Patients without Increased Lymphocyte Counts and Decreased CT Scores During the Early 2nd Week of Illness Onset may Develop to Severe COVID-19.

BACKGROUND: Lymphopenia and high CT score is associated with COVID-19 severity. Herein we describe the change pattern in lymphocyte count and CT score during hospitalization and explore a possible association with the severity of COVID-19. METHODS: In this retrospective study, 13 non-severe COVID-19 patients diagnosed at admission were enrolled. One patient progressed to severe disease. Change patterns in lymphocyte counts and CT scores of all patients were analyzed. RESULTS: Lymphocyte count increased gradually from day 5 post-illness onset (day 5 vs. day 15, p = 0.001). Lymphocyte count of the severe patient fluctuated at low levels throughout the 15-day period. Chest CT scores of non-severe patients increased significantly during the first 5 days of illness onset, but decreased gradually beginning day 9 (illness onset vs. day 5, p = 0.002, day 9 vs. day 15, p = 0.015). In the severe patient, CT score continued to increase over the 11 days post-illness onset period. CONCLUSIONS: Non-severe COVID-19 patients had significantly increased lymphocyte counts and decreased CT scores beginning day 5 and day 9 of illness onset, respectively. The patients without increased lymphocyte counts and decreased CT scores during the early 2nd week of illness onset may develop to severe COVID-19.

The informative value of CD3+CD4+ and CD3+CD8+ T-cell count and cHIS scale as predictors of severe COVID-19 when using interleukin-6 receptor blockers in the in-hospital setting.

BACKGROUND: Clinical and laboratory signs of hyperinflammatory response in COVID-19 may serve as prognostic markers of the disease scenario. In real-world practice, there is an unmet need to determine the optimal timing of identifying predictors of SARS-CoV-2 adverse outcomes in the context of patient stratification to improve the effectiveness of anti-IL-6R therapy. Lymphopenia has a high informative value for the adverse prognosis of the COVID-19 course; however, the informative value of CD3+CD4+, CD3+CD8+ T-cell count remains questionable. In addition to lymphocyte phenotyping, a six-criterion additive scale (cHIS) was used in the study. AIM: To study the informative value of CD3+CD4+, CD3+CD8+ T-cell phenotyping and cHIS scale as predictors of severe COVID-19 when using IL-6R blockers. MATERIALS AND METHODS: A single-center, bi-directional study included 179 patients with SARS-CoV-2-induced community-acquired pneumonia with severe acute inflammation and progressing respiratory failure. Data were obtained from electronic patient records. Anti-IL-6R was administered in addition to standard therapy in the cohorts. The following disease outcomes were used to determine the informative value of the studied parameters: mortality and hospital discharge. Inflammatory markers were measured before and after administering anti-IL-6R, followed by monitoring. Statistical analysis was performed using SPSS (version 25.0). The quantitative indices were described using the median and interquartile range. Quantitative indices were compared using nonparametric methods: Mann-Whitney U-test, Kruskal-Wallis test. The groups were compared by qualitative characteristics using Pearson's chi-square test. Correlation analysis of quantitative indicators was performed using Spearman rank correlation. For additional analysis of the cHIS scale, odds ratio and decision tree methods were used. Differences were considered statistically significant at р≤0,05. RESULTS: Immunophenotyping of lymphocytes as a predictor of the severe SARS-CoV-2 requires further research. The cHIS scale may be implemented in routine clinical practice due to its high predictive value. A cHIS score of ≥2 on the first day of admission is a critical threshold for intensification and revision of therapy. The prognosis with cHIS is logically relevant in the first three days of hospitalization. CONCLUSION: The main result of the study is the definition of target groups of patients with community-acquired SARS-CoV-2 pneumonia for the IL-6R-blockers, considering the timing of their effective use in real clinical practice.

The characteristics and predictive role of lymphocyte subsets in COVID-19 patients.

OBJECTIVE: To investigate the characteristics and predictive roles of lymphocyte subsets in COVID-19 patients. METHOD: We evaluated lymphocyte subsets and other clinical features of COVID-19 patients, and analyzed their potential impacts on COVID-19 outcomes. RESULTS: 1. Lymphocyte subset counts in the peripheral blood of patients with COVID-19 were significantly reduced, especially in patients with severe disease. 2. In patients with non-severe disease, the time from symptom onset to hospital admission was positively correlated with total T cell counts. 3. Among COVID-19 patients who did not reach the composite endpoint, lymphocyte subset counts were higher than in patients who had reached the composite endpoint. 4. The Kaplan-Meier survival curves showed significant differences in COVID-19 patients, classified by the levels of total, CD8+, and CD4+ T cells at admission. CONCLUSION: Our study showed that total, CD8+, and CD4+ T cell counts in patients with COVID-19 were significantly reduced, especially in patients with severe disease. Lower T lymphocyte subsets were significantly associated with a higher occurrence of composite endpoint events. These subsets may help identify patients with a high risk of composite endpoint events.

[Changes of the T cell composition in the thymus during the COVID-19 pandemic]. / A csecsemomirigy T-sejtjeinek összetételében létrejövo változások a COVID­19-pandémia alatt.

INTRODUCTION: In our study, we aimed to investigate whether the COVID-19 infection itself or the vaccination against it affect the differentiation of T cells in the thymus, and whether the reduction in T cell counts observed in the blood of COVID-19-infected individuals is also observed at the tissue level in the thymus. METHOD: Data from a total of 55 thymectomy patients were processed to create three groups: 1) the pre-COVID-19 (PC) group included 22 patients, 12 women and 10 men, who underwent thymectomy between 2008 and 2013; 2) in the no-COVID-19 (NC) group (patients without verified infection or vaccination), 20 patients, 11 women and 9 men, underwent thymectomy in 2020-2021; 3) the vaccinated or infected COVID-19 (VIC) group included 13 patients, 4 women and 9 men, who underwent thymectomy also in 2020-2021. The pathological samples were immunohistochemically tested for CD4, CD8, CD25 and FOXP3 to verify the helper, cytotoxic and regulatory T cells. RESULTS: The VIC group had significantly lower values for CD4, compared to the PC and NC groups. The FOXP3 value was significantly lower in the VIC and NC groups compared to the PC group. No significant differences were found for CD8 and CD25 between the groups studied. DISCUSSION: The COVID-19 infection or vaccination affects the T cell composition of the thymus. Decreased expression of CD4 has been demonstrated in the VIC group, which confirms a decrease in the T cell counts that also occurs in the thymus. The low FOXP3 levels observed in the NC group during the COVID-19 era, compared to the PC group, may be indicative of a high rate of asymptomatic coronavirus infections and a worsening of immunetolerance. CONCLUSION: First in the world, we have verified that the helper T cell composition of the thymus in COVID-19 infection era is reduced, and in the asymptomatic patients the immune function is decreased as well. Orv Hetil. 2022; 163(52): 2062-2066.

Comparison of T Lymphocyte Subsets and Natural Killer Lymphocytes in Moderate Versus Severe COVID-19 Patients.

Severe respiratory involvement that follows a process of immune dysregulation and intense cytokine production remains to be the most dreaded complication of Coronavirus Disease-2019 (COVID-19) infection. The aim of this study was to analyze T lymphocyte subsets and natural killer (NK) lymphocytes in moderate and severe cases of COVID-19 infection and assess their significance in disease severity and prognosis. Twenty moderate cases and 20 severe cases of COVID-19 were studied and compared regarding blood picture, biochemical markers, T lymphocyte population subsets, and NK lymphocytes, which were determined by flow cytometric analysis. On analyzing the flow cytometric data of T lymphocyte cells and their subsets and NK cells in two groups of COVID-19 infection (one group moderate and the other severe cases), some immature NK lymphocyte relative and absolute counts were higher in the severe patients with worse outcome and death, while some mature NK lymphocyte relative and absolute counts were depressed in both groups. Also, interleukin (IL)-6 was significantly higher in severe cases when compared to moderate cases, and there was a positive significant correlation between immature NK lymphocyte relative and absolute counts and IL-6. There was no statistically significant difference between T lymphocyte subsets (T helper and T cytotoxic) with disease severity or outcome. Some immature NK lymphocyte subsets contribute to the widespread inflammatory response that complicates severe cases of COVID-19; therapeutic approaches directed to enhancing NK maturation or drugs that block NK cell inhibitory receptors have a potential role in controlling COVID-19 induced cytokine storm.

Additional malignancies shorten overall survival in chronic lymphocytic leukemia irrespective of chromosomal aberrations: A retrospective cohort study.

The aim of this study was to determine the incidence of other malignancies (OMs) in patients with chronic lymphocytic leukemia (CLL) and to identify parameters associated with the occurrence of OMs in addition to CLL. This retrospective cohort study was conducted by examining the records of CLL patients who applied to a tertiary hospital between January 2013 and December 2021. The cases were divided into 2 groups, CLL (n = 107) and CLL + OM (n = 25), according to the presence of additional malignancy. Lymphocyte count (P = .014), white blood cell count (P = .006), and hemoglobin (P = .034) were significantly higher in the CLL group. Rai stage IV percentage (P = .015), Binet stage B percentage (P = .043), progression, and sepsis percentages (P = .008) were significantly higher in the CLL + OM group. Overall survival time was significantly lower in the CLL + OM group (P = .032). Most OMs had been diagnosed before CLL (63.64%) in the no-treatment group, while the majority of OMs were diagnosed after CLL (78.57%) in the treatment group (P = .032). CLL patients with OM had a more advanced CLL stage, and survival was significantly shorter in these patients. In addition, CLL-associated OM appears to occur more frequently in the post-treatment period.

Adaptive immune dysfunction in patients with COVID-19 and impaired kidney function during the omicron surge.

BACKGROUND: Little is known about the characteristics of lymphocyte subsets and the association with patient outcomes in COVID-19 with and without impaired kidney function. METHODS: Lymphocyte subsets were compared in COVID-19 patients with or without kidney dysfunction. The primary outcome was a composite of all-cause mortality or intensive care unit admission. Secondary outcomes included duration of viral shedding, length of hospital stay, and acute kidney injury. RESULTS: Lymphocyte subset cell counts demonstrated the lowest in patients with severe/critical COVID-19 and kidney dysfunction. Among all lymphocyte subset parameters, Th cell count was the most significant indicator for outcomes. ROC of the combined model of Th cell count and eGFR presented better predictive value than that of the other parameters. Th cell count <394.5 cells/µl and eGFR <87.5 ml/min/1·73m2 were independently associated with poor outcomes. The propensity score matching analysis revealed consistent results. CONCLUSIONS: Reduced Th cell count and eGFR may be applied as promising predictive indicators for identifying COVID-19 patients with high risk and poor outcomes.

Inflammation-based Indices Predicting Mortality in COVID-19.

Efficiency of various inflammation-based indices, including neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), lymphocyte/monocyte ratio (LMR), C-reactive protein/lymphocyte ratio (CLR), albumin/globulin ratio (AGR), haemoglobin, albumin, lymphocyte, and platelet (HALP), systemic immune-inflammatory index (SII) and prognostic nutritional index (PNI), was examined in predicting mortality in COVID-19 patients. The study population consisted of 827 COVID-19 patients, including 733 survivors and 94 non-survivors. Compared with the survivor group, the NLR, PLR, CLR, and SII values of the non-survivor group were markedly higher; however, the LMR, PNI, HALP and AGR values were markedly lower. Multivariate analysis identified PNI, NLR, CLR, older age, male gender and dyslipidemia as independent factors for mortality in COVID-19 patients. PNI had the largest area under the curve to predict mortality, followed by CLR, NLR, and other indexes. This data revealed that PNI, NLR, and CLR are independent factors of mortality in COVID-19 patients among inflammation-based indexes. Key Words: COVID-19 mortality, Prognostic nutritional index, C-reactive protein/lymphocyte ratio, Neutrophil/lymphocyte ratio.

Anti-SARS-CoV-2 antibodies following vaccination are associated with lymphocyte count and serum immunoglobulins in SLE.

OBJECTIVES: Patients with Systemic Lupus Erythematosus are known to have dysregulated immune responses and may have reduced response to vaccination against COVID-19 while being at risk of severe COVID-19 disease. The aim of this study was to identify whether vaccine responses were attenuated in SLE and to assess disease- and treatment-specific associations. METHODS: Patients with SLE were matched by age, sex and ethnic background to healthcare worker healthy controls (HC). Anti-SARS-CoV-2 spike glycoprotein antibodies were measured at 4-8 weeks following the second COVID-19 vaccine dose (either BNT162b2 or ChAdOx1 nCoV-19) using a CE-marked combined ELISA detecting IgG, IgA and IgM (IgGAM). Antibody levels were considered as a continuous variable and in tertiles and compared between SLE patients and HC and associations with medication, disease activity and serological parameters were determined. RESULTS: Antibody levels were lower in 43 SLE patients compared to 40 HC (p < 0.001). There was no association between antibody levels and medication, lupus disease activity, vaccine type or prior COVID infection. Higher serum IgA, but not IgG or IgM, was associated with being in a higher anti-SARS-CoV-2 antibody level tertile (OR [95% CI] 1.820 [1.050, 3.156] p = 0.033). Similarly, higher lymphocyte count was also associated with being in a higher tertile of anti-SARS-CoV-2 (OR 3.330 [1.505, 7.366] p = 0.003). CONCLUSION: Patients with SLE have lower antibody levels following 2 doses of COVID-19 vaccines compared to HC. In SLE lower lymphocyte counts and serum IgA levels are associated with lower antibody levels post vaccination, potentially identifying a subgroup of patients who may therefore be at increased risk of infection.

Peripheral lymphocyte subset alteration in patients with COVID-19 having differential clinical manifestations.

Background & objectives: The COVID-19 disease profile in Indian patients has been found to be different from the Western world. Changes in lymphocyte compartment have been correlated with disease course, illness severity and clinical outcome. This study was aimed to assess the peripheral lymphocyte phenotype and subset distribution in patients with COVID-19 disease from India with differential clinical manifestations. Methods: Percentages of peripheral lymphocyte subsets were measured by flow cytometry in hospitalized asymptomatic (n=53), mild symptomatic (n=36), moderate and severe (n=30) patients with SARS-CoV-2 infection, recovered individuals (n=40) and uninfected controls (n=56) from Pune, Maharashtra, India. Results: Percentages of CD4+Th cells were significantly high in asymptomatic, mild symptomatic, moderate and severe patients and recovered individuals compared to controls. Percentages of Th memory (CD3+CD4+CD45RO+), Tc memory (CD3+CD8+CD45RO+) and B memory (CD19+CD27+) cells were significantly higher in the recovered group compared to both asymptomatic, mild symptomatic patient and uninfected control groups. NK cell (CD56+CD3-) percentages were comparable among moderate +severe patient and uninfected control groups. Interpretation & conclusions: The observed lower CD4+Th cells in moderate+severe group requiring oxygen support compared to asymptomatic+mild symptomatic group not requiring oxygen support could be indicative of poor prognosis. Higher Th memory, Tc memory and B memory cells in the recovered group compared to mild symptomatic patient groups might be markers of recovery from mild infection; however, it remains to be established if the persistence of any of these cells could be considered as a correlate of protection.

High Number and Specific Comorbidities Could Impact the Immune Response in COVID-19 Patients.

Background: Cellular immunodeficiency and comorbidities are common in COVID-19 patients. Aim: The purpose of this study was to investigate comorbidities impacting on the cellular immunity in COVID-19 patients. Methods: The research objects included 55 healthy controls and 718 COVID-19 patients who divided into the control group and the COVID-19 group, respectively. Those in the COVID-19 group were divided into subgroups on the basis of the number and types of comorbidities present. Lymphocyte itself and its subsets were compared between the control group and the COVID-19 group, the groups with comorbidities based on the different number and types of comorbidities, and the relationship between the lymphocyte counts and subsets with the number and types of comorbidities was investigated. Results: Compared with the control group, the lymphocyte counts and T cell subsets were significantly increased in the groups with comorbidities, but both B and NK cell subsets were significantly decreased in the no comorbidity group and in most of the groups with comorbidities (all P<0.05). In the three comorbidities group, the lymphocyte counts and T cell subsets were all significantly decreased, but the CD56+ percentage was obviously increased (all P<0.05). The number of comorbidities was negatively correlated with the lymphocyte counts and the T and NK cell subsets. A negative correlation also existed between cancer and both the lymphocyte counts and the T cell subsets, between chronic hepatitis B and the lymphocyte counts, and between chronic kidney disease and the CD3+ counts. A positive correlation existed between nonalcoholic fatty liver disease (NAFLD) disease and both lymphocyte and CD3+ counts. The risk factors were number of comorbidities for the lymphocyte count, CD3+CD4+ and CD3+CD8+ percentages, NAFLD for the lymphocyte and CD3+ counts, cardiovascular diseases for CD3+CD4+ and CD3+CD8+ percentages, diabetes mellitus for the CD3+CD8+ percentage, and cancer for the CD3+ percentage, respectively. Conclusions: High numbers of comorbidities and specific comorbidities could impact the immune response of COVID-19 patients. This study provides a reference for clinicians in the identification of suitable and timely immunotherapy for COVID-19 patients. Clinical Trial Registry: https://www.chictr.org.cn/enindex.aspx, identifier ChiCTR2000034563.

Evaluation of inflammatory and hematological parameters in patients diagnosed with COVID-19.

INTRODUCTION: This study aims to research the effects of hematological and inflammatory parameters on the prognosis of COVID-19 disease and hospitalization duration. METHODOLOGY: One hundred and eighty-six patients with COVID-19 and a control group consisting of 187 healthy individuals were included in the study. Hematological variables and inflammatory parameters of the patients were recorded on the first and the fifth days of hospitalization. RESULTS: White blood cell count, lymphocyte count, and platelet count were statistically lower, and mean platelet volume (MPV), neutrophil to lymphocyte ratio (NLR), and platelet to lymphocyte ratio (PLR) levels were higher in the patient group compared to the control group. It was observed that the neutrophil count and MPV level were lower, and the platelet count and ferritin level were statistically higher on the fifth day of follow-up compared to the admission day. In contrast, there was a significantly positive correlation between the duration of hospitalization and the fifth day D-dimer (r = 0.546, p < 0.001) and ferritin (r = 0.568, p < 0.001); in addition, there was a negative correlation between the duration of hospitalization and admission day lymphocyte count and the fifth-day lymphocyte count. CONCLUSIONS: Increased levels of ferritin and D-dimer, and decreased count of lymphocytes are among the important factors affecting the duration of hospitalization for COVID-19 patients. Furthermore, we think that neutrophil count and MPV levels are low, and platelet count and ferritin levels are high during the disease. Therefore, these parameters can be used as prognostic indicators of the disease.

A robust COVID-19 mortality prediction calculator based on Lymphocyte count, Urea, C-Reactive Protein, Age and Sex (LUCAS) with chest X-rays.

There have been numerous risk tools developed to enable triaging of SARS-CoV-2 positive patients with diverse levels of complexity. Here we presented a simplified risk-tool based on minimal parameters and chest X-ray (CXR) image data that predicts the survival of adult SARS-CoV-2 positive patients at hospital admission. We analysed the NCCID database of patient blood variables and CXR images from 19 hospitals across the UK using multivariable logistic regression. The initial dataset was non-randomly split between development and internal validation dataset with 1434 and 310 SARS-CoV-2 positive patients, respectively. External validation of the final model was conducted on 741 Accident and Emergency (A&E) admissions with suspected SARS-CoV-2 infection from a separate NHS Trust. The LUCAS mortality score included five strongest predictors (Lymphocyte count, Urea, C-reactive protein, Age, Sex), which are available at any point of care with rapid turnaround of results. Our simple multivariable logistic model showed high discrimination for fatal outcome with the area under the receiving operating characteristics curve (AUC-ROC) in development cohort 0.765 (95% confidence interval (CI): 0.738-0.790), in internal validation cohort 0.744 (CI: 0.673-0.808), and in external validation cohort 0.752 (CI: 0.713-0.787). The discriminatory power of LUCAS increased slightly when including the CXR image data. LUCAS can be used to obtain valid predictions of mortality in patients within 60 days of SARS-CoV-2 RT-PCR results into low, moderate, high, or very high risk of fatality.

Immunological evaluation of patients with 2019 novel coronavirus pneumonia: CD4+ and CD16+ cells may predict severity and prognosis.

PURPOSE: Available but insufficient evidence shows that changes may occur in the immune system following coronavirus disease 2019 (COVID-19). The present study aimed at evaluating immunological changes in patients with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pneumonia compared with the control group. METHOD: The present study was performed on 95 patients with COVID-19 (32 severe and 63 moderate cases) and 22 healthy controls. Relationship between immune cells, disease severity and lung involvement was assessed. Binary logistic regression and ROC curve tests were used for statistical analysis. RESULTS: A significant decrease was observed in CD20+ cell counts of the patients. To differentiate patients from healthy individuals, the cutoff point for the CD4+ cell count was 688 /µL, sensitivity 0.96, and specificity 0.84. An increase in CD4+ cells reduces the odds of severe disease (odds ratio = 0.82, P = 0.047) and death (odds ratio = 0.74, P = 0.029). CD4+ cells play a pivotal role in the severity of lung involvement (P = 0.03). In addition to CD4+ cells, Fc gamma receptor III (FcγRIII) (CD16) also played a significant prognosis (odds ratio = 0.55, P = 0.047). In severe cases, C-reactive protein, Blood urea nitrogen, and Creatine phosphokinase levels, as well as neutrophil counts, were significantly higher than those of moderate ones whereas lymphocyte count in severe cases was lower than that of moderate ones. CONCLUSION: The number of total T-cells and B-cells in patients with COVID-19 was lower than that of controls; however, their NK cells increased. FcγRIII and CD4+ cells are of great importance due to their association with COVID-19 prognosis.

Serum creatinine to absolute lymphocyte count ratio effectively risk stratifies patients who require intensive care in hospitalized patients with coronavirus disease 2019.

Patients with preexisting kidney disease or acute kidney injury had poorer outcomes in coronavirus disease 2019 (COVID-19) illness. Lymphopenia was associated with more severe illness. Risk stratification with simple laboratory tests may help appropriate site patients in a cost-effective manner and ease the burden on healthcare systems. We examined a ratio of serum creatinine level to absolute lymphocyte count at presentation (creatinine-lymphocyte ratio, CLR) in predicting outcomes in hospitalized patients with COVID-19. We analyzed 553 consecutive polymerase chain reaction-positive SARS-COV-2 hospitalized patients. Patients with end-stage kidney disease were excluded. Serum creatinine and full blood count (FBC) examination were obtained within the first day of admission. We examined the utility of CLR in predicting adverse clinical outcomes (requiring intensive care, mechanical ventilation, acute kidney injury requiring renal replacement therapy or death). An optimized cutoff of CLR > 77 was derived for predicting adverse outcomes (72.2% sensitivity, and 83.9% specificity). Ninety-seven patients (17.5%) fell within this cut off. These patients were older and more likely to have chronic medical conditions. A higher proportion of these patients had adverse outcomes (13.4% vs 1.1%, P < .001). On receiver operating curve analyses, CLR predicted patients who had adverse outcomes well (area under curve [AUC] = 0.82, 95%CI 0.72-0.92), which was comparable to other laboratory tests like serum ferritin, C-reactive protein and lactate dehydrogenase. Elevated CLR on admission, which may be determined by relatively simple laboratory tests, was able to reasonably discriminate patients who had experienced adverse outcomes during their hospital stay. This may be a simple and cost-effective means of risk stratification and triage.

Lymphocyte count is a universal predictor of health outcomes in COVID-19 patients before mass vaccination: A meta-analytical study.

Background: Several laboratory data have been identified as predictors of disease severity or mortality in COVID-19 patients. However, the relative strength of laboratory data for the prediction of health outcomes in COVID-19 patients has not been fully explored. This meta-analytical study aimed to evaluate the prediction capabilities of laboratory data on the prognosis of COVID-19 patients during 2020 while mass vaccination has not started yet. Methods: Two electronic databases, MEDLINE and EMBASE, from inception to October 10, 2020 were searched. Observational studies of laboratory-confirmed COVID-19 patients with well-defined severity or survival status, and with the desired laboratory data at initial hospital administrations, were selected. Meta-regression analysis with the generalized estimating equations (GEE) method for clustered data was performed sequentially. Primary outcome measures were to compare the level of laboratory data and their impact on different health outcomes (severe vs non-severe, critically severe vs non-critically severe, and dead vs alive). Results: Meta-data of 13 clinical laboratory items at initial hospital presentations were extracted from 76 selected studies with a total of 26 627 COVID-19 patients in 16 countries. After adjusting for the effect of age, 1.03 0.87 (OR = 0.0576; 95% CI = 0.0043-0.4726; P = 0.0079) had a much lower risk of severity, critical severity, and mortality from COVID-19, respectively. Conclusions: Lymphocyte count was the most powerful predictor among the 13 common laboratory variables explored from COVID-19 patients to differentiate disease severity and to predict mortality. Lymphocyte count should be monitored for the prognoses of COVID-19 patients in clinical settings in particular for patients not fully vaccinated.

The role of B cells in COVID-19 infection and vaccination.

B cells secrete antibodies and mediate the humoral immune response, making them extremely important in protective immunity against SARS-CoV-2, which caused the coronavirus disease 2019 (COVID-19) pandemic. In this review, we summarize the positive function and pathological response of B cells in SARS-CoV-2 infection and re-infection. Then, we structure the immunity responses that B cells mediated in peripheral tissues. Furthermore, we discuss the role of B cells during vaccination including the effectiveness of antibodies and memory B cells, viral evolution mechanisms, and future vaccine development. This review might help medical workers and researchers to have a better understanding of the interaction between B cells and SARS-CoV-2 and broaden their vision for future investigations.

Are neutrophil-to-lymphocyte ratios and large unstained cells different in hospitalized COVID-19 PCR-positive patients with and without diabetes mellitus?

OBJECTIVE: SARS-CoV-2 might present with multisystem involvement due to its entry into many cells with ACE2 receptors on their surfaces, such as heart, endothelial, and lung alveoli cells. Studies have indicated that COVID-19 infection causes a severe clinical presentation in diabetic patients due to dysregulation of the metabolic and immune systems. The hematological effects of COVID-19 and the relationship of lymphopenia with the severity of the disease have been reported previously. The parameter of percentage of large unstained cells (LUCs) reflects active lymphocytes and peroxidase-negative cells. The neutrophil-to-lymphocyte ratio (NLR) is another reliable marker of inflammation in cases of cardiac diseases, solid tumors, and sepsis. The present study aimed to evaluate whether the parameters of LUCs and NLR differed between diabetic and nondiabetic individuals with COVID-19. Associations with disease severity were also sought. MATERIALS AND METHODS: In our retrospective study, the data of 1,053 patients [230 diabetic patients (21.83%) and 823 nondiabetic patients (78.15%)] were reviewed. The white blood cell (WBC) count, neutrophil count, neutrophil%, lymphocyte count, lymphocyte%, LUC count, %LUCs, NLR, platelet count, hemoglobin level, HbA1c, history of diabetes, surveillance during hospitalization, and pulmonary infiltration status within the first 24 hours after admission to the hospital were analyzed from the records. RESULTS: When diabetic patients were compared with nondiabetics, the age [65 (20-90) vs. 42 (18-94) years], WBC count [6.72 (2.6-24.04) vs.  5.91 (1.35-52.68)], neutrophil count [4.29 (1.28-65) vs. 3.68 (0.02-50.47)], neutrophil% [67.53±12.3 vs.  64.08±13.28], NLR [3.35 (0.83-38.11) vs. 2.48 (0.01-68.58)], and LUC count [0.11 (0.03-0.98) vs. 0.1 (0.02-3.06)] of the diabetic group were found to be higher and these differences were statistically significant (p<0.001, p<0.001, p<0.001, p<0.001, p<0.001, and p=0.015, respectively). CONCLUSIONS: We determined that LUC counts and NLR values in COVID-19-positive patients with diabetes were statistically significantly higher compared to nondiabetic patients.