Hemophagocytic Lymphohistiocytosis Secondary to Peripheral T Cell Lymphoma with Rapid Onset and Fatal Progression in a Young Patient: A Case Report and Review of the Literature.

BACKGROUND Constant stimulation of lymphocytes and histiocytes can result in hemophagocytic lymphohistiocytosis (HLH), which can be primary or secondary (sHLH). The main causes of sHLH are infections and hematological malignancies, especially non-Hodgkin lymphoma. Despite new insights into the pathogenesis of HLH, the diagnosis and treatment of this immune disorder remain a great challenge. CASE REPORT We present a case of a young adult without comorbidities whose clinical course was nonspecific for several months and resulted in late diagnosis of HLH secondary to peripheral T cell lymphoma (PTCL). The etiological factor of recurring fever, hepatosplenomegaly, and deteriorating condition was unidentified for a long time before fatal sHLH was finally diagnosed. The patient was treated according to the HLH-2004 protocol; however, he did not achieve any response. Unfortunately, due to nonspecific symptoms, lack of lymphadenopathy for a long time, and negative positron emission tomography results, the diagnosis of PTCL was established only after the patient's death. CONCLUSIONS It should be emphasized that early diagnosis is crucial for better prognosis of patients with sHLH. Bone marrow biopsy is worth considering in patients with prolonged fever of unknown origin, hyperferritinemia, splenomegaly, and unexplained cytopenia of 2 or more lineages. Despite the existence of diagnostic and therapeutic protocols available in the literature, the prompt diagnosis and treatment of HLH remains a great challenge. More precise and specific diagnostic tools for HLH are needed.

Immunosuppression as a Hallmark of Critical COVID-19: Prospective Study.

The dysregulation of both the innate and adaptive responses to SARS-CoV-2 have an impact on the course of COVID-19, and play a role in the clinical outcome of the disease. Here, we performed a comprehensive analysis of peripheral blood lymphocyte subpopulations in 82 patients with COVID-19, including 31 patients with a critical course of the disease. In COVID-19 patients who required hospitalization we analyzed T cell subsets, including Treg cells, as well as TCRα/ß and γ/δ, NK cells, and B cells, during the first two weeks after admission to hospital due to the SARS-CoV-2 infection, with marked reductions in leukocytes subpopulations, especially in critically ill COVID-19 patients. We showed decreased levels of Th, Ts cells, Treg cells (both naïve and induced), TCRα/ß and γ/δ cells, as well as CD16+CD56+NK cells in ICU compared to non-ICU COVID-19 patients. We observed impaired function of T and NK cells in critically ill COVID-19 patients with extremely low levels of secreted cytokines. We found that the IL-2/INFγ ratio was the strongest indicator of a critical course of COVID-19, and was associated with fatal outcomes. Our findings showed markedly impaired innate and adaptive responses in critically ill COVID-19 patients, and suggest that the immunosuppressive state in the case of a critical course of SARS-CoV-2 infection might reflect subsequent clinical deterioration and predict a fatal outcome.

Lymphocyte subsets in haematological patients with COVID-19: Multicentre prospective study.

The role of immune dysregulation in the course and prognosis of COVID-19 is not clearly established. In particular, immune status in specific populations such as haematological patients, who have an impaired immunological system, has not been described so far. Here, we performed a comprehensive analysis of peripheral blood lymphocyte subsets in 27 SARS-CoV-2-infected patients, including 16 patients with haematological malignancies. We identified T cell subpopulations, B cells, NK cells and TCR α/ß and É£/ƍ-expressing T cells during COVID-19 infection, with significant changes observed in immune profiles during the course of disease, especially in haematological patients. We observed an increase in activated T lymphocytes (CD3+HLA-DR+ and CD3+CD8+HLA-DR+) in the early stages of SARS-CoV-2 infection with a concomitant decrease in the CD4/CD8 ratio in haematological patients compared to non-haematological patients affected by COVID-19. We also found a decrease in É£/ƍ T cells in both studied groups of patients, with lower numbers of CD25+ T cells and CD16+CD56+ NK cells in haematological patients compared to non-haematological patients with COVID-19. Our findings demonstrate, for the first time, impaired adaptive immunity in patients with haematological malignancies infected with COVID-19, resulting in impaired cellular immune responses to SARS-CoV-2. This warrants further investigation of this disease group in COVID-19 patient cohorts.

Nosocomial outbreak of SARS-CoV-2 infection in a haematological unit - High mortality rate in infected patients with haematologic malignancies.

BACKGROUND: Here we report nosocomial outbreak of COVID-19 among patients in a haematological unit. To our knowledge this is the first report from Central Europe comparing morbidity and mortality in infected and non-infected patients after exposure to SARS-CoV-2. METHODS: The outbreak involved 39 individuals: 19 patients and 20 health care workers. The SARS-CoV-2 test by nasopharyngeal swabs was performed by real-time RT-PCR. Exposed patients were divided into two groups: quarantine patients with and without COVID-19. All patients were prospectively examined at the following time points: 0, 7 days, 14 days, 21 days and 28 days after confirmation or exclusion of SARS-CoV-2. RESULTS: Infection was confirmed in a total of 5/20 health care workers and 10/19 patients. Among the patients positive for SARS-CoV-2 infection, the mortality rate was 36.8 %. The probability of death in patients infected with SARS-CoV-2 increased 8-fold (p = 0.03). Bacterial, fungal, and viral co-infection significantly decreased survival in these patients (p < 0.05). Additionally, the probability of death was much higher in patients older than 40 years of age (p = 0.032). CONCLUSION: This study showed significantly higher mortality rate in COVID-19 patients with haematologic diseases compared to the non-infected patient group. Haematologic patients with COVID-19 have 50 % less chance of survival.