POS0796 TREATMENT, ADVERSE EVENTS AND FOLLOW UP IN PATIENTS WITH GIANT CELL ARTERITIS IN THE ARTESER MULTICENTER STUDY

Background

Glucocorticoids (GC) are the mainstay therapy in Giant Cell Arteritis (GCA), initially at high doses (40-60 mg/day) followed by gradual glucocorticoid tapering. This treatment, especially in older patients, is associated with numerous adverse effects (AE). In addition, there are frequent relapses. Therefore, conventional synthetic immunosuppressants such as methotrexate (MTX), leflunomide, azathioprine, cyclophosphamide or mycophenolate, have been used with controversial results. Studies with biological immunosuppressants, such as TNFi have been ineffective; in contrast, tocilizumab (TCZ) has obtained positive results and was approved for the treatment of GCA.

Objectives

In the ARTESER study we describe a) treatment with GC, synthetic or biological immunosuppressants; b) AE of CG; and c) evolution.

Methods

ARTESER is a retrospective observational study sponsored by the Spanish Society of Rheumatology. 26 Spanish centers participated and all new patients diagnosed with GCA from June 1, 2013 to March 29, 2019 were included. Data on GC and immunosuppressants were collected at the beginning and during the follow-up of GCA patients. For the calculation of the cumulative dose of GC, an application was developed that, by including the periods of time, dose and type of GC received during follow-up, performs the automatic calculation in mg of prednisone.

Results

Of the 1675 patients included, GC treatment was adequately recorded in 1650 patients (Table 1). All received oral treatment, being prednisone the most frequently drug used (N=1602, 97.09%). In addition, 426 (25.82%) patients received at least one iv pulse of methylprednisolone, being the 1000 mg regimen the most frequent (n=217; 50.9%). The total mean duration of GC treatment was 22.65 months. The mean cumulative dose per patient at the end of follow-up was 8514.98 mg of prednisone.

Table 1.

Corticosteroid treatment and immunosuppressive treatment

Patients taking oral corticosteroid1650 Prednisone, n (%)1602 (97.09) Methylprednisolone, n (%)164 (9.94) Deflazacort, n (%)64 (3.88)Patients receiving intravenous corticosteroid, n (%)426 (25.82)Mean duration of steroid treatment, mean (SD)22.65 (17.36)Mean cumulative dose at the end of follow-up per patient, mg of prednisone, mean (SD)8514.98 (6570.21)Methotrexate at diagnosis*, n (%)165 (9.9)Leflunomide at diagnosis*, n (%)2 (0.1)Azathioprine at diagnosis*, n (%)3 (0.2)Cyclophosphamide at diagnosis*, n (%)7 (0.4)Mycophenolate at diagnosis*, n (%)1 (0.1)Tocilizumab at diagnosis*, n (%)22 (1.3)Methotrexate during follow-up, n (%)532 (31.8)Leflunomide during follow-up, n (%)19 (1.2)Azathioprine during follow-up, n (%)26 (1.5)Cyclophosphamide during follow-up, n (%)10 (0.6)Mycophenolate during follow-up, n (%)10 (0.6)Tocilizumab during follow-up, n (%)153 (9.1)

The most widely used immunosuppressant was MTX both at diagnosis (n=165; 9.9%) and during follow-up (n=532; 31.8%), followed by TCZ, at diagnosis (22; 1.3%) and at follow-up (153; 9.1%).

AE with GC were described in 393 patients (23.8%), highlighting serious infections (n=67; 10.03%) followed by diabetes mellitus (n=63; 9.43%), steroid myopathy (n=53; 7.9%), vertebral fractures (n=47; 7.04%), non-vertebral fractures (n=36; 5.39%), heart failure (n=36; 5.39%), arterial hypertension (n=34; 5.09%) and neuropsychiatric alterations (n=27; 4.04%).

During the follow-up, 334 (19.9%) patients had relapses, 532 (31.8%) were hospitalized on some occasion, and 142 patients (8.48%) died. The main cause of death were infections (n=44; 30.99%), neoplasms (n=23; 16.2%), cardiovascular (n=15; 10.56%), and cerebrovascular (n=10; 7.04%).

Conclusion

The main treatment for GCA was oral GC, which were required for almost two years on average, in a quarter of patients associated with IV pulses. The cumulative steroid dose was high as well as the side effects. MTX was the most widely used immunosuppressant and TCZ was prescribed in 10%. Relapses and admissions at the hospital were relatively frequent.

Acknowledgements

This study has been funded by ROCHE Farma. The funder has not participated in the design, analysis, or interpretation of the results

Disclosure of Interests

None declared

POS0264 CHARACTERIZATION OF THE IMMUNE RESPONSE IN PATIENTS WITH INFLAMMATORY IMMUNE-MEDIATED DISEASES ON IMMUNOSUPPRESSIVE TREATMENT AFTER ONE MONTH OF SARS-CoV-2 VACCINATION

Background

The relevance of studying immune response after SARS-CoV-2 vaccination in patients with inflammatory immune-mediated diseases (IMIDs) represents a deep concern regarding the risk estimation and management of patients with these diseases on immunomodulatory drugs. It is well known that certain treatments as anti CD20 therapies results in a diminished immunogenicity against common vaccines but it is a scarce data regarding the cellular protection obtained upon vaccination between patients with different IMID and between different treatments.

Objectives

To compare a potential detriment on cellular and antibody-mediated protection upon SARS-CoV-2 vaccination in patients with IMIDs treated with immunosuppressive drugs.

Methods

We recruited 73 patients with rheumatoid arthritis-RA-(n=49), spondylarthritis-SpA-(n=19), inflammatory bowel disease-IBD-(n=5), idiopathic juvenile arthritis-IJA- (n=2) and heterogenous group composed of sclerodermia, lupus, uveitis…(n=6). They were treated mainly with rituximab (n=27), TNFi (n=37) or JAKi (n=3). We collected data of age,sex, csDMARDs, previous SARS-CoV-2 infection, last RTX infusion and prednisone use.

After one month of vaccination, we assessed the humoral response performing the Thermo Scientific EliA SARS-CoV-2-Sp1 IgG Test (positivity cut-off >0.70 IU/ml) which was also compared with the data with of 35 healthy controls. In addition, in 40 patients who had serum antibody levels under 100UI/ml, we analysed the cellular response by the use of the QuantiFERON SARS-CoV-2 Starter Pack (Quiagen). A cut-off value of 0.15 IU/ml discriminate between positive or negative cell-mediated immune responses. We compared differences among the different IMIDs and between the different immunosuppressive treatments through non-parametric test (p<0.05)

Results

Regarding demographic characteristics of patients, older patients (>56 years) and female sex were factors which were associated with low titles of serum antibodies.

Anti-spike IgG antibodies were present in an 86% of the IMIDs patients and in 100% healthy controls with significant different IgG titre (median [IQR]): 51[11-184] vs 700[440-940]; p<0.0001.

The differences between (median [IQR]) serum antibody levels were statistically different between IMID type: 33[1-138] in RA vs 94[34-191] in SpA vs 204[187-204] in IBD vs 133[61-204] in IJA vs 13[1.5-31.8] in the rest; p=0.04. Remarkably, patients with IBD who had the highest antibodies titles were the youngest compared with the other patients.

Target of the therapy played also an important role in serum antibody levels being these: 3.6 [0.7-51] in RTX patients vs 156 [45-204] in TNFi vs 40 [18-58] in JAKi patients; p<0.0001. In those patients who the last infusion of rituximab was, at least, one year before vaccination presented CD19+ B cells detected by flow cytometry and anti-spike IgG antibodies as well.

Cell-mediated responses to SARS-CoV-2 were positive in 33% of IMIDs patients, indeterminated in 3% and negative in 65% of the patients. Strikingly, out of the 33% positive patients, 85% were treated with RTX. A 61% of the RTX patients had inducible cell-mediated responses vs 14% of the patients treated with TNFi; p<0.01. On the other hand, there were not differences in cell-mediated responses between positive and negative antibody patients.

Conclusion

Titres of serum antibodies against spike protein of SARS-CoV-2 were lower in IMIDs patients than in controls. Patients with RTX had lower rates of positivity humoral response as well as lower serum titles than patients treated with other therapies regardless the patients ‘age. Neverthless, in those patients in whom RTX infusion was delayed because of vaccination they conserved a humoral response.

On the other hand, more patients treated with RTX had inducible cell-mediated responses compared with patients with TNFi.

Disclosure of Interests

ANA MARTÍNEZ-FEITO: None declared, Pilar Nozal: None declared, Marta Novella-Navarro: None declared, Elisa Fernández-Fernández: None declared, Lucia del pino molina: None declared, Milagros Casas Temprano: None declared, Ibtissam Akatbach Bousaid: None declared, Maria Dolores Martin Arranz: None declared, Alejandro Balsa Speakers bureau: Pfizer,Abbvie,Lilly, Galapos,BMS, Sandoz,Nordic,Gebro,Roche, UCB, Consultant of: Pfizer,Abbvie,Lilly, Galapos,BMS, Sandoz,Nordic, Sanofi,UCB, Grant/research support from: Pfizer,Abbvie,BMS,Nordic,Gebro,Roche, UCB, Chamaida Plasencia Grant/research support from: Abbvie, Pfizer, UCB, Sandoz, Sanofi, Biogen, Lilly, Roche and Novartis

POS0795 EPIDEMIOLOGY, DIAGNOSIS AND CLINICAL CHARACTERISTICS OF GIANT CELL ARTERITIS IN PATIENTS INCLUDED IN THE ARTESER MULTICENTER STUDY

Background

Epidemiological information on Giant Cell Arteritis (GCA) comes mainly from the Scandinavian countries of northern Europe, which show a higher incidence than the countries of southern Europe. GCA clinical manifestations can be divided into cranial, extracranial, and general syndrome.

Objectives

In a large series of GCA from Spain, we studied a) the incidence of GCA, b) clinical manifestations, and c) comorbidities at the time of disease diagnosis.

Methods

ARTESER is a retrospective epidemiological observational study of GCA promoted by the Spanish Society of Rheumatology in which 26 hospitals participate. The inclusion criteria were: all new patients diagnosed with GCA by a) ACR criteria, b) positive diagnostic test (temporal artery biopsy, temporal artery ultrasound or other relevant imaging techniques) and/or c) investigator’s clinical judgment. The patient recruitment period ranged from June 1, 2013 to March 29, 2019. The overall incidence of GCA per 100,000 people ≥50 years for the whole period and the mean annual incidence were evaluated. The clinical variables were collected by reviewing the patient’s medical history.

Results

1675 patients were included. The average annual incidence rate was 7.42 (95% CI: 6.57-8.27). All the cases were older than 50 years, and the age group with the highest annual incidence was that of 80 to 84 years, where it reached a value of 22.63 (95% CI: 22.04 -23.22). The mean annual incidence is higher in women than in men 10.07 (95% CI: 8.74-11.55) vs 4.81 (95% CI 3.84-5.93) (Table 1).

Table 1.

General characteristics, comorbidities and clinical manifestations

Epidemiologic, demographic and diagnosisMenWomenTotalGender, n (%)497 (29.7)1178 (70.3)1675Incidence annual rate (95% CI)4.81 (3.84-5.93)10.07 (8.74-11.55)7.42 (6.57-8.27)Age at diagnosis, years, mean (SD)76.9 (8.3)76.9 (8.0)76.9 (8.1)Diagnosis only by ACR Criteria89 (17.91)266 (22.58)355 (21.19)Diagnosis only with objective tests73 (14.69)140 (11.88)213 (12.72)Diagnosis ACR criteria + diagnosis objective tests311 (62.58)734 (62.31)1045 (62.39)Diagnosis by clinical judgment24 (4.8)38 (3.2)62 (3.7)Comorbidities at diagnosisArterial hypertension, n (%)330 (66.8)749 (63.7)1079 (64.6)Dyslipidemia, n (%)238 (48.3)563 (47.9)801 (48.0)Cranial clinical manifestationsNew-onset headache, n (%)382 (76.9)955 (81.1)1337 (79.9)Visual Clinic, n (%)194 (39.0)411 (34.9)605 (36.1)Extracranial manifestations and general syndromePolymyalgia rheumatica, n (%)178 (35.8)521 (44.3)699 (41.8)Asthenia, n (%)239 (48.1)634 (53.9)873 (52.2)Analysis at diagnosisErythrocyte sedimentation rate mm/h, mean (SD)72.3 (34.7)77.4 (33.0)75.9 (33.6)

The principal clinical characteristics of the population is shown in Table 1, the mean age at diagnosis was 76.9±8.1 years, 1178 (70.3%) were women. 1045 patients (62.39%) had ACR criteria and some positive objective test, 355 patients (21.9%) presented only ACR criteria and 213 (12.72%) only had a positive diagnostic test; 62 (3.7%) of the patients underwent diagnosis based on clinical judgment. The more frequent comorbidity was arterial hypertension (n=1079; 64.6%), followed by dyslipidemia (n=801, 48%). The predominant cranial manifestation was headache (n= 1337; 79.9%) and 605 patients experienced visual symptoms (36.1%). Polymyalgia rheumatica (n=699; 41.8%) and asthenia (n=837; 52.2%) were the most frequent extracranial and general syndrome manifestation, respectively. Regarding laboratory parameters, the most characteristic data was the increase of ESR (75.9±33.6 mm/1st h).

Conclusion

The mean annual incidence of GCA in Spain, 7.42 (95% CI: 6.57-8.27), is lower than that of the Scandinavian countries. It is higher in people older than 80 years. More than 60% of the patients met the ACR criteria and had a positive diagnostic test. Cranial manifestations constituted the most clinical features. The most frequent clinical manifestations are cranial. Up to a third of patients had visual manifestations.

Acknowledgements

This study has been funded by ROCHE Farma. The funder has not participated in the design, analysis, or interpretation of the results

Disclosure of Interests

None declared

AB0604 Influence of the location and severity of vascular involvement on the basal phenotypic expression and on the evolution of giant cell arteritis

Background

Giant cell arteritis (GCA) is the most common systemic vasculitis in adults. There is increasing evidence about clinical subtypes of the disease depending on the cranial or extracranial vessels involvement. However, how this type of affectation influences the phenotypic expression of the disease and whether there are differences between them in terms of the thickness of the vessels wall, are still aspects that remain to be clarified.

Objectives

To evaluate the association between the subtypes of GCA and the basal phenotypic expression and severity of the artery walls affectation in the disease.

Methods

This is a retrospective study of new consecutive patients diagnosed with GCA in our hospital from July 2018 to December 2020. The patients underwent Color Doppler ultrasound at the time of diagnosis of cranial arteries (superficial temporal arteries in the common superficial temporal artery and their frontal and parietal branches) and extra-cranial arteries (axillary, subclavian, and carotid arteries). The ultrasound diagnosis was made according to the OMERACT definitions of the halo sign and cut-off the intima media thickness was established as ≥0.34 mm for the branches of the temporal arteries, ≥0.42 in the common superficial temporal artery and ≥1 mm for the axillary, subclavian, and carotid arteries. The “halo score” (HScore) was calculated according to the criteria published by Van der Geest KSM et al. 1 In addition, the clinical records of the patients were reviewed and their demographic, clinical and laboratory data were compared between the different sonographic subtypes of GCA. A p < 0.05 limit of statistical significance was established. The Statistical analysis was performed using SPSS version 25.

Results

A total of 74 patients were included, of which 44 (58.7%) were women with a mean age of 78.6 ± 8.6 years. Analyzing the GCA subtypes: 18 (24.3%) had exclusively cranial involvement (CGCA), 12 (16.2%) patients had GCA of extra-cranial large vessels (LVGCA) and 44 (59.5%) patients had mixed forms cranial and extra-cranial (MGCA). The characteristics of the population and of each of the GCA subtypes, as well as thickening of the wall of the arteries are described in Table 1.

Table 1.

Clinical characteristics of the study population.

Conclusion

The constitutional syndrome was always present in LVGCA but it is also very common in subtypes with cranial involvement. The ischemic syndrome occurs preferentially in groups with cranial vessel involvement, but not exclusively. The thickening of the arterial wall of the cranial arteries shows no difference between CGCA and MGCA; and the same occurs in the large vessels between the LVGCA and the MGCA. Serious adverse effects due to ischemia showed a similar risk regardless of whether it was CGCA or MGCA.

References

[1]van der Geest KSM., Borg F., Kayani A., et al. Novel ultrasonographic Halo Score for giant cell arteritis: assessment of diagnostic accuracy and association with ocular ischaemia. Ann Rheum Dis. 2020;79:393–9.

Disclosure of Interests

None declared

OP0183 VALIDITY OF THE EULAR RECOMMENDATIONS ON THE USE OF ULTRASOUND IN THE DIAGNOSIS OF GIANT CELL ARTERITIS

Background

The EULAR recommendations for the use of imaging in large vessel vasculitis establish that an imaging test supported by clinical pre-test probability (PTP) is sufficient for the diagnosis of giant cell arteritis (GCA)1.

Objectives

To determine the validity of the EULAR recommendations on the use of Colour doppler ultrasound (CDUS) in GCA after calculating the PTP based on the Southend pre-test probability score (SPTPS).

Methods

We collected data of all patients referred to our fast-track clinic between 2016 and 2020. The SPTPS was calculated and classified as low (LR), intermediate (IR) and high risk (HR) according to the values obtained by its authors, <9, 9-12 and >12, respectively2. All patients underwent a CDUS of the temporal arteries with their common, parietal and frontal branches, and the most also axillary (86.5%), subclavian and carotid arteries. Other diagnostic tests were performed when deemed necessary by the responsible physician. TAB was performed in 34 patients (11.4%), PET-CT in 48 (16.2%) and other imaging tests such as AngioMRI or AngioCT in 8 (2.7%). The gold standard diagnosis was made according to the physician’s criteria after at least nine months of follow-up.

Results

Of the 297 referred patients, 97 (32.7%) were diagnosed with GCA. The SPTPS area under the ROC curve was 0.787. The LR category included 105 patients (35.4%), of which 10 (9.5%) had GCA. The IR category included 125 patients (42.1%), 40 with GCA (32%) and 85 without (68%). The HR category included 67 patients (22.5%), 47 with GCA (70.1%). In 4 of the 97 patients with GCA, the CDUS was negative and the diagnosis was confirmed with PET-CT. On the other hand, 6 of the 200 included patients without GCA (3%) had a false positive result of CDUS.

There were 93 patients classified as LR with negative CDUS, and 1 of them has a final clinical diagnosis of GCA. Of the 46 patients classified as HR with positive CDUS, 1 was a false positive diagnosis of GCA. And, within the IR group, of the 84 patients with negative CDUS one had a final GCA diagnosis and of those with positive CDUS 2 were not GCA (Figure 1). Therefore, the combined use of SPTPS + CDUS only miscassified 5/297 cases (<2%).

Figure 1.

Flow-chart of the results of the diagnostic performance of SPTPS + CDUS.

Conclusion

Combining the results of a pre-test probability score, such as SPTPS, and the CDUS allows for an accurate diagnosis of GCA, as established by the EULAR group, with less than 2% misclassification of diagnosis. Even a negative CDUS in patients with IR shows a strong association with a negative diagnosis.

References

[1]Dejaco C, Ramiro S, Duftner C, et al. EULAR recommendations for the use of imaging in large vessel vasculitis in clinical practice. Ann Rheum Dis. 2018;77(5):636-643.

[2]Sebastian A, Tomelleri A, Kayani A, Prieto-Pena D, Ranasinghe C, Dasgupta B. Probability-based algorithm using ultrasound and additional tests for suspected GCA in a fast-track clinic. RMD Open. 2020;6(3).

Disclosure of Interests

None declared

AB0591 ANALYSIS OF THE CLINICAL DIFFERENCES BETWEEN THE SUBTYPES OF GIANT CELL ARTERITIS

Background

Giant cell arteritis GCA is the most frequent vasculitis over the age of 50. Nowadays, it is known that there are several subtypes of GCA depending on the vessels that are involved: cranial, extracranial and mixed. However, the clinical manifestations that differentiate these three subtypes have not been extensively examined until now. In the future, it is likely that the differential characteristics in the expression of the disease will be relevant in the prognosis and the follow up of these patients.

Objectives

The objective of the study is to investigate the clinical differences associated with these different patterns of GCA involvement.

Methods

This is a retrospective study of new consecutive patients diagnosed with GCA in our hospital for three years. All patients underwent color Doppler ultrasound of both cranial (superficial temporal arteries in the common superficial temporal artery and their frontal and parietal branches) and extracranial arteries (axillary, subclavian and carotid arteries) were explored. The ultrasound diagnosis was made according to the OMERACT definitions of the halo sign and a cut-off the intima media thickness of ≥0.34 mm for the branches of the temporal arteries ≥0.42 in the common superficial temporal artery and ≥ 1 mm for the axillary, subclavian, and carotid arteries was established. The clinical records of the patients were reviewed and their demographic, clinical and laboratory data were compared between the different patterns of ultrasound involvement of GCA. A p< 0.05 was established as the limit of statistical significance. The EULAR recommendations of 20191 were used to establish the definitions of remission and relapse. The statistical analysis was performed using SPSS version 25.

Results

A total of 74 patients were included, 44(58.7%) women with a mean age of 78.6±8.6 years. Regarding the GCA subtypes, 18 (24.3%) patients had exclusive involvement of cranial giant cell arteritis CGCA, 12 (16.2%) patients had isolated involvement of extracranial giant cell arteritis LVGCA and 44 (59.5%) patients had mixed forms with cranial and extracranial MGCA. The characteristics of the population and of the GCA subtypes are shown in Table 1.

Table 1.

Clinical characteristics and GCA subtypes.

Clinical characteristicsTotal GCA = 74CGCA = 18LVGCA = 12MGCA = 44CGCA vs. MGCA pCGCA vs LVGCA pLVGCA vs MGCA PFemale sex, n (%)44 (59.4)10(55.5)6 (50)27 (61.3)0.6720.7650.478Age, mean ± S.D.years78.6 ± 8.679.0 ± 8.173.2 ± 9.480.7 ± 7.90.5050.0310.077ESR, (mm/h) mean S.D.57.1 ± 35.566.1 ± 39.239.6 ± 24.556.6 ± 34.10.3910.0210.115CRP (mg/dL) mean± S.D.56.4 ± 57.150.1 ± 45.652.3 ± 52.560.7 ± 63.70.1790.7580.417Constitutional symptoms, n (%)59 (78.7)12 (66.6)12 (100)35 (79.5)0.2820.0250.087Ischemic symptoms, n (%)66 (82.66)15 (83.3)5 (41.6)35 (79.5)0.7320.0180.010Remission for 6 months, n (%)25 (33.3)7 (38.8)5 (41.6)13 (29.5)0.8470.8790.425Glucocorticoid free remission, n (%)8 (10.7)1 (5.5)2 (16.6)5 (11.3)0.4750.3200.622Major relapse, n (%)4 (5.3)0 (0)1 (8.3)3 (6.8)0.4790.2130.857Minor relapse, n (%)12 (16)2(11.1)3 (25)8 (18.1)0.4920.3170.598

GCA: giant cell arteritis; CGCA: Cranial giant cell arteritis; LVGCA: Large vessel giant cell arteritis; MGCA: Mixed giant cell arteritis; SD: standard deviation; p: value.

The analysis of the results showed that patients with LVGCA are younger, have less ischemic symptoms and have lower ESR than patients with CGCA p<0.05. Cranial involvement was associated with more ischemic symtoms than GCA with large vessel involvement, even in the mixed forms in which the cranial vessels are involved p<0.05. Additionally, we observed a trend towards a higher percentage of present greater constitutional syndrome in the LVGCA group. The main limitation of the study is its low sample size when analyzing the subgroups, which does not allow confirming some of the trends observed in Table 1.

Conclusion

There are significant clinical phenotypic differences in the presentation of the different subtypes of vascular involvement in GCA.

References

[1]Hellmich B et al. Ann Rheum Dis. 2020 Jan;79(1):19-30.

Disclosure of Interests

None declared

Pharmaceuticals in farms and surrounding surface water bodies: Hazard and ecotoxicity in a swine production area in Costa Rica

The presence of pharmaceuticals in the environment is known to have multiple origins; livestock activities comprise one scarcely studied source, both globally and specially in Latin-America. This work aims to study the occurrence of pharmaceuticals in wastewater from swine farms and their surrounding surface waters, in a highland livestock production area of Costa Rica. The monitoring of 70 pharmaceutical active compounds resulted in the detection of 10 molecules in farm wastewater (influents and effluents of the on-farm treatment system), including compounds of animal and human use. A 57% of effluents showed high hazard (ΣHQ > 1), mainly due to the compounds risperidone, ketoprofen, ibuprofen and naproxen. Additionally, ecotoxicological tests with Daphnia magna and Microtox classified at least 21% of the effluents as very toxic (10 < TU ≤ 100); likewise, 86% of effluents exhibited germination index (GI) inhibition values over 90% for Lactuca sativa. Seven molecules were detected in surface water, six of them of human use (1,7-dimethylxanthine, caffeine, cephalexin, carbamazepine, gemfibrozil, ibuprofen) and one (acetaminophen) of dual (human and veterinary) use; nonetheless, most of the detections were found in sampling points closer to human settlements than animal farms. Considering the set of molecules and their distribution, the livestock influence on surface water seems minimal in comparison with the urban influence. Only 16% of surface water samples showed high risk, mainly due to ibuprofen, gemfibrozil and caffeine; similarly, 45% samples presented GI inhibition >20% (no toxicity was determined towards Daphnia magna or Microtox). These findings in surface water suggest an incipient environmental risk in the area.

POS0821 THE DIFFERENT SUBTYPES OF GIANT CELL ARTERITIS BY ULTRASOUND: RESULTS FROM A FAST-TRACK CLINIC

Background:

Giant cell arteritis (GCA) is a vasculitis that affects the medium and large vessels (LV). Although cranial artery involvement is better known, awareness of the importance of LV involvement is increasing. Imaging techniques currently constitute the basis for the diagnosis of LV-GCA and have improved its diagnosis and prevalence. In recent years, differences in clinical patterns and different inflammatory and etiopathogenic mechanisms of the disease have been suggested. Therefore, improving sensitivity to diagnosis is essential to improve the knowledge and care of our population.

Objectives:

The aim of this study was to know the prevalence of the different ultrasound patterns of GCA in our area.

Methods:

Retrospective records of available data were collected from all patients referred to our ACG fast track clinic in the past three years. The clinical and laboratory characteristics were evaluated at the time of referral. All patients underwent an ultrasound scan of cranial vessels (superficial temporal arteries (TA) and their frontal and parietal branches) and large vessels (axillary, subclavian and carotid arteries). The doctor confirmed the GCA diagnosis after at least six months of follow-up. The OMERACT definitions of halo sign with a hypoechoic wall thickness ≥ 0.34 mm were used for TA pathology for the ultrasound diagnosis of GCA and for axillary, subclavian and carotid arteries and homogeneous hypoechoic thicknesses ≥ 1 mm of the arterial wall were applied. Atherosclerosis lesions were evaluated to detect this disease as a possible false positive halo sign. An Esaote Mylab Twice with a 13 MHz probe in BT and 22 MHz for cranial vessels in 2017-2019 and an Esaote Mylab X8plus with a 15 MHz probe for BT and a 24 MHz probe for cranial arteries in 2019-2020 were used by two rheumatologist with long experience in ACG ultrasound.

Results:

A total of 261 patients (180 women / 81 men) with suspected GCA were evaluated in our fast track clinic. The mean age (± SD) was 76 ± 9.2 years and CRP at diagnosis was 75.7 ± 68.6 mg/L. The time elapsed since the first symptoms was less than 6, 6-12, 12-24 or >24 weeks in 37.5%, 19.9%, 12.3% and 15.7% respectively. Of the 261 cases explored, 160 had GCA, of which 102 were women and 58 men, and had a mean age of 77.21 ± 7.9 years. The ultrasound patterns of GCA were: 71 patients had exclusive involvement of the TA (cranial-GCA), 54 had a mixed pattern with involvement of both TA and LV (mixed-CGA), and 35 had isolated involvement of the LV (LV-GCA). That is, 125 patients had cranial involvement with or without LV involvement and 89 had LV-GCA associated or not with cranial involvement (Figure 1).

Figure 1.

Ultrasound patters of GCA

Conclusion:

Ultrasound is a useful tool for the screening of GCA and its different subtypes of vascular involvement. The isolated cranial subtype or associated with LV-GCA is the most common (78% of cases), but LV-GCA is also very common (55.6% of cases of GCA) and 21.9% presents as an isolated LV-GCA standard. The LV arteries should be included in the ultrasound examination for suspected GCA.

Disclosure of Interests:

Irene Monjo Speakers bureau: Roche, Novartis, UCB, Gedeon Richter, Consultant of: Roche, Elisa Fernández-Fernández: None declared, Javier Ortega: None declared, Eugenio de Miguel Speakers bureau: AbbVie, Novartis, Pfizer, MSD, BMS, UCB, Roche, Grunental, Janssen, Sanofi, Paid instructor for: Janssen, Novartis, Roche, Consultant of: AbbVie, Novartis, Pfizer, Galapagos, Grant/research support from: Abbvie, Novartis, Pfizer

AB0378 UTILITY AND ACCURACY OF SOUTHEND PRETEST PROBABILITY SCORE IN GCA FAST-TRACK CLINIC: ANALYSIS IN 261 CONSECUTIVE PATIENTS

Background:

Strategies for early diagnosis of Giant Cell Arteritis (GCA) have been implemented in the last decade in order to reduce the occurrence of blindness, ischemic events and other manifestations of the disease. The Southend pretest probability score (SPTPS) 1 seem to be useful in stratifying and select the referral patients sent to the GCA fast-track clinics.

Objectives:

The aim of this study was to test the validity and utility of this score in our patients.

Methods:

Retrospective available data records of all the patients referred to our GCA fast-track clinic in the last three years were collected. The clinical and laboratory features at referral were evaluated, and the SPTPS was generated. All patients had ultrasound of cranial and large vessel examination (axillary, subclavian and carotid arteries). GCA diagnosis was confirmed by the doctor after at least six months of follow-up. Quartile frequencies, ROC curves and accuracy of the SPTPS was calculated.

Results:

261 patients (180 females) with suspicions of GCA were evaluated in our fast-track clinic. Mean age (±SD) was 76±9.2 years, and C-reactive protein 75.7±68.6 mg/l. The time since the first symptoms was less of 6, 6-12, 12-24 or >24 weeks in 37.5%, 19.9, 12.3 and 15.7 respectively. Mean SPTPS was 11.4±4.4, with values of 9.1±3.2 and 12.9±4.4. The area under the ROC curve was 0.761 (95% confidence interval: 0.703-0.819). PTPS overall showed a 50th percentile score of 11 and a 75th percentile score of 14. We, therefore, classified “Low Risk” (LR) as SPTPS <11, “Intermediate Risk” (IR) 11–14 and “High Risk” (HR) >14. Of 261 referrals, 156 had GCA with cases categorised as LR (119), IR (91) and HR (51). HR score showed a specificity of 96.2% and in IR the specificity ranged between 86.7 and 94.3% (Table 1). Score below 7 appears in 29 cases with only 8 cases of GCA with a probability of GCA < 5%, more of these cases was associated a large vessel vasculitis: 3 cranial arteritis (CA), 4 large vessel vasculitis (LVV) and 1 mixed pattern (MP). LR score included 72 of the 105 (68.6%) non-GCA cases but 47 of 156 (30.1%) GCA patients (20 CA, 11 LVV and 16 MP). IR risk score included 26 (24.8%) of the non-GCA cases and 65 (41.7%) of GCA patients (31 CA, 13 LVV and 21 MP). Finally HR score had only 7 non-GCA cases and 44 (28.2%) patients with GCA (20 CA, 11 LVV and 13 MP). Mean score in cranial forms was 13.1±4.5 and in large vessel vasculitis 12.8±5.0 (p=0.807).

Table 1.

Sensitivity and Specificity of SPTPS at different cut-off points

Cut-off pointSensitivity1-Specificity21.0001.0003.50.9940.9714.50.9870.9435.50.9870.8766.50.949 0.7907.50.8970.6768.50.8460.4769.50.7500.36210.50.6790.24811.50.5380.13312.50.4490.08613.50.3530.05714.50.2180.03815.50.1470.01916.50.1280.01917.50.0770.010190.0380,00020.50.0320,00021.50.0190,00022.50.0130,000240.0000,000

Conclusion:

The SPTPS is helpful to stratified patients sent to the fast-track clinic. Scores below of 7 points has a very low probability to have GCA. The diagnostic probability increases directly with the score. There were minor differences without statistical significance between cranial or large vessel vasculitis patterns in the score.

References:

[1]Sebastian A, Tomelleri A, Kayani A, Prieto-Pena D, Ranasinghe C, Dasgupta B. Probability-based algorithm using ultrasound and additional tests for suspected GCA in a fast-track clinic. RMD Open. 2020 Sep;6(3):e001297. doi: 10.1136/rmdopen-2020-001297. PMID: 32994361; PMCID: PMC7547539.

Disclosure of Interests:

Javier Ortega: None declared, Irene Monjo Speakers bureau: Roche, Novartis, UCB, Gedeon Richter, Consultant of: Roche, Elisa Fernández-Fernández: None declared, Eugenio de Miguel Speakers bureau: AbbVie, Novartis, Pfizer, MSD, BMS, UCB, Roche, Grunental, Janssen, Sanofi., Paid instructor for: Janssen, Novartis, Roche, Consultant of: AbbVie, Novartis, Pfizer, Galapagos, Grant/research support from: Abbvie, Novartis, Pfizer

AB0382 DOES THE ULTRASOUND IMAGE OF THE LARGE VESSEL WALLS DIFFER IN THE SUBTYPES OF GCA AND PMR OR THERE IS A SYSTEMIC SUBCLINICAL COMMON INFLAMMATION?

Background:

Several clinical patterns of giant cell arteritis (GCA) have been described including cranial GCA (c-GCA), large vessel GCA (LV-GCA), mixed forms of c-GCA and LV-GCA (mixed-GCA), and even polymyalgia rheumatica (PMR) that has been associated with GCA and some degree of subclinical vascular inflammation could be present in the patients. However, many questions about this disease and its subtypes remain unanswered.

Objectives:

To investigate the affectation of the arterial wall of GCA and its subtypes and PMR and to know if there really are different ultrasound patterns that can be determined or if otherwise they present a common subclinical systemic inflammation with only different degrees of involvement of the vascular wall.

Methods:

All available ultrasound examinations of patients referred to our fast-track GCA clinic for suspected GCA in the last three years were reviewed and retrospectively collected data. Patients who had undergone ultrasound examination of both cranial and large vessels (axillary, subclavian and carotid arteries) were included. The videos and images of the large vessels of each patient were reviewed and intima-media thickness (IMT) and hypoechoic halo measurements were taken. The data of the following groups, established according to the final diagnosis confirmed by the doctor after a follow-up between six months and three years, were compared: GCA group (within it 3 other groups were included: c-GCA, LV-GCA and mixed-GCA), PMR group and the group without ACG or PMR (non-GCA).

Results:

We analyzed the examinations of 300 patients and 161 baseline examinations were included: 76 with GCA (32 c-GCA, 14 LV-GCA and 30 mixed-GCA), 29 with PMR and 56 non-GCA. The mean IMT for each large vessel explored and the statistical significance between the different groups are shown in Table 1. All arteries except the carotid arteries had a significantly higher IMT in the LV-GCA and mixed-GCA groups when compared with both c-GCA and non-GCA groups. There were no differences in IMT between mixed-GCA and LV-GCA. There were also no differences in any explored artery between PMR and non-GCA. There were statistically significant differences in the IMT of the bilateral axillary and subclavian arteries between the PMR group and all the GCA subtypes, being greater in the latter. IMT tended to be higher in the c-GCA group when compared to non-GCA, reaching statistical significance in the left arteries (axillary, subclavian, and distal carotid). Although there was also a tendency for IMT to be higher in mixed-GCA patients than in LV-GCA patients, the differences did not reach statistical significance.

Table 1.

Ultrasound IMT and halo measures in the different subtypes of GCA, PMR and controls

ArteriesNon-GCAn=56GCAn=76c-GCAn=32LV-GCAn=14Mixed-GCA n=30PMRn=29p < 0.05Right axillary (mean ± SD)0.67±0.190.95±0.300.75±0.201.03±0.331.11±0.270.65±0.132*, 3*, 4*, 5*, 6, 7*, 8*Left axillary(mean ± SD)0.61±0.120.92±0.290.77±0.190.99±0.251.03±0.330.66±0.131*, 2*, 3*, 4, 5*, 6, 7*, 8*Right subclavian(mean ± SD)0.70±0.151.00±0.310.79±0.161.09±0.361.10±0.290.70±0.202*,3*, 4*, 5*, 7*, 8*Left Subclavian(mean ± SD)0.62±0.140.95±0.270.76±0.161.05±0.251.06±0.260.64±0.181*, 2*, 3*, 4*, 5*, 7*, 8*Right CCD(mean ± SD)0.79±0.220.97±0.260.99±0.220.91±0.291.05±0.280.81±0.101*, 3*, 6*, 8*Left CCD(mean ± SD)0.81±0.160.99±0.220.95±0.200.97±0.171.03±0.270.82±0.201, 2, 3*, 8

SD: Standard deviation; CCD: common distal carotid artery.

1=c-GCA vs non-GCA; 2=LV-GCA vs non-GCA; 3=mixed-GCA vs non-GCA; 4=c-GCA vs LV-GCA; 5=c-GCA vs mixed-GCA; 6=PMR vs c-GCA; 7=PMR vs LV-GCA; 8=PMR vs mixed-GCA; *p < 0.01.

Conclusion:

Large vessel ultrasound does not differ between healthy patients and those with PMR without confirmed GCA. Our data suggest that mixed-GCA subtype is not an intermediate form between the cranial and LV-GCA suptypes but could have a higher inflammatory burden.

Disclosure of Interests:

Elisa Fernández-Fernández: None declared, Iñigo González-Mazón: None declared, Irene Monjo Speakers bureau: Roche, Novartis, UCB, Gedeon Richter, Consultant of: Roche, José María Mostaza: None declared, Carlos Lahoz: None declared, Eugenio de Miguel Speakers bureau: AbbVie, Novartis, Pfizer, MSD, BMS, UCB, Roche, Grunental, Janssen, Sanofi, Paid instructor for: Janssen, Novartis, Roche, Consultant of: AbbVie, Novartis, Pfizer, Galapagos, Grant/research support from: Abbvie, Novartis, Pfizer

POS0342 DISCRIMINANT VALUE OF ULTRASOUND OF THE WALL OF LARGE VESSELS IN THE DIAGNOSIS OF GIANT CELL ARTERITIS

Background:

The EULAR recommendations for the use of imaging in large vessel vasculitis in clinical practice suggest the performance of diagnostic imaging tests in all patients with suspected GCA and ultrasound is the recommended first-line test in patients with suspected cranial GCA (c-GCA)1. However, a priority imaging modality has not been established in cases of suspected GCA involving large vessels (LV-GCA). Since patients with LV-GCA often undergo extensive screening programs for suspected infection or malignancy before the diagnosis of GCA is established, our knowledge in this field needs to be improved.

Objectives:

The aim of this study is to investigate the wall affectation of vasculitis of the proximal arm and neck arteries in patients with suspected GCA, polymyalgia rheumatica (PMR), atherosclerosis and non-GCA patients.

Methods:

Retrospective available ultrasound examination from all the patients referred to our GCA fast-track clinic in the last three years were collected. All patients had ultrasound of cranial and large vessel examination (axillary, subclavian and carotid arteries). GCA diagnosis was confirmed by the doctor after a follow-up between six months to three years. Every patient had videos and pictures of every referred vessel. Examination was performed by two rheumatologists with long experience in GCA ultrasound from the same Rheumatology Department with a Esaote Mylab Twice with probe of 13 MHz (2017-2019) and a Esaote Mylab X8plus with a probe of 15 MHz (2019-2020). IMT and hypoechoic halo measures were taken.

Results:

We analyzed 300 examinations and selected 196 baseline cases of four different pathologies (29 PMR, 40 atherosclerosis, 71 GCA of which 14 LV-GCA without cranial involvement and 56 non-GCA non-PMR controls). Intima-media thickness (IMT) with the statistical significance between different diseases and controls are showed in the Table 1.

Table 1.

Ultrasound IMT and halo measures in large vessels of different diseases and controls

Non-GCA n=56GCA n=71Atherosclerosis n=40PMR n=29LV-GCAn=14Axillary right # *0.67±.190.95±0.300.70±0.180.65±0.131.03±0.33Axillary left # **0.61±0.120.92±0.290.72±0.190.66±0.130.99±0.25Subclavian right # *0.70±0.151.00±0.310.86±0.290.70±0.201.09±0.36Subclavian left # *0.62±0.140.95±0.270.70±0.140.64±0.181.05±0.25CCD right #0.79±0.220.97±0.261.01±0.300.81±0.100.91±0.29CCD left #0.81±0.160.99±0.220.98±0.320.82±0.200.97±0.17

GCA= Giant cell arteritis (cranial, large vessel and mixed forms); Non-GCA = Patients suspected but not confirmed as GCA; Atherosclerosis = patients with high arteriosclerosis risk without suspected GCA; PMR = Patients with polymyalgia rheumatica without GCA; LV-GCA= Large vessel vasculitis GCA without cranial involvement.

# p<0.01 GCA vs non-GCA and GCA vs PMR

* p<0.01 GCA vs Atherosclerosis; ** p<0.05 GCA vs Atherosclerosis

Conclusion:

GCA ultrasound of large vessels shows significant differences with other diseases. The differences seem to support the use of ultrasound in the fast-track clinic of GCA not only in c-GCA but also in LV-GCA.

References:

[1]Dejaco C et al. EULAR recommendations for the use of imaging in large vessel vasculitis in clinical practice. Ann Rheum Dis. 2018 May;77(5):636-643. doi: 10.1136/annrheumdis-2017-212649. Epub 2018 Jan 22. PMID: 29358285.

Disclosure of Interests:

Iñigo González-Mazón: None declared, Elisa Fernández-Fernández: None declared, Irene Monjo Speakers bureau: Roche, Novartis, UCB, Gedeon Richter, Consultant of: Roche, Eugenio de Miguel Speakers bureau: AbbVie, Novartis, Pfizer, MSD, BMS, UCB, Roche, Grunental, Janssen, Sanofi., Paid instructor for: Janssen, Novartis, Roche, Consultant of: AbbVie, Novartis, Pfizer, Galapagos, Grant/research support from: Abbvie, Novartis, Pfizer

Alendronate after denosumab discontinuation in women previously exposed to bisphosphonates was not effective in preventing the risk of spontaneous multiple vertebral fractures: two case reports

At denosumab discontinuation, an antiresorptive agent is indicated to reduce the high bone turnover, the rapid bone loss, and the risk of spontaneous vertebral fractures. We report two cases of postmenopausal women, previously exposed to bisphosphonates, treated with alendronate at denosumab discontinuation. Alendronate was ineffective to avoid spontaneous clinical vertebral fractures. They presented three and nine spontaneous vertebral fractures 8 and 12 months after denosumab discontinuation, respectively. Ineffectiveness of alendronate was attributed to insufficient control of the rebound as assessed by B-crosslaps measures in the first case, and partially to the high risk of fractures in the later. In both situations, the increased fracture risk may have favoured these new fractures. It is urgent to define effective therapeutic strategies to avoid spontaneous vertebral fractures after denosumab discontinuation.

Expanding the application scope of on-farm biopurification systems: Effect and removal of oxytetracycline in a biomixture

Antibiotic-containing wastewaters produced in agricultural activities may depress the pesticide-degrading capacity of biomixtures contained in biopurification systems. This work aimed to assay the effect of oxytetracycline (OTC) on the removal of carbofuran (CFN) in an optimized biomixture, and to determine the capacity of the system to dissipate OTC. During co-application of CFN+OTC, CFN removal and its accelerated degradation were not negatively affected. Similarly, different doses of OTC (10-500mgkg^-1) did not significantly affect CFN mineralization, and the process even exhibited a hormetic-like effect. Moreover, the biomixture was able to remove OTC with a half-life of 34.0 d. DGGE-cluster analyses indicated that fungal and bacterial communities remained relatively stable during OTC application and CFN+OTC co-application, with similarities of over 70% (bacteria) and 80% (fungi). Overall, these findings support the potential use of this matrix to discard OTC-containing wastewater in this system originally intended for CFN removal.

Ultrasonic monitoring of malolactic fermentation in red wines

The progress of malolactic fermentation in red wines has been monitored by using ultrasonic techniques. The evolution of ultrasonic velocity of a tone burst 1MHz longitudinal wave was measured, analyzed and compared to those parameters of oenological interest obtained simultaneously by analytical methods. Semi-industrial tanks were used during measurements pretending to be in real industrial conditions. Results showed that the ultrasonic velocity mainly changes as a result of the conversion by lactic acid bacteria of malic acid into lactic acid and CO2. Overall, the present study has demonstrated the potential of the ultrasonic technique in monitoring the malolactic fermentation process.

Antioxidant properties of sparkling wines produced with β-glucanases and commercial yeast preparations

The aim of this study was to evaluate the in vitro antioxidant potential of sparkling wines produced with β-glucanases, autolysated yeasts, yeast cell walls, and purified mannoproteins. Total antioxidant capacity (measured by 2,2-diphenyl-1-picrylhydrazyl [DPPH] radical-scavenging method and ferric reducing antioxidant power [FRAP] assay), and hydroxyl radical-scavenging activity (HRSA) were higher in the wine samples with coadjuvants (in relation to the control wine). The highest values of antioxidant activity were achieved with purified mannoproteins and, in lesser extent, with β-glucanases. Neutral polysaccharides and total proteins were highly and positively correlated with DPPH, FRAP, and HRSA assays. However, correlations between the levels of each different phenolic family and antioxidant and radical-scavenging activities were not found. β-Glucanase and commercial yeast preparations can be excellent coadjuvants to increase the antioxidant properties of sparkling wines.

PRACTICAL APPLICATION

β-Glucanase and commercial yeast preparations can be excellent coadjuvants to increase the antioxidant properties of sparkling wines. The suggested improvement has significant implication for the production of high added value sparkling wines.

Development of an environmental friendly method for the analysis of organochlorine pesticides in sediments

This work proposes a pressurized hot water extraction (PHWE) followed by solid phase microextraction (SPME) and determination by gas chromatography-mass spectrometry method for the analysis of organochlorine pesticides in sediment samples. For SPME, extraction temperature and time, desorption temperature and desorption time, and effect of an organic modifier were studied. For PHWE, parameters such as organic modifier, percentage of organic modifier, temperature, and static extraction time were studied. When these parameters were selected, the figures of merit were calculated in order to assess the performance of the proposed method. Quantitative recoveries (80-115%) and satisfactory precisions were obtained. The detection and quantification limits were between 0.11 and 16 microg kg(-1) and between 0.24 and 22 microg kg(-1), respectively with good linearity between LOQs and 500 microg kg(-1) for most of the studied pesticides. The method was validated by the analysis of a reference marine sediment material (SRM 1944). The obtained results are in excellent agreement with the certificate material. Another sediment reference material (SRM 1941b), with a very low concentration of pesticides was also analyzed with good results. In addition, this method was successfully applied to the analysis of three marine sediment samples. The developed method seems to be a nearly full automated, environmental friendly, sensitive, simple and less-time consuming method. Moreover this method, look for the implementation of the principles of green analytical chemistry and has demonstrated to be suitable for the analysis of organochlorine pesticides at trace levels in environmental matrices as sediment samples.

Effect of Nut Paste Enrichment on Physical Characteristics and Consumer Acceptability of Bread

Four kinds of nut paste (almond, hazelnut, peanut, walnut) in three different percentages (5, 10, and 15%) were added to bread formula to study the morphogeometric and textural characteristics, and the consumer acceptability of enriched breads. The change of texture along time was also studied. Control bread presented the lowest volume, water loss and height, and the highest firmness and chewiness. The enrichment with 15% of nut paste caused a decrease in loaf volume, weight loss, cohesiveness, and resilience but an increase in height, firmness, and chewiness. Almond and walnut breads presented the lowest values in firmness and chewiness. The lowest cohesiveness and resilience corresponded to hazelnut bread. The increased firmness during storage was slower in enriched than in nonenriched breads. The adhesiveness, cohesiveness, and resilience decreases were more important in the first 2 days of storage. Breads added with 10 and 15% nut paste showed the highest intent for consumption, persistence, and texture values. Peanut-enriched bread was the least accepted bread. Only a third of the consumers were able to correctly identify the nuts added.

Evaluation of HCH isomers and metabolites in soils, leachates, river water and sediments of a highly contaminated area

In this work we evaluate the contamination caused by HCH residues in the soil, leachates, river water and sediments of an industrial estate of the NW of Spain. We study the distribution of the isomers in the different matrices, analysing 37 soil samples, collected in eight points at several depths, six natural leachates, four river water samples and three river sediments. Soil and leachate samples present very high levels of HCH isomers, higher than the established by legislation, and some pesticides were also detected in the analysed river water whereas no pesticides were detected in the river sediments. The distribution of isomers was different depending on the matrix analysed. Some natural degradation products and also other organochlorine pesticides were detected in the samples analysed.

Determination of 21 organochlorine pesticides in tree leaves using solid-phase extraction clean-up cartridges

A method to determine 21 organochlorine pesticides (OCPs) in tree leaves [chestnut (Castanea sativa), hazel (Corylus avellana), oak (Quercus robur) and walnut tree (Juglans regia)] based on microwave-assisted extraction (MAE) followed by solid-phase extraction (SPE) clean-up is described. After extraction with hexane:acetone (50:50), four different sorbents (Florisil, tandem Florisil + alumina, silica and ENVI-Carb) were assayed for the clean-up step. Pesticides were eluted with 5 mL of hexane:ethyl acetate (80:20) and determined by gas chromatography and electron capture detection (GC-ECD). Carbon was the sorbent, which provided colourless eluates and chromatograms with less interferent compounds. Analytical recoveries obtained were ca. 100% for all the studied pesticides with this sorbent.

C1 to C9 volatile organic compound measurements in urban air

Urban atmospheric samples were collected in A Coruna (NW Spain) and analysed for volatile organic compounds. One hundred and twenty one hour samples were collected in winter 2000. The ambient air was rich in benzene, toluene, ethyl-benzene and xylenes (BTEX) and especially toluene (mean: 23.6 microg m(-3), median: 14.66 microg m(-3)), but the presence of chlorinated compounds was also notable. High concentrations of 1,4-dichlorobenzene (mean: 11.4 microg m(-3), max: 90.4 microg m(-3)) were recorded. Multivariate analysis of VOC, trace gases (NO(x), NO(2), NO, SO(2) and O(3)) and meteorological variables (temperature, wind direction and speed, precipitation and radiation) was applied and correlations between VOC were also studied. Principal component analysis and correlation analysis confirm traffic as the main source of VOC in the area, although the importance of evaporative sources is also reflected. Three groups of samples were obtained by cluster analysis; these groups are formed depending on the content of aromatics and ozone and, in many cases, on the sampling hour.

Development of pressurized liquid extraction and cleanup procedures for determination of organochlorine pesticides in soils

The scope of this work is the development of a rapid, reliable and sensitive method for the analysis of organochlorine pesticides from soils by pressurized liquid extraction (PLE). The effect of four parameters (temperature, pressure, static time and cell volume) on the extraction efficiency was studied. The great extracting power of the PLE causes the extraction of numerous interfering substances, so a more efficient purification of this extract was necessary. In this work several sorbents have also been assayed to carry out the purification of soil samples: Florisil, silica, alumina, carbon, as well as combinations of them. Finally, the proposed analytical method was validated using a certified reference soil material (CRM804-050) and the results were compared with those obtained by other extraction techniques (Soxhlet and microwave-assisted extraction).

Improvement of sensitivity in the determination of organochlorine pesticides using a PSS injector with GC-ECD

This paper describes the optimisation of a PSS injector in a gas chromatograph with a programmed pneumatic control (PPC) for the determination of 21 organochlorine pesticides. The injection of high volumes of sample (20 microl) improves the detection limits and allows a reduction in the amount of sample processed. The injection conditions were selected by a Plackett-Burman design followed by a central composite design. The LODs obtained in the optimum conditions were compared with those obtained with splitless/ECD. Finally, the method was successfully applied to the analysis of a leachate and vegetable samples.

Microwave-assisted extraction versus Soxhlet extraction in the analysis of 21 organochlorine pesticides in plants

A method to determine 21 organochlorine pesticides in vegetation samples using microwave-assisted extraction (MAE) is described and compared with Soxhlet extraction. Samples were extracted with hexane-acetone (1:1, v/v) and the extracts were cleaned using solid-phase extraction with Florisil and alumine as adsorbents. Pesticides were eluted with hexane-ethyl acetate (80:20, v/v) and determined by gas chromatography and electron-capture detection. Recoveries obtained (75.5-132.7% for Soxhlet extraction and 81.5-108.4% for MAE) show that both methods are suitable for the determination of chlorinated pesticides in vegetation samples. The method using microwave energy was applied to grass samples from parks of A Coruña (N.W. Spain) and to vegetation from the contaminated industrial area of Torneiros (Pontevedra, N.W. Spain).

Optimisation of a programmed split-splitless injector in the gas chromatographic-mass spectrometric determination of organochlorine pesticides

Large-volume injection techniques in gas chromatography are used to compensate for the at times limited detection sensitivity of mass spectrometric detection. In this work a programmed split-splitless injector in solvent split mode was employed to determine organochlorine pesticides in environmental samples. The injection conditions were selected by a Plackett-Burman design followed by a central composite design. The LODs obtained in the optimum conditions were compared with those obtained with splitless-MS and splitless-ECD. Finally, the method was applied to a soil sample.

Determination of volatile organic compounds in emissions by coal-fired power stations from Spain

This study concerns the emissions of volatile organic compounds (VOCs) by coal fired power stations. The main compounds are monoaromatic hydrocarbons and aliphatic hydrocarbons, chlorinated compounds have less importance. The influence of combustion parameters can not be clearly established. Emissions factors were calculated and they are smaller than those of other anthropogenic combustions. A comparative study of two sources of VOCs, power stations and motor vehicles, indicates that the environmental impact of the latter are most important.

Multivariate optimisation of hydride generation procedures for single element determinations of As, Cd, Sb and Se in natural waters by electrothermal atomic absorption spectrometry

Continuous flow hydride generation procedures for As(III), total inorganic As, Cd, total inorganic Sb, Se(IV) and total inorganic Se from sea and hot-spring water samples were optimised by experimental designs. Ir-coated graphite tubes were used as preconcentration and atomisation medium of the hydrides generated. Several factors affecting the hydride generation efficiency were studied. Results obtained from Plackett-Burman designs suggest that sodium borohydride flow rate and reduction coil length, are significant factors for total inorganic arsenic hydride generation. For cadmium hydride generation the significant factors are hydrochloric acid concentration, hydrochloric acid and sodium borohydride flow rates and reduction coil length. For total inorganic antimony hydride generation the factors affecting the hydride generation procedure are hydrochloric acid and potassium iodide concentrations and reduction coil length; finally, pre-reduction coil length and oven temperature for the pre-reduction step are statistically significant factors for total inorganic selenium hydride generation. In addition, the factors studied for the arsenic and selenium hydride generation from As(III) and Se(IV) are not significant. From these studies, the significant variables were optimised by central composite designs. Validation carried out analysis on three reference materials: SLRS-4 (Riverie water), CASS-3 (seawater) and NIST-1643d.

Microwave assisted extraction of polycyclic aromatic hydrocarbons from atmospheric particulate samples

For several years, microwave assisted extraction (MAE) was applied to extract organic compounds such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls, etc., from soils, sediments and standard reference materials. Very few authors applied this methodology for the extraction of PAHs from atmospheric particulate matter. In the present study, MAE of polycyclic aromatic hydrocarbons with hexane/acetone (1:1) from real atmospheric particulate samples was investigated and the effect of microwave energy and irradiation time studied. The yields of extracted compounds obtained by microwave irradiation were compared with those obtained using traditional Soxhlet extraction. MAE was evaluated using spiked real atmospheric particulate samples and two standard reference materials. Analytical determinations of PAHs were carried out by high performance liquid chromatography (HPLC) with ultraviolet and fluorescence detection. The best recoveries were achieved with a microwave energy of 400 W and an irradiation time of 20 min.

Speciation of inorganic and organic arsenic in marine sediments from La Coru�a estuary

The speciation of As(III), As(V), MMA and DMA in marine sediments from La Coruña estuary is described. The arsenic species have been separated by ion-exchange chromatography and detected by hydride generation atomic absorption spectrometry (HGAAS). The redox potential has been determined in order to relate the concentration of arsenic species to this parameter.

Synaptic and non-synaptic immunolocalization of GABA and glutamate acid decarboxylase (GAD) in cerebellar cortex of rat

The existence of a large number of GABA receptors in the cerebellar molecular layer, and the observation of numerous punctate immunoreactive deposits of GABA synthesizing enzyme (GAD) throughout this layer, could indicate the existence of numerous axon terminals that may be involved in neurotransmission modulated by GABA. These axon terminals may be different from those considered classically as cerebellar GABAergic axon terminals. Therefore, we have reinvestigated the localization of GABA- and GAD-immunoreactivities in the cerebellar cortex of the rat with the PAP method, using different antisera obtained from rabbits immunized with GABA, baclofen and GAD. The results observed in our investigation have demonstrated GABA- and GAD-immunoreactivities in the axon terminals considered classically as GABAergic, as well as in others which, until now, have not been considered GABAergic. This fact leads us to think that the distribution of GABA or molecules structurally similar to GABA is far more extended than previously thought in the cerebellum. We have also observed both GABA- and GAD-immunoreactivities within dendrites and glial cells. These facts suggest us a possible extrasynaptic release of GABA.