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.

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.

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.

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 alleles as predisposal factors for postmenopausal osteoporosis in a Greek population

It is well established that genetic factors play an important role in the pathogenesis of osteoporosis, a common condition characterized by reduced bone mass and increased fracture risk. The major histocompatibility complex in humans, known as human leukocyte antigen (HLA) region, is the most polymorphic human genetic system and it is known as a cluster of genetic markers, associated with several diseases. In order to evaluate the contribution of HLA alleles in bone mass loss, polymorphisms in the HLA class I (-A, -B and -Cw) and class II (-DR and -DQ) antigens were studied in 126 postmenopausal women of Greek origin. It was found that HLA-B7 (P= 0.069), -DR15 (P= 0.019) and -DQ6 (P= 0.026) were associated with a lower bone mineral density measured at the forearm. This study shows a significant association between HLA alleles and bone mass loss in the population studied.