Nucleic acid biomarkers of immune response and cell and tissue damage in children with COVID-19 and MIS-C.

Differential host responses in coronavirus disease 2019 (COVID-19) and multisystem inflammatory syndrome in children (MIS-C) remain poorly characterized. Here, we use next-generation sequencing to longitudinally analyze blood samples from pediatric patients with COVID-19 or MIS-C across three hospitals. Profiling of plasma cell-free nucleic acids uncovers distinct signatures of cell injury and death between COVID-19 and MIS-C, with increased multiorgan involvement in MIS-C encompassing diverse cell types, including endothelial and neuronal cells, and an enrichment of pyroptosis-related genes. Whole-blood RNA profiling reveals upregulation of similar pro-inflammatory pathways in COVID-19 and MIS-C but also MIS-C-specific downregulation of T cell-associated pathways. Profiling of plasma cell-free RNA and whole-blood RNA in paired samples yields different but complementary signatures for each disease state. Our work provides a systems-level view of immune responses and tissue damage in COVID-19 and MIS-C and informs future development of new disease biomarkers.

Using trends and outliers in managing delayed transfusions.

OBJECTIVES: To investigate if time to initiate a blood transfusion after an informative laboratory test could feasibly be used by the transfusion medicine service as a metric to monitor for transfusion delays. BACKGROUND: Delayed transfusions may result in patient morbidity and mortality, but no standards for timely transfusion have been developed. Information technology tools could be implemented to identify gaps in provision of blood and to recognise areas of improvement. MATERIALS AND METHODS: Data obtained from a children's hospital's data science platform and time from the release of laboratory results to the initiation of transfusions were calculated and weekly medians were used for trend analyses. Outlier events were obtained using locally estimated scatterplot smoothing and generalised extreme studentized deviate test. RESULTS: Overall, the number of outlier events on the timing of transfusions based on patients' haemoglobin level and platelet count were small (n = 1 and n = 0 for 139 weeks, respectively). Investigation of these events for adverse clinical outcomes was non-significant. CONCLUSIONS: Herein, we propose that the trends and outlier events could be further investigated and used to make decisions and implement protocols to improve patient care.

Measuring the Impact of a Blood Supply Shortage Using Data Science.

BACKGROUND: Transfusion medicine is the only section of the clinical laboratory that performs diagnostic testing and dispenses a drug (blood) on the basis of those results. However, not all of the testing that informs the clinical decision to prescribe a blood transfusion is performed in the blood bank. To form a holistic assessment of blood bank responsiveness to clinical needs, it is important to be able to merge blood bank data with datapoints from the hematology laboratory and the electronic medical record. METHODS: We built an interactive visualization of the time from hemoglobin result availability to initiation of red blood cell (RBC) transfusion and monitored the result over a 2-year period that coincided with several severe blood shortages. The visualization runs entirely on free software and was designed to be feasibly deployed on a variety of hospital information technology platforms without the need for significant data science expertise. RESULTS: Patient factors, such as hemoglobin concentration, blood type, and presence of minor blood group antibodies influenced the time to initiation of transfusion. Time to transfusion initiation did not appear to be significantly affected by periods of blood shortage. CONCLUSION: Overall, we demonstrate a proof of concept that complex, but clinically important, blood bank quality metrics can be generated with the support of a free, user-friendly system that aggregates data from multiple sources.

Variability in Serum Concentrations and Clinical Response in Artisanal Versus Pharmaceutical Cannabidiol Treatment of Pediatric Pharmacoresistant Epilepsy.

OBJECTIVE: We hypothesized that serum cannabidiol (CBD) concentrations would be higher in patients taking pharmaceutical- versus artisanal-CBD oil, and higher serum CBD concentrations would correlate with increased side effects and decreased seizure frequency. METHODS: This was a retrospective chart review. We included patients with pharmacoresistant epilepsy, treated with artisanal-CBD or pharmaceutical-CBD (Epidiolex), and with quantitative serum CBD concentrations. We tracked epilepsy diagnosis, artisanal-CBD dosage, pharmaceutical-CBD dose, serum CBD concentration, clobazam concentration, N-desmethylclobazam concentration, seizure history (frequency of motor seizures), response to medication (percentage reduction in motor seizures), and side effects. RESULTS: Forty-two patients met inclusion criteria. Mean serum CBD concentration was 51.1 ng/mL (artisanal group) and 124 ng/mL (pharmaceutical group) (p = 0.022). Patients receiving artisanal-CBD had no change in median overall seizures (IQR, -50% to 50%); the pharmaceutical-CBD group had median 50% reduction (IQR, -90% to no change) (p = 0.199). CONCLUSIONS: Pharmaceutical-CBD achieves higher serum CBD concentrations than artisanal-CBD in pediatric patients with refractory epilepsy. These higher CBD concentrations are associated with increased reported adverse effects, but no detectable difference in seizure frequency.

The immunologic response to severe acute respiratory syndrome coronavirus 2.

Background: The spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has precipitated the worst global pandemic in a century, which has caused millions of infections and deaths as well as massive economic repercussions. Objective: As with any pathogenic virus, it is crucial to understand its unique interactions with the human immune system so that pharmaceutical and prophylactic interventions can be deployed to effectively control the pandemic. Methods: A literature search by using PubMed was conducted in 2020 with variants of the terms "COVID-19," "SARS-CoV-2," and "immunological response." English language articles that presented original data about the immunologic response to coronavirus disease 2019 (COVID-19) were selected for review. This article reviewed the current understanding of the innate and adaptive immune responses to SARS-CoV-2 infection, including their relationship to current therapeutic and diagnostic strategies. Results: SARS-CoV-2 uses several unique molecular techniques to evade detection by the innate immune system early in the course of infection, and upregulation of these innate immune pathways may possibly accelerate the time to recovery and prevent severe disease. Although the majority of cases results in the patients' recovery, a significant proportion of infections result in deaths prompted by the host's inflammatory overreaction to the infection, a response that can be attenuated with corticosteroids and potentially other immune modulators. Conclusion: Current work by the scientific community to further understand how SARS-CoV-2 interacts with the human immune system will be invaluable to our response and preparedness for future coronavirus pandemics.

Estimated SARS-CoV-2 Seroprevalence in Healthy Children and Those with Chronic Illnesses in the Washington Metropolitan Area as of October 2020.

The estimated severe acute respiratory syndrome coronavirus 2 seroprevalence in children was found to be 9.46% for the Washington Metropolitan area. Hispanic/Latinx individuals were found to have higher odds of seropositivity. While chronic medical conditions were not associated with having antibodies, previous fever and body aches were predictive symptoms.

Transfusion-associated hyperkalemia in pediatric population: Prevalence, risk factors, survival, infusion rate, and RBC unit features.

BACKGROUND: Hyperkalemia is a rare life-threatening complication of red blood cell (RBC) transfusion. Stored RBCs leak intracellular potassium (K+) into the supernatant; irradiation potentiates the K+ leak. As the characteristics of patients and implicated RBCs have not been studied systematically, a multicenter study of transfusion-associated hyperkalemia (TAH) in the pediatric population was conducted through the AABB Pediatric Transfusion Medicine Subsection. STUDY DESIGN: The medical records of patients <18 years old were retrospectively queried for hyperkalemia occurrence during or ≤12 h after the completion of RBC transfusion in a 1-year period. Collected data included patient demographics, diagnosis, medical history, timing of hyperkalemia and transfusion, mortality, and RBC unit characteristics. RESULTS/FINDINGS: A total of 3777 patients received 19,649 RBC units during the study period in four facilities. TAH was found in 35 patients (0.93%) in 37 occurrences. The patient median age and weight were 1.28 years and 9.80 kg, respectively. All patients had multiple serious comorbidities. There were 79 RBC units transfused in the TAH events; 62% were irradiated, and the median age of the units was 10 days. The median total RBC volume transfused ≤12 h before TAH was 24% of patient estimated total blood volume, and the median infusion rate (IR) was19.6 ml/kg/h. Mortality rate within 1 day after the TAH event was 20%. CONCLUSIONS: The prevalence of TAH in children was low; however, the 1-day mortality rate was 20%. Patients with multiple comorbidities may be at higher risk for TAH. The IR was higher for patients who had TAH than the IR threshold for safe transfusion.

Spontaneous recovery in a patient with acquired thrombotic thrombocytopenic purpura (TTP): observation of a 'subclinical' TTP state.

OBJECTIVES: Thrombotic thrombocytopenic purpura (TTP) is a thrombotic microangiopathy that can have high mortality rates without prompt treatment. Standard treatment is urgent plasma exchange (PLEX), which leads to disease remission in the vast majority of patients. Deficiency of ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13) alone is not sufficient to cause the clinical manifestations characteristic of TTP. We present a case of acquired TTP, where spontaneous recovery was observed prior to initiation of any TTP-specific therapy. CLINICAL PRESENTATION: A 73-year-old asymptomatic female presented with new-onset mild haemolytic anaemia and thrombocytopenia. Further testing revealed a significantly reduced ADAMTS13 activity level and an ADAMTS13 inhibitor, concerning for acquired TTP. On reassessment, the patient's haematologic parameters had been corrected prior to initiation of therapy. During subsequent follow-up three months later, she developed acute worsening thrombocytopenia indicative of relapsed, acute TTP. The patient was then successfully managed with PLEX and rituximab and achieved a sustained remission. DISCUSSION AND CONCLUSION: TTP is a haematologic emergency that requires urgent therapy to reduce morbidity and mortality. However, it is well documented that individuals with hereditary TTP and a proportion with acquired TTP in clinical remission can have low or nearly absent ADAMTS13 activity levels without evidence of microangiopathic haemolytic anaemia (MAHA) or thrombotic manifestations. Our patient represents a unique case of confirmed ADAMTS13 deficiency due to a documented inhibitor, leading to mild haemolytic anaemia and thrombocytopenia both of which recovered spontaneously. We propose that this scenario could represent a 'subclinical' TTP state that precedes the development of clinically significant disease.

Kinetics of Viral Clearance and Antibody Production Across Age Groups in Children with Severe Acute Respiratory Syndrome Coronavirus 2 Infection.

OBJECTIVES: To improve understanding of transition from viral infection to viral clearance, and antibody response in pediatric patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. STUDY DESIGN: This retrospective analysis of children tested for SARS-CoV-2 by reverse transcription (RT) polymerase chain reaction (PCR) and immunoglobulin G antibody at a quaternary-care, free-standing pediatric hospital between March 13, 2020, and June 21, 2020, included 6369 patients who underwent PCR testing and 215 patients who underwent antibody testing. During the initial study period, testing focused primarily on symptomatic children; the later study period included asymptomatic patients who underwent testing as preadmission or preprocedural screening. We report the proportion of positive and negative tests, time to viral clearance, and time to seropositivity. RESULTS: The rate of positivity varied over time due to viral circulation in the community and transition from targeted testing of symptomatic patients to more universal screening of hospitalized patients. Median duration of viral shedding (RT-PCR positivity) was 19.5 days and time from RT-PCR positivity to negativity was 25 days. Of note, patients aged 6 through 15 years demonstrated a longer time of RT-PCR positivity to negativity, compared with patients aged 16 through 22 years (median 32 vs 18 days, P = .015). Median time to seropositivity, by chemiluminescent testing, from RT-PCR positivity was 18 days, whereas median time to reach adequate levels of neutralizing antibodies (defined as comparable with 160 titer by plaque reduction neutralization testing) was 36 days. CONCLUSIONS: The majority of patients demonstrated a prolonged period of viral shedding after infection with SARS CoV-2. It is unknown whether this correlates with persistent infectivity. Only 17 of 33 patients demonstrated adequate neutralizing antibodies during the time frame of specimen collection. It remains unknown whether immunoglobulin G antibody against spike structured proteins correlates with immunity, and how long antibodies and potential protection persist.

Blood utilisation and transfusion reactions in adult patients transfused with conventional or pathogen-reduced platelets.

Pathogen-reduced (PR) platelets are routinely used in many countries. Some studies reported changes in platelet and red blood cell (RBC) transfusion requirements in patients who received PR platelets when compared to conventional (CONV) platelets. Over a 28-month period we retrospectively analysed platelet utilisation, RBC transfusion trends, and transfusion reaction rates data from all transfused adult patients transfused at the Yale-New Haven Hospital, New Haven, CT, USA. We determined the number of RBC and platelet components administered between 2 and 24, 48, 72 or 96 h. A total of 3767 patients received 21 907 platelet components (CONV = 8912; PR = 12 995); 1,087 patients received only CONV platelets (1578 components) and 1,466 patients received only PR platelets (2604 components). The number of subsequently transfused platelet components was slightly higher following PR platelet components (P < 0·05); however, fewer RBCs were transfused following PR platelet administration (P < 0·05). The mean time-to-next platelet component transfusion was slightly shorter following PR platelet transfusion (P = 0·002). The rate of non-septic transfusion reactions did not differ (all P > 0·05). Septic transfusion reactions (N = 5) were seen only after CONV platelet transfusions (P = 0·011). These results provide evidence for comparable clinical efficacy of PR and CONV platelets. PR platelets eliminated septic transfusion reactions without increased risk of other types of transfusions with only slight increase in platelet utilisation.

Blood Utilization and Transfusion Reactions in Pediatric Patients Transfused with Conventional or Pathogen Reduced Platelets.

OBJECTIVES: To assess the safety and efficacy of a Food and Drug Administration-approved pathogen-reduced platelet (PLT) product in children, as ongoing questions regarding their use in this population remain. STUDY DESIGN: We report findings from a quality assurance review of PLT utilization, associated red blood cell transfusion trends, and short-term safety of conventional vs pathogen-reduced PLTs over a 21-month period while transitioning from conventional to pathogen-reduced PLTs at a large, tertiary care hospital. We assessed utilization in neonatal intensive care unit (NICU) patients, infants 0-1 year not in the NICU, and children age 1-18 years (PED). RESULTS: In the 48 hours after an index conventional or pathogen-reduced platelet transfusion, respectively, NICU patients received 1.0 ± 1.4 (n = 91 transfusions) compared with 1.2 ± 1.3 (n = 145) additional platelet doses (P = .29); infants 0-1 year not in the NICU received 2.8 ± 3.0 (n = 125) vs 2.6 ± 2.6 (n = 254) additional platelet doses (P = .57); and PEDs received 0.9 ± 1.6 (n = 644) vs 1.4 ± 2.2 (n = 673) additional doses (P < .001). Time to subsequent transfusion and red cell utilization were similar in every group (P > .05). The number and type of transfusion reactions did not significantly vary based on PLT type and no rashes were reported in NICU patients receiving phototherapy and pathogen-reduced PLTs. CONCLUSIONS: Conventional and pathogen-reduced PLTs had similar utilization patterns in our pediatric populations. A small, but statistically significant, increase in transfusions was noted following pathogen-reduced PLT transfusion in PED patients, but not in other groups. Red cell utilization and transfusion reactions were similar for both products in all age groups.

Microbial pathogen primary sequence inversely correlates with blood group antigen immunogenicity.

BACKGROUND: It is well known that specific groups of patients immunologically respond more readily than others to red blood cell (RBC) antigens. While allogeneic RBC antigen exposure is the primary determinant of alloantibody formation, other variables are also involved. Given the significant primary sequence identity between common RBC and microbial antigens, we hypothesized that certain individuals may be immunologically primed to form RBC alloantibodies via environmental exposure to cross-reactive microbial epitopes, and that such a correlation may be linked to blood group antigen immunogenicity. STUDY DESIGN AND METHODS: We examined the relationship between RBC-microbe peptide homology and the formation of alloantibodies to the most immunogenic RBC antigens, using the BLASTp homology database. Thirteen-residue peptides centered on the polymorphic amino acids of K, Jka , Lua , E, c, M, C, and S antigens were queried for identity with microbial peptides using the BLASTp database. Results were restricted to bacteria and fungi, with a selective threshold of >80% identity for inclusion, to allow for minor peptide variability. RESULTS: Significant peptide identity was found between RBC antigens and pathogenic organisms including B. fragilis, P. aeruginosa, and Candida spp., among others. Linear regression and k-medoids clustering analysis of the microbial genera meeting the inclusion criteria showed a statistically significant inverse correlation with RBC immunogenicity (b = -0.0017, r2 = 0.624 & p = 0.0197), with lower immunogenicity antigens associated with larger number of genera. CONCLUSIONS: Our findings raise a potential relationship between microbial exposure and alloantibody formation, and lead to interesting questions regarding the potential relationship between RBC antigen immunogenicity and microbial prevalence.

Cryoglobulinemia as a Possible Primer for TRALI: Report of a Case.

Waldenström macroglobulinemia (WM) is a form of lymphoplasmacytic lymphoma that can cause hyperviscosity syndrome due to unchecked monoclonal antibody production. Some patients are also found to have associated cryoglobulinemia, which can cause systemic complications including vasculitis, renal disease, and pulmonary complications. Cryoglobulins can also serve as a source of interference with various laboratory assays. Therapeutic plasma exchange (TPE) is one of the recommended treatment modalities to manage hyperviscosity. Herein, we present the case of an 84-year-old female patient with Waldenström macroglobulinemia who presented with hyperviscosity syndrome and discrepant laboratory findings, and who then developed transfusion-related acute lung injury (TRALI) during TPE. This case is one of many in the emerging possible linkages observed between cryoglobulinemia and TRALI.

The Use and Misuse of Statistical Methods in Cytopathology Studies: Review of 6 Journals.

BACKGROUND: The misuse of statistical methods in diagnostic accuracy studies has been criticized in many publications. OBJECTIVE: To assess the use and misuse of statistical methods in medical journal articles. METHODS: We reviewed 141 original articles from 6 cytopathology journals published in 2014. RESULTS: In total, 16 articles used no descriptive statistics and 66 articles used no inferential statistics. Also, 82 articles did not report using any tests for diagnostic accuracy. The most commonly adopted statistical measure for diagnostic accuracy was sensitivity, followed by specificity. The most common inferential statistical methods were χ2 testing, the Fisher exact test, and the Cohen kappa coefficient, respectively. Only 78 articles were free of statistical errors. "No statistics were used although statistical methods were required" was the most common type of error, followed by "failure to select proper statistical methods." CONCLUSION: Our assessment of use of statistical methods in this subsection of pathology demonstrated a need for improvement.

Prevention of Transfusion-Associated Graft-Versus-Host Disease With Blood Product Irradiation: The Past, Present, and Future.

Transfusion-associated graft-versus-host disease (TA-GVHD) is a disease with a very high mortality rate. In this report, we discuss TA-GVHD from a historical perspective, highlight the pathogenesis of TA-GVHD, and emphasize the importance of blood product irradiation, which is a very effective means to prevent this disease. We summarize the current recommendations in different patient populations from different countries and review recent developments, such as alternatives for the use of radioactive materials. We also speculate on future directions.

Early Recognition and Treatment of Sepsis After the Addition of Lactate to the Laboratory's Critical Result Call List.

PURPOSE: Screening of patients with sepsis is needed to increase recognition and allow for earlier interventions. There is no consensus on whether the addition of lactate to the critical result laboratory's call list should be a standard practice. MATERIALS AND METHODS: This was a retrospective cohort study that compared management and outcomes of patients with sepsis having lactate ≥4 mmol/L before (group 1) and after (group 2) the addition of a critical result threshold of lactate of ≥4 mmol/L to the critical result laboratory's call list and its effects on time to antibiotics and intravenous fluids (IVFs). RESULTS: One hundred twenty-one patients were included. Lactate was higher in group 1 (7.0 ± 4.3 vs 5.6 ± 2.0, P = 0.03). More patients in group 2 received hydrocortisone (1.9% vs 22.4%, P = .001). Hospital mortality, 30-day mortality, and 90-day mortality were significantly lower in group 2 (59.3% vs 32.8%, P = .003; 68.5% vs 37.3%, P ≤ .001; 68.5% vs 41.8%, P = .002). There were no significant differences in total volume of IVFs (2400.8 ± 1720.0 vs 2483.7 ± 2155.7, P = 0.83), time to start IVFs (184.0 ± 283.2 vs 115.6 ± 190.5, P = 0.27), or antibiotics (184.8 ± 187.1 vs 133.7 ± 137.4, P = 0.16). CONCLUSION: Addition of lactate to the critical result laboratory's call list did not lead to a statistically significant improvement in time to IVFs or antibiotics, although the average time to antibiotics and IVFs decreased by 51.1 and 68.4 minutes, respectively. Hospital mortality, 30-day mortality, and 90-day mortality were lower in group 2, which may be, in part, due to increased recognition of severe sepsis by critical result notification and earlier intervention.