A novel HLA-C*04 variant, HLA-C*04:01:01:174, identified in a healthy individual from Greece

HLA-C*04:01:01:174 differs from the HLA-C*04:01:01:06 allele by one nucleotide substitution in the intron 5.

A novel HLA-C*01 variant, HLA-C*01:02:01:70, identified in a healthy individual from Greece

HLA-C*01:02:01:70 differs from the HLA-C*01:02:01:01 allele by one nucleotide substitution in the intron 4.

A novel HLA-C*17 variant, HLA-C*17:01:01:29, identified in a healthy individual from Greece

HLA-C*17:01:01:29 differs from the HLA-C*17:01:01:05 allele by one nucleotide substitution in the 3'UTR.

Discovery of the novel HLA-A*01:01:01:112 allele in a Greek volunteer bone marrow donor

HLA-A*01:01:01:112 differs from the HLA-A*01:01:01:01 allele by one nucleotide substitution in the 5'UTR.

Genomic sequence of the novel HLA-B*41:02:01:11, and -C*08:266 alleles identified in a solid organ recipient

HLA-B*41:02:01:11 and -C*08:266 were detected in a solid organ recipient during the HLA typing process.

Discovery of the novel HLA-B*47:01:01:07 allele in a Greek volunteer bone marrow donor

HLA-B*47:01:01:07 differs from the HLA-B*47:01:01:03 allele by one nucleotide deletion in the 3'UTR.

Utilizing Massively Parallel Sequencing (MPS) of Human Leukocyte Antigen (HLA) Gene Polymorphism to Assess Relatedness in Deficiency Parentage Testing

In the realm of DNA testing with legal implications, the reliability and precision of genetic markers play a pivotal role in confirming or negating paternity claims. This study aimed to assess the potential utility of human leukocyte antigen (HLA) gene polymorphism through massively parallel sequencing (MPS) technology as robust forensic markers for parentage testing involving genetic deficiencies. It sought to redefine the significance of HLA genes in this context. Data on autosomal short tandem repeat (aSTR) mutational events across 18 paternity cases involving 16 commonly employed microsatellite loci were presented. In instances where traditional aSTR analysis failed to establish statistical certainty, kinship determination was pursued via HLA genotyping, encompassing the amplification of 17 linked HLA loci. Within the framework of this investigation, phase-resolved genotypes for HLA genes were meticulously generated, resulting in the definition of 34 inherited HLA haplotypes. An impressive total of 274 unique HLA alleles, which were classified at either the field 3 or 4 level, were identified, including the discovery of four novel HLA alleles. Likelihood ratio (LR) values, which indicated the likelihood of the observed data under a true biological relationship versus no relationship, were subsequently calculated. The analysis of the LR values demonstrated that the HLA genes significantly enhanced kinship determination compared with the aSTR analysis. Combining LR values from aSTR markers and HLA loci yielded conclusive outcomes in duo paternity cases, showcasing the potential of HLA genes and MPS technology for deeper insights and diversity in genetic testing. Comprehensive reference databases and high-resolution HLA typing across diverse populations are essential. Reintegrating HLA alleles into forensic identification complements existing markers, creating a potent method for future forensic analysis.

Characterization of the novel HLA-A*02:01:01:243 allele by next generation sequencing in a Greek individual

HLA-A*02:01:01:243 differs from the HLA-A*02:01:01:01 allele by one nucleotide substitution in the 5'UTR.

Full-length sequence of the novel HLA-A*02:05:01:23 allele by next-generation sequencing in a Greek individual

HLA-A*02:05:01:23 differs from HLA-A*02:05:01:01 by one nucleotide substitution in intron 6.

Full-length sequence of the novel HLA-B*18:01:01:73 allele by next generation sequencing in a Greek individual

HLA-B*18:01:01:73 differs from HLA-B*18:01:01:02 by one nucleotide substitution in intron 2.

Characterization of the novel HLA-B*51:01:01:109 allele by next generation sequencing in a Greek individual

HLA-B*51:01:01:109 differs from HLA-B*51:01:01:01 by one nucleotide substitution in intron 5.

Identification of the novel HLA-A*01:426 allele in a Greek bone marrow donor

Characterization of the novel HLA-A*01:426 allele in a 21-year-old Greek male bone marrow donor.

HLA-B*51:380, a novel HLA-B allele with one exonic mutation identified in a Greek individual

Characterization of the novel HLA-B*51:380 allele in a Greek individual using next-generation sequencing.

Identification of the novel HLA-DPB1*02:01:68 allele in a Greek individual

Characterization of the novel HLA-DPB1*02:01:68 allele in a 27-year-old Greek hematopoietic stem cell transplant candidate.

Discovery of the novel HLA-C*07:1052 allele, a variant of HLA-C*07:02:01:01, in a Greek individual

Characterization of the novel HLA-C*07:1052 allele in a Greek individual using next-generation sequencing.

Identification of the novel HLA-A*02:09:01:04 allele in a Greek individual

Characterization of the novel HLA-A*02:09:01:04 allele in a 36-year-old Greek female.

Genomic sequence of the HLA-A*24:587 allele identified in a Greek individual

Characterization of the novel HLA-A*24:587 allele in a Greek individual using next-generation sequencing.

Kinetics of Immune Subsets in COVID-19 Patients Treated with Corticosteroids

RATIONALE

Changes in anti-SARS-CoV-2 defense immune subsets in patients treated with dexamethasone (DXM) for severe COVID-19 and their relation to disease outcomes are poorly understood.

METHODS

Blood-lymphocyte subsets of 110 hospitalized COVID-19 patients were prospectively examined. A first sample was taken at enrollment and a second one 7-10 days later. Total B-, T-lymphocytes, CD4+, CD8+, T-regulatory (Treg), Natural-Killer (NK) and NK T-cells were counted using flow cytometry.

RESULTS

At enrollment, patients with respiratory failure, characterized by DXM failure (intubation/death) or DXM success (hospital discharge) exhibited significantly fewer CD3+, CD4+ and CD8+ cells and B-lymphocytes compared to the control group (no respiratory failure/no DXM). At the time of treatment completion, the DXM-failure group exhibited significantly fewer CD3+, CD4+ and CD8+ cells, memory CD4+ and CD8+ T-lymphocytes, compared to the control and the DXM-success groups and fewer activated CD4+ T-lymphocytes, Tregs and NK cells compared to the control group. At the time of treatment completion, the number of all investigated lymphocyte subsets increased in the DXM-success group and was similar to those of the control group. NK cells significantly decreased over time in the DXM-failure group.

CONCLUSION

The lymphocyte kinetics differ between DXM-treated and control COVID-19 patients and are associated with clinical outcomes.

Association of sleep duration and quality with immunological response after vaccination against severe acute respiratory syndrome coronavirus-2 infection

Growing evidence suggests that sleep could affect the immunological response after vaccination. The aim of this prospective study was to investigate possible associations between regular sleep disruption and immunity response after vaccination against coronavirus disease 2019 (COVID-19). In total, 592 healthcare workers, with no previous history of COVID-19, from eight major Greek hospitals were enrolled in this study. All subjects underwent two Pfizer-BioNTech messenger ribonucleic acid (mRNA) COVID-19 vaccine BNT162b2 inoculations with an interval of 21 days between the doses. Furthermore, a questionnaire was completed 2 days after each vaccination and clinical characteristics, demographics, sleep duration, and habits were recorded. Blood samples were collected and anti-spike immunoglobulin G antibodies were measured at 20 ± 1 days after the first dose and 21 ± 2 days after the second dose. A total of 544 subjects (30% males), with median (interquartile range [IQR]) age of 46 (38-54) years and body mass index of 24·84 (22.6-28.51) kg/m² were eligible for the study. The median (IQR) habitual duration of sleep was 6 (6-7) h/night. In all, 283 participants (52%) had a short daytime nap. In 214 (39.3%) participants the Pittsburgh Sleep Quality Index score was >5, with a higher percentage in women (74·3%, p < 0.05). Antibody levels were associated with age (r = -0.178, p < 0.001), poor sleep quality (r = -0.094, p < 0.05), insomnia (r = -0.098, p < 0.05), and nap frequency per week (r = -0.098, p < 0.05), but after adjusting for confounders, only insomnia, gender, and age were independent determinants of antibody levels. It is important to emphasise that insomnia is associated with lower antibody levels against COVID-19 after vaccination.

AB1165 THE ROLE OF MOLECULAR MIMICRY IN SARS-CoV-2 RELATED AUTOIMMUNE RHEUMATIC DISEASES

Background

Several studies suggested that SARS-CoV-2 infection may induce autoantibodies related to autoimmune rheumatic diseases (ARD).

Objectives

To determine whether polyclonal antibodies from SARS-CoV-2 uninfected patients with ARDs cross-react with SARS-CoV-2 and vice versa.

Methods

90 sera positive at high-titres for 23 common autoantibodies (all sera stored before 2018), were tested for reactivity against proteins of SARS-CoV-2 (spike protein S1, nucleocapsid NC etc) by ELISA and CMIA. Vice versa, 10 monoclonal antibodies against S1 protein (most of them against RBD) were tested for autoantibody reactivity by indirect immunofluorescence, ELISA, immunoblot and dot/line immunoassays coated with different antigens. Ten post-COVID sera with high titers of anti-Spike abs were tested by ELISAs for reactivity against various autoantigens related to ARDs.

Results

88 out of 90 samples (%), were totally unreactive to SARS-CoV-2 proteins; 2 sera, one anti-CCP and one anti-CENP reacted against S protein. All sera tested negative for neutralized abs against SARS-CoV-2. None of 10 sera from SARS-CoV-2 infected patients reacted with different autoantigens by molecular assays. None of the 10 monoclonal abs against S1 protein reacted with 23 different self-antigens. On HEp2 cells as substrate for IIF, 3 of the 10 monoclonal abs gave a low-titre coarse speckled pattern. No reactivity was found by IIFL using tissue substrates.

Conclusion

Our data do not suggest a dominant role for molecular mimicry and immunological cross reactivity as a trigger of autoantibodies related to ARDs.

Disclosure of Interests

Christos Liaskos: None declared, Eleni Patrikiou: None declared, Lars Komorowski Employee of: emploee of EUROIMMUN Medizinische Labordiagnostika, Christina Tsigalou: None declared, Alexandra Tsirogianni: None declared, Lazaros Sakkas: None declared, Dimitrios Bogdanos: None declared

MO906: Antibody Response to COVID-19 Vaccination in Patients Under Dialysis

BACKGROUND AND AIMS

Patients (pts) with end-stage kidney disease (ESRD) may be more vulnerable to infections and may have a suboptimal response to vaccination. Dialysis patient (pt) began to be vaccinated against COVID-19 in February 2021. However, there were many doubts about whether immunization would be effective for them, as these pts have an impaired immune system, and it seems that this population responds poorly to vaccinations. Serum neutralizing antibodies (AbN) rapidly appear after the SARS-CoV-2 infection and the vaccination and are maintained for several months. The emergence of SARS-CoV-2 variants has raised concerns about the breadth of the neutralizing antibody responses.

METHOD

Serum samples were obtained from 181 patients receiving dialysis. Levels of circulating SARS-CoV-2 anti-spike IgG(S) and anti-nucleocapsid IgG (N) antibodies were quantified using the Abbott Diagnostics SARS-CoV-2 IgG chemiluminescent microparticle immunoassay (Abbott Diagnostics, Abbott Park, IL, USA) on an Abbott Diagnostics Architect i2000 SR and an Alinity analyzer, according to the manufacturer's instructions. Serum neutralizing antibodies (AbN) by commercially available assays (cPass SARS-CoV-2 Neutralization Antibody Detection Kit), at the first and the third months after the vaccination, were identified.

RESULTS

The IgG-spike Abs had a statistically significant decrease at 3 months after the vaccination in relation to the measurements 1 month after that.

AbN had a statistically significant decline at 3 months after the vaccination in relation to the measurements 1 month after. Pts with cardiovascular disease (CD) had significantly lower levels of antibodies than those who did not have CD. Additionally, CD was an aggravating factor in combination with the other comorbidities for the development of antibodies. Pts with a history of malignancy had significantly lower levels of antibodies in relation to those who did not. Those under therapy with antihistamines in the 1st month after the vaccination presented a statistically lower level of the AbNs, but this difference did not exist in the measurements 3 months after vaccination. There was a correlation between the AbNs and the age, also between the time these patients underwent dialysis. Those who had COVID-19 infection presented higher levels of the antibodies AbN/IgG-spiked Ab at 3 months.

CONCLUSION

It is presented that the IgG-spike Abs and the AbN had a statistically significant decrease at 3 months after the vaccination, which shows the importance of completing vaccination with the third dose after 3 months. Also, it is presented that CD is a risk factor for lower levels of Abs. Randomized clinical trials for COVID-19 vaccines included a few patients with kidney disease; therefore, the vaccine immunogenicity is uncertain in this population.

The impact of the COVID-19 pandemic on autoimmune diagnostics in Europe: A lesson to be learned

INTRODUCTION

The first wave of COVID-19 pandemic has disrupted almost all areas of the health care services to some extent throughout the world. Although the negative impact of COVID-19 on patients with autoimmune diseases has also been recognized, available data in this regard are limited. In the current study of the European Autoimmunity Standardisation Initiative (EASI) we aimed to provide reliable data on the extent of the impact of COVID-19 pandemic on test requests for different autoantibodies in European countries.

METHODS

Data on test numbers and on the number of positive results were collected in 97 clinical laboratories from 15 European countries on a monthly basis for the year before (2019) and the year during (2020) the COVID-19 pandemic.

RESULTS

A reduction in the number of autoantibody tests was observed in all European countries in the year 2020 compared to 2019. The reduction affected all autoantibody tests with an overall decrease of 13%, ranging from 1.4% (Switzerland) to 25.5% (Greece). In all countries, the decrease was most pronounced during the first wave of the pandemic (March-May 2020) with an overall decrease in those three months of 45.2%. The most affected autoantibodies were those commonly requested by general practitioners (anti-tTG IgA (-71%), RF IgM (-66%) and ACPA (-61%)). In the second wave of the pandemic (October-December 2020) the decrease was less pronounced (6.8%). With respect to the rate of positive results, subtle differences were observed for distinct autoantibodies during the pandemic, but the total rate of positive results was similar in both years.

CONCLUSIONS

Our study demonstrated a strong decrease in autoantibody requests during the first wave of the COVID-19 pandemic in 15 European countries. The second wave was characterized by a less pronounced impact, with some participating countries hardly affected, while some other countries experienced a second decline. The decrease was clearly associated with the level of lock-down and with the required adjustments in the health care systems in different countries, supporting the importance of an effective strategy for the coordination of autoimmune testing in challenging situations as the COVID-19 pandemic.

Combination of the CD8+:B-cell and Neutrophil-to-Lymphocyte Ratio as a Novel Prediction Model for Intubation Need and Disease Severity in COVID-19 Patients

BACKGROUND

The study provides a novel prediction model for COVID-19 progression and outcome by the combination of the CD8⁺: B-cells ratio with neutrophil-to-lymphocyte ratio (NLR).

PATIENTS AND METHODS

Immune phenotyping was performed in 120 COVID-19 patients.

RESULTS

A decrease in CD8⁺:B-cell (p<0.0001) and in lymphocyte-to-CRP (LCR) ratio (p<0.0001) was observed in intubated patients versus non-intubated with an increase for CD4⁺:CD8⁺ (p<0.01), NLR (p<0.0001) and CRP: Albumin (p<0.001). Receiving operating curve (ROC) analysis predicting requirement for mechanical ventilation revealed the highest AUC for CD8⁺:B-cells, (AUC=0.795, p<0.001) versus NLR (AUC=0.783, p<0.001), LCR (AUC=0.779, p<0.001), Albumin:CRP (AUC=0.750, p<0.001) and CD4⁺:CD8⁺ (AUC=0.779, p<0.001). Combination of the CD8⁺: B-cell ratio with the NLR increased the AUC (AUC=0.845, p<0.001). The combined ratios correlated with outcome defined as duration of hospital (r=0.435, p<0.001) or ICU stay (r=0.596, p<0.001).

CONCLUSION

Combination of the CD8⁺: B-cell ratio and NLR serves as a useful prognostic tool for COVID-19 patient progression.

Demographic, Clinical and Immunogenetic Profiles of a Greek Cohort of COVID-19 Patients

The present cross-sectional study consists of a comprehensive analysis of epidemiological, laboratory, and clinical characteristics of COVID-19 patients in relation to their immunogenetic profiles. We studied 125 COVID-19 patients comprising different stages of disease severity; non-hospitalized (mild n = 69) and hospitalized (n = 56). Analysis of disease characteristics revealed no major differences between males and females of each group of patients while hospitalized patients were older and presented with comorbidities. A positive allele association was observed for HLA-DRB1*01 in total COVID-19 patients versus healthy controls. Subgrouping of COVID-19 patients in mild and hospitalized further identified a statistically significant increase in HLA-DRB1*01 in mild COVID-19 patients versus controls. The frequency of A*11, A*23, and DRB1*09 alleles was higher, while the frequency of C*12 was lower, in hospitalized patients versus healthy controls albeit with uncorrected statistical significance. The identification of specific allele associations may provide useful future markers for disease susceptibility in order to allow successful clinical management of COVID-19 patients.

Occurrence and Antigenic Specificity of Perinuclear Anti-Neutrophil Cytoplasmic Antibodies (P-ANCA) in Systemic Autoimmune Diseases

Perinuclear anti-neutrophilic cytoplasmic antibodies (P-ANCA) recognize heterogeneous antigens, including myeloperoxidase (MPO), lactoferrin, elastase, cathepsin-G and bactericidal/permeability-increasing protein. Although P-ANCA have diagnostic utility in vasculitides, they may also be found in patients with various other systemic autoimmune rheumatic diseases (SARDs). Nevertheless, the clinical significance and the targets recognized by P-ANCA in such patients remain unclear. For this purpose, herein we investigated the occurrence of ANCA-related antigenic specificities in 82 P-ANCA-positive sera by multiplex ELISA, as well as their association with other autoantibodies. The P-ANCA-positive sera corresponded to patients with vasculitides (n = 24), systemic lupus erythematosus (n = 28), antiphospholipid syndrome (n = 5), Sjögren’s syndrome (n = 7), rheumatoid arthritis (n = 3), systemic scleroderma (n = 1), sarcoidosis (n = 1) and Hashimoto′s thyroiditis (n = 13). In most P-ANCA-positive patients studied (51/82, 62.3%), these autoantibodies occurred in high titers (>1:160). The analysis of P-ANCA-positive sera revealed reactivity to MPO in only 50% of patients with vasculitides, whereas it was infrequent in the other disease groups studied. Reactivity to other P-ANCA-related autoantigens was also rarely detected. Our findings support that high P-ANCA titers occur in SARD. The P-ANCA-positive staining pattern is associated with MPO specificity in vasculitides, while in other autoimmune diseases, it mostly involves unknown autoantigens.

POS0829 SPECIFICITY OF PANCA AUTOANTIBODIES IN AUTOIMMUNE DISEASES

Background:

The clinical significance of pANCA by indirect immunofluorescence is well-established. However, their clinical utility is sometimes hindered by the fact that pANCA are also detected in various autoimmune diseases. Myeloperoxidase (MPO) is considered as the major autoantigen recognized by pANCA in ANCA-associated vasculitides (AAV) and predominantly in microscopic polyangiitis (MPA). However, information regarding the targets of pANCA in other autoimmune diseases is still elusive.

Objectives:

To investigate the specific autoantigens recognized by pANCA in autoimmune diseases.

Methods:

Sera from all patients that were found positive for pANCA in the diagnostic laboratories of the Department of Pathophysiology, School of Medicine, National and Kapodistrian University of Athens and the Department of Immunology and Histocompatibility, Evangelismos General Hospital, Athens, Greece during the last two years were studied. The pANCA+ sera were evaluated for reactivity with the major antigens that are recognized by pANCA [MPO, lactoferrin, neutrophil elastase, cathepsin G and bactericidal/permeability increasing protein (BPI)] by a commercially available multiplex ELISA (ANCA profile ELISA, Euroimmun, Lubeck, Germany).

Results:

A total of 82 patients were included in the study. All patients had positive pANCA by indirect immunofluorescence with a title ranging from 1/160 to 1/640. According to respective classification criteria, 21 patients had systemic vasculitides (15 MPA, 1 granulomatosis with polyangiitis; GPA, 1 Behcet’s disease; BD, 1 aortitis, 2 Henoch-Schonlein purpura; HSP and 1 cryoglobulinemic vasculitis; CV), 29 had systemic lupus erythematosus (SLE), 6 antiphospholipid syndrome (APS), 8 Sjögren’s syndrome (SS), 2 rheumatoid arthritis (RA), 1 systemic scleroderma (SScl), 14 Hashimoto thyroiditis and 1 sarcoidosis. The specificities of pANCA in each entity are shown in the following table.

Autoimmune DiseasesAntigens recognized by pANCA+ seraMPOElastaseCathepsin GBPILactoferrinVasculitidesMPA66.7 (10/15)0 (0/15)0 (0/15)0 (0/15)0 (0/15)GPA100 (1/1)0 (0/1)0 (0/1)0 (0/1)0 (0/1)BD100 (1/1)0 (0/1)0 (0/1)0 (0/1)0 (0/1)Aortitis0 (0/1)0 (0/1)0 (0/1)0 (0/1)0 (0/1)HSP0 (0/2)0 (0/2)0 (0/2)0 (0/2)0 (0/2)CV0 (0/1)0 (0/1)0 (0/1)0(0/1)100 (1/1)SLE6.9 (2/29)0 (0/29)0 (0/29)0 (0/29)6.9 (2/29)APS16.6 (1/6)16.6 (1/6)0 (0/6)0 (0/6)0 (0/6)SS0 (0/8)12.5 (1/8)0 (0/8)12.5 (1/8)0 (0/8)RA50 (1/2)0 (0/2)0 (0/2)0 (0/2)0 (0/2)SScl100 (1/1)0 (0/1)0 (0/1)0 (0/1)0 (0/1)Hashimoto0 (0/14)0 (0/14)0 (0/14)0 (0/14)0 (0/14)Sarcoidosis0 (0/1)0 (0/1)0 (0/1)0 (0/1)0 (0/1)

Conclusion:

pANCA positive staining in AAVs is highly restricted to MPO specificity. On the contrary, pANCA staining pattern in other autoimmune diseases, involves unknown autoantigens that are under investigation in our laboratory.

Disclosure of Interests:

None declared

A novel ratio of CD8+:B-cells as a prognostic marker of coronavirus disease 2019 patient progression and outcome

Infection with SARS-COV-2 may result in severe pneumonia potentially leading to mechanical ventilation and intensive care treatment. The aim of the present study was to analyze the immune responses in critically ill coronavirus 2019 (COVID-19) patients requiring mechanical ventilation and assess their potential use as markers of clinical progression and outcome. Confirmed COVID-19 patients were grouped into those requiring mechanical ventilation (intubated) and non-intubated. Immune phenotyping was performed and cytokine levels were determined. A novel ratio of CD8⁺:B cells was significantly lower in intubated versus non-intubated (p = 0.015) and intubated non-survivors (NSV) versus survivors (SV) (p = 0.015). The same ratio correlated with outcome, CRP, IL-6 levels and neutrophil count. Receiving operating curve (ROC) analysis for prediction of requirement of mechanical ventilation by the CD8⁺:B cells ratio revealed an AUC of 0.747 and a p = 0.007. The ratio of CD8⁺:B cells may serve as a useful prognostic marker for disease severity and outcome.

Quality and best practice in medical laboratories: specific requests for autoimmunity testing

Special conditions associated with laboratory autoimmune testing are not well compatible with recent developments in regulatory frameworks such as EN/ISO 15189 accreditation or in vitro diagnostic medical device regulation (IVD-R). In addition, international recommendations, guidelines and disease criteria are poorly defined with respect to requirements on autoantibody testing. Laboratory specialists from Austria, Belgium, Croatia, Estonia, Finland, France, Germany, Greece, Hungary, Italy, Norway, Poland, Portugal, South Africa, Spain, Sweden, Switzerland, and The Netherlands collected information, reported national experience, and identified quality issues in relation to autoantibody testing that require consensus on interpretation of the regulatory frameworks and guidelines. This process has been organized by the European Autoimmunity Standardisation Initiative (EASI). By identifying the critical items and looking for a consensus, our objective was to define a framework for, in particular, EN/ISO accreditation purposes. Here, we present a review of current publications and guidelines in this field to unify national guidelines and deliver in this way a European handout on quality control and accreditation for laboratories involved in autoantibody testing. We focus on quality items that can be checked during accreditation visits. Despite various local varieties, we encountered an overwhelming dedication to quality assurance in all contributing countries.

Neurolisteriosis in a previously asymptomatic patient with serum IgM deficiency: a case report

Background

Listeria monocytogenes is an opportunistic pathogen of the central nervous system commonly associated with impaired cell-mediated immunity. We hereby present a case of adult neurolisteriosis where the only immunological feature persistently present was serum IgM deficiency, suggesting that non-specific humoral immunity may also play a central role in the control of neuroinvasion by Listeria monocytogenes.

Case presentation

A 62-year-old male who had never experienced severe infections presented with headache, nuchal rigidity and confusion. Neuroimaging was normal and lumbar puncture revealed pleiocytosis (760 leukocytes/mm³) and hypoglycorrhachia (34 mg/dL). The patient was treated empirically for bacterial meningitis. Indeed, further analysis of the CSF showed infection by Listeria monocytogenes, which was accompanied by reduced serum IgM levels that persisted well beyond the period of acute bacterial infection. Levels of IgG and IgA isotypes, along with peripheral blood counts of major leukocyte subsets, were at the same time largely preserved. Intriguingly, the absence of membrane-bound IgM on B cells was essentially complete in the acute post-infection period leading to a remarkable recovery after 12 months, suggesting that mechanisms other than defective membrane expression are underlying serum deficiency.

Conclusions

As far as we know, this is the first reported case of neurolisteriosis associated with IgM deficiency in an adult individual without a history of severe infections or other underlying conditions. A possible role of circulating IgM against invasive disease caused by Listeria monocytogenes, particularly in the early course of host-pathogen interaction, is discussed.

AB0208 ASSOCIATION OF RHEUMATOID FACTOR, HLA-DRB1 SHARED EPITOPE (SE) AND SMOKING WITH RADIOGRAPHIC OUTCOME IN RHEUMATOID ARTHRITIS

Background:

Genetic and environmental factors interact in aetiopathogenesis of Rheumatoid Arthritis (RA). However, it remains unclear whether current smoking, presence of Rheumatoid factor (RF) and HLA-DRB1 SE influence the radiographic outcome.

Objectives:

To clarify the possible associations between radiographic outcome, HLA-DRB1 SE, RF and smoking status in patients with longstanding RA.

Methods:

An observational study of 240 consecutive Greek patients with RA, whose mean age and mean disease duration was 65.31±12.5 and 12.7±11.8 years respectively. Among them 74.17% were female, 40% were smokers, 60.42% had positive RF and 68.33% possessed at least one SE allele. HLA-DRB1 alleles were typed by molecular techniques (PCR-SSOP and SSP). X-rays of hands and feet were performed and scored by the Sharp-van der Hejde score (SHS) method.

Results:

Results were stratified by RF and smoking status and analyzed by multivariate logistic regression. Overall, the mean SHS was significantly higher in RF positive than RF negative patients and in smokers than non-smokers (52.76±31.1 vs 38.4±31.96, p: 0.0007, 55.33±38.56 vs 26.8±22.32, p <0.0001, respectively). Furthermore, patients that possessed at least one SE allele had higher SHS than SE negative (35.49±24.76 vs 25.74±19.22, p: 0.0013). An association between radiographic severity and SE was found in RF positive patients. More specifically, seropositive patients carrying at least one SE allele had higher SHS than those lacking SE (40.85±33.21 vs 29.23±24.72, p: 0.037). On the other hand, smokers with at least one SE allele had higher SHS when compared to smokers without SE (29.27±25.20 vs 20±17.22, p: 0.048). Among RF negative and non-smokers RA patients, no significant association was found between the presence of HLA-DRB1 SE and radiographic severity.

Conclusion:

Our data indicate that in longstanding RA there is an association between RF positivity, the presence of SE, current smoking status and radiographic outcome.

Disclosure of Interests:

None declared

HLA Haplotypes In 250 Families: The Baylor Laboratory Results And A Perspective On A Core NGS Testing Model For The 17th International HLA And Immunogenetics Workshop

Since their inception, the International HLA & Immunogenetics Workshops (IHIW) served as a collaborative platform for exchange of specimens, reference materials, experiences and best practices. In this report we present a subset of the results of human leukocyte antigen (HLA) haplotypes in families tested by next generation sequencing (NGS) under the 17th IHIW. We characterized 961 haplotypes in 921 subjects belonging to 250 families from 8 countries (Argentina, Austria, Egypt, Jamaica, Germany, Greece, Kuwait, and Switzerland). These samples were tested in a single core laboratory in a high throughput fashion using 6 different reagents/software platforms. Families tested included patients evaluated clinically as transplant recipients (kidney and hematopoietic cell transplant) and their respective family members. We identified 486 HLA alleles at the following loci HLA-A, -B, -C, -DRB1, -DRB3, -DRB4, -DRB5, -DQA1, -DQB1, -DPA1, -DPB1 (77, 115, 68, 69, 10, 6, 4, 44, 31, 20 and 42 alleles, respectively). We also identified nine novel alleles with polymorphisms in coding regions. This approach of testing samples from multiple laboratories across the world in different stages of technology implementation in a single core laboratory may be useful for future international workshops. Although data presented may not be reflective of allele and haplotype frequencies in the countries to which the families belong, they represent an extensive collection of 3rd and 4th field resolution level 11-locus haplotype associations of 486 alleles identified in families from 8 countries.

Anti-Ro60 Seropositivity Determines Anti-Ro52 Epitope Mapping in Patients With Systemic Sclerosis

Epitope mapping of anti-Ro52 antibodies (Abs) has been extensively studied in patients with Sjögren's syndrome (SjS) and systemic lupus erythematosus (SLE). Comprehensive epitope mapping in systemic sclerosis (SSc), where anti-Ro52 antibodies are also frequently detected, has not been performed. The aim of the present study was to fully characterize Ro52 epitopes in anti-Ro52-positive SSc using Ro52 fragments spanning the full antigen. Further analysis was made according to anti-Ro60 status. Epitope mapping was performed in 43 anti-Ro52-positive SSc patients. Seventy eight anti-Ro52-positive pathological controls, including 20 patients with SjS, 28 patients with SLE, 15 patients with dermatomyositis (DM), and 15 patients with primary biliary cholangitis (PBC), and 20 anti-Ro52-negative healthy individuals as normal controls were also tested. Five recombinant Ro52 fragments [Ro52-1 (aa 1-127), Ro52-2 (aa 125-268), Ro52-3 (aa 268-475), Ro52-4 (aa 57-180), and Ro52-5 (aa 181-320) were used to test reactivity by line-immunoassay and in house ELISA. Anti-Ro60 reactivity was tested by ELISA. All anti-Ro52 positive sera reacted with Ro52-2; none recognized Ro52-3. Antibodies against Ro52-1 were less frequently found in SSc than in SjS/SLE (11.6 vs. 41.7%, p = 0.001); and antibodies against Ro52-4 were less frequently found in SSc than in SjS/SLE (27.9 vs. 50%, p = 0.03). In SSc patients, reactivity against Ro52-1 was more frequent in anti-Ro52+/anti-Ro60+ than in anti-Ro52+/anti-Ro60-patients (33.3 vs. 0%, p = 0.003). In this comprehensive analysis of Ro52 epitope mapping in SSc, the coiled coil domain remains the predominant epitope on Ro52. Contrary to SjS and SLE, patients with SSc fail to identify epitopic regions within the N-terminus of the protein, especially if they lack con-current anti-Ro60 reactivity.

Immunosenescence in patients with chronic systolic heart failure

AIM

Chronic heart failure (CHF) is characterized by hemodynamic compromise, neurohormonal and immune activation. We sought to examine the presence and severity of immunosenescence and its relation with the stages of CHF.

METHODS

We enrolled 86 consecutive stable systolic CHF patients and examined the relationship of leukocyte and lymphocyte subpopulation counts by flow cytometry with their functional status according to New York Heart Association (NYHA) class.

RESULTS

Patients with advanced heart failure were characterized by significantly increased neutrophil and reduced lymphocyte counts. T-helper cells were increased, whereas B-cells and T cytotoxic cells were decreased. T-helper cells exhibited significant differentiation and aging across the NYHA classes; naïve T-cells, CD4 + CD45RA +, were significantly reduced in NYHA Class IV and memory T-cells, CD4 + CD45RO +, were significantly increased.

CONCLUSION

Patients with CHF develop intense T-cell differentiation and aging. The presence of significant immunosenescence in advanced CHF may indicate a population at increased risk for adverse events.

Glomerular Epithelial Cells-Targeted Heme Oxygenase-1 Over Expression in the Rat: Attenuation of Proteinuria in Secondary But Not Primary Injury

BACKGROUND/AIMS

Induction of heme oxygenase 1 (HO-1) in glomerular epithelial cells (GEC) in response to injury is poor and this may be a disadvantage. We, therefore, explored whether HO-1 overexpression in GEC can reduce proteinuria induced by puromycin aminonucleoside (PAN) or in anti-glomerular basement membrane (GBM) antibody (Ab)-mediated glomerulonephritis (GN).

METHODS

HO-1 overexpression in GEC (GECHO-1) of Sprague-Dawley rats was achieved by targeting a FLAG-human (h) HO-1 using transposon-mediated transgenesis. Direct GEC injury was induced by a single injection of PAN. GN was induced by administration of an anti-rat GBM Ab and macrophage infiltration in glomeruli was assessed by immunohistochemistry and western blot analysis, which was also used to assess glomerular nephrin expression.

RESULTS

In GECHO-1 rats, FLAG-hHO-1 transprotein was co-immunolocalized with nephrin. Baseline glomerular HO-1 protein levels were higher in GECHO-1 compared to wild type (WT) rats. Administration of either PAN or anti-GBM Ab to WT rats increased glomerular HO-1 levels. Nephrin expression markedly decreased in glomeruli of WT or GECHO-1 rats treated with PAN. In anti-GBM Ab-treated WT rats, nephrin expression also decreased. In contrast, it was preserved in anti-GBM Ab-treated GECHO-1 rats. In these, macrophage infiltration in glomeruli and the ratio of urine albumin to urine creatinine (Ualb/Ucreat) were markedly reduced. There was no difference in Ualb/Ucreat between WT and GECHO-1 rats treated with PAN.

CONCLUSION

Depending on the type of injury, HO-1 overexpression in GEC may or may not reduce proteinuria. Reduced macrophage infiltration and preservation of nephrin expression are putative mechanisms underlying the protective effect of HO-1 overexpression following immune injury.

Patients with eating disorders showed no signs of coeliac disease before and after nutritional intervention

AIM

This study assessed the presence of specific antibodies for coeliac disease in outpatients suffering from eating disorders before and after nutritional intervention. We also evaluated whether those patients should undergo regular screening for coeliac disease.

METHODS

The sample consisted of 154 patients with a mean age of 16.7 years - ranging from one to 19 years of age - suffering from eating disorders. Serology screening for coeliac disease and total immunoglobulin A (IgA) levels was evaluated in the 154 children before the nutritional intervention and in 104 patients after the intervention. The patients consumed an adequate amount of gluten in both phases.

RESULTS

Postintervention evaluation revealed that 92 patients (88.5%) achieved a normal body weight, while the remaining 12 (11.5%) became obese. Postprandial abdominal discomfort and pain were resolved. The serology tests were negative in all patients, before and after intervention. None displayed IgA deficiency.

CONCLUSION

To the best of our knowledge, this was the first prospective study where patients underwent a screening serology for coeliac disease before and after nutritional intervention. No indication of the coexistence of eating disorders and coeliac disease was documented, and the patients in our study were unlikely to require regular screening for coeliac disease.

Distinct clinical and laboratory characteristics of latent autoimmune diabetes in adults in relation to type 1 and type 2 diabetes mellitus

Ever since its first appearance among the multiple forms of diabetes, latent autoimmune diabetes in adults (LADA), has been the focus of endless discussions concerning mainly its existence as a special type of diabetes. In this mini-review, through browsing important peer-reviewed publications, (original articles and reviews), we will attempt to refresh our knowledge regarding LADA hoping to enhance our understanding of this controversial diabetes entity. A unique combination of immunological, clinical and metabolic characteristics has been identified in this group of patients, namely persistent islet cell antibodies, high frequency of thyroid and gastric autoimmunity, DR3 and DR4 human leukocyte antigen haplotypes, progressive loss of beta cells, adult disease onset, normal weight, defective glycaemic control, and without tendency to ketoacidosis. Although anthropomorphic measurements are useful as a first line screening, the detection of C-peptide levels and the presence of glutamic acid decarboxylase (GAD) autoantibodies is undoubtedly the sine qua non condition for a confirmatory LADA diagnosis. In point of fact, GAD autoantibodies are far from being solely a biomarker and the specific role of these autoantibodies in disease pathogenesis is still to be thoroughly studied. Nevertheless, the lack of diagnostic criteria and guidelines still puzzle the physicians, who struggle between early diagnosis and correct timing for insulin treatment.

Antineutrophil cytoplasmic antibodies testing in a large cohort of unselected greek patients

Objective. To retrospectively evaluate ANCA testing in a cohort of unselected Greek in- and outpatients. Methods. In 10803 consecutive serum samples, ANCA were tested by indirect immunofluorescence (IIF) and ELISA. ELISA in inpatients was performed only on IIF positive sera. Results. Low prevalence (6.0%) of IIF positive samples was observed. Among these samples, 63.5% presented perinuclear (p-ANCA), 9.3% cytoplasmic (c-ANCA) and 27.2% atypical (x-ANCA) pattern. 16.1% of p-ANCA were antimyeloperoxidase (anti-MPO) positive, whereas 68.3% of c-ANCA were antiproteinase-3 (anti-PR3) positive. Only 17 IIF negative outpatients' samples were ELISA positive. ANCA-associated vasculitides (AAV), connective tissue disorders and gastrointestinal disorders represented 20.5%, 23.9%, and 21.2% of positive results, respectively. AAV patients exhibited higher rates of MPO/PR3 specificity compared to non-AAV (93.8% versus 8%). Conclusions. This first paper on Greek patients supports that screening for ANCA by IIF and confirming positive results by ELISA minimize laboratory charges without sacrificing diagnostic accuracy.

Antiglycan antibodies in Greek patients with inflammatory bowel disease

BACKGROUND

Antiglycan antibodies have recently been reported to be associated with Crohn's disease (CD). These antibodies include anti-Saccharomyces cerevisiae mannan antibodies (ASCA), anti-laminariobioside carbohydrate antibodies (ALCA), anti-chitobioside carbohydrate antibodies (ACCA), and anti-mannobioside carbohydrate antibodies (AMCA).

AIMS

The aim of this study was to evaluate their diagnostic accuracy in Greek patients with inflammatory bowel disease (IBD).

METHODS

Serum was collected from 191 patients with IBD (85 with ulcerative colitis (UC) and 106 with CD), 29 cases with other causes of intestinal inflammation and 96 healthy controls. Antiglycan antibodies were measured using commercially available enzyme immunoassays.

RESULTS

Higher levels of antiglycan antibodies were detected in patients with CD compared to patients with UC and controls. Although all types of antiglycan antibodies had a high specificity for diagnosing CD, their sensitivity was rather low, with best results obtained with ASCA and ALCA (41.5 and 52.8%, respectively). Increased levels of ASCA and ALCA were associated with stricturing and penetrating disease phenotype, and the need for surgery (p < 0.05).

CONCLUSIONS

Antiglycan antibodies in Greek IBD patients are significantly associated with CD, and especially to phenotypes of complicated disease, with ASCA and ALCA exhibiting the highest sensitivity.

Relevance of anti-C1q autoantibodies to lupus nephritis

The first component of the classical pathway of the complement system (C1q) is considered to have a crucial role in the clearance of immune complexes (ICs) as well as in the removal of waste material originating from apoptotic cells. A prolonged exposure of C1q epitopes to the immune system could eventually lead to an autoimmune response against itself. Although autoantibodies against C1q are found in several diseases, their clinical interest originates from their strong association to active lupus nephritis (LN). Several studies indicate that anti-C1q autoantibodies could serve as a reliable serologic marker in the assessment of LN activity compared to other immunological tests. Additionally, it was suggested that anti-C1q autoantibodies could play a role in LN pathogenesis. Their potential pathogenic actions likely depend on genetic background, titers, Ig classes and subclasses, and specific epitopes of anti-C1q autoantibodies as well as C1q availability and allocation. It is still unclear which different types of anti-C1q autoantibodies dominate in each case and if their upregulation is pathogenic, an epiphenomenon of aberrant tissue damage, or compensatory to an uncontrolled immune response.

Specificity of islet cell autoantibodies and coexistence with other organ specific autoantibodies in type 1 diabetes mellitus

Type 1 diabetes mellitus (T1DM) has been shown to be a disease characterized by immune-mediated destruction of the insulin-producing islet beta-cells (beta-cells) in the pancreas. Intensive studies, in both patients and animal models are trying to elucidate the specific antigenic targets that are responsible for islet cell autoimmunity. So far, the most important molecules that have been recognized are the native insulin, the 65-kDa form of glutamic acid decarboxylase (GAD(65)) and the insulinoma-antigen 2 (IA-2). Identification of those specific autoantibodies that are involved in the primary immunological events of the autoimmune disease process will allow the development of novel diagnostic procedures for early detection and initiation of potential therapy prior to irreversible loss of beta-cells. Within the framework of polyglandular disorders, T1DM may coexist with other organ specific autoimmune diseases such as autoimmune thyroid disease (ATD), autoimmune gastritis (AG), celiac disease (CD) and Addison's disease (AD), which are associated with the production of organ-specific autoantibodies. So, as a subset of patients with those autoantibodies will develop clinical disease, screening T1DM patients could prognosticate morbidity relative to unrecognised clinical entities. The close follow-up of patients with organ-specific autoantibodies could lead to seasonable identification of those requiring therapy.

Anti-smooth muscle antibodies (ASMAs) and anti-cytoskeleton antibodies (ACTAs) in liver diseases: a comparison of classical indirect immunofluorescence with ELISA

In the diagnosis of autoimmune hepatitis type I (AIH-I), the routine assay of indirect immunofluorescence (IFL), used for the detection of anti-smooth muscle antibodies (ASMAs), has a low predictive value. On the other hand, the enzyme-linked immunosorbent assay (ELISA), which detects anti-cytoskeleton antibodies (ACTAs), presents contradictory results concerning their specific antigenic target. In this study, we first looked for the immunological properties (isotypes and antigenic targets) of autoantibodies in AIH-I and two other control liver diseases: primary biliary cirrhosis (PBC) and viral hepatitis (VH), using ELISA based on cytoskeleton proteins: F-actin, G-actin, myosin, tropomyosin, troponin, desmin, vimentin, keratin, and an extract of HEp-2 carcinoma cells. We also compared the diagnostic value of IFL and ELISA. In contrast to previous studies, we found that actin was not specific for AIH-I. No autoantigen and no antibody class or subclass discriminated AIH-I from the control diseases. IFL is more suitable for AIH-I diagnosis, as 97% of AIH-I sera but only 22% of PBC sera were ASMA-positive. Additionally, 96% of ASMA-positive, and all ASMA-negative sera from all three liver diseases were ACTA-positive. ASMA were mainly IgG, while >50% of ACTA also contained IgA and IgM. These data suggest that ACTAs recognize additional epitopes as compared to ASMAs, and they frequently occur in all liver diseases.

Serum IL-6, TNFalpha, p55 srTNFalpha, p75srTNFalpha, srIL-2alpha levels and disease activity in systemic lupus erythematosus

The aim of this study was to determine whether the levels of serum cytokines IL-6 and TNFalpha and of the soluble receptors p55 srTNFalpha, p75 srTNFalpha and srIL-2ac are valuable markers of disease activity in patients with systemic lupus erythematosus (SLE) compared with the established parameters of anti-dsDNA, C3, C4 and CH50. Forty patients with SLE, 19 ambulatory and 21 hospitalised, were included in this study. On the day of blood sampling a clinical examination was performed and SLEDAI and ECLAM disease activity scores were used to assess disease activity. Nineteen patients had inactive disease and 21 patients had active disease. Thirteen patients from the second group developed nephritis. In these patients the blood sampling and disease activity assessment were performed twice (at presentation and 6 months after treatment). Serum levels of cytokines and soluble receptors were measured by ELISA. Serum levels of cytokines and soluble receptors of patients with active disease were significantly higher than in patients with inactive disease (IL-6 p = 0.0004, TNFalpha p = 0.0015, srIL-2c p<0.0001, p55 srTNFalpha p<0.0001, p75 srTNFalpha p<0.0001). Serum soluble receptor levels of patients with inactive disease were higher than those of healthy controls (p55 srTNFalpha p<0.0001, p75 srTNFalpha p = 0.0002, srIL-2alpha p = 0.0012). No significant difference was found for TNFalpha and IL-6 (TNFalpha p=0.015, IL-6 p=0.019). Serum TNFalpha levels and especially srIL-2alpha, p55 srTNFalpha( and p75 srTNFalpha levels correlated strongly with SLEDAI and ECLAM disease activity scores, anti-dsDNA, C3, C4 and CH50 (p<0.0001). Serum soluble receptor (srIL-2alphac, p55 srTNFa, p75 srTNFalpha) levels were higher in patients with nephritis before treatment and decreased significantly 6 months after treatment (p=0.005). The same trend was noticed with SLEDAI and ECLAM disease activity scores (p = 0.005) and anti-dsDNA (p = 0.008). In contrast, no significant differences were observed for C3 and C4 levels before and after treatment, which suggests that soluble receptors of cytokines are more sensitive markers of disease activity than C3 or C4 in predicting improvement. Serum levels of srIL-2alpha, p55 srTNFalpha and p75 srTNFalpha could provide useful information about disease activity in SLE patients, especially in cases where the other markers do not.