FRI0441 INFECTIOUS DISEASES RISK ASSESSMENT PRIOR TO IMMUNOMODULATION THERAPY - EXPERIENCE FROM AN INFECTIOUS DISEASES UNIT

Background:

The increasing use of immunomodulatory therapies has motivated the development of strategies to assess and prevent infectious diseases in these immunosuppressed patients, in whom the risk of serious infections is higher.

Objectives:

The aim of this study was to recognize the need to standardize prophylactic and therapeutic strategies in this population.

Methods:

Retrospective review of clinical files of patients evaluated in the infectious risk assessment in an outpatient clinic at the Infectious Diseases Unit at Hospital de Curry Cabral in Lisbon, between June 2016 and November 2019. We reviewed information regarding sex, age, origin, occupation, past travels as well as plans of future ones, contact with live animals, intake of unpasteurized products or unsafe drinking water, along with relevant data regarding past medical history and previous and/or ongoing treatments, including immunomodulatory ones.

Results:

During the established timeline,1305 appointments were carried out, corresponding to a total of 415 patients. The majority of patients were female (263; 63.7%), the average age was 50 years and 82% were of Portuguese nationality. The most frequent groups of diseases were autoimmune/inflammatory (84.1%) and demyelinating (10.1%). At the date of the first consultation, 70% were already under immunosuppression. Screening for latent tuberculosis infection (LTBI) was done in 99% of the patients (n = 410) and treatment was proposed to 160 patients (38.5%). At the time of screening, 56,8% of the patients were under immunossuppressive therapies, which included high doses of systemic corticosteroids (37%), anti-TNF alpha (7,7%) and combine therapy with non-biologic agents. Active disease was diagnosed and treated in two patients. Interferon gamma release assay test (IGRA) was positive in 56.8% of patients (n = 91), negative in 32.5% (n = 52) and indeterminate in 7.5% (n=12). Of the 69 patients (43%) with indeterminate/negative or not performed IGRA, Mantoux test (TST) was positive in 48 patients. In the remainder, the treatment proposal for LTBI was based on clinical, epidemiological or radiological signs suggestive of past infection.

In order to prevent hyperinfection/disseminated strongyloidiasis, 354 individuals were screened withStrongyloides stercoralisserology, of which 51 patients (14.4%) had a positive result and were treated with ivermectin. Regarding vaccination, the recommendation for annual influenza vaccination was reinforced, together with the prevention of invasive pneumococcal disease. In view of future travelling plans, vaccination against yellow fever (n = 10), meningococcal disease (n = 7), typhoid fever (n = 6), and polio (n = 2) was recommended. In cases without a previous history of measles and according to the year of birth, VASPR was prescribed to 6 patients. Vaccination to prevent herpes zoster was recommended to 20 patients. After serological evaluation, the vaccine against hepatitis A and hepatitis B was prescribed to 89 and 132 patients, respectively, the latter when serological evidence of previous vaccination or contact was absent. We identified 10 cases of positive anti-HCV antibodies, with undetectable viral load. Primary prophylaxis forPneumocystis jiroveciipneumonia was recommended to 104 patients. Prophylaxis against reactivation of Herpes simplex infection was initiated in 4 patients.

Conclusion:

The decision to start immunosuppressive therapy comes with benefits and risks. Appropriate screening prior to starting therapy is an essential tool for its safe use. Referral to a specialised Infectious Risk Assessment consultation should be done promptly in order to review and address accordingly the risk of specific infections taking in to account the patients clinical and epidemiologic history.

Disclosure of Interests:

None declared

Adenosine A2A receptor regulation of microglia morphological remodeling-gender bias in physiology and in a model of chronic anxiety

Developmental risk factors, such as the exposure to stress or high levels of glucocorticoids (GCs), may contribute to the pathogenesis of anxiety disorders. The immunomodulatory role of GCs and the immunological fingerprint found in animals prenatally exposed to GCs point towards an interplay between the immune and the nervous systems in the etiology of these disorders. Microglia are immune cells of the brain, responsive to GCs and morphologically altered in stress-related disorders. These cells are regulated by adenosine A_2A receptors, which are also involved in the pathophysiology of anxiety. We now compare animal behavior and microglia morphology in males and females prenatally exposed to the GC dexamethasone. We report that prenatal exposure to dexamethasone is associated with a gender-specific remodeling of microglial cell processes in the prefrontal cortex: males show a hyper-ramification and increased length whereas females exhibit a decrease in the number and in the length of microglia processes. Microglial cells re-organization responded in a gender-specific manner to the chronic treatment with a selective adenosine A_2A receptor antagonist, which was able to ameliorate microglial processes alterations and anxiety behavior in males, but not in females.

[Antimicrobial prophylaxis for caesarean delivery: changes in practice and administration before incision, feasibility study to paediatricians in Auvergne]

OBJECTIVE

To describe the knowledge of paediatricians regarding the practice of antimicrobial prophylaxis for caesarean section in reference to the Consensus Conference of the French Society of Anesthesia and Intensive Care (SFAR) and assess the feasibility of a change in attitude (injection of the antibiotic prior to incision) among paediatricians Perinatal Health Network of Auvergne (RSPA) working in maternity.

STUDY DESIGN

Cross sectional study by survey.

METHODS

First questionnaire was sent to 46 RSPA paediatricians working in maternity. Almost one-third of paediatricians who returned the questionnaire said they were not concerned. A second questionnaire was developed with two paediatricians of the CHU and sent to the same 46 paediatricians. The statistical part involved percentages.

RESULTS

Response rates were respectively 61% and 67%. For the first questionnaire, only 25% of the paediatricians knew the antibiotic and the time for injection. For the second questionnaire, 87% were in favour of an administration before incision and 42% thought it will not affect the care of the newborn. For 35% of respondents, it could lead to a change in the duration of antibiotic therapy in cases of perinatal infection and for 13% only a delay in the implementation of antibiotic therapy in children.

CONCLUSION

The RSPA paediatricians did not know the practices of antibiotic prophylaxis for caesarean section. However, they did not appear opposed to an administration before cord clamping as it would not delay the implementation of any antibiotics in the newborn.

CDH1 structural alterations as novel prognostic biomarker in gastric cancer patients

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Background: Loss of CDH1 function occurs in sporadic gastric cancer (GC) progression by different molecular mechanisms. Hypermethylation and somatic mutations are considered the most frequent events. About 50% of sporadic diffuse GC shows CDH1 promoter of hypermethylation and 30% harbor somatic mutations; loss of heterozygosity (LOH) is documented in only 5% of diffuse GC cases. The present study aims to asses CDH1 alterations in 246 GC and study associated clinicopathologic features and family history of GC.

Methods: Bisulphite treated tumoral DNA was used for E-cad promoter methylation. A region of 221 bps was amplified using flanking primers and direct sequencing. To search for somatic mutations the hotspot region of E-cad was amplified and directly sequenced. For LOH analysis tumor and matched normal mucosae were amplified in three microsatellite markers (D16S3025, D16S496, D16S3067) flanking the CDH1 locus.

Results: Promoter hypermethylation was the most frequent event occurring in 20.7% (51 of 246) of the cases. We found 26 (10.6%) cases affected by structural alterations (three with somatic mutations and 23 with LOH). Promoter CDH1 methylation is associated with the diffuse type of GC (p = 0.017) and the presence of distant lymph node metastasis (p = 0.043). We identified association between male gender and structural CDH1 alterations (p = <0.001), R1/2 radicality of resection (p = 0.015). We verified a correlation between advanced stages and CDH1 promoter methylation (p = 0.033). Kaplan-Meier survival analysis estimates that CDH1 structural alterations participate as poor prognostic factor in GC patients (p = 0.017).

Conclusions: Considering the reversible nature of hypermethylation phenomena, demethylating drugs have emerged as possible chemopreventive strategies in solid tumors. Moreover, we verify that epigenetic changes of E-cadherin leading to its decrease protein expression induce an invasive behaviour to neoplastic cells; as structural alterations of CDH1 gene is assess as predictive of worse prognosis we found a new molecular biomarker of prognosis in GC that can be used to predict the clinical prognosis of the patients.

No significant financial relationships to disclose.

Electrochemical degradation applied to the metabolites of Acid Orange 7 anaerobic biotreatment

The electrochemical oxidation of the biotic degradation products of the textile dye C.I. Acid Orange 7 (AO7) was achieved using a boron doped diamond electrode (BDD). Tests were performed with model solutions of the biotic degradation products, sulphanilic acid (SA) and 1-amino-2-naphthol (AN), and also with real effluents obtained in experiments carried out in an up-flow anaerobic sludge blanket (UASB) reactor, fed with a simulated textile effluent containing AO7, working in mesophilic or thermophilic conditions. Bulk electrolysis was studied using two different supporting electrolytes - NaCl and Na(2)SO(4). The influence of initial metabolite concentration and current density on the electrodegradation rates of the biotic products was investigated. For the UASB effluents, oxidation tests were carried out for different electrolytes and at different current densities. Samples were collected at pre-selected intervals and absorbance measurements, chemical oxygen demand (COD) and total organic carbon (TOC) tests and high performance liquid chromatography (HPLC) analysis were performed. Results have shown an almost complete elimination of the persistent pollutants and a COD removal higher than 70% for both AN and SA. For the UASB effluents, COD removals between 45% and 90% and TOC removals varying from 19% to 41% were obtained.

A comparison of AT1 angiotensin II antagonists at pre- and postjunctional angiotensin II receptors of the rat tail artery

A comparison was made of the influence of candesartan, ZD7155, losartan and eprosartan on angiotensin II effects at pre- and postjunctional AT(1) receptors of the rat tail artery. To study the anti-angiotensin II effect at prejunctional receptors, the tissues were preincubated with [(3)H]noradrenaline and then superfused and electrically stimulated (1 Hz, 2 ms, 50 mA, during 5 min); to study the angiotensin II effect at postjunctional receptors, non-cumulative concentration-response curves to angiotensin II were determined in the absence and in the presence of the antagonist. p A(2) values were calculated for competitive antagonists and p D'(2) values for insurmountable antagonists. At the prejunctional level, losartan and eprosartan displayed competitive antagonism with p A(2) values of 6.50 and 8.08, respectively, whereas candesartan and ZD7155 displayed non-competitive antagonism with p D'(2) values of 8.71 and 7.98, respectively. At the postjunctional level, the four antagonists displayed the same kind of antagonism as prejunctionally with p A(2) values for losartan and eprosartan of 8.52 and 8.22, respectively, and p D'(2) values of 10.62 and 9.01, for candesartan and ZD7155, respectively. The ratios between post- and prejunctional potencies were: losartan 101, candesartan 81, ZD7155 11, and eprosartan 1.4. We conclude that, at least functionally, pre- and postjunctional angiotensin II AT(1) receptors are different and propose that the prejunctional receptors in this tissue belong to the AT(1B)-subtype.

Modulation of insulin transport in rat brain microvessel endothelial cells by an ecto-phosphatase activity

The physiological function of alkaline phosphatase (ALP) remains controversial. It was recently suggested that this membrane-bound enzyme has a role in the modulation of transmembranar transport systems into hepatocytes and Caco-2 cells. ALP activity expressed on the apical surface of blood-brain barrier cells, and its relationship with (125)I-insulin internalization were investigated under physiological conditions using p-nitrophenylphosphate (p-NPP) as substrate. For this, an immortalized cell line of rat capillary cerebral endothelial cells (RBE4 cells) was used. ALP activity and (125)I-insulin internalization were evaluated in these cells. The results showed that RBE4 cells expressed ALP, characterized by an ecto-oriented active site which was functional at physiological pH. Orthovanadate (100 microM), an inhibitor of phosphatase activities, decreased both RBE4-ALP activity and (125)I-insulin internalization. In the presence of L-arginine (1 mM) or adenosine (100 microM) RBE4-ALP activity and (125)I-insulin, internalization were significantly reduced. However, D-arginine (1 mM) had no significant effect. Additionally, RBE4-ALP activity and (125)I-insulin internalization significantly increased in the presence of the bioflavonoid kaempferol (100 microM), of the phorbol ester PMA (80 nM), IBMX (1 mM), progesterone (200 microM and 100 microM), beta-estradiol (100 microM), iron (100 microM) or in the presence of all-trans retinoic acid (RA) (10 microM). The ALP inhibitor levamisole (500 microM) was able to reduce (125)I-insulin internalization to 69.1 +/- 7.1% of control. Our data showed a positive correlation between ecto-ALP activity and (125)I-insulin incorporation (r = 0.82; P < 0.0001) in cultured rat brain endothelial cells, suggesting that insulin entry into the blood-brain barrier may be modulated through ALP.

Differential effects of eprosartan and losartan at prejunctional angiotensin II receptors

A comparison was made of the influence of losartan and eprosartan on angiotensin II effects at pre- and postjunctional receptors of the canine pulmonary artery and at prejunctional receptors of the rat left ventricle. To study postjunctional contractile responses to angiotensin II, non-cumulative concentration-response curves were determined; to study prejunctional effects of angiotensin II, the tissues were preincubated with [3H]noradrenaline and then superfused and electrically stimulated (1 Hz, 2 ms, 50 mA, 5 min). Postjunctionally, both losartan and eprosartan caused a parallel shift of the concentration-response curve of angiotensin II to the right (pKd of 8.15 and 8.28, respectively). At the prejunctional level, while eprosartan, in concentrations similar to those which were effective postjunctionally (30-100 nM), antagonized the facilitatory effect on noradrenaline release in both the dog pulmonary artery and the rat ventricle, losartan was ineffective in concentrations up to 1 microM. It is concluded that pre-junctional receptors for angiotensin II in the canine pulmonary artery and in the rat left ventricle are different from postjunctional receptors of the canine pulmonary artery. It is proposed that the prejunctional receptors of these tissues are atypical AT1 or "AT1B-like" receptors.

Identifying genetic markers to assess the presence of gene-environment interactions

We analyzed a randomly chosen replicate with the goals of locating the closest markers to the genes involved in the discrete trait and utilizing these as surrogates for the genes in assessing the presence of gene-environment interactions. We screened the markers with an association test prior to using the transmission-disequilibrium test. We performed a segregation analysis, with regressive models and including the selected markers, to understand the underlying genetic mechanism and the role of the environmental factor. We were unsuccessful in locating the relevant markers due to the absence of linkage disequilibrium. Nevertheless, some insights were gained from the methods used.

Prejunctional effects of angiotensin II and bradykinin in the heart and blood vessels

1. Angiotensin and bradykinin facilitate the release of noradrenaline from sympathetic nerve terminals and cause positive inotropy in rat isolated atria and ventricles. The effect of bradykinin was enhanced by the ACE inhibitor, ramiprilat. 2. The facilitated release of noradrenaline in rat ventricle by bradykinin was blocked by the beta2-receptor antagonist HOE-140. This response is also reduced by removing the endocardium, suggesting the release of a mediator from the endocardium. 3. The facilitated noradrenaline release by angiotensin II and bradykinin was blocked by the angiotensin receptor antagonist saralasin to the same extent. In contrast, losartan caused only minor blockade in a range of vascular and cardiac tissues. This suggests that angiotensin and bradykinin exert these responses by interacting with a prejunctional receptor different from the established AT1 subtype. 4. These results suggest that bradykinin mediates facilitation of noradrenaline release via the local release of angiotensin onto an atypical AT1 receptor.

Biotransformation in organic media by enzymes and whole cells

Biotransformation of poorly water soluble compounds in organic media by immobilized enzyme and whole cells is illustrated in this paper taking the following examples from the author's laboratory: (1) controlled hydrolysis of triglycerides and synthesis reactions by a recombinant lipolytic enzyme (cutinase); (2) enzymatic synthesis of dipeptides; (3) continuous production of isovaleraldehyde by Gluconobacter oxydans in isooctane; and (4) sitosterol side chain cleavage by Mycobacterium sp. The role of water and organic solvent are evaluated, namely the increase in the volumetric productivity of the reaction system and the shift of the reaction equilibrium in favour of product synthesis. High product yields have been obtained due to the reduction of substrate/product inhibition. Biocatalyst stability in the presence of the organic phase was also performed.