suggest applying a therapeutic hypothermia approach when a previously healthy newborn develops moderate or severe encephalopathy after a sudden postnatal collapse occurring within the first hours or days after birth. However, this technique has still not been validated by randomized trials. Only a few cases have been reported in the literature. This article describes five apparently healthy newborns, born between 2007 and 2012, who suffered moderate to severe encephalopathy following a postnatal collapse on their first day of life. It describes their clinical history as well as their treatment and follow-up. The article focuses on the implementation of hypothermia in this indication and its limitations. Two newborns underwent classic therapeutic hypothermia, two others underwent temperature regulation (one at 34.5 °C, the other one for only 15 h because she quickly improved). One newborn, with severe pulmonary arterial hypertension, did not receive therapeutic hypothermia. Two newborns died (one had classic hypothermia and the other hypothermia at 34.5 °C), the outcome of the three survivors at three years, 18 months, and 15 months is good with only transient postural anomalies. Follow-up must be continued to assess their cognitive development and particularly their memorization processes. Additional research and centralization of the cases is required to evaluate the feasibility, safety, and benefits of therapeutic hypothermia in this situation.

[Patients with brain injury in a psychiatric setting; assessment of health care needs and received care]

BACKGROUND

In some Dutch mental health care organisations specific neuropsychiatric departments have been developed for patients with brain injury.

AIM

To identify the characteristics of patients with brain injury who form a specific population in mental health care and to determine whether such patients require either specialised care or a special type of care.

METHOD

A cross-sectional analysis of typical brain injury inpatients was performed. We noted the age and gender of these patients and recorded any previous periods of inpatient care. We listed patients’ impairments, the diagnoses they had been given and the treatment they had received. This inventory formed the basis of our conclusions.

RESULTS

The typical clinical patient with brain injury in this setting was a male of 51 years or older, most probably affected by a stroke or traumatic brain injury, admitted for a period of 6 months, many years after the incident. He was mostly referred from home or hospital by a physician and was expected to return home again. A combination of cognitive and psychiatric impairments was often found. Physically the patient had no or only mild disabilities, but societal participation was low and many cognitive-affective disorders were seen. Treatment was relatively infrequent and mostly directed at daily activities. The most frequent diagnosis was & lquo;cognitive deficits not otherwise specified’. Irritability, agitation, apathy and depression were frequent symptoms.

CONCLUSION

This inventory suggests that brain injury patients in a mental health care setting need special care which is not available in other health care settings.

[Implementation of the intestinal micro flora in the early stage and adequate immunity later on]

The pre and postnatal development of human immunity are remarkably continuous. The feto-placental unit builds up to promote a climate of immune tolerance specifically driven in this way by the maternal immunity. The process of birth triggers the development of the infant's postnatal immunity, in first place through the bacterial colonisation of a sterile intestinal mucosa. The progressive immune response stabilisation at the sub-mucosa level during the first year of life will arise from the interface between the host and its microflora. It will take place progressively and will occur thanks to a variety of successive and complementary very complex immune mechanisms, under the influence of a rich and diversified intestinal microbiotia. Solid scientific arguments allow hypothesising that immune deviances later in life could be the consequence of an inadequate bacterial pressure on the intestinal mucosa at the early stage. A variety of epigenetic modifications taking place in this early stage could account for the deviant programming of later immunity. Each health care provider should acknowledge that some therapeutic and nutritional interventions during the first year of life may interfere with this complex immune development, giving rise to a risk of increasing immune deviancies later on.

Macrolides inhibit IL17-induced IL8 and 8-isoprostane release from human airway smooth muscle cells

Lung transplantation is hampered by bronchiolitis obliterans syndrome (BOS), although recently azithromycin treatment has a published response rate of about 42% in patients with established BOS. We linked this improvement to a reduction in airway neutrophilia and IL8. In the present study, we further investigated the intracellular mechanisms of azithromycin, looking at the possible involvement of mitogen-activated-protein kinases (MAPK) and oxidative stress. Simultaneously, currently used immunosuppressive agents were investigated. Human primary airway smooth muscle cells were stimulated with IL17 and incubated with increasing concentrations of steroids, immunosuppressive agents (tacrolimus, cyclosporine and rapamycin) or macrolides (erythromycin and azithromycin). We measured supernatant IL8 protein, 8-isoprostane and cell lysate MAPK. IL17-induced IL8 production was decreased by both erythromycin and azithromycin. In nonstimulated condition, IL8 production only increased at the highest dose of azithromycin. Dexamethasone failed to attenuate IL8 production, whereas immunosuppressive agents significantly increased IL8 production in both IL17-stimulated and nonstimulated conditions. 8-isoprostane production and MAPK activation proved to be decreased by the macrolides. We conclude that macrolides (but not steroids/immunosuppressive agents) inhibit IL17-induced IL8 production in human primary airway smooth muscle cells via a reduction in MAPK activation and 8-isoprostane production. In BOS patients, these phenomena may explain the anti-inflammatory effects of azithromycin.