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Biomedical subjects

Eleni E Magira

Publications and source records attributed to Eleni E Magira.

4 recordsLinked to original sources

Identification of HLA-DQalpha and -DRbeta residues associated with susceptibility and protection to epithelial ovarian cancer.

Substantial evidence has been accumulated suggesting that T cells in patients with epithelial ovarian carcinoma (EOC) exhibit an antigen-driven immune response directed against the tumor cells. In the context of human leukocyte antigen (HLA), this suggests its possible involvement in the disease. Therefore, we examined the distribution of the HLA-DRB1*, -DQA1*, and -DQB1* alleles in 47 patients with EOC and 67 healthy Caucasian women. The frequency of D(70) and E(71) polymorphic residues of the DRB1 alleles was significantly reduced in EOC patients versus controls (pD(70)E(71) = 0.009), suggesting a protective role against the disease. The DQalpha residues R(52) and Y(11)R(55) were increased in the patients (p = 0.008 and 0.012, respectively). Because residues 11 and 55 participate in the formation of pocket 1, they may be functionally important amino acid positions that influence disease susceptibility. The frequency of the DQalpha susceptibility epitope (R(52)Y(11)R(55)) among the DRbetaD(70)E(71)-positive EOC patients was increased when compared with DRbetaD(70)E(71)-positive controls (EOC, 100%; control, 52%; p = 0.028). Among individuals without the DQalpha susceptibility epitope, the distribution of DRbetaD(70)E(71)-positive cases was significantly different between EOC patients and controls (EOC, 0%; control, 60%; p = 0.039). Therefore, it appears that the presence of DQalpha susceptibility elements overrides the protective effect of the DRbetaD(70)E(71) epitope and suggests an interactive relationship between DRbeta and DQalpha epitopes that may be of importance for disease susceptibility. Because positions DRbeta 70,71 and DQalpha 52 have been implicated in immunologic diseases, it is likely that besides being critical for T-cell recognition, they may also play a role in T-cell development and acquisition of the T-cell repertoire.

Amino Acid Sequence↗

Whipple's disease: multiple hospital admissions of a man with diarrhoea, fever and arthralgia.

Whipple's disease is a rare chronic multi-systemic infectious disorder caused by the Gram-positive bacillus, Tropheryma whippelii. Infection may involve any organ in the body, and most commonly affects white men in the fourth to sixth decades of life. The most common presenting symptoms are gastrointestinal and include abdominal pain, diarrhoea, anorexia and associated weight loss. However, the variability in presentation is considerable and some patients may present with intermittent low-grade fever, neurological abnormalities (nystagmus, ophthalmoplegia, cranial nerve defects), migratory arthralgia, lymphadenopathy, or involvement of the cardiovascular system. In typical Whipple's disease, the most severe changes are seen in the proximal small intestine and biopsy reveals mucosal and lymph node infiltration with large, foamy histocytes, containing granules that stain positive with periodic acid-Schiff (PAS) reagent and represent intact or partially degraded bacteria. Extended antibiotic treatment (up to 1-year) is indicated. Life-long surveillance for recurrence is essential, once primary treatment has been completed. We report the case of a 58-year-old man who developed a rare infection with the actinobacterium, T. whippelii. The patient had suffered intermittent episodes of varying clinical symptoms associated with multiple hospital admissions and clinical diagnoses, spanning a period of 22 years. Historically, arthralgia was the primary manifestation in this patient and also was the chief complaint for which he was first hospitalized 22 years ago. At his most recent admission to our hospital department, his presenting symptoms were persistent fatigue, weight loss, arthralgia and diarrhoea. Thus, it is essential that clinicians retain a high index of suspicion for T. whippelii infection in patients who have a long-term history of arthritis, fever and diarrhoea.

Anti-Bacterial Agents↗

Differential distribution of HLA-DQ beta/DR beta epitopes in the two forms of Guillain-Barré syndrome, acute motor axonal neuropathy and acute inflammatory demyelinating polyneuropathy (AIDP): identification of DQ beta epitopes associated with susceptibility to and protection from AIDP.

Guillain-Barré syndrome (GBS), an acute, immune-mediated paralytic disorder affecting the peripheral nervous system, is the most common cause of acute flaccid paralysis in the post-polio era. GBS is classified into several subtypes based on clinical and pathologic criteria, with acute inflammatory demyelinating polyneuropathy (AIDP) and acute motor axonal neuropathy (AMAN) being the most common forms observed. To better understand the pathogenesis of GBS and host susceptibility to developing the disease, the distribution of HLA class II Ags along with the seroreactivity to Campylobacter jejuni were investigated in a population of GBS patients from northern China. Using DNA-based typing methods, 47 patients with AMAN, 25 patients with AIDP, and 97 healthy controls were studied for the distribution of class II alleles. We found that the DQ beta RLD(55-57)/ED(70-71) and DR beta E(9)V(11)H(13) epitopes were associated with susceptibility to AIDP (p = 0.009 and p = 0.004, respectively), and the DQ beta RPD(55-57) epitope was associated with protection (p = 0.05) from AIDP. These DQ beta/DR beta positional residues are a part of pockets 4 (DQ beta 70, 71, DR beta 13), 6 (DR beta 11), and 9 (DQ beta 56, 57, DR beta 9); have been demonstrated to be important in peptide binding and T cell recognition; and are associated with other diseases that have a pathoimmunological basis. Class II HLA associations were not identified with AMAN, suggesting a different immunological mechanism of disease induction in the two forms of GBS. These findings provide immunogenetic evidence for differentiating the two disease entities (AMAN and AIDP) and focuses our attention on particular DR beta/DQ beta residues that may be instrumental in understanding the pathophysiology of AIDP.

Acute Disease↗