SUMMARY The purpose of this study was to investigate the relation between venous blood gas and chest computerized tomography findings and the clinical conditions of COVID-19 pneumonia. METHODS: A total of 309 patients admitted to the emergency department and subsequently confirmed COVID-19 cases was examined. Patients with pneumonia symptoms, chest computerized tomography scan, venous blood gas findings, and confirmed COVID-19 on reverse transcription-polymerase chain reaction (PCR) were consecutively enrolled. Multiple linear regression was used to predict computerized tomography and blood gas findings by clinical/laboratory data. RESULTS: The median age of patients was 51 (interquartile range 39–66), and 51.5% were male. The mortality rate at the end of follow-up was 18.8%. With respect to survival status of patients pCO2 and HCO3 levels and total computerized tomography score values were found to be higher in the surviving patients (p<0.001 and p=0.003, respectively), whereas pH and lactate levels were higher in patients who died (p=0.022 and p=0.001, respectively). With logistic regression analysis, total tomography score was found to be significantly effective on mortality (p<0.001). The diffuse and random involvement of the lungs had a significant effect on mortality (p<0.001, 95%CI 3.853–38.769, OR 12.222 and p=0.027; 95%CI 1.155–11.640, OR 3.667, respectively). With linear regression analysis, the effect of pH and lactate results were found to have a positive effect on total tomography score (p=0.003 and p<0.001, respectively), whereas pCO2 was found to have a negative effect (p=0.029). CONCLUSION: There was correlation between venous blood gas indices and radiologic scores in COVID-19 patients. Venous blood gas taken in emergency department can be a fast, applicable, minor-invasive, and complementary test in terms of diagnosing COVID-19 pneumonia and predicting the prognosis of disease.

RESUMO OBJETIVO: A pandemia de COVID-19 tem afetado o mundo todo, constituindo uma ameaça grave para a saúde humana. As células T desempenham um papel crítico na imunidade celular contra infecções virais. Procuramos desvendar a relação entre sub grupos de células T e a severidade da doença. MÉTODOS: Um total de 40 pacientes com COVID-19 foram aleatoriamente recrutados para o presente estudo transversal. Todos os casos foram confirmados por RT-PCR quantitativo. Os pacientes foram divididos em dois grupos equivalentes, um grave e um não-grave. Os dados da avaliação clínica, laboratorial e da citometria de fluxo foram obtidos para ambos os grupos e comparados. RESULTADOS: Os subconjuntos de linfócitos, células T CD4+ e CD8+, células T de memória CD4+, células T de memória CD8+, células T CD4+ virgens, células T efetoras CD4+, células T de memória central CD4+ e células T CD3+ CD4+ CD25+ estavam significativamente mais baixas nos pacientes graves. A razão células T virgens/células T efetoras TCD4+, que é um indicador da diferenciação entre células T virgens e células de memória, estava relativamente reduzida em casos graves da doença. As células T duplo-positivas CD4+CD8+ periféricas estavam notavelmente mais baixas em casos graves da doença (mediana das células T DP: 11,12 µL vs. 1,95 µL; p< 0,001). CONCLUSÃO: Conforme aumenta a gravidade da doença nos casos de COVID-19, o número de subconjuntos de células T diminui significativamente. A supressão da diferenciação de células T virgens para células T efetoras é o resultado do comprometimento grave das funções imunológicas adaptativas. As células T duplo-positivas CD4+CD8+ periféricas estavam notavelmente mais baixas em casos graves da doença e podem ser um marcador útil para predizer a severidade da doença.

SUMMARY BACKGROUND: The COVID-19 pandemic has affected the entire world, posing a serious threat to human health. T cells play a critical role in the cellular immune response against viral infections. We aimed to reveal the relationship between T cell subsets and disease severity. METHODS: 40 COVID-19 patients were randomly recruited in this cross-sectional study. All cases were confirmed by quantitative RT-PCR. Patients were divided into two equivalent groups, one severe and one nonsevere. Clinical, laboratory and flow cytometric data were obtained from both clinical groups and compared. RESULTS: Lymphocyte subsets, CD4+ and CD8+ T cells, memory CD4+ T cells, memory CD8+ T cells, naive CD4+ T cells, effector memory CD4+ T cells, central memory CD4+ T cells, and CD3+CD4+ CD25+ T cells were significantly lower in severe patients. The naive T cell/CD4 + EM T cell ratio, which is an indicator of the differentiation from naive T cells to memory cells, was relatively reduced in severe disease. Peripheral CD4+CD8+ double-positive T cells were notably lower in severe presentations of the disease (median DP T cells 11.12 µL vs 1.95 µL; p< 0.001). CONCLUSIONS: As disease severity increases in COVID-19 infection, the number of T cell subsets decreases significantly. Suppression of differentiation from naive T cells to effector memory T cells is the result of severe impairment in adaptive immune functions. Peripheral CD4+CD8+ double-positive T cells were significantly reduced in severe disease presentations and may be a useful marker to predict disease severity.

RESUMO OBJETIVO O objetivo do presente estudo foi investigar o papel da razão neutrófilos/linfócitos (RNL), um marcador de inflamação, hemograma completo e parâmetros bioquímicos no diagnóstico de COVID-19. MÉTODOS Um total de 80 pacientes internados na clínica médica foram incluídos no estudo. Os casos foram alocados em dois grupos, COVID (+) e (-), de acordo com a reação em cadeia da polimerase com transcrição reversa em tempo real. Os dados demográficos, clínicos e laboratoriais [NLR, relação plaquetas / linfócitos (PLR), hemograma completo, bioquímica e sorologia]) dos pacientes foram obtidos retrospectivamente no sistema de gerenciamento de dados hospitalares. RESULTADOS Os níveis de NLR e febre foram maiores nos casos de COVID-19 (+) (P = 0,021, P = 0,001,respectivamente). Não houve diferença entre homens e mulheres em relação à positividade para COVID-19 (P = 0,527). Os níveis totais de bilirrubina foram menores nos casos de COVID-19 (+) (P = 0,040). Quando a análise ROC foi realizada para NLR nos casos COVID-19 (+), o valor da AUC foi de 0,660 (P = 0,021), sensibilidade 69,01%, especificidade 65,40%, LR +: 1,98 e LR-: 0,48 , PPV: 80,43 e NPV: 50,00 quando o NLR era> 2,4. The risk of COVID-19 was found to be 20.3-fold greater when NLR was ≥ 2.4 in the logistic regression (P=0.007). CONCLUSÃO NLR é um preditor independente para o diagnóstico de COVID-19. Também concluímos que aferições de febre e bilirrubina total podem ser úteis para o diagnóstico de COVID-19 nesta população.

SUMMARY OBJECTIVE The present study aimed to investigate the role of neutrophil/lymphocyte ratio (NLR), an inflammation marker, complete blood count, and biochemical parameters in the diagnosis of COVID-19. METHODS A total of 80 patients who had been hospitalized in the internal medicine clinic were enrolled in the study. The cases were allocated into two groups, i.e., COVID (+) and (-), based on real-time reverse transcription-polymerase chain reaction. The demographic, clinical, and laboratory [NLR, platelet/lymphocyte ratio (PLR), complete blood count, biochemistry, and serology] data of the patients were retrospectively obtained from the hospital data management system. RESULTS NLR and fever levels were found to be higher in COVID-19 (+) cases (P=0.021, P=0.001, respectively). There was no difference between males and females with regard to COVID-19 positivity (P=0.527). Total bilirubin levels were found to be lower in COVID-19 (+) cases (P=0.040). When the ROC analysis was carried out for NLR in COVID-19 (+) cases, the AUC value was found to be 0.660 (P=0.021), sensitivity as 69.01 %, specificity as 65.40 %, LR+: 1.98 and LR- : 0.48, PPV: 80.43, and NPV: 50.00, when the NLR was ≥2.4. The risk of COVID-19 was found to be 20.3-fold greater when NLR was ≥ 2.4 in the logistic regression (P=0.007). CONCLUSION NLR is an independent predictor for the diagnosis of COVID-19. We also found that fever and total bilirubin measurements could be useful for the diagnosis of COVID-19 in this population.

RESUMO ANTECEDENTES A doença de coronavírus 2019 é uma doença respiratória inflamatória aguda. Causa muitas alterações nos parâmetros do hemograma. Baixos níveis de albumina estão associados ao risco de mortalidade em pacientes hospitalizados. O objetivo do presente estudo é revelar o local da razão entre contagem de neutrófilos e albumina na predição de mortalidade em pacientes com COVID-19. MÉTODOS Cento e quarenta e quatro pacientes do sexo feminino e 79 do sexo masculino foram incluídos no estudo. Os pacientes foram divididos em dois grupos: Grupo 1 não grave (n: 85), Grupo 2 grave (n: 59). Dados demográficos, contagem de neutrófilos, linfócitos e plaquetas, níveis de albumina e proteína C reativa (PCR) foram registrados. A razão de contagem de neutrófilos para albumina (NAR) foi calculada dividindo-se as contagens absolutas de neutrófilos pelos níveis de albumina. O NAR e os níveis dos dois grupos foram comparados. RESULTADOS Não houve diferenças significativas no sexo e na contagem de plaquetas (201 vs 211 K/mL) entre os grupos (p>0,05). Idade (62,0±14,3 vs 68,6±12,2 anos), albumina (33,1 vs 29,9 gr/L), PCR (33 vs 113 mg/l), contagem de neutrófilos (4 vs 7,24 K/mL), contagem de leucócitos (6,70 vs 8,50 K/mL), valores de NAR (113,5 vs 267,2) e número de óbitos (5 vs 33) foram estatisticamente maiores (p<0,001) no Grupo 2 que no Grupo 1. O valor NAR de 201,5 mostrou mortalidade em todos os pacientes com COVID-19 com sensibilidade de 71,1% e especificidade de 71,7% (AUC: 0,736, IC 95%: 0,641-0,832, p<0,001). CONCLUSÃO O presente estudo mostrou que os níveis de NAR podem ser um marcador barato e simples para predizer mortalidade em pacientes com COVID-19.

SUMMARY BACKGROUND Coronavirus Disease 2019 is an acute inflammatory respiratory disease. It causes many changes in hemogram parameters. Low albumin levels are associated with mortality risk in hospitalized patients. The aim of the present study is to reveal the place of neutrophil count to albumin ratio in predicting mortality in patients with COVID-19. METHODS 144 patients, 65 females and 79 males, were included in the study. Patients were divided into 2 groups. Group 1 was the non-severe group (n:85), and Group 2 was severe (n:59). Demographic data, neutrophil, lymphocyte and platelet counts, albumin and C-reactive protein (CRP) levels were recorded. Neutrophil count to albumin ratio (NAR) was calculated by dividing the absolute neutrophil counts by the albumin levels. The NAR and levels of the two groups were then compared. RESULTS There were no significant differences in gender and platelet count (201 vs. 211 K/mL) between the groups (p>0,05). Ages (62.0 ± 14.3 vs 68.6 ± 12.2 years), albumin (33.1 vs 29.9 gr/L), CRP (33 vs 113 mg/l), neutrophil count (4 vs 7.24 K/mL), WBC counts (6.70 vs 8.50 K/mL), NAR values (113.5 vs 267.2) and number of Death (5 vs 33) were found to be statistically higher (p <0.001) in Group 2 than in Group 1. The NAR value of 201.5 showed mortality in all patients with COVID-19 to have 71.1% sensitivity and 71.7% specificity (AUC:0.736, 95% CI: 0.641-0.832, p<0.001) CONCLUSION The present study showed that NAR levels can be a cheap and simple marker for predicting mortality in patients with COVID-19.