Interpreting coagulation mixing study results in the era of direct oral anticoagulants.

Interpretation of coagulation mixing studies is complicated by interference arising from direct oral anticoagulants (DOACs), which are increasingly prescribed. In this retrospective study, we reviewed 1035 consecutive coagulation mixing studies performed from 2017 to 2021. Three hundred and ninety-nine cases with normal prothrombin time (PT) and activated partial thromboplastin time (aPTT) were excluded. aPTT mixing studies were performed at time 0 and after 60 min of incubation. We confirmed the presence of interfering factors with additional laboratory testing, medication records, and medical history. Mixing corrected most prolonged PT samples (93%), but 32 cases showed incomplete correction. Of these 32 cases, 18 were confounded by DOAC use, and 3 by factor V (FV) inhibitor. We observed an unusual pattern of prolongation of aPTT after incubation, which was previously considered a characteristic of specific factor inhibitors, most commonly FVIII inhibitor. However, we found that lupus anticoagulant (28%) and DOAC (25%) contributed to this pattern similarly as specific factor inhibitors (28%). Coagulation laboratories should be aware of interference arising from DOACs and other factors in PT/aPTT mixing studies, especially in some unusual correction patterns.

Recurrent Gastrointestinal Bleeding in a Middle-Aged Man.

Acquired von Willebrand disease (avWD) arises because of mechanisms that destroy, decrease, absorb, or clear von Willebrand factor (vWF). A 59-year-old man presented with a 3-year history of recurrent gastrointestinal bleeding. Laboratory workup revealed a prolonged platelet function assay-100. The vWF antigen was decreased, and a low vWF immunofunctional activity/antigen ratio, low collagen binding/antigen ratio, and decreased intermediate and high molecular weight multimers were noted. The patient had no high-shear stress conditions, and an antibody-mediated process was suspected. A vWF mixing study showed complete correction of vWF activity, suggesting no direct functional inhibitor. The patient was given a bolus of vWF concentrate with serial measurements of vWF; the vWF half-life was 2.5 hours. The vWF propeptide/antigen ratio was 4:1, supporting a diagnosis of aVWD resulting from increased antibody-mediated vWF clearance. This case study emphasizes the laboratory's role in the diagnosis and treatment of rare, overlooked acquired bleeding disorders.

Ultrasound-based criteria for adequate peripheral venous access in therapeutic apheresis procedures.

BACKGROUND: Apheresis procedures require adequate vascular access to achieve adequate inlet flow rates. Central dialysis-type catheters are often used in apheresis, despite their multiple risks. Peripheral venous access is a safe and effective option for many patients. AIM: We previously demonstrated that ultrasound guidance reduces central venous catheter use in apheresis patients; however, no validated criteria for preprocedural evaluation of peripheral veins exist. Here, we hypothesized that ultrasound-based criteria could predict the adequacy of a peripheral vein for apheresis procedures. PATIENTS/METHODS: In this pilot cohort study, we reviewed the procedural outcomes for 50 cases of peripheral venous procedures that used our ultrasound-based criteria. RESULTS: Of the procedures that met our criteria, 96% (46/48) were successfully completed. Overall, our criteria had 100% sensitivity, 50% specificity, 96% positive predictive value, and 100% negative predictive value. CONCLUSION: Our criteria justify an evidence-based ultrasound-guided standard for evaluation of peripheral venous access for apheresis procedures.

Pathology Residency Curriculum: Time for a Change?

The current Anatomical and Clinical Pathology residency curriculum, as outlined by the American Board of Pathology (ABP), emphasizes resident exposure to a wide variety of subjects without in-depth training. This has led to a large number of residents pursuing fellowship training. With the demand for further sub-specialization, there is a necessity for the establishment of an updated curriculum that not only encompasses the basic knowledge of pathology but is also focused on training residents in their desired subspecialty.We herein propose a new comprehensive AP/CP residency syllabus. The new curriculum will be divided into two major categories: preliminary and subspecialty training. The curriculum will require residents to undergo basic pathology training within the first two preliminary years, followed by two subspecialty years. In their subspecialty years, each resident will be required to either pick two subjects as majors, each having a duration of one year, or one subject as a major and two subjects as minors, in which case the major will have a one-year duration and the minors will each be six months in length. The proposed curriculum meets the current guidelines of the ABP, reduces the burden of residents to complete multiple fellowships, and allows residents earlier entrance into the workforce.

Limited window for donation of convalescent plasma with high live-virus neutralizing antibody titers for COVID-19 immunotherapy.

Millions of individuals who have recovered from SARS-CoV-2 infection may be eligible to participate in convalescent plasma donor programs, yet the optimal window for donating high neutralizing titer convalescent plasma for COVID-19 immunotherapy remains unknown. Here we studied the response trajectories of antibodies directed to the SARS-CoV-2 surface spike glycoprotein and in vitro SARS-CoV-2 live virus neutralizing titers (VN) in 175 convalescent donors longitudinally sampled for up to 142 days post onset of symptoms (DPO). We observed robust IgM, IgG, and viral neutralization responses to SARS-CoV-2 that persist, in the aggregate, for at least 100 DPO. However, there is a notable decline in VN titers ≥160 for convalescent plasma therapy, starting 60 DPO. The results also show that individuals 30 years of age or younger have significantly lower VN, IgG and IgM antibody titers than those in the older age groups; and individuals with greater disease severity also have significantly higher IgM and IgG antibody titers. Taken together, these findings define the optimal window for donating convalescent plasma useful for immunotherapy of COVID-19 patients and reveal important predictors of an ideal plasma donor.

Significantly Decreased Mortality in a Large Cohort of Coronavirus Disease 2019 (COVID-19) Patients Transfused Early with Convalescent Plasma Containing High-Titer Anti-Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Spike Protein IgG.

Coronavirus disease 2019 (COVID-19) convalescent plasma has emerged as a promising therapy and has been granted Emergency Use Authorization by the US Food and Drug Administration for hospitalized COVID-19 patients. We recently reported results from interim analysis of a propensity score-matched study suggesting that early treatment of COVID-19 patients with convalescent plasma containing high-titer anti-spike protein receptor binding domain (RBD) IgG significantly decreases mortality. We herein present results from a 60-day follow-up of a cohort of 351 transfused hospitalized patients. Prospective determination of enzyme-linked immunosorbent assay anti-RBD IgG titer facilitated selection and transfusion of the highest titer units available. Retrospective analysis by the Ortho VITROS IgG assay revealed a median signal/cutoff ratio of 24.0 for transfused units, a value far exceeding the recent US Food and Drug Administration-required cutoff of 12.0 for designation of high-titer convalescent plasma. With respect to altering mortality, our analysis identified an optimal window of 44 hours after hospitalization for transfusing COVID-19 patients with high-titer convalescent plasma. In the aggregate, the analysis confirms and extends our previous preliminary finding that transfusion of COVID-19 patients soon after hospitalization with high-titer anti-spike protein RBD IgG present in convalescent plasma significantly reduces mortality.

Convalescent plasma anti-SARS-CoV-2 spike protein ectodomain and receptor-binding domain IgG correlate with virus neutralization.

The newly emerged severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) highlights the urgent need for assays that detect protective levels of neutralizing antibodies. We studied the relationship among anti-spike ectodomain (anti-ECD), anti-receptor-binding domain (anti-RBD) IgG titers, and SARS-CoV-2 virus neutralization (VN) titers generated by 2 in vitro assays using convalescent plasma samples from 68 patients with COVID-19. We report a strong positive correlation between both plasma anti-RBD and anti-ECD IgG titers and in vitro VN titers. The probability of a VN titer of ≥160, the FDA-recommended level for convalescent plasma used for COVID-19 treatment, was ≥80% when anti-RBD or anti-ECD titers were ≥1:1350. Of all donors, 37% lacked VN titers of ≥160. Dyspnea, hospitalization, and disease severity were significantly associated with higher VN titer. Frequent donation of convalescent plasma did not significantly decrease VN or IgG titers. Analysis of 2814 asymptomatic adults found 73 individuals with anti-ECD IgG titers of ≥1:50 and strong positive correlation with anti-RBD and VN titers. Fourteen of these individuals had VN titers of ≥1:160, and all of them had anti-RBD titers of ≥1:1350. We conclude that anti-RBD or anti-ECD IgG titers can serve as a surrogate for VN titers to identify suitable plasma donors. Plasma anti-RBD or anti-ECD titers of ≥1:1350 may provide critical information about protection against COVID-19 disease.

Treatment of Coronavirus Disease 2019 Patients with Convalescent Plasma Reveals a Signal of Significantly Decreased Mortality.

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2, has spread globally, and proven treatments are limited. Transfusion of convalescent plasma collected from donors who have recovered from COVID-19 is among many approaches being studied as potentially efficacious therapy. We are conducting a prospective, propensity score-matched study assessing the efficacy of COVID-19 convalescent plasma transfusion versus standard of care as treatment for severe and/or critical COVID-19. We present herein the results of an interim analysis of 316 patients enrolled at Houston Methodist hospitals from March 28 to July 6, 2020. Of the 316 transfused patients, 136 met a 28-day outcome and were matched to 251 non-transfused control COVID-19 patients. Matching criteria included age, sex, body mass index, comorbidities, and baseline ventilation requirement 48 hours from admission, and in a second matching analysis, ventilation status at day 0. Variability in the timing of transfusion relative to admission and titer of antibodies of plasma transfused allowed for analysis in specific matched cohorts. The analysis showed a significant reduction (P = 0.047) in mortality within 28 days, specifically in patients transfused within 72 hours of admission with plasma with an anti-spike protein receptor binding domain titer of ≥1:1350. These data suggest that treatment of COVID-19 with high anti-receptor binding domain IgG titer convalescent plasma is efficacious in early-disease patients.

Relationship between Anti-Spike Protein Antibody Titers and SARS-CoV-2 In Vitro Virus Neutralization in Convalescent Plasma.

Newly emerged pathogens such as SARS-CoV-2 highlight the urgent need for assays that detect levels of neutralizing antibodies that may be protective. We studied the relationship between anti-spike ectodomain (ECD) and anti-receptor binding domain (RBD) IgG titers, and SARS-CoV-2 virus neutralization (VN) titers generated by two different in vitro assays using convalescent plasma samples obtained from 68 COVID-19 patients, including 13 who donated plasma multiple times. Only 23% (16/68) of donors had been hospitalized. We also studied 16 samples from subjects found to have anti-spike protein IgG during surveillance screening of asymptomatic individuals. We report a strong positive correlation between both plasma anti-RBD and anti-ECD IgG titers, and in vitro VN titer. Anti-RBD plasma IgG correlated slightly better than anti-ECD IgG titer with VN titer. The probability of a VN titer ≥160 was 80% or greater with anti-RBD or anti-ECD titers of ≥1:1350. Thirty-seven percent (25/68) of convalescent plasma donors lacked VN titers ≥160, the FDA-recommended level for convalescent plasma used for COVID-19 treatment. Dyspnea, hospitalization, and disease severity were significantly associated with higher VN titer. Frequent donation of convalescent plasma did not significantly decrease either VN or IgG titers. Analysis of 2,814 asymptomatic adults found 27 individuals with anti-RBD or anti-ECD IgG titers of ≥1:1350, and evidence of VN ≥1:160. Taken together, we conclude that anti-RBD or anti-ECD IgG titers can serve as a surrogate for VN titers to identify suitable plasma donors. Plasma anti-RBD or anti-ECD titer of ≥1:1350 may provide critical information about protection against COVID-19 disease.

Treatment of COVID-19 Patients with Convalescent Plasma in Houston, Texas.

BACKGROUND: COVID-19 disease, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread globally, and no proven treatments are available. Convalescent plasma therapy has been used with varying degrees of success to treat severe microbial infections for more than 100 years. METHODS: Patients (n=25) with severe and/or life-threatening COVID-19 disease were enrolled at the Houston Methodist hospitals from March 28 to April 14, 2020. Patients were transfused with convalescent plasma obtained from donors with confirmed SARS-CoV-2 infection and had been symptom free for 14 days. The primary study outcome was safety, and the secondary outcome was clinical status at day 14 post-transfusion. Clinical improvement was assessed based on a modified World Health Organization 6-point ordinal scale and laboratory parameters. Viral genome sequencing was performed on donor and recipient strains. RESULTS: At baseline, all patients were receiving supportive care, including anti-inflammatory and anti-viral treatments, and all patients were on oxygen support. At day 7 post-transfusion with convalescent plasma, nine patients had at least a 1-point improvement in clinical scale, and seven of those were discharged. By day 14 post-transfusion, 19 (76%) patients had at least a 1-point improvement in clinical status and 11 were discharged. No adverse events as a result of plasma transfusion were observed. The whole genome sequencing data did not identify a strain genotype-disease severity correlation. CONCLUSIONS: The data indicate that administration of convalescent plasma is a safe treatment option for those with severe COVID-19 disease. Randomized, controlled trials are needed to determine its efficacy.

Treatment of Coronavirus Disease 2019 (COVID-19) Patients with Convalescent Plasma.

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2, has spread globally, and no proven treatments are available. Convalescent plasma therapy has been used with varying degrees of success to treat severe microbial infections for >100 years. Patients (n = 25) with severe and/or life-threatening COVID-19 disease were enrolled at the Houston Methodist hospitals from March 28, 2020, to April 14, 2020. Patients were transfused with convalescent plasma, obtained from donors with confirmed severe acute respiratory syndrome coronavirus 2 infection who had recovered. The primary study outcome was safety, and the secondary outcome was clinical status at day 14 after transfusion. Clinical improvement was assessed on the basis of a modified World Health Organization six-point ordinal scale and laboratory parameters. Viral genome sequencing was performed on donor and recipient strains. At day 7 after transfusion with convalescent plasma, nine patients had at least a one-point improvement in clinical scale, and seven of those were discharged. By day 14 after transfusion, 19 (76%) patients had at least a one-point improvement in clinical status, and 11 were discharged. No adverse events as a result of plasma transfusion were observed. Whole genome sequencing data did not identify a strain genotype-disease severity correlation. The data indicate that administration of convalescent plasma is a safe treatment option for those with severe COVID-19 disease.

Anticoagulation of Impella with a Bivalirudin Purge Solution.

The use of percutaneous ventricular assist devices (VADs) in the acute management of cardiogenic shock is becoming increasingly common. The Impella is a percutaneous VAD, which requires a heparin-containing purge solution to prevent thrombosis and maintain proper pump functionality. In this report, we describe two patients with heparin-induced thrombocytopenia (HIT) supported with an Impella using a bivalirudin-containing purge solution. Case 1 involved a 39-year-old man with cardiogenic shock, initially implanted with an intraaortic balloon pump, who developed HIT early in his hospital course. His worsening hemodynamics necessitated the placement of an Impella and later venoarterial extracorporeal membrane oxygenation until he eventually underwent durable left VAD implantation. Case 2 involved a 69-year-old man who had an Impella implanted for worsening cardiogenic shock. HIT was suspected shortly after device insertion, necessitating switching his anticoagulation to bivalirudin. He was successfully bridged directly to heart transplantation. Both patients' courses resulted in therapeutic anticoagulation without major bleeding or thrombotic events. These cases demonstrate the safe and effective use of bivalirudin-containing purge solutions for patients with confirmed HIT requiring temporary mechanical circulatory support with Impella.

Utilization of therapeutic plasma exchange for hyperbilirubinemia in a premature newborn on extracorporeal membrane oxygenation.

BACKGROUND: We report a case of a premature newborn girl with a hospital course complicated by suspected respiratory syncytial virus pneumonitis for which she was placed on veno-arterial extracorporeal membrane oxygenation (VA-ECMO). Despite phototherapy, her total bilirubin steadily increased to a peak of 50.4 mg/dL with concern for bilirubin-induced neurologic dysfunction, kernicterus. STUDY DESIGN AND METHODS: Therapeutic plasma exchange (TPE) was achieved via connection with the VA-ECMO circuit. Our institution's standard apheresis procedural parameters were adjusted to account for the small body weight and thus the low blood volume of the neonate while on ECMO. These included calculating the total blood volume to include the patient as well as the ECMO circuit, priming of the apheresis instrument with packed red blood cells to limit the extracorporeal volume, using a lower inlet flow rate, the connection setup of the inlet and return line, and monitoring of ionized calcium and anticoagulation throughout the procedure. RESULTS: A total of three TPE procedures were performed over three consecutive days. This resulted in improvement and stabilization of the patient's bilirubin. CONCLUSION: This case emphasizes that TPE is feasible on a neonate with a suboptimal body weight and thus a low blood volume due to the increased blood volume provided while on ECMO. In the absence of ECMO, whole blood manual exchange transfusion is recommended as TPE would be unsafe due to significant extracorporeal volume that would occur during TPE in a pediatric patient with low body weight.

New Onset Iron Deficiency Anemia in Chronic Therapeutic Plasma Exchange Patients.

Iron deficiency has been recognized as a complication of whole blood and red blood cell apheresis donation; however, the effect of chronic therapeutic plasma exchange (TPE) on patient iron status is largely unknown. We performed a retrospective review of all patients undergoing chronic TPE (at least 1 TPE every 2 weeks for 1 month with a minimum of 8 TPE treatments) with 5% albumin at our institution from 2011 to 2016. After review of serum iron level and iron saturation status, six out of ten (60%) of the patients who meet the study criteria were found to develop iron deficiency anemia (IDA). This data supports the notion that chronic TPE, especially when combined with additional risk factors, can increase the risk of IDA.

A Case of Suspected Streptococcus Pneumoniae Hemolytic Uremic Syndrome (pHUS) with Utilization of Minor Crossmatching for Platelet Blood Products Lead to a Diagnosis of Atypical Hemolytic Uremic Syndrome (aHUS).

BACKGROUND: The action of bacterial neuraminidase of Streptococcus pneumoniae (SPN) results in exposure of the normally "hidden" Thomsen-Freidenreich antigen (T-antigen) found on erythrocytes and other tissues. This may lead to SPN-induced hemolytic uremic syndrome (pHUS) with subsequent hemolysis and end organ damage. pHUS can be identified by minor crossmatch incompatibility. We present a case of suspected pHUS that resulted in a compatible minor crossmatch which led to concern and eventually diagnosis of atypical HUS (aHUS). DESIGN: A 6-month-old boy presented with respiratory failure. He was found to have blood cultures positive for SPN. Shiga toxin was negative and he had normal levels of ADAMTS 13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13). The clinical team was concerned for pHUS and requested washed platelet product prior to a surgical procedure. Alternatively, a minor crossmatching was performed to determine the presence of T activation. An aHUS genetic panel was performed to sequence and analyze 12 genes encoding complement factors. RESULTS: Minor crossmatch was performed using the patient's erythrocytes and plasma of ABO-identical platelets to be transfused. No agglutination was seen at immediate spin, 37°C, or anti-human globulin phase with valid controls. Genetics testing for complement mutations was consistent with aHUS. CONCLUSIONS: We present a case that is clinically consistent with pHUS. Confirmation of this entity is done with lectins or anti-sera that are not readily available. An alternative means of identifying pHUS is by demonstrating minor crossmatch incompatibility. By doing so, we excluded the possibility of pHUS and helped to elucidate a definitive diagnosis of aHUS. Our goal is to share our experience of a practical approach in a time-sensitive situation that other clinical pathologists could utilize in suspected cases of T activation with a clinical picture of thrombotic microangiopathy.

Successful management of severe red blood cell alloimmunization in pregnancy with a combination of therapeutic plasma exchange, intravenous immune globulin, and intrauterine transfusion.

BACKGROUND: Antibodies to Rhesus and Kell antigens have been associated with severe hemolytic disease of the fetus and newborn (HDFN) necessitating intrauterine transfusion (IUT) of red blood cells (RBCs). We report a case series of five women with severe HDFN secondary to maternal RBC alloimmunization who were successfully managed with therapeutic plasma exchange (TPE), intravenous immune globulin (IVIG), and IUT. STUDY DESIGN AND METHODS: This is a retrospective case series of five women with severe HDFN who underwent a total of three TPE procedures during Weeks 10 to 13 of pregnancy, followed by weekly IVIG infusions. They were followed with serial middle cerebral artery peak systolic velocity studies beginning at 16 weeks' gestation to detect fetal anemia. For IUT, fetuses were administered RBC units that fully matched the maternal phenotype to D, C, E, K, Fy, Jk, and S antigen groups. The delivery outcomes and newborn information were followed. RESULTS: Anti-D and anti-K alloantibodies were implicated in HDFN. A two- to fourfold dilution reduction in anti-D and anti-K titers was observed after TPE. IUT was initiated between 21 to 27 weeks' gestation. The total number of IUTs for each patient ranged from four to seven. All five women delivered healthy infants at 33 to 38 weeks' gestation. CONCLUSION: A combined regimen of TPE and IVIG early in pregnancy and IUT later in pregnancy results in successful management of severe maternal RBC alloimmunization and HDFN. IUT with fully phenotypically matched RBC units may help prevent further RBC alloimmunization in complex cases of HDFN.

Intra-Pericardial Use of Recombinant Factor VIIa in a Patient With Acute Hemorrhagic Pericardial Effusion Following Transcutaneous Aortic Valve Replacement-A Case Report.

Perioperative bleeding can be a serious life-threatening complication in adult patients undergoing cardiac surgery, given the older age and additional comorbidities present in this patient population. The standard treatment options include transfusion of blood components and surgical re-exploration. We report the first case of an elderly female patient treated with local administration of recombinant factor VIIa (rFVIIa) for intractable hemorrhagic pericardial effusion, which developed following a transcutaneous aortic valve replacement (TAVR) procedure for severe aortic stenosis. No thromboembolic phenomena or adverse effects were observed. Local administration of rFVIIa is an efficacious treatment option for cardiac surgery patients as opposed to systemic administration of rFVIIa, use of massive blood products, or surgical re-exploration.

Historical Perspectives, Current Status, and Ethical Issues in Granulocyte Transfusion.

The goal of this commentary is to provide a historical aspect of granulocyte transfusion, present practices in granulocyte transfusion, accentuate the complexity of the issue, and foster contemplation of ethical issues assimilated with this practice. Clinical aspects of granulocyte transfusion in the light of ethical issues are also discussed.

Providing Hemostatic and Blood Conservation Options for Jehovah's Witness Patients in a Large Medical System.

People of the Jehovah's Witness faith believe that they shall "abstain from blood." Because of this belief, we encounter the challenges from Jehovah's Witness patients who actively seek medical care for themselves and their children, but refuse the transfusion of blood products, which may result in increased morbidity and mortality in this patient population. With the development/availability of new hemostatic/coagulation products and the advances in medical technology, we, in collaboration with our clinical colleagues and our local Jehovah's Witness leadership, have developed a clinical guideline comprising medical protocol and surgical strategy for patients refusing blood products. Included in the medical protocol is an informative handout on related details to help treating physicians and patients make informed decisions about transfusion alternatives. Together, we have entered the medical protocol into the entire Memorial Hermann Hospital's electronic system. We report the detailed development and implementation process in order to share our experience and encourage others to develop their own management plan for this patient population.

A Rare Case of Acquired Fanconi's Syndrome With Monoclonal Gammopathy in an Infant.

BACKGROUND: Monoclonal gammopathies associated with acquired Fanconi's syndrome (AFS) have been reported in the adult population. AFS is characterized by renal dysfunction resulting in proteinuria, aminoaciduria, hypophosphatemia, glucosuria, and hyperchloremic metabolic acidosis. In this case report, we document the clinical and laboratory findings of a preterm infant with features of both AFS and monoclonal gammopathy in the urine. METHODS: Clinical suspicion of AFS prompted the following laboratory studies to be performed: urine protein electrophoresis (UPEP), urine immunofixation, and urine amino acid analysis with high performance liquid chromatography (HPLC). RESULTS: Urine amino acid analysis revealed aminoaciduria. On UPEP, nonselective glomerular proteinuria was seen with a faint band in the gamma region. Urine immunofixation confirmed the presence of a monoclonal IgG lambda component with free monoclonal lambda light chains. CONCLUSION: To the best of our knowledge, this is the first case of pediatric AFS reported with a monoclonal gammopathy and monoclonal free light chains.