Multi-organ failure is one of the common causes of fatal outcome in COVID-19 patients. However, the pathogenetic association of the SARS-CoV-2 viral load (VL) level with fatal dysfunctions of the lungs, liver, kidneys, heart, spleen and brain, as well as with the risk of death in COVID-19 patients remains poorly understood. SARS-CoV-2 VL in the lungs, heart, liver, kidneys, brain, spleen and lymph nodes have been measured by RT qPCR using the following formula: NSARS-CoV−2/NABL1 × 100. Dissemination of SARS-CoV-2 in 30.5% of cases was mono-organ, and in 63.9% of cases, it was multi-organ. The average SARS-CoV-2 VL in the exudative phase of diffuse alveolar damage (DAD) was 60 times higher than in the proliferative phase. The SARS-CoV-2 VL in the lungs ranged from 0 to 250,281 copies. The “pulmonary factors” of SARS-CoV-2 multi-organ dissemination are the high level of SARS-CoV-2 VL (≥4909) and the exudative phase of DAD. The frequency of SARS-CoV-2 dissemination to lymph nodes was 86.9%, heart–56.5%, spleen–52.2%, liver–47.8%, kidney–26%, and brain–13%. We found no link between the SARS-CoV-2 VL level in the liver, kidneys, and heart and the serum level of CPK, LDH, ALP, ALT, AST and Cr of COVID-19 patients. Isolated detection of SARS-CoV-2 RNA in the myocardium of COVID-19 patients who died from heart failure is possible. The pathogenesis of COVID-19-associated multi-organ failure requires further research in a larger cohort of patients.

Lymphopenia is a frequent hematological manifestation, associated with a severe course of COVID-19, with an insufficiently understood pathogenesis. We present molecular genetic immunohistochemical, and electron microscopic data on SARS-CoV-2 dissemination and viral load (VL) in lungs, mediastinum lymph nodes, and the spleen of 36 patients who died from COVID-19. Lymphopenia <1 × 109/L was observed in 23 of 36 (63.8%) patients. In 12 of 36 cases (33%) SARS-CoV-2 was found in lung tissues only with a median VL of 239 copies (range 18–1952) SARS-CoV-2 cDNA per 100 copies of ABL1. Histomorphological changes corresponding to bronchopneumonia and the proliferative phase of DAD were observed in these cases. SARS-CoV-2 dissemination into the lungs, lymph nodes, and spleen was detected in 23 of 36 patients (58.4%) and was associated with the exudative phase of DAD in most of these cases. The median VL in the lungs was 12,116 copies (range 810–250281), lymph nodes—832 copies (range 96–11586), and spleen—71.5 copies (range 0–2899). SARS-CoV-2 in all cases belonged to the 19A strain. A immunohistochemical study revealed SARS-CoV-2 proteins in pneumocytes, alveolar macrophages, and bronchiolar epithelial cells in lung tissue, sinus histiocytes of lymph nodes, as well as cells of the Billroth pulp cords and spleen capsule. SARS-CoV-2 particles were detected by transmission electron microscopy in the cytoplasm of the endothelial cell, macrophages, and lymphocytes. The infection of lymphocytes with SARS-CoV-2 that we discovered for the first time may indicate a possible link between lymphopenia and SARS-CoV-2-mediated cytotoxic effect.

Safe follow-up is possible in about 50% of the patients with CML and stable deep MRs without TKI therapy. The introduction of this approach into clinical practice requires regular molecular genetic monitoring and organizational activities. Biological factors in maintaining remission after TKI discontinuation need to be separately studied.

Chronic myeloproliferative disease that is characterized by the JAK2 V617F mutation, borderline hemoglobin counts, and morphological features of a bone marrow trephine biopsy specimen, which are specific for PV, is an independent PV variant, namely: latent PV.

Purpose of the study. A comparative evaluation of the effectiveness of different therapeutic strategies in patients with polycythemia vera (PV) and essential thrombocythemia (ET). Materials and methods. Patients with PV or ET, diagnosed according to the criteria WHO 2016 were included in the study. The primary endpoint - 6 months of therapy (clinical-hematological and molecular responses). The secondary endpoint - 12 months of therapy (clinico-hematologic, molecular, histological responses). Sixty three patients were included in the analysis: the first group consisted of 33 patients who received the therapy with ce-pegiterferone alpha-2b (ce-pegalpha-INF-α-2b), 10 of them received previous treatment; the second group - 23 patients btained hydroxycarbamide; the third group - 7 patients were treated with recombinant interferon alpha therapy (rINFα). In comparison groups, differences in age were revealed: patients receiving hydroxycarbamide therapy were older. Phlebotomy occurred in 36% of patients in the first group, 9% in the second group, and 14% in the third group. Results. By the 6th month of therapy, 43% of the patients receiving the ce-pegalpha-INF-α-2b had complete clinical-hematologic response, 36% had partial clinical-hematologic remission and stabilization of the disease was established in 21% cases. No disease progression occured. By the 12th month of therapy, statistically significant differences in terms of efficacy between the different therapeutic groups (p = 0.2462, Fisher's exact test). In all three groups, the allelic load of JAK2V617F decreased: from 50 to 19%, from 22.3 to 15.8%, from 50 to 7.19%, respectively. The lower the allele load positively correlated with better response to therapy, which was observed in all analyzed groups. Hematologic adverse events (AEs) were more frequently observed in patients receiving ce-pegalpha-INF-α-2b therapy. Local reactions developed on 3-7 days of therapy as a hyperemic macula at the injection site. Both these reactions and hair loss did not influence on patient’s condition. In the second group (patients with hydroxycarbamide therapy) there were changes in the skin and mucous membranes: dry skin, stomatitis, and in older patients new keratomas appeared. The flu-like syndrome was the most common adverse event associated with the therapy of ce-pegalpha-INF-α-2b, which fully relived during the first month of therapy. There was only one case with the flu-like syndrome we observed at the 11th month of therapy. As a rule, the biochemical blood test changes did not influence on patient’s condition, were mostly associated with dietary violations, had a tendency to self-resolution and did not require medical interventions. Serious AEs were reported in one case - pulmonary embolism in a patient treated with rINFα. The reasons for the therapy discontinue in group 1: toxic hepatitis, intolerance, by the request of the patient, inadequate efficacy of therapy; in group 2: skin toxicity, in group 3: thromboses. The conclusion. Treatment of ce-pegalpha-INF-α-2b in patients with PV and ET is highly effective - the most patients pbtained clinical and hematological responses. There were no statistically significant differences in these parameters in comparison with hydroxycarbamide and rINFα. The use of the ce-pegalpha-INF-α-2b had an acceptable safety profile. The estimated therapeutic dose should be calculated according to body weight. To reduce the frequency of hematologic AE, titration of the drug dose is required.