Predictive value of C-reactive protein for disease severity and survival in COVID-19 patients: a systematic review and meta-analysis

Predicting coronavirus disease 2019 severity using explainable artificial intelligence techniques

Predictive models for determining coronavirus disease 2019 (COVID-19) severity have been established; however, the complexity of the interactions among factors limits the use of conventional statistical methods. This study aimed to establish a simple and accurate predictive model for COVID-19 severity using an explainable machine learning approach. A total of 3,301 patients ≥ 18 years diagnosed with COVID-19 between February 2020 and October 2022 were included. The discovery cohort comprised patients whose disease onset fell before October 1, 2020 (N = 1,023), and the validation cohort comprised the remaining patients (N = 2,278). Pointwise linear and logistic regression models were used to extract 41 features. Reinforcement learning was used to generate a simple model with high predictive accuracy. The primary evaluation was the area under the receiver operating characteristic curve (AUC). The predictive model achieved an AUC of ≥ 0.905 using four features: serum albumin levels, lactate dehydrogenase levels, age, and neutrophil count. The highest AUC value was 0.906 (sensitivity, 0.842; specificity, 0.811) in the discovery cohort and 0.861 (sensitivity, 0.804; specificity, 0.675) in the validation cohort. Simple and well-structured predictive models were established, which may aid in patient management and the selection of therapeutic interventions.

Utility of Protein Markers in COVID-19 Patients

COVID-19 has been a challenge at the healthcare level not only in the early stages of the pandemic, but also in the subsequent appearance of long-term COVID-19. Several investigations have attempted to identify proteomic biomarkers in an attempt to improve clinical care, guide treatment and predict possible patient outcomes. Proteins such as C-reactive protein (CRP) or interleukin 6 (IL-6) are clear markers of severe disease, but many others have been proposed that could help in risk stratification and in the prediction of specific complications. This review aims to bring together the most relevant studies in this regard, providing information to identify the most notable biomarkers in relation to COVID-19 found to date.

Low-Grade Inflammation in Long COVID Syndrome Sustains a Persistent Platelet Activation Associated With Lung Impairment

In the present study, we provide evidence on the potential mechanisms involved in the residual pulmonary impairment described in long COVID syndrome. Data highlight that lung damage is significantly associated with a proinflammatory platelet phenotype, characterized mainly by the formation of platelet-leukocyte aggregates. In ex vivo experiments, long COVID plasma reproduces the platelet activation observed in vivo and highlights low-grade inflammation as a potential underpinning mechanism, exploiting a synergistic activity between C-reactive protein and subthreshold concentrations of interleukin-6. The platelet-activated phenotype is blunted by anti-inflammatory and antiplatelet drugs, suggesting a potential therapeutic option in this clinical setting.

Inflammatory, Hematological, and Biochemical Biomarkers in COVID-19 Patients

INTRODUCTION

There are few accurate prognostic indications of the illness's development and severity for COVID-19, despite certain biomarkers having been investigated. The unexpected nature of COVID-19's course, which can quickly progress from asymptomatic to life-threatening symptoms, lies at the heart of the disease's intricacy. Predicting SARS-CoV-2 pathogenicity through laboratory biomarkers and as such, identifying the patients' illness severity at the time of their initial admission would be crucial in improving patient care. In this study, we sought to evaluate the potential of hematological, biochemical, and inflammatory biomarkers in predicting the course of COVID-19 at a tertiary hospital in western Kenya.

METHODS

This cross-sectional study involved 48 COVID-19 patients (16 asymptomatic; 16 moderate symptomatic; and 16 severe symptomatic) and 48 age-sex-matched COVID-19-negative clients attending the Moi Teaching and Referral Hospital, Kenya. Demographic information, self-reported chronic illnesses, symptoms, and laboratory results were collected at recruitment.

RESULTS

Significantly, the severity of COVID-19 was associated with; hemoglobin (p < 0.0001), white blood cells (p = 0.0022), hematocrit (p < 0.0001), blood urea nitrogen (p = 0.01), blood sodium (p = 0.0002), potassium (p = 0.0483), C-reactive protein (p = 0.0002), and Lactate Dehydrogenase (p < 0.0001). Regression analysis of CRP revealed a strong positive correlation (p = 0.0006) whereas LDH revealed a weak positive correlation (p < 0.0001) with COVID-19 disease severity. Discriminative accuracy was highest when asymptomatic was compared to severe COVID-19 for CRP and LDH (AUC: 0.8867, 95% CI: 0.7532-1.000) and (AUC: 1.000, 95% CI: 1.000-1.000) respectively.

CONCLUSION

The hematological indices, inflammatory and biochemical biomarkers studied have the potential to predict the course of COVID-19. These parameters may be useful in helping design appropriate care for COVID-19 patients.

COVID-19 inflammatory signature in a Mozambican cohort: unchanged red blood series and reduced levels of IL-6 and other proinflammatory cytokines

BACKGROUND

Alterations in haematological, biochemical parameters and cytokine levels, were reported in patients with COVID-19, however, there is an underrepresentation of the African population, which could provide evidence for understanding SARS-CoV-2 pathogenesis and useful tools for clinical management of cases. In this study, we aimed to determine the haematological, biochemical and cytokine profile in Mozambican individuals with SARS-CoV-2.

METHODS

A cohort of 85 Mozambican individuals with RT-PCR SARS-CoV-2 results, was stratified into negative, asymptomatic, mild, moderate, and severe categories. Haematological, biochemical and cytokines measurement were performed on samples from the study participants. Principal component analysis (PCA) was performed to identify similar patterns among the study cases. Comparisons between groups were performed using the Kruskal-Wallis test. Receiver operating characteristic (ROC) and area under the curve (AUC) analysis were conducted to evaluate the ability of these parameters to distinguish severe from non-severe cases of SARS-CoV-2 infection.

RESULTS

SARS-CoV-2 infection was associated with a significant (p < 0.05) decrease in peripheral blood absolute counts of total lymphocytes and eosinophils, below the reference values along with no abnormal change (p > 0.05) in red blood cell count, haemoglobin, platelets and other red series parameters. At the serum level, SARS-CoV-2 infection was associated with an increase in serum levels of C-reactive protein (C-RP) and glucose above the reference values and to a significant reduction a significant (p < 0.05) reduction in levels of interferon-gamma (INF-γ), Tumour Necrosis Factor alfa (TNF-α) and the interleukin 1 beta (IL-1β) and IL-6 in severe cases, when compared to negative cases. Haematological, biochemical and cytokine profiles segregate severe from non-severe cases of COVID-19 with an excellent performance of C-RP (AUC = 0.95; p < 0.001) and good performance of lymphocytes (AUC = 0.88; p < 0.001) and IL-15 (AUC = 0.86; p < 0.001).

CONCLUSION

The lack of variation in red and platelet series, coupled with a decrease in the levels of classical pro-inflammatory in severe cases, deviates from what has been reported in other contexts suggesting, that there may be peculiarities in COVID-19 manifestation within the context of this study population. Furthermore, these results identify parameters with potential for clinical management of COVID-19 and therefore good resource allocation, particularly for severe cases.

Does timing of tocilizumab administration affect mortality in COVID-19? A Scottish multicentre retrospective cohort study

BACKGROUND

The optimal timing of tocilizumab treatment during the disease course of COVID-19 has yet to be adequately defined in the context of randomised controlled trials and the effect of tocilizumab on real-world populations remains unclear. We examined the effect of different timing of tocilizumab, on mortality, in a cohort of adults with COVID-19.

METHODS

All adults (≥18 years old) with confirmed COVID-19 admitted to four hospitals in the West of Scotland between 8 January 2021 and 31 March 2021 and who received tocilizumab were included in a retrospective observational cohort study. Patients were assigned to either an early (day of admission or first day after admission) or late (days 2-7 of admission) cohort based on tocilizumab initiation. The primary outcome was 90-day all-cause mortality in early versus late cohorts. Secondary outcomes were 28 and 180-day all-cause mortality.

RESULTS

203 patients were included in the analysis (138 in the early cohort, 65 in the late cohort). Mortality in 90 days in the early cohort was 22% (n=30) compared with 45% (n=29) in the late cohort (p<0.001). The adjusted mortality was significantly higher in the late cohort compared with the early cohort (adjusted OR: 3.33; 95% CI: 1.29 to 8.54; p=0.012). The secondary outcomes demonstrated the same effect with higher rates of death in 28 days (late cohort adjusted OR: 3.28; 95% CI: 1.23 to 8.75; p=0.018) and 180 days (late cohort adjusted OR: 3.70; 95% CI: 1.45 to 9.45; p=0.006). The effect was seen whether the outcome was adjusted or unadjusted.

CONCLUSION

Early administration of tocilizumab within the first 2 days of hospitalisation was associated with a significant survival benefit compared with late exposure. Late administration was associated with particularly high mortality. The observed association may be a result of residual confounders and further research is needed.

Efficacy and safety of mesenchymal stem cells therapy in COVID-19 patients: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The coronavirus disease 2019 (COVID-19) has become a serious public health issue. In COVID-19 patients, the elevated levels of inflammatory cytokines lead to the manifestation of COVID-19 symptoms, such as lung tissue edema, lung diffusion dysfunction, acute respiratory distress syndrome (ARDS), secondary infection, and ultimately mortality. Mesenchymal stem cells (MSCs) exhibit anti-inflammatory and immunomodulatory properties, thus providing a potential treatment option for COVID-19. The number of clinical trials of MSCs for COVID-19 has been rising. However, the treatment protocols and therapeutic effects of MSCs for COVID-19 patients are inconsistent. This meta-analysis was performed to systematically determine the safety and efficacy of MSC infusion in COVID-19 patients.

METHODS

We conducted a comprehensive literature search from PubMed/Medline, Web of Science, EMBASE, and Cochrane Library up to 22 November 2023 to screen for eligible randomized controlled trials. Inclusion and exclusion criteria for searched literature were formulated according to the PICOS principle, followed by the use of literature quality assessment tools to assess the risk of bias. Finally, outcome measurements including therapeutic efficacy, clinical symptoms, and adverse events of each study were extracted for statistical analysis.

RESULTS

A total of 14 randomized controlled trials were collected. The results of enrolled studies demonstrated that patients with COVID-19 pneumonia who received MSC inoculation showed a decreased mortality compared with counterparts who received conventional treatment (RR: 0.76; 95% CI [0.60, 0.96]; p = 0.02). Reciprocally, MSC inoculation improved the clinical symptoms in patients (RR: 1.28; 95% CI [1.06, 1.55]; p = 0.009). In terms of immune biomarkers, MSC treatment inhibited inflammation responses in COVID-19 patients, as was indicated by the decreased levels of CRP and IL-6. Importantly, our results showed that no significant differences in the incidence of adverse reactions or serious adverse events were monitored in patients after MSC inoculation.

CONCLUSION

This meta-analysis demonstrated that MSC inoculation is effective and safe in the treatment of patients with COVID-19 pneumonia. Without increasing the incidence of adverse events or serious adverse events, MSC treatment decreased patient mortality and inflammatory levels and improved the clinical symptoms in COVID-19 patients. However, large-cohort randomized controlled trials with expanded numbers of patients are required to further confirm our results.

Presepsin as a prognostic biomarker in COVID-19 patients: combining clinical scoring systems and laboratory inflammatory markers for outcome prediction

BACKGROUND

There is still limited research on the prognostic value of Presepsin as a biomarker for predicting the outcome of COVID-19 patients. Additionally, research on the combined predictive value of Presepsin with clinical scoring systems and inflammation markers for disease prognosis is lacking.

METHODS

A total of 226 COVID-19 patients admitted to Beijing Youan Hospital's emergency department from May to November 2022 were screened. Demographic information, laboratory measurements, and blood samples for Presepsin levels were collected upon admission. The predictive value of Presepsin, clinical scoring systems, and inflammation markers for 28-day mortality was analyzed.

RESULTS

A total of 190 patients were analyzed, 83 (43.7%) were mild, 61 (32.1%) were moderate, and 46 (24.2%) were severe/critically ill. 23 (12.1%) patients died within 28 days. The Presepsin levels in severe/critical patients were significantly higher compared to moderate and mild patients (p < 0.001). Presepsin showed significant predictive value for 28-day mortality in COVID-19 patients, with an area under the ROC curve of 0.828 (95% CI: 0.737-0.920). Clinical scoring systems and inflammation markers also played a significant role in predicting 28-day outcomes. After Cox regression adjustment, Presepsin, qSOFA, NEWS2, PSI, CURB-65, CRP, NLR, CAR, and LCR were identified as independent predictors of 28-day mortality in COVID-19 patients (all p-values < 0.05). Combining Presepsin with clinical scoring systems and inflammation markers further enhanced the predictive value for patient prognosis.

CONCLUSION

Presepsin is a favorable indicator for the prognosis of COVID-19 patients, and its combination with clinical scoring systems and inflammation markers improved prognostic assessment.

Association of Coagulopathy and Inflammatory Biomarkers with Severity in SARS-CoV-2-Infected Individuals of the Al-Qunfudhah Region of Saudi Arabia

BACKGROUND

Identifying prognosticators/predictors of COVID-19 severity is the principal focus for early prediction and effective management of the disease in a time-bound and cost-effective manner. We aimed to evaluate COVID-19 severity-dependent alteration in inflammatory and coagulopathy biomarkers.

METHODS

A hospital-dependent retrospective observational study (total: n = 377; male, n = 213; and female, n = 164 participants) was undertaken. COVID-19 exposure was assessed by performing real-time PCR on nasopharyngeal (NP) swabs. Descriptive and inferential statistics were applied for both continuous and categorical variables using Rstudio-version-4.0.2. Pearson correlation and regression were executed with a cut-off of p < 0.05 for evaluating significance. Data representation by R-packages and ggplot2.

RESULTS

A significant variation in the mean ± SD (highly-sever (HS)/moderately severe (MS)) of CRP (HS/MS: 102.4 ± 22.9/21.3 ± 6.9, p-value < 0.001), D-dimer (HS/MS: 661.1 ± 80.6/348.7 ± 42.9, p-value < 0.001), and ferritin (HS/MS: 875.8 ± 126.8/593.4 ± 67.3, p-value < 0.001) were observed. Thrombocytopenia, high PT, and PTT exhibited an association with the HS individuals (p < 0.001). CRP was correlated with neutrophil (r = 0.77), ferritin (r = 0.74), and WBC (r = 0.8). D-dimer correlated with platelets (r = -0.82), PT (r = 0.22), and PTT (r = 0.37). The adjusted odds ratios (Ad-OR) of CRP, ferritin, D-dimer, platelet, PT, and PTT for HS compared to MS were 1.30 (95% CI -1.137, 1.50; p < 0.001), 1.048 (95% CI -1.03, 1.066; p < 0.001), 1.3 (95% CI -1.24, 1.49, p > 0.05), -0.813 (95% CI -0.734, 0.899, p < 0.001), 1.347 (95% CI -1.15, 1.57, p < 0.001), and 1.234 (95% CI -1.16, 1.314, p < 0.001), respectively.

CONCLUSION

SARS-CoV-2 caused alterations in vital laboratory parameters and raised ferritin, CRP, and D-dimer presented an association with disease severity at a significant level.

Serum interleukin-6, procalcitonin, and C-reactive protein at hospital admission can identify patients at low risk for severe COVID-19 progression

Background

COVID-19 can show a variable course, from asymptomatic infections to acute respiratory failure and death. For efficient allocation of resources, patients should be stratified according to their risk for a severe course as early as possible.

Methods

135 hospitalized patients with COVID-19 pneumonia at four German hospitals were prospectively included in this observational study. A standardized clinical laboratory profile was taken at hospital admission and a panel of serum markers with possible roles in the COVID-associated cytokine storm were also determined. 112 patients could be evaluated. The primary endpoint of ventilator requirement or death within 30 days of symptom onset was met by 13 patients.

Results

Serum elevations of interleukin-6 (IL-6), procalcitonin (PCT), and C-reactive protein (CRP) at hospital admission were each highly significantly (p < 0.001) associated with ventilator requirement/death within 30 days of symptom onset. With a sensitivity of 92% and a specificity of 65-67%, IL-6 ≥ 52.8 pg/ml, PCT ≥ 0.11 ng/ml, and CRP ≥ 71.1 mg/L were predictive of a severe course of COVID-19. Positive likelihood ratios were between 2.6-2.8 and negative likelihood ratios were between 0.11-0.13 for these three markers.

Conclusion

Negative likelihood ratios indicate that IL-6, PCT, and CRP at hospital admission can be used for identifying patients at low risk for severe COVID-19 progression.

Lower levels of FOXP3 are associated with prolonged inflammatory responses in kidney transplant recipients

Background

Immunosuppressive treatment of kidney transplant recipients is mainly aimed at pro-inflammatory T effector cells, yet they also target the immunosuppressive T regulatory cells. Here, we test the hypothesis that low levels of the master gene regulator of T regulatory cells, forkhead box P3 (FOXP3) splice variants, are associated with prolonged inflammatory responses to stimuli.

Methods

From blood samples obtained the first - and 29th day post-transplant, we extracted peripheral blood mononuclear cells and measured mRNA levels of Total FOXP3, pre-mature RNA FOXP3 (pre-mRNA FOXP3), full length FOXP3 (FOXP3fl) and, FOXP3 splice variant excluding exon two (FOXP3d2). We defined the primary outcome as the number of days in which C reactive protein (CRP) was above 50 mg/L. CRP levels were gathered in two periods, the first from the second to 29 days post-transplant, and the second from 30 to 57 days post-transplant. The association was tested using adjusted negative binomial regression.

Results

From 507 included kidney transplant recipients, 382 recipients had at least one CRP measurement >50 mg/L in the first period, median duration of elevated CRP was 4 days [interquartile range (IQR) 2 to 6]. In the second period, 69 recipients had at least one CRP measurement >50 mg/L, median duration of elevated CRP was 3 days [IQR 2 to 5]. In the first period, we found a significant association between lower levels of Total FOXP3 and prolonged duration of CRP elevation, incidence rate ratio 0.61 (95% confidence interval 0.46-0.80), p<0.01.

Conclusion

Lower levels of total FOXP3 mRNA levels in peripheral blood of kidney transplant recipients are associated with prolonged duration of inflammatory responses regardless of the underlying stimuli.