Serological Features Research Articles

Biological, serological and molecular characterization of Potato virus Y strains isolated from potato (Solanum tuberosum L.)

Viral diseases are among the most critical determinants of potato production in many parts of the world, and this is reflected in the importance of developing early diagnosis methods to detect these diseases in the fields. The study showed that potato fields in Nineveh Province are infected with several strains of Potato Y virus, depending on the symptoms of potato or indicator plants and serological tests. For the first time locally in Nineveh Province and at the level of Iraq, using a single molecular test and one step, it was possible to distinguish between the ancient parental strains (PVYº and PVYN), as well as between the PVYNTNT hybrid strain resulting from recombination between the genome of the parental strains when using the pairs of primers N-868-7-F + N -9236-R, which yielded a genome segment of DNA with a length of 441 bp. The emergence of such a new strain in the tested samples in the potato fields in Nineveh province infected with PVY may have arisen from mixed infections. Keywords: PVY strains; PVYN; RT-PCR; Solanum tuberosum L.

Anti-Peptidylarginine Deiminase 4 Autoantibodies and Disease Duration as Predictors of Treatment Response in Rheumatoid Arthritis.

Given that autoantibodies to peptidylarginine deiminase 4 (PAD4) are associated with erosive disease in established rheumatoid arthritis (RA), this study was conducted to compare the clinical and prognostic use of anti-PAD4 antibodies in patients with early and established RA. Sera from patients with early (duration <2 years; n=422) or established (duration ≥2 years; n=359) RA from two randomized clinical trials of tofacitinib ± methotrexate compared with adalimumab + MTX or MTX alone were evaluated for the presence of anti-PAD4 and anti-PAD3/4 antibodies at baseline and posttreatment time points. Summary statistics were calculated for demographic, clinical, and serological characteristics, and generalized estimating equations were used to model clinical outcomes by disease duration according to anti-PAD4 status. Anti-PAD4 antibodies were present in 22% and 40% of patients with early and established RA, respectively, stable following treatment, and associated with baseline joint damage only in established RA. In early RA, baseline anti-PAD4 antibodies were associated with a greater improvement in disease activity score 28-joint count using C-reactive protein levels after treatment compared with individuals with negative anti-PAD4 (P = 0.049). Tofacitinib ± MTX was more broadly efficacious than MTX alone at improving clinical outcomes in early and established RA, irrespective of anti-PAD4 status (P < 0.05 for all), whereas adalimumab + MTX exhibited differential benefits in achieving disease activity score remission in early RA (P = 0.036) and American College of Rheumatology 20 responses in established RA (P = 0.002). Differences in prevalence, clinical associations, and treatment-response outcomes according to anti-PAD4 antibody status in early and established RA suggests the existence of a therapeutic window to prevent the accumulation of irreversible joint damage in early patients with RA with anti-PAD4 antibodies.

Serology and genomic analysis of para-Bombay individuals in a hospital in Hunan Province

To investigate the serological and genetic characteristics of para-Bombay patients in a hospital in Hunan Province. A retrospective analysis was conducted on the blood type results of 175 439 hospitalized patients born in Hunan Province from the Third Xiangya Hospital, Central South University from 2016 to 2021. Phenotypes of ABO blood group was analyzed by blood group serology, and molecular biological methods were used to analyze the genotype, including ABO genotyping by polymerase chain reaction-sequence specific primers (PCR-SSP) and fucosyltransferase 1 (FUT1) and fucosyltransferase 2 (FUT2) gene sequencing. The results showed that 3 cases of Ah and 1 case of Bh were detected. FUT1 sequencing showed that there were 2 cases of h3h3, 1 case of h1h1 and 1 case of h302h1, of which h302 (c.302C>T) was the first discovered mutation. FUT2 sequencing revealed that 4 cases were all Se357Se357. The pedigree study showed that the inheritance of para-Bombay blood group was consistent with autosomal dominant inheritance. In conclusion, the FUT1 gene mutations leading to para-Bombay blood group mainly include h3, h1 and h302, of which h3 mutation is the most common.

Clinical, Serological, and Immunological Characteristics of Greek Patients with Polymyalgia Rheumatica and/or Giant Cell Arteritis: A Research Protocol.

Polymyalgia Rheumatica (PMR) and Giant Cell Arteritis (GCA) are chronic inflammatory disorders that usually affect older people. Although the aetiology of these diseases remains unknown, genetic, environmental, and immune factors have been implicated. Specific cytokines such as the IL-6, IL-1β, IL-12, IL-17, and interferon -γ seem to play an essential role. The diagnosis of the disease is usually based on clinical manifestations and the use of histology or imaging, while disease monitoring is based on physical examination, laboratory, and imaging findings. However, there is the unmet need in identifying possible biomarkers that could help the diagnosis and the monitoring as well. The present study aims to investigate the epidemiological, clinical, and immunological characteristics of PMR and/or GCA patients in the region of northwest Greece and to evaluate the role of specific molecules associated with the pathogenesis of the diseases, giving evidence to possible future biomarkers.

Особливості ювенільного Rhupus-синдрому з ураженням нирок: аналіз літератури та власний досвід

Rhupus syndrome is a rare coexistence of systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA), characterized by symmetrical erosive polyarthritis and permanent deformities in addition to the clinical and serological features of SLE. Its prognosis is further complicated by neurological, and/or hematological, nephrological lesions, which sharply reduce the quality of life of patients. Clinical signs and consequences of Rhupus syndrome may differ in children and adults. Purpose - to acquaint doctors with the peculiarities of diagnosis, treatment, and observation of children with Rhupus syndrome, the importance of early diagnosis of complicated courses and disabilities. Clinical case. The authors present a clinical case of a 15-year-old girl with severe arthritis, which manifested simultaneously with clinical and serological signs of systemic lupus and developed secondary nephropathy at an early stage. JIA with the presence of specific autoantibodies to SLE in this case confirms the diagnosis of Rhupus. The child was treated with a disease-modifying antirheumatic drug (Methotrexate), steroids (Methylprednisolone), an angiotensin II receptor blocker, and other drugs in the treatment complex. Conclusions. Accurate diagnosis is the key to the correct diagnosis and choice of treatment strategy, as Rhupus syndrome is a very rare disorder with a very limited number of reported cases, but with the early realization of possible complications, such as kidney damage. The research was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of the participating institution. The informed consent of the patient was obtained for conducting the studies. No conflict of interests was declared by the authors.

1315. Clinical, Radiological and Serologic Characteristics of Patients with Subarachnoid Neurocysticercosis: A Large Series from a Single Center in New York City

Abstract Background Subarachnoid neurocysticercosis (SANCC) is the most severe and difficult-to-treat form of neurocysticercosis (NCC). Methods We describe the clinical, radiologic, and serologic characteristics of the largest series of patients with SANCC in a non-endemic area by reviewing the medical records of patients seen at Jacobi Medical Center in New York. Results From 313 cases of NCC, 103 patients (32.9%) had subarachnoid involvement. Most individuals were male (65.1%) and born in Mexico (37.9%); the mean age was 41.4 years. Thirty-seven patients had only subarachnoid involvement, 50 patients had both parenchymal and SANCC, 5 patients had both intraventricular and SANCC, and 11 patients had all three spaces involved. Seventy-one patients (68.9%) presented with headaches. Of these, 35 patients had intracranial hypertension, and 27 required shunt placement. Thirty patients (29.1%) presented with seizures, most of whom had concomitant parenchymal disease. Fourteen patients (13.6%) presented as an ischemic event, 12 patients (11.7%) had symptoms due to spinal disease, and 8 patients (7.8%) had aseptic meningitis. Screening for spinal disease was performed on 61 patients. Of these, 14 patients (23.0%) had asymptomatic spinal involvement. Delay in diagnosis was found in 48 patients (49.0%) with a median of 12 months; chronic headache was the most common missed symptom (48.2%). Calcified SANCC was found in 37 patients (35.9%). Of these, 18 patients (18.4%) did not receive previous antiparasitic. Based on both CT scans and MRIs, 14 of these patients were categorized as completely calcified, and 23 patients were partially calcified with a cystic component seen on MR T2 images. The cysticercosis antigen in serum and CSF were negative in all cases of completely calcified and only in one partially calcified SANCC. Conclusion This is the largest series of SANCC reported from a single center in the US and highlights the clinical spectrum. Our data also shows an important under-recognition of this severe form by the clinician and reports that calcified SANCC is common and can occur before and after treatment. Disclosures All Authors: No reported disclosures

Dyslipidaemia and Oxidative Stress in Primary Knee Osteoarthritis: Analysis of Clinical and Serological Features

Background: Osteoarthritis (OA) is a prevalent and debilitating joint disorder with complex etiology, leading to substantial morbidity worldwide. This study aimed to provide a comprehensive and integrative analysis of the clinical and serological features of OA, focusing on primary knee OA as a representative model.

Antigenic and Structural Properties of the Lipopolysaccharide of the Uropathogenic Proteus mirabilis Dm55 Strain Classified to a New O85 Proteus Serogroup.

The aim of the study was the serological and structural characterization of the lipopolysaccharide (LPS) O antigen from P. mirabilis Dm55 coming from the urine of a patient from Lodz. The Dm55 LPS was recognized in ELISA only by the O54 antiserum, suggesting a serological distinction of the Dm55 O antigen from all the 84 Proteus LPS serotypes described. The obtained polyclonal rabbit serum against P. mirabilis Dm55 reacted in ELISA and Western blotting with a few LPSs (including O54), but the reactions were weaker than those observed in the homologous system. The LPS of P. mirabilis Dm55 was subjected to mild acid hydrolysis, and the obtained high-molecular-mass O polysaccharide was chemically studied using sugar and methylation analyses, mass spectrometry, and 1H and 13C NMR spectroscopy, including 1H,1H NOESY, and 1H,13C HMBC experiments. The Dm55 O unit is a branched three-saccharide, and its linear fragment contains α-GalpNAc and β-Galp, whereas α-GlcpNAc occupies a terminal position. The Dm55 OPS shares a disaccharide epitope with the Proteus O54 antigen. Due to the structural differences of the studied O antigen from the other described Proteus O polysaccharides, we propose to classify the P. mirabilis Dm55 strain to a new Proteus O85 serogroup.

Primary Biliary Cholangitis (PBC)-Autoimmune Hepatitis (AIH) Variant Syndrome: Clinical Features, Response to Therapy and Long-Term Outcome.

Standardization of diagnostic criteria of autoimmune hepatitis (AIH) and primary biliary cholangitis (PBC) variant syndrome (AIH-PBC VS) has not been achieved so far and evidence-based recommendations for monitoring and treatment of the disease are still lacking. Our study aimed to assess the prevalence, biochemical, and serological features, as well as the clinical course, of VS. We performed a retrospective study including all patients with VS between 1999 and 2020 in four German centers. Data on demographic parameters, biochemical and serological tests, treatment, and outcome were collected. Of 90 patients (3.1%) meeting Paris criteria for VS diagnosis, 65.6% showed AIH and PBC histological features, while biochemical Paris criteria were observed comparatively rarely. Further antibodies, which were not part of the diagnostic criteria of VS, were found in a subgroup of patients with available data (ACA: 30.0%; anti-CENP-A: 25.0%; anti-CENP-B: 33.3%; anti-SP100: 21.4%). Biochemical response was more frequently observed in patients treated with a combined therapy of ursodeoxycholic acid (UDCA) and immunosuppression (IS). Liver cirrhosis was detected in 31 patients (34.4%) and 25 patients (27.8%) developed clinical manifestations of portal hypertension. Biochemical Paris criteria of VS were rarely detected, thus implying that these cut-off values should be redefined. Regarding pharmacological treatment, combined therapy of UDCA and IS appeared to be more effective than monotherapy with UDCA.

Detection and phenotype analysis of a novel Ael blood group allele.

The presence of blood subtypes may lead to difficulties in blood group identification; however, third-generation sequencing (TGS) can help in accurately identifying difficult blood groups, and study the serological characteristics and molecular mechanism of Ael subtypes. ABO blood group was identified by the standard serological technique, weak blood group antigen was identified by adsorption-elution experiments, ABH substance in the saliva was determined and glycosyltransferase activity of A and B was detected. The ABO gene full-length sequence and promoter region were amplified by specific primers using single-molecule real-time sequencing, with the amplified products being sequenced directly and analysed in real time. The patient was serologically identified as Ael subtype, and TGS analysis revealed new intron mutations in Ael patients (c.467C>T; c.29-10T>A). The discovery of the new allele and the identification of ABO subtypes can be combined with serological characterization and molecular biological methods.

Abstract 13 — Comparison of Clinical and Serological Features in Juvenile and Adult-Onset Systemic Lupus Erythematosus

Background Systemic lupus erythematosus (SLE) has varying clinical and serological features in juvenile and adult-onset disease groups, depending on the ethnicity. Objectives: To compare the disease characteristics of patients with adult-onset (ASLE) and juvenile-onset systemic lupus erythematosus (JSLE). Methods It is a cross-sectional study, carried out at Rheumatology department Fauji Foundation Hospital. 184 SLE patients were included. They were divided into adult (n=152) and juvenile (n=32) group. The clinical and serological features at the time of disease onset were compared between the two groups. Statistical analysis was done using chi square and t-test. Results The mean age was 36.22 ± 11.48 in adults and 19.94 ± 7.17 in the juvenile group (t = 7.71, p&lt;0.001). The duration of disease was 46.05 ± 45.74 months(adult) and 62.43 ± 84.00 months (juvenile). There was no significant difference in disease activity, SLE disease activity index (SLEDAI) was 13 in adult lupus patients and 14.5 in the juvenile, t-value=1.1 and p-value=0.39. Sicca symptoms were significant in the ASLE (p=0.004). Neuropsychiatric manifestations (p=0.03), thrombocytopenia (p=0.048) and low complement levels (0.02) were significantly higher in JSLE. Serological profiles did not differ significantly in the two groups. Conclusion The features of SLE differ in adult and juvenile patients. Neurological involvement and thrombocytopenia were more prevalent in JSLE, whereas sicca symptoms were more frequently found in ASLE.

Serological and molecular analysis of the B(A) subtype in China-A systematic review.

To study the serological and molecular biological characteristics of the B(A) subtype and its geographical distribution in China through case discussion and systematic review. A case of the B(A)02 subtype previously found in our laboratory was retrospectively analysed. The distribution characteristics and specific serological and genotypic characteristics of the B(A) subtype in China were systematically evaluated by searching four major Chinese databases. In a previous case of an abnormal blood group, both the proband and her father were found to be genotype B(A)02/O02, while the mother was normal type B. After a systematic search, irrelevant studies were screened out, and 88 studies were included for analysis. The results showed that the B(A)04 subtype was significantly more frequently reported in the north than in the south, while the B(A)02 subtype was predominant in the southwest. The A antigen of the B(A)02 subtype reacts with monoclonal anti-A reagents in a wide range, while the A antigen of the B(A)04 subtype has a weak agglutination intensity of less than or equal to 2+. The results showed that the B(A) subtype has specific characteristics in the Chinese population, and this study further enriched the serological and molecular biological characteristics of the B(A) subtype.

Clinicopathological Profile of Dermatitis Herpetiformis Patients in Saudi Arabia.

Objectives The aim of this study was to describe the clinical, serological, and histopathological features of patients with dermatitis herpetiformis (DH) in Saudi Arabia. Methods We retrospectively reviewed the medical charts of all patients diagnosed with DH in the dermatology departments of National Guard Health Affairs (NGHA) hospitals in five different cities, from 2016 to 2022. We included patients who had been diagnosed by a dermatologist and had a combination of typical DH skin lesions, positive immunoglobulin A (IgA) on direct immunofluorescence (DIF), and/or positive tissue transglutaminase (tTG) IgA. Results A total of 11 patients were included. Their average age was 43.6 ± 12.5 years, and the ratio of females: males was 2.7: 1. Among the eight skin biopsies performed, IgA was detected on DIF in five patients. Seven out of nine patients (77.8%) had positive tTG IgA. Nine patients were managed with dapsone and a gluten-free diet (GFD); they had excellent responses within months. Conclusion The profiles of Saudi patients with DH were similar to those of Caucasian patients, but DH appears to be less common in Saudi Arabia. The high positive rates of tTG IgA make it an important tool for diagnosis in unclear cases. Dermatitis herpetiformis is likely associated with underlying gluten-sensitive enteropathy in Saudi patients.

Factors associated to long-term retention rate of Janus kinase inhibitors in a multi-failure rheumatoid arthritis population.

We aimed to retrospectively evaluate retention rate and causes of discontinuation of JAKi in rheumatoid arthritis (RA) patients with particular regards to difficult-to-treat subgroups. The diffusion of Janus kinase inhibitors (JAKi) for the treatment of RA has rapidly increased in recent years due to their effectiveness, even in difficult-to-treat subgroups of patients. After the publication of the Oral Surveillance study, the labelling of JAKi was modified, advising against their use in elderly patients and those at risk for cardiovascular events and malignancies. Demographic, clinical, serological and therapeutic characteristics of RA patients treated with JAKi were recorded, including smoking habit and comorbidities. Three hundred and thirty consecutive RA patients were enrolled in the study. Among them, 50.3% patients had previously failed at least two biologic DMARDs. Risk factors for the use of JAKi were reported in 75.5% of patients, 41.5% of them were older than 65 years, 37.6% had smoked, while 48.8% had increased cardiovascular or cancer risk. Anticitrullinated peptide antibodies (ACPA) and combination therapy with conventional synthetic DMARDs were associated with a longer drug persistence and ACPA remained independently associated to a higher retention rate of JAKi also in the subgroup of difficult-to-treat patients. In conclusion, our study supports the clinical effectiveness of JAKi in RA, even in the multi-failure subgroup of patients, where the risk/benefit ratio overcomes the safety risk. The presence of ACPA and the concurrent use of + cs-DMARD may increase the survival on JAKi in the long term.

Anti-PF4 immunothrombosis without proximate heparin or adenovirus vector vaccine exposure

AbstractPlatelet-activating anti-platelet factor 4 (PF4)/heparin antibodies and anti-PF4 antibodies cause heparin-induced thrombocytopenia (HIT) and vaccine-induced immune thrombocytopenia and thrombosis (VITT), respectively. Diagnostic and treatment considerations differ somewhat between HIT and VITT. We identified patients with thrombocytopenia and thrombosis without proximate heparin exposure or adenovirus-based vaccination who tested strongly positive by PF4/polyanion enzyme-immunoassays and negative/weakly positive by heparin-induced platelet activation (HIPA) test but strongly positive by PF4-induced platelet activation (PIPA) test (ie, VITT-like profile). We tested these patients by a standard chemiluminescence assay that detects anti-PF4/heparin antibodies found in HIT (HemosIL AcuStar HIT-IgG(PF4-H)) as well as a novel chemiluminescence assay for anti-PF4 antibodies found in VITT. Representative control sera included an exploratory anti-PF4 antibody-positive but HIPA-negative/weak cohort obtained before 2020 (n = 188). We identified 9 patients with a clinical-pathological profile of a VITT-like disorder in the absence of proximate heparin or vaccination, with a high frequency of stroke (arterial, n = 3; cerebral venous sinus thrombosis, n = 4), thrombocytopenia (median platelet count nadir, 49 × 109/L), and hypercoagulability (greatly elevated D-dimer levels). VITT-like serological features included strong reactivity by PIPA (aggregation <10 minutes in 9/9 sera) and positive testing in the novel anti-PF4 chemiluminescence assay (3/9 also tested positive in the anti-PF4/heparin chemiluminescence assay). Our exploratory cohort identified 13 additional patient sera obtained before 2020 with VITT-like anti-PF4 antibodies. Platelet-activating VITT-like anti-PF4 antibodies should be considered in patients with thrombocytopenia, thrombosis, and very high D-dimer levels, even without a proximate exposure to heparin or adenovirus vector vaccines.

A large cohort comparison of very late-onset systemic lupus erythematosus with younger-onset patients.

Age has a significant impact on systemic lupus erythematosus (SLE). However, data on very late-onset SLE (vlSLE) are scarce. We have compared the clinical and serological features of vlSLE patients with younger-onset patients. We assessed the clinical and laboratory data of all patients fulfilling SLE classification criteria evaluated at a university hospital from 1978 to 2023. Patients were divided into 4 groups according to age at diagnosis: juvenile SLE (jSLE <8 years); adult SLE (aSLE 18-49 years); late SLE (lSLE 50-59 years); vlSLE (≥60 years). 845 patients were enrolled. The jSLE, aSLE, lSLE, and vlSLE groups included 153, 630, 47, and 15 patients, respectively. The vlSLE group tended to have a lower female-to-male ratio (4:1; p=0.282), was mainly Caucasian (93.3%; p<0.001), and had the lowest survival time (20.3 years; p<0.001). vlSLE patients had the lowest prevalence of positive anti-dsDNA antibodies (26.7%; p=0.010) and low C3 levels (13.3%; p<0.001). Although arthritis was less common among vlSLE patients (73.3%; p=0.043), they more commonly developed Sjögren's syndrome (SS 33.3%; p<0.001) and rheumatoid arthritis (RA 13.3%; p<0.001). Infections and malignancy were the main causes of death. Compared with younger patients, in vlSLE, female predominance is less pronounced. Arthritis, anti-dsDNA antibodies and low C3 levels are less frequent. SS and RA are more common. Despite lower disease activity, vlSLE patients have the lowest survival rate. While uncommon, SLE should not be excluded as a possible diagnosis in the elderly.

A 20-year study of autoimmune polyendocrine syndrome type II and III in Taiwan.

Autoimmune polyendocrine syndrome (APS) is a rare immune-endocrinopathy characterized by the failure of at least two endocrine organs. Clinical characteristics have mainly been described in the Western population. This study comprehensively analyzed the demographic and clinical manifestations of APS II and APS III in Taiwan. Patients aged ≥20 years with a diagnosis of APS II or APS III in ten hospitals between 2001 and 2021 were enrolled. The clinical and serological characteristics of the patients were retrospectively reviewed. Among the 187 enrolled patients (45 men and 142 women); only seven (3.7%) had APS II, while the others had APS III. Fifty-five patients developed hyperthyroidism and 44 patients developed hypothyroidism. Men were diagnosed with APS at a younger age than women (16.8 vs 27.8 years old, P = 0.007). Most patients were initially diagnosed with type 1 diabetes mellitus. There was a positive correlation between age at diagnosis and the likelihood of developing thyroid dysfunction. For every year older patients were diagnosed with APS III, the risk of developing hyperthyroidism increased by 3.6% (P = 0.002), and the risk of developing hypothyroidism increased by 3.7% (P = 0.035). Positive anti-parietal cell antibodies (APCA) were associated with a higher risk of anemia in patients with APS III (P < 0.001). This study provides the most comprehensive analysis of APS II and APS III in Asia. The percentage of patients with APS II was significantly lower than in the Western population. A second autoimmune endocrinopathy may develop several years after the first one. APCA examination is valuable when evaluating anemia in patients with APS.

Impact of COVID-19 and vaccination campaign on 1,755 systemic sclerosis patients during first three years of pandemic. Possible risks for individuals with impaired immunoreactivity to vaccine, ongoing immunomodulating treatments, and disease-related lung involvement during the next pandemic phase

IntroductionThe impact of COVID-19 pandemic represents a serious challenge for ‘frail’ patients' populations with inflammatory autoimmune systemic diseases such as systemic sclerosis (SSc). We investigated the prevalence and severity of COVID-19, as well the effects of COVID-19 vaccination campaign in a large series of SSc patients followed for the entire period (first 38 months) of pandemic. Patients and methodThis prospective survey study included 1755 unselected SSc patients (186 M, 1,569F; mean age 58.7 ± 13.4SD years, mean disease duration 8.8 ± 7.3SD years) recruited in part by telephone survey at 37 referral centers from February 2020 to April 2023. The following parameters were carefully evaluated: i. demographic, clinical, serological, and therapeutical features; ii. prevalence and severity of COVID-19; and iii. safety, immunogenicity, and efficacy of COVID-19 vaccines. ResultsThe prevalence of COVID-19 recorded during the whole pandemic was significantly higher compared to Italian general population (47.3 % vs 43.3 %, p < 0.000), as well the COVID-19-related mortality (1.91 % vs 0.72 %, p < 0.001). As regards the putative prognostic factors of worse outcome, COVID-19 positive patients with SSc-related interstitial lung involvement showed significantly higher percentage of COVID-19-related hospitalization compared to those without (5.85 % vs 1.73 %; p < 0.0001), as well as of mortality rate (2.01 % vs 0.4 %; p = 0.002). Over half of patients (56.3 %) received the first two plus one booster dose of vaccine; while a fourth dose was administered to 35.6 %, and only few of them (1.99 %) had five or more doses of vaccine. Of note, an impaired seroconversion was recorded in 25.6 % of individuals after the first 2 doses of vaccine, and in 8.4 % of patients also after the booster dose. Furthermore, the absence of T-cell immunoreactivity was observed in 3/7 patients tested by QuantiFERON® SARSCoV-2 Starter Set (Qiagen). The efficacy of vaccines, evaluated by comparing the COVID-19-related death rate recorded during pre- and post-vaccination pandemic periods, revealed a quite stable outcome in SSc patients (death rate from 2.54 % to 1.76 %; p = ns), despite the significant drop of mortality observed in the Italian general population (from 2.95 % to 0.29 %; p < 0.0001). ConclusionsAn increased COVID-19 prevalence and mortality rate was recorded in SSc patients; moreover, the efficacy of vaccines in term of improved outcomes was less evident in SSc compared to Italian general population. This discrepancy might be explained by concomitant adverse prognostic factors: increased rate of non-responders to vaccine in SSc series, low percentage of individuals with four or more doses of vaccine, ongoing immunomodulating treatments, disease-related interstitial lung disease, and/or reduced preventive measures in the second half of pandemic. A careful monitoring of response to COVID-19 vaccines together with adequate preventive/therapeutical strategies are highly recommendable in the near course of pandemic in this frail patients’ population.

PB0757 Comparison of Clinical and Serological Features in Thrombotic Antiphospholipid Syndrome Patients, with and without Associated SLE, Followed for up to 42 Years: A Single Centre Retrospective Study

PB0757 Comparison of Clinical and Serological Features in Thrombotic Antiphospholipid Syndrome Patients, with and without Associated SLE, Followed for up to 42 Years: A Single Centre Retrospective Study

S921 Are We Meeting Celiac Disease Benchmarks in Inflammatory Bowel Disease Patients With Celiac Disease? Evaluation of Clinical, Serological, and Histological Characteristics: Case-Control Study From a Tertiary Referral Center

S921 Are We Meeting Celiac Disease Benchmarks in Inflammatory Bowel Disease Patients With Celiac Disease? Evaluation of Clinical, Serological, and Histological Characteristics: Case-Control Study From a Tertiary Referral Center