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Abstract We stratified post-COVID patients into four newly established clinical groups based on the presence or absence of at least one subjective respiratory symptom and at least one objective sign of pulmonary involvement. Nearly half of outpatients and one third of hospitalized post-COVID patients had objective signs of pulmonary involvement without accompanying subjective respiratory symptoms three months after diagnosis.

Background: The diagnosis of SARS-CoV-2 is almost exclusively performed by PCR or antigen detection. The detection of specific antibodies has not yet been considered in official diagnostic guidelines as major laboratory evidence for a case definition. The aim the present study is to analyze antibody responses in outpatient and inpatient cohorts of COVID-19 patients in the Czech Republic over a 12-month period, and assess the potential of antibodies as a diagnostic tool. Methods: A total of 644 patients was enrolled in the prospective study. IgA, IgM and IgG antibody levels, as well as virus neutralization titers, were analyzed over a 12-month period. Results: Our study showed low antibody positivity levels at the admission. However, at 2 weeks after infection, 98.75% and 95.00% of hospitalized patients were IgA and IgG positive, respectively. Even in the outpatient cohort characterized by milder disease courses, the IgG antibody response was still sustained at 9 and 12 months. The data show a high correlation between the IgG levels and virus neutralization titers (VNTs). Samples from later time-points showed positive antibody responses after vaccination in both cohorts characterized by high IgG levels and VNT over 1:640. The samples from unvaccinated persons indicated a relatively high level of reinfection at 6.87%. Conclusions: Our results show that the detection of antibodies against the SARS-CoV-2 shows an increasing sensitivity from week 2 after infection and remains highly positive over the 12-month period. The levels of IgG antibodies correlate significantly with the VNTs. This suggests that the serological data may be a valuable tool in the diagnosis of SARS-CoV-2 infection.

Cardiotoxicity is a serious adverse reaction to cancer chemotherapy and may lead to critical heart damage. Imatinib mesylate (IMB), a selective tyrosine kinase inhibitor, is sometimes accompanied by severe cardiovascular complications. To minimize risk, early biomarkers of such complications are of utmost importance. At the present time, microRNAs (miRNAs) are intensively studied as potential biomarkers of many pathological processes. Many miRNAs appear to be specific in some tissues, including the heart. In the present study we have explored the potential of specific miRNAs to be early markers of IMB-induced cardiotoxicity. Doxorubicin (DOX), an anthracycline with well-known cardiotoxicity, was used for comparison. NMRI mice were treated with IMB or DOX for nine days in doses corresponding to the highest recommended doses in oncological patients, following which plasmatic levels of miRNAs were analyzed in miRNA microarrays and selected cardio-specific miRNAs were quantified using qPCR. The plasmatic level of miR-1a, miR-133a, miR-133b, miR-339, miR-7058, miR-6236 and miR-6240 were the most different between the IMB-treated and control mice. Interestingly, most of the miRNAs affected by DOX were also affected by IMB showing the same trends. Concerning selected microRNAs in the hearts of individual mice, only miR-34a was significantly increased after DOX treatment, and only miR-205 was significantly decreased after IMB and DOX treatment. However, no changes in any miRNA expression correlated with the level of troponin T, a classical marker of heart injury.