Effect of dynamic exclusion and the use of FAIMS, DIA and MALDI-mass spectrometry imaging with ion mobility on amyloid protein identification.

Amyloidosis is a disease characterized by local and systemic extracellular deposition of amyloid protein fibrils where its excessive accumulation in tissues and resistance to degradation can lead to organ failure. Diagnosis is challenging because of approximately 36 different amyloid protein subtypes. Imaging methods like immunohistochemistry and the use of Congo red staining of amyloid proteins for laser capture microdissection combined with liquid chromatography tandem mass spectrometry (LMD/LC-MS/MS) are two diagnostic methods currently used depending on the expertise of the pathology laboratory. Here, we demonstrate a streamlined in situ amyloid peptide spatial mapping by Matrix Assisted Laser Desorption Ionization-Mass Spectrometry Imaging (MALDI-MSI) combined with Trapped Ion Mobility Spectrometry for potential transthyretin (ATTR) amyloidosis subtyping. While we utilized the standard LMD/LC-MS/MS workflow for amyloid subtyping of 31 specimens from different organs, we also evaluated the potential introduction in the MS workflow variations in data acquisition parameters like dynamic exclusion, or testing Data Dependent Acquisition combined with High-Field Asymmetric Waveform Ion Mobility Spectrometry (DDA FAIMS) versus Data Independent Acquisition (DIA) for enhanced amyloid protein identification at shorter acquisition times. We also demonstrate the use of Mascot's Error Tolerant Search and PEAKS de novo sequencing for the sequence variant analysis of amyloidosis specimens.

Epigenetic memory of coronavirus infection in innate immune cells and their progenitors.

Inflammation can trigger lasting phenotypes in immune and non-immune cells. Whether and how human infections and associated inflammation can form innate immune memory in hematopoietic stem and progenitor cells (HSPC) has remained unclear. We found that circulating HSPC, enriched from peripheral blood, captured the diversity of bone marrow HSPC, enabling investigation of their epigenomic reprogramming following coronavirus disease 2019 (COVID-19). Alterations in innate immune phenotypes and epigenetic programs of HSPC persisted for months to 1 year following severe COVID-19 and were associated with distinct transcription factor (TF) activities, altered regulation of inflammatory programs, and durable increases in myelopoiesis. HSPC epigenomic alterations were conveyed, through differentiation, to progeny innate immune cells. Early activity of IL-6 contributed to these persistent phenotypes in human COVID-19 and a mouse coronavirus infection model. Epigenetic reprogramming of HSPC may underlie altered immune function following infection and be broadly relevant, especially for millions of COVID-19 survivors.

Defibrotide mitigates endothelial cell injury induced by plasmas from patients with COVID-19 and related vasculopathies.

BACKGROUND AND OBJECTIVES: COVID-19 progression is characterized by systemic small vessel arterial and venous thrombosis. Microvascular endothelial cell (MVEC) activation and injury, platelet activation, and histopathologic features characteristic of acute COVID-19 also describe certain thrombotic microangiopathies, including atypical hemolytic-uremic syndrome (aHUS), thrombotic thrombocytopenic purpura (TTP), and hematopoietic stem cell transplant (HSCT)-associated veno-occlusive disease (VOD). We explored the effect of clinically relevant doses of defibrotide, approved for HSCT-associated VOD, on MVEC activation/injury. METHODS: Human dermal MVEC were exposed to plasmas from patients with acute TMAs or acute COVID-19 in the presence and absence of defibrotide (5µg/ml) and caspase 8, a marker of EC activation and apoptosis, was assessed. RNAseq was used to explore potential mechanisms of defibrotide activity. RESULTS: Defibrotide suppressed TMA plasma-induced caspase 8 activation in MVEC (mean 60.2 % inhibition for COVID-19; p = 0.0008). RNAseq identified six major cellular pathways associated with defibrotide's alteration of COVID-19-associated MVEC changes: TNF-α signaling; IL-17 signaling; extracellular matrix (ECM)-EC receptor and platelet receptor interactions; ECM formation; endothelin activity; and fibrosis. Communications across these pathways were revealed by STRING analyses. Forty transcripts showing the greatest changes induced by defibrotide in COVID-19 plasma/MVEC cultures included: claudin 14 and F11R (JAM), important in maintaining EC tight junctions; SOCS3 and TNFRSF18, involved in suppression of inflammation; RAMP3 and transgelin, which promote angiogenesis; and RGS5, which regulates caspase activation and apoptosis. CONCLUSION: Our data, in the context of a recent clinical trial in severe COVID-19, suggest benefits to further exploration of defibrotide and these pathways in COVID-19 and related endotheliopathies.

Immunogenicity of COVID-19 mRNA vaccines in patients with acute myeloid leukemia and myelodysplastic syndrome.

Immunocompromised patients are susceptible to complications from severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). The mRNA vaccines BNT162b2 and mRNA-1273 are effective in immunocompetent adults, but have diminished activity in immunocompromised patients. We measured anti-spike SARS-CoV-2 antibody (anti-S) response, avidity, and surrogate neutralizing antibody activity in COVID-19 vaccinated patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). Anti-S was induced in 89% of AML and 88% of MDS patients, but median levels were significantly lower than in healthy controls. SARS-CoV-2 antibody avidity and neutralizing activity from AML patients were significantly lower than controls. Antibody avidity was significantly greater in patients after mRNA-1273 versus BNT162b2; there were trends toward higher anti-S levels and greater neutralizing antibody activity after mRNA-1273 vaccination. Patients with AML and MDS are likely to respond to COVID-19 mRNA vaccination, but differences in anti-S levels, avidity, and neutralizing antibody activity may affect clinical outcomes and require further study.

Premortem Skin Biopsy Assessing Microthrombi, Interferon Type I Antiviral and Regulatory Proteins, and Complement Deposition Correlates with Coronavirus Disease 2019 Clinical Stage.

Apart from autopsy, tissue correlates of coronavirus disease 2019 (COVID-19) clinical stage are lacking. In the current study, cutaneous punch biopsy specimens of 15 individuals with severe/critical COVID-19 and six with mild/moderate COVID-19 were examined. Evidence for arterial and venous microthrombi, deposition of C5b-9 and MASP2 (representative of alternative and lectin complement pathways, respectively), and differential expression of interferon type I-driven antiviral protein MxA (myxovirus resistance A) versus SIN3A, a promoter of interferon type I-based proinflammatory signaling, were assessed. Control subjects included nine patients with sepsis-related acute respiratory distress syndrome (ARDS) and/or acute kidney injury (AKI) pre-COVID-19. Microthrombi were detected in 13 (87%) of 15 patients with severe/critical COVID-19 versus zero of six patients with mild/moderate COVID-19 (P < 0.001) and none of the nine patients with pre-COVID-19 ARDS/AKI (P < 0.001). Cells lining the microvasculature staining for spike protein of severe acute respiratory syndrome coronavirus 2, the etiologic agent of COVID-19, also expressed tissue factor. C5b-9 deposition occurred in 13 (87%) of 15 patients with severe/critical COVID-19 versus zero of six patients with mild/moderate COVID-19 (P < 0.001) and none of the nine patients with pre-COVID-19 ARDS/AKI (P < 0.001). MASP2 deposition was also restricted to severe/critical COVID-19 cases. MxA expression occurred in all six mild/moderate versus two (15%) of 13 severe/critical cases (P < 0.001) of COVID-19. In contrast, SIN3A was restricted to severe/critical COVID-19 cases co-localizing with severe acute respiratory syndrome coronavirus 2 spike protein. SIN3A was also elevated in plasma of patients with severe/critical COVID-19 versus control subjects (P ≤ 0.02). In conclusion, the study identified premortem tissue correlates of COVID-19 clinical stage using skin. If validated in a longitudinal cohort, this approach could identify individuals at risk for disease progression and enable targeted interventions.

Rapid Absolute Neutrophil Count Testing Guides Targeted Antimicrobial Therapy in Febrile Pediatric Oncology Patients.

OBJECTIVES: It is well established that early antibiotic administration leads to improved outcomes in febrile neutropenic patients. To achieve this, many institutions administer empiric antibiotics to all febrile oncology patients in the emergency setting, before knowing their neutropenic status. This study evaluates the role of rapid absolute neutrophil count (ANC) testing in the targeted antimicrobial management of nonneutropenic febrile oncology patients. METHODS: We conducted a retrospective review of patients 19 years or younger presenting to the pediatric emergency service with an oncologic process and fever or history of fever. We examined the administration of antibiotics and outcomes in nonneutropenic patients. RESULTS: We included 101 patient encounters, representing 62 distinct patients. The rapid ANC test influenced antibiotic management in 94% (95/101) of patient encounters and resulted in no antibiotics or targeted antibiotic therapy in 88% (60/68) of nonneutropenic patients. Use of the rapid ANC test to guide treatment would have spared antibiotic administration in 68% (46/68) of well-appearing nonneutropenic patients with no alternate indication. No well-appearing, nonneutropenic patient had a positive blood culture, and only 1 required hospital admission on a repeat visit. CONCLUSIONS: The rapid ANC is a useful tool to balance the goal of early antibiotic administration in febrile neutropenic oncology patients while promoting antibiotic stewardship in this vulnerable population.

An Interesting Case of Isolated False-Reactive Hepatitis B Surface Antigen.

The standard serologic markers used to diagnose hepatitis B infection include hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs), total hepatitis B core antibody (anti-HBc), and IgM antibody to hepatitis B core antigen (IgM anti-HBc). Different markers or combinations of markers are used to identify different phases of HBV infection and determine whether a patient has acute or chronic infection or immunity due to prior infection or vaccination or is seronegative and susceptible to future infection. Isolated HBsAg seropositivity is a peculiar serological pattern that requires investigation. Herein, we present a case of an asymptomatic female without a history of liver disease or evident risk factors for hepatitis, who underwent screening for infectious disease prior to resection of basal cell carcinoma involving her eyelid. The patient's laboratory testing showed positivity for HBsAg and the HIV 1/2 screen. To investigate, we performed serial dilutions, utilized heterophilicantibody blocking tubes, and repeated analysis using a different commercial assay (Abbott Architect i2000), all in support of a false-positive result attributed to a heterophilic antibody. Hence, we demonstrate that heterophilic antibody interference can result in isolated HBsAg positivity and recommend considering this form of interference in the differential where there is low clinical suspicion for viral infection.

Overcoming Drug Interference in Transfusion Testing: A Spotlight on Daratumumab.

Daratumumab, a monoclonal antibody therapeutic, is highly efficacious and widely used in all stages of multiple myeloma and amyloidosis and has promising activity in other hematologic disorders. Daratumumab interacts with red blood cells, interfering with pre-transfusion testing. This interference can lead to compromising transfusion safety, extensive blood bank work ups and delays in provision of compatible units. Several methods have been developed to negate daratumumab interference with indirect antiglobulin testing. They are based on i) standard blood bank techniques including dithiothreitol and enzymatic treatment of reagent cells, using reagent red blood cells negative for CD38, ii) blocking CD38 antigens on reagent or donor cells, iii) neutralization of anti-CD38 antibody in patient plasma prior to testing, and iv) extended antigen typing of patient red blood cells in conjunction with provision of phenotypically matched units for transfusion. Implementation of those methods by the blood bank should be a planned effort coordinated with the patient's clinical team. Timely involvement of blood bank and transfusion services and educational efforts by both blood banks and clinical providers can improve the overall daratumumab safety profile in regard to blood transfusion.

Red blood cells donated by smokers: A pilot investigation of recipient transfusion outcomes.

BACKGROUND: Current regulations do not require blood collection facilities to ask donors about cigarette smoking, and the prevalence of nicotine and its metabolites in blood products is not well established. Although smokers have higher hemoglobin (Hb) levels, smoking may adversely affect the quality of donated red blood cells through higher carboxyhemoglobin (COHb) content and premature hemolysis. STUDY DESIGN AND METHODS: Red blood cell (RBC) unit segments from 100 unique donors were tested for nicotine and its metabolite cotinine by mass spectrometry and for COHb spectrophotometrically. Outcomes were evaluated retrospectively in adult non-bleeding patients receiving single RBC units. RESULTS: Thirteen of 100 RBC segments (13%) were positive for cotinine at levels consistent with current smoking (> 10 ng/mL). The cotinine positive RBCs showed significantly greater COHb content compared to cotinine negative units (median 3.0% vs. 0.8%, p = 0.007). For patients transfused cotinine-positive units, there was no significant change in their vital signs following transfusion and no transfusion reactions were observed. However, patients transfused cotinine-positive units showed significantly reduced hematocrit and hemoglobin increments (median +1.2% and +0.4 g/dL) following transfusion compared to patients receiving cotinine negative units (median +3.6% and +1.4 g/dL) (p = 0.014). CONCLUSION: Thirteen percent of RBC units tested positive for cotinine at levels consistent with active smoking, accordant with the estimated national smoking rate of 15.5%. Cotinine-positive RBC units had greater COHb content and showed reduced hematocrit and hemoglobin increments following transfusion. These preliminary results should be validated in a larger cohort.

The impact of Daratumumab on transfusion service costs.

BACKGROUND: Daratumumab (DARA) is a human IgG1κ monoclonal antibody directed against CD38, approved for the treatment of multiple myeloma. As CD38 is expressed on RBCs, DARA can interfere with pretransfusion testing. DARA interference can be negated by denaturation of CD38 on RBCs with dithiothreitol (DTT) reagents. Because of this interference in pretransfusion testing, our hospital implemented a notification and testing/transfusion algorithm (NATTA) for pretransfusion testing and RBC product provision for DARA patients. This standardized approach combines DTT-based testing with selective genotyping and the provision of phenotypically similar RBCs for patients with clinically significant antibodies. STUDY DESIGN AND METHODS: We evaluated pretransfusion test results and transfusion requirements for 91 DARA patients in an academic medical center over 1 year to determine the incremental cost of pretransfusion testing and RBC selection. The actual costs for the NATTA approach were compared to a theoretical approach using universal genotyping with a provision of phenotypically similar RBC transfusions. RESULTS: The annual cost of testing related to DARA after NATTA implementation was $535.76 per patient. The simulated annual cost for the alternative genotyping with provision of phenotypically similar RBC transfusions approach was $934.83 per patient. CONCLUSION: In our entire cohort of DARA patients, a DTT-based testing algorithm with selective genotyping and provision of phenotypically similar RBCs only for patients with clinically significant antibodies was less expensive than a simulated model of universal genotyping and provision of phenotypically similar RBCs.