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    Assessment of mimicking by EBV-CMV immunoglobulin M of anti-HLA antibodies
    (Elsevier, 2023) Gulec, Rasime Derya; Arslan, Fatma Demet; Ozyilmaz, Berk; Yilmaz, Nisel; Hanci, Sevgi Yilmaz; Kose, Sukran
    Objective: We aimed to show the cross-reactivity that may occur between immunoglobulin (Ig) M antibodies that form against Cytomegalovirus (CMV) and/or Epstein-Barr virus (EBV) and human leukocyte antigens (HLA).Methods: Complement-dependent cytotoxicity (CDC) cross-reactivity between serum samples of 57 patients with IgM positive CMV and/or EBV infections and T and B cells from 15 healthy donors were evaluated. Dithiothreitol was used to distinguish cross-reactivity caused by IgM antibodies from IgG.Results: The cross-reactivity ratio between pathogenic IgM antibodies with T cell of the 12th donor, and B cell of the 3rd, 4th, and 8th donors was significantly higher (p = 0.011, <0.001, <0.001 and 0.013, respectively). The ratio of B cell CDC cross-reactivity of all donors (26.4%) was higher than the ratio of T cell CDC cross-reactivity (5.2%) (p < 0.001). The ratio of T cell CDC cross-reactivity of sera containing both anti-CMV IgM and anti-EBV IgM antibodies was significantly higher than those of sera containing only anti-CMV IgM or only anti-EBV IgM antibodies (p = 0.002 and p < 0.001, respectively). There was no difference between B cell CDC cross-reactivity rates according to the presence of anti-CMV and/or anti-EBV IgM antibodies.Conclusion: Cross-reactivity may occur between anti-CMV and anti-EBV IgM antibodies with HLA molecules. Thus, in graft recipients, pathogenic IgMs can also act as de novo anti-HLA antibodies and aggravate the rejection process.
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    Usefulness of laboratory parameters and chest CT in the early diagnosis of COVID-19
    (Inst Medicina Tropical Sao Paulo, 2022) Colak, Ayfer; Oncel, Dilek; Altin, Zeynep; Turken, Melda; Arslan, Fatma Demet; Iyilikci, Veli; Yilmaz, Nisel
    In the present study, the importance of laboratory parameters and CT findings in the early diagnosis of COVID-19 was investigated. To this end, 245 patients admitted between April 1st, and May 30th, 2020 with suspected COVID-19 were enrolled. The patients were divided into three groups according to chest CT findings and RT-PCR results. The non-COVID-19 group consisted of 71 patients with negative RT-PCR results and no chest CT findings. Ninety-five patients with positive RT-PCR results and negative chest CT findings were included in the COVID-19 group; 79 patients with positive RT-PCR results and chest CT findings consistent with COVID-19 manifestations were included in COVID-19 pneumonia group. Chest CT findings were positive in 45% of all COVID-19 patients. Patients with positive chest CT findings had mild (n=30), moderate (n=21) andor severe (n=28) lung involvement. In the COVID-19 group, CRP levels and the percentage of monocytes increased significantly. As disease progressed from mild to severe, CRP, LDH and ferritin levels gradually increased. In the ROC analysis, the area under the curve corresponding to the percentage value of monocytes (AUC=0.887) had a very good accuracy in predicting COVID-19 cases. The multinomial logistic regression analysis showed that CRP, LYM and % MONO were independent factors for COVID-19. Furthermore, the chest CT evaluation is a relevant tool in patients with clinical suspicion of COVID-19 pneumonia and negative RT-PCR results. In addition to decreased lymphocyte count, the increased percentage of monocytes may also guide the diagnosis.