Monocyte Distribution Width as a Diagnostic Marker for Infection: A Systematic Review and Meta-analysis.

BACKGROUND: Monocyte distribution width (MDW) is an emerging biomarker for infection. It is available easily and quickly as part of the CBC count, which is performed routinely on hospital admission. The increasing availability and promising results of MDW as a biomarker in sepsis has prompted an expansion of its use to other infectious diseases. RESEARCH QUESTION: What is the diagnostic performance of MDW across multiple infectious disease outcomes and care settings? STUDY DESIGN AND METHODS: A systematic review of the diagnostic performance of MDW across multiple infectious disease outcomes was conducted by searching PubMed, Embase, Scopus, and Web of Science through February 4, 2022. Meta-analysis was performed for outcomes with three or more reports identified (sepsis and COVID-19). Diagnostic performance measures were calculated for individual studies with pooled estimates created by linear mixed-effects models. RESULTS: We identified 29 studies meeting inclusion criteria. Most examined sepsis (19 studies) and COVID-19 (six studies). Pooled estimates of diagnostic performance for sepsis differed by reference standard (Second vs Third International Consensus Definitions for Sepsis and Septic Shock criteria) and tube anticoagulant used and ranged from an area under the receiver operating characteristic curve (AUC) of 0.74 to 0.94, with mean sensitivity of 0.69 to 0.79 and mean specificity of 0.57 to 0.86. For COVID-19, the pooled AUC of MDW was 0.76, mean sensitivity was 0.79, and mean specificity was 0.59. INTERPRETATION: MDW exhibited good diagnostic performance for sepsis and COVID-19. Diagnostic thresholds for sepsis should be chosen with consideration of reference standard and tube type used. TRIAL REGISTRY: Prospero; No.: CRD42020210074; URL: https://www.crd.york.ac.uk/prospero/.

Monocyte distribution width as a pragmatic screen for SARS-CoV-2 or influenza infection.

Monocyte distribution width (MDW) is a novel marker of monocyte activation, which is known to occur in the immune response to viral pathogens. Our objective was to determine the performance of MDW and other leukocyte parameters as screening tests for SARS-CoV-2 and influenza infection. This was a prospective cohort analysis of adult patients who underwent complete blood count (CBC) and SARS-CoV-2 or influenza testing in an Emergency Department (ED) between January 2020 and July 2021. The primary outcome was SARS-CoV-2 or influenza infection. Secondary outcomes were measures of severity of illness including inpatient hospitalization, critical care admission, hospital lengths of stay and mortality. Descriptive statistics and test performance measures were evaluated for monocyte percentage, MDW, white blood cell (WBC) count, and neutrophil to lymphocyte ratio (NLR). 3,425 ED patient visits were included. SARS-CoV-2 testing was performed during 1,922 visits with a positivity rate of 5.4%; influenza testing was performed during 2,090 with a positivity rate of 2.3%. MDW was elevated in patients with SARS-Cov-2 (median 23.0U; IQR 20.5-25.1) or influenza (median 24.1U; IQR 22.0-26.9) infection, as compared to those without (18.9U; IQR 17.4-20.7 and 19.1U; 17.4-21, respectively, P < 0.001). Monocyte percentage, WBC and NLR values were within normal range in patients testing positive for either virus. MDW identified SARS-CoV-2 and influenza positive patients with an area under the curve (AUC) of 0.83 (95% CI 0.79-0.86) and 0.83 (95% CI 0.77-0.88), respectively. At the accepted cut-off value of 20U for MDW, sensitivities were 83.7% (95% CI 76.5-90.8%) for SARS-CoV-2 and 89.6% (95% CI 80.9-98.2%) for influenza, compared to sensitivities below 45% for monocyte percentage, WBC and NLR. MDW negative predictive values were 98.6% (95% CI 98.0-99.3%) and 99.6% (95% CI 99.3-100.0%) respectively for SARS-CoV-2 and influenza. Monocyte Distribution Width (MDW), available as part of a routine complete blood count (CBC) with differential, may be a useful indicator of SARS-CoV-2 or influenza infection.

A traumatic pandemic: High acuity pediatric trauma in the COVID19 era.

OBJECTIVE: Gaps remain in our understanding on how COVID19 affects trends in pediatric trauma, the leading cause of mortality and morbidity during childhood and adolescence. METHODS: We compared high acuity trauma visits (requiring admission, surgery, or fatality) presenting between March through February 2021 to corresponding months in 2017-2019. We evaluated the differences in mechanisms of injury, age, and Area Deprivation Index (ADI), a measure of socioeconomic disadvantage, during this time period. Data were analyzed using longitudinal time series analyses and t-tests. RESULTS: Of 687 traumas presenting from March 2020 through February 2021, 322 were high acuity traumas. High acuity traumas declined significantly to a nadir of 16 in April 2020. High acuity traumas increased and surpassed previous years to a peak of 40 visits in August 2020 and from October through December 2020. There were more visits for high acuity assaults and confirmed or suspected physical child abuse but fewer for falls, drownings, and motor vehicle accidents from March to August 2020 and from October through December 2020 compared to prior years. High acuity assaults and physical child abuse cases on average were from the most disadvantaged areas, and physical child abuse patients were younger during the peak of the Pandemic compared to Pre-Pandemic months. CONCLUSION: This analysis provides insight into how the COVID19 pandemic has affected high acuity trauma in an inner-city pediatric population. Findings may be used to guide public health measures on safety and injury prevention as the pandemic continues.

Heterogeneity in the evaluation of suspected MIS-C: a cross-sectional vignette-based survey.

BACKGROUND AND OBJECTIVES: Multisystem Inflammatory Syndrome in Children (MIS-C) is an emerging complication of COVID-19 which lacks a definitive diagnostic test and evidence-based guidelines for workup. We sought to assess practitioners' preferences when initiating a workup for pediatric patients presenting with symptoms concerning for MIS-C. METHODS: In a cross-sectional vignette-based survey, providers were presented with clinical vignettes of a patient presenting with 24 h of fever from a community with high rates of COVID-19. Respondents were asked about their general practices in pursuing a workup for potential MIS-C including testing obtained, criteria for diagnosis, and timing to confirm or rule out the diagnosis. RESULTS: Most of the 174 respondents were physicians from the United States at academic medical centers. The majority of providers would not initiate MIS-C workup for fever and non-specific symptoms unless the fever lasted more than 72 h. Skin rash, abdominal pain, and shortness of breath were symptoms that raised greatest concern for MIS-C. Most providers would obtain COVID-19 PCR or antigen testing, plus blood work, in the initial workup. The list of laboratory studies providers would obtain is extensive. Providers primarily rely on cardiac involvement to confirm a MIS-C diagnosis, and establishing a diagnosis takes 24-48 h. CONCLUSIONS: Significant heterogeneity exists amongst providers as to when to initiate the MIS-C workup, the order and content of the workup, and how to definitively diagnose MIS-C. A diagnostic test with high sensitivity and specificity for MIS-C and refined evidence-based guidelines are needed to expedite diagnosis and treatment.

Monocyte anisocytosis increases during multisystem inflammatory syndrome in children with cardiovascular complications.

BACKGROUND: Multisystem inflammatory syndrome in children (MIS-C) is a life-threatening complication that can develop weeks to months after an initial SARS-CoV-2 infection. A complex, time-consuming laboratory evaluation is currently required to distinguish MIS-C from other illnesses. New assays are urgently needed early in the evaluation process to expedite MIS-C workup and initiate treatment when appropriate. This study aimed to measure the performance of a monocyte anisocytosis index, obtained on routine complete blood count (CBC), to rapidly identify subjects with MIS-C at risk for cardiac complications. METHODS: We measured monocyte anisocytosis, quantified by monocyte distribution width (MDW), in blood samples collected from children who sought medical care in a single medical center from April 2020 to October 2020 (discovery cohort). After identifying an effective MDW threshold associated with MIS-C, we tested the utility of MDW as a tier 1 assay for MIS-C at multiple institutions from October 2020 to October 2021 (validation cohort). The main outcome was the early screening of MIS-C, with a focus on children with MIS-C who displayed cardiac complications. The screening accuracy of MDW was compared to tier 1 routine laboratory tests recommended for evaluating a child for MIS-C. RESULTS: We enrolled 765 children and collected 846 blood samples for analysis. In the discovery cohort, monocyte anisocytosis, quantified as an MDW threshold of 24.0, had 100% sensitivity (95% CI 78-100%) and 80% specificity (95% CI 69-88%) for identifying MIS-C. In the validation cohort, an initial MDW greater than 24.0 maintained a 100% sensitivity (95% CI 80-100%) and monocyte anisocytosis displayed a diagnostic accuracy greater that other clinically available hematologic parameters. Monocyte anisocytosis decreased with disease resolution to values equivalent to those of healthy controls. CONCLUSIONS: Monocyte anisocytosis detected by CBC early in the clinical workup improves the identification of children with MIS-C with cardiac complications, thereby creating opportunities for improving current practice guidelines.

National survey of home injuries during the time of COVID-19: who is at risk?

BACKGROUND: Prior to the COVID-19 pandemic, 44% of all reported injuries in U.S. households occurred in the home. Spending more time at home due to the pandemic may increase the number of home injuries. METHODS: A nationally representative sample of 2011 U.S. adults were surveyed online between June 17 - June 29, 2020. Propensity score weighting and T-tests were used. RESULTS: Twenty-eight percent (28%) of households reported a home injury or ingestion during the pandemic; 13% reported experiencing both. Injuries were most often due to falls (32%). Medication ingestions were reported by 6%; household product ingestions were reported by 4%. Relative to households that experienced no injuries or ingestions, those that reported either or both were more likely to: be in urban areas, have household incomes > $100,000, and have children living in them. Among households reporting more time spent at home, those with children were significantly more likely than those without to report an injury or ingestion. CONCLUSIONS: Results help target prevention messages while U.S. families are continuing to work and learn remotely. During this pandemic and future stay-at-home orders, there is a need for public health efforts to prevent home injuries and ingestions.