Early Outpatient Treatment for Covid-19 with Convalescent Plasma.

BACKGROUND: Polyclonal convalescent plasma may be obtained from donors who have recovered from coronavirus disease 2019 (Covid-19). The efficacy of this plasma in preventing serious complications in outpatients with recent-onset Covid-19 is uncertain. METHODS: In this multicenter, double-blind, randomized, controlled trial, we evaluated the efficacy and safety of Covid-19 convalescent plasma, as compared with control plasma, in symptomatic adults (≥18 years of age) who had tested positive for severe acute respiratory syndrome coronavirus 2, regardless of their risk factors for disease progression or vaccination status. Participants were enrolled within 8 days after symptom onset and received a transfusion within 1 day after randomization. The primary outcome was Covid-19-related hospitalization within 28 days after transfusion. RESULTS: Participants were enrolled from June 3, 2020, through October 1, 2021. A total of 1225 participants underwent randomization, and 1181 received a transfusion. In the prespecified modified intention-to-treat analysis that included only participants who received a transfusion, the primary outcome occurred in 17 of 592 participants (2.9%) who received convalescent plasma and 37 of 589 participants (6.3%) who received control plasma (absolute risk reduction, 3.4 percentage points; 95% confidence interval, 1.0 to 5.8; P = 0.005), which corresponded to a relative risk reduction of 54%. Evidence of efficacy in vaccinated participants cannot be inferred from these data because 53 of the 54 participants with Covid-19 who were hospitalized were unvaccinated and 1 participant was partially vaccinated. A total of 16 grade 3 or 4 adverse events (7 in the convalescent-plasma group and 9 in the control-plasma group) occurred in participants who were not hospitalized. CONCLUSIONS: In participants with Covid-19, most of whom were unvaccinated, the administration of convalescent plasma within 9 days after the onset of symptoms reduced the risk of disease progression leading to hospitalization. (Funded by the Department of Defense and others; CSSC-004 ClinicalTrials.gov number, NCT04373460.).

Transfusing Convalescent Plasma as Post-Exposure Prophylaxis Against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection: A Double-Blinded, Phase 2 Randomized, Controlled Trial.

BACKGROUND: The efficacy of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) convalescent plasma (CCP) for preventing infection in exposed, uninfected individuals is unknown. CCP might prevent infection when administered before symptoms or laboratory evidence of infection. METHODS: This double-blinded, phase 2 randomized, controlled trial (RCT) compared the efficacy and safety of prophylactic high titer (≥1:320 by Euroimmun ELISA) CCP with standard plasma. Asymptomatic participants aged ≥18 years with close contact exposure to a person with confirmed coronavirus disease 2019 (COVID-19) in the previous 120 hours and negative SARS-CoV-2 test within 24 hours before transfusion were eligible. The primary outcome was new SARS-CoV-2 infection. RESULTS: In total, 180 participants were enrolled; 87 were assigned to CCP and 93 to control plasma, and 170 transfused at 19 sites across the United States from June 2020 to March 2021. Two were excluded for screening SARS-CoV-2 reverse transcription polymerase chain reaction (RT-PCR) positivity. Of the remaining 168 participants, 12/81 (14.8%) CCP and 13/87 (14.9%) control recipients developed SARS-CoV-2 infection; 6 (7.4%) CCP and 7 (8%) control recipients developed COVID-19 (infection with symptoms). There were no COVID-19-related hospitalizations in CCP and 2 in control recipients. Efficacy by restricted mean infection free time (RMIFT) by 28 days for all SARS-CoV-2 infections (25.3 vs 25.2 days; P = .49) and COVID-19 (26.3 vs 25.9 days; P = .35) was similar for both groups. CONCLUSIONS: Administration of high-titer CCP as post-exposure prophylaxis, although appearing safe, did not prevent SARS-CoV-2 infection. CLINICAL TRIALS REGISTRATION: NCT04323800.

Current advances in 2022: A critical review of selected topics by the Association for the Advancement of Blood and Biotherapies (AABB) Clinical Transfusion Medicine Committee.

BACKGROUND: The Association for the Advancement of Blood and Biotherapies Clinical Transfusion Medicine Committee (CTMC) composes a summary of new and important advances in transfusion medicine (TM) on an annual basis. Since 2018, this has been assembled into a manuscript and published in Transfusion. STUDY DESIGN AND METHODS: CTMC members selected original manuscripts relevant to TM that were published electronically and/or in print during calendar year 2022. Papers were selected based on perceived importance and/or originality. References for selected papers were made available to CTMC members to provide feedback. Members were also encouraged to identify papers that may have been omitted initially. They then worked in groups of two to three to write a summary for each new publication within their broader topic. Each topic summary was then reviewed and edited by two separate committee members. The final manuscript was assembled by the first and senior authors. While this review is extensive, it is not a systematic review and some publications considered important by readers may have been excluded. RESULTS: For calendar year 2022, summaries of key publications were assembled for the following broader topics within TM: blood component therapy; infectious diseases, blood donor testing, and collections; patient blood management; immunohematology and genomics; hemostasis; hemoglobinopathies; apheresis and cell therapy; pediatrics; and health care disparities, diversity, equity, and inclusion. DISCUSSION: This Committee Report reviews and summarizes important publications and advances in TM published during calendar year 2022, and maybe a useful educational tool.

Clinical Practice Guidelines From the Association for the Advancement of Blood and Biotherapies (AABB): COVID-19 Convalescent Plasma.

DESCRIPTION: Coronavirus disease 2019 convalescent plasma (CCP) has emerged as a potential treatment of COVID-19. However, meta-analysis data and recommendations are limited. The Association for the Advancement of Blood and Biotherapies (AABB) developed clinical practice guidelines for the appropriate use of CCP. METHODS: These guidelines are based on 2 living systematic reviews of randomized controlled trials (RCTs) evaluating CCP from 1 January 2019 to 26 January 2022. There were 33 RCTs assessing 21 916 participants. The results were summarized using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) method. An expert panel reviewed the data using the GRADE framework to formulate recommendations. RECOMMENDATION 1 (OUTPATIENT): The AABB suggests CCP transfusion in addition to the usual standard of care for outpatients with COVID-19 who are at high risk for disease progression (weak recommendation, moderate-certainty evidence). RECOMMENDATION 2 (INPATIENT): The AABB recommends against CCP transfusion for unselected hospitalized persons with moderate or severe disease (strong recommendation, high-certainty evidence). This recommendation does not apply to immunosuppressed patients or those who lack antibodies against SARS-CoV-2. RECOMMENDATION 3 (INPATIENT): The AABB suggests CCP transfusion in addition to the usual standard of care for hospitalized patients with COVID-19 who do not have SARS-CoV-2 antibodies detected at admission (weak recommendation, low-certainty evidence). RECOMMENDATION 4 (INPATIENT): The AABB suggests CCP transfusion in addition to the usual standard of care for hospitalized patients with COVID-19 and preexisting immunosuppression (weak recommendation, low-certainty evidence). RECOMMENDATION 5 (PROPHYLAXIS): The AABB suggests against prophylactic CCP transfusion for uninfected persons with close contact exposure to a person with COVID-19 (weak recommendation, low-certainty evidence). GOOD CLINICAL PRACTICE STATEMENT: CCP is most effective when transfused with high neutralizing titers to infected patients early after symptom onset.

Vaccination of COVID-19 convalescent plasma donors increases binding and neutralizing antibodies against SARS-CoV-2 variants.

BACKGROUND: COVID-19 convalescent plasma (CCP) was widely used as passive immunotherapy during the first waves of SARS-CoV-2 infection in the US. However, based on observational studies and randomized controlled trials, the beneficial effects of CCP were limited, and its use was virtually discontinued early in 2021, in concurrence with increased vaccination rates and availability of monoclonal antibody (mAb) therapeutics. Yet, as new variants of the SARS-CoV-2 spread, interest in CCP derived from vaccine-boosted CCP donors is resurging. The effect of vaccination of previously infected CCP donors on antibodies against rapidly spreading variants is still under investigation. STUDY DESIGN/METHODS: In this study, paired-samples from 11 CCP donors collected before and after vaccination was tested to measure binding antibody levels and neutralization activity against the ancestral Wuhan-Hu-1 and SARS-CoV-2 variants (Wuhan-Hu-1 with D614G, alpha, beta, gamma, delta, epsilon) on the Ortho Vitros Spike Total Ig and IgG assays, the MSD V-PLEX SARS-CoV-2 arrays for IgG binding and ACE2 inhibition, and variant-specific Spike Reporter Viral Particle Neutralization (RVPN) assays. RESULTS/FINDINGS: Binding and neutralizing antibodies were significantly boosted by vaccination, with several logs higher neutralization for all the variants tested post-vaccination compared to the pre-vaccination samples, with no difference found among the individual variants. DISCUSSION: Vaccination of previously infected individuals boosts antibodies including neutralizing activity against all SARS-CoV-2 variants.

Current advances in transfusion medicine 2021: A critical review of selected topics by the AABB Clinical Transfusion Medicine Committee.

BACKGROUND: Each year the AABB Clinical Transfusion Medicine Committee (CTMC) procures a synopsis highlighting new, important, and clinically relevant studies in the field of transfusion medicine (TM). This has been made available as a publication in Transfusion since 2018. METHODS: CTMC members reviewed and identified original manuscripts covering TM-related topics published electronically (ahead-of-print) or in print from December 2020 to December 2021. Selection of publications was discussed at committee meetings and chosen based on perceived relevance and originality. Next, committee members worked in pairs to create a synopsis of each topic, which was then reviewed by additional committee members. The first and senior authors assembled the final manuscript. Although this synopsis is extensive, it is not exhaustive, and some articles may have been excluded or missed. RESULTS: The following topics are included: blood products; convalescent plasma; donor collections and testing; hemoglobinopathies; immunohematology and genomics; hemostasis; patient blood management; pediatrics; therapeutic apheresis; and cell therapy. CONCLUSIONS: This synopsis highlights and summarizes recent key developments in TM and may be useful for educational purposes.

How do I implement an outpatient program for the administration of convalescent plasma for COVID-19?

Convalescent plasma, collected from donors who have recovered from a pathogen of interest, has been used to treat infectious diseases, particularly in times of outbreak, when alternative therapies were unavailable. The COVID-19 pandemic revived interest in the use of convalescent plasma. Large observational studies and clinical trials that were executed during the pandemic provided insight into how to use convalescent plasma, whereby high levels of antibodies against the pathogen of interest and administration early within the time course of the disease are critical for optimal therapeutic effect. Several studies have shown outpatient administration of COVID-19 convalescent plasma (CCP) to be both safe and effective, preventing clinical progression in patients when administered within the first week of COVID-19. The United States Food and Drug Administration expanded its emergency use authorization (EUA) to allow for the administration of CCP in an outpatient setting in December 2021, at least for immunocompromised patients or those on immunosuppressive therapy. Outpatient transfusion of CCP and infusion of monoclonal antibody therapies for a highly transmissible infectious disease introduces nuanced challenges related to infection prevention. Drawing on our experiences with the clinical and research use of CCP, we describe the logistical considerations and workflow spanning procurement of qualified products, infrastructure, staffing, transfusion, and associated management of adverse events. The purpose of this description is to facilitate the efforts of others intent on establishing outpatient transfusion programs for CCP and other antibody-based therapies.

SARS-CoV-2 neutralization and serology testing of COVID-19 convalescent plasma from donors with nonsevere disease.

BACKGROUND: The transfer of passive immunity with convalescent plasma is a promising strategy for treatment and prevention of COVID-19, but donors with a history of nonsevere disease are serologically heterogenous. The relationship between SARS-Cov-2 antigen-binding activity and neutralization activity in this population of donors has not been defined. STUDY DESIGN AND METHODS: Convalescent plasma units from 47 individuals with a history of nonsevere COVID-19 were assessed for antigen-binding activity of using three clinical diagnostic serology assays (Beckman, DiaSorin, and Roche) with different SARS-CoV-2 targets. These results were compared with functional neutralization activity using a fluorescent reporter strain of SARS-CoV-2 in a microwell assay. RESULTS: Positive correlations of varying strength (Spearman r = 0.37-0.52) between antigen binding and viral neutralization were identified. Donors age 48 to 75 years had the highest neutralization activity. Units in the highest tertile of binding activity for each assay were enriched (75%-82%) for those with the highest levels of neutralization. CONCLUSION: The strength of the relationship between antigen-binding activity and neutralization varies depending on the clinical assay used. Units in the highest tertile of binding activity for each assay are predominantly comprised of those with the greatest neutralization activity.

Current advances in transfusion medicine 2020: A critical review of selected topics by the AABB Clinical Transfusion Medicine Committee.

BACKGROUND: The AABB Clinical Transfusion Medicine Committee (CTMC) compiles an annual synopsis of the published literature covering important developments in the field of transfusion medicine (TM), which has been made available as a manuscript published in Transfusion since 2018. METHODS: CTMC committee members reviewed original manuscripts including TM-related topics published electronically (ahead) or in print from December 2019 to December 2020. The selection of topics and manuscripts was discussed at committee meetings and chosen based on relevance and originality. Next, committee members worked in pairs to create a synopsis of each topic, which was then reviewed by two additional committee members. The first and senior authors of this manuscript assembled the final manuscript. Although this synopsis is extensive, it is not exhaustive, and some papers may have been excluded or missed. RESULTS: The following topics are included: COVID-19 effects on the blood supply and regulatory landscape, COVID convalescent plasma, adult transfusion practices, whole blood, molecular immunohematology, pediatric TM, cellular therapy, and apheresis medicine. CONCLUSIONS: This synopsis provides easy access to relevant topics and may be useful as an educational tool.

Persistence of SARS-CoV-2 nasopharyngeal swab PCR positivity in COVID-19 convalescent plasma donors.

BACKGROUND: Nucleic acid persists after symptom resolution and infectivity for many viral infections via delayed clearance of nucleic acid fragments, non-infectious particles, or transmissible virus. For Coronavirus Disease 2019 (COVID-19), the relationship between nasopharyngeal (NP) swab positivity, the development of antibodies against COVID-19, and clinical history are unclear. STUDY DESIGN AND METHODS: Individuals who recovered from COVID-19 and volunteered to donate convalescent plasma (CP) were screened by NP swab PCR, responded to a questionnaire, and were tested for anti-COVID-19 antibodies. RESULTS: A proportion of 11.8% of individuals tested positive for SARS-CoV-2 by NP swab PCR greater than 14 days after the resolution of symptoms of active disease, including one donor who had asymptomatic disease and tested positive by NP swab 41 days after her initial diagnosis. Clinical history did not show a significant correlation with persistence of NP swab positivity. Also, NP swab positivity >14 days from symptom resolution did not correlate with anti-COVID-19 serology results. IgG anti-SARS-CoV-2 spike antibody strength correlated with hospitalization for COVID-19 using two different assays. Total anti-SARS-CoV-2 nucleocapsid antibody strength correlated with time from symptom resolution to sample collection and symptom duration. CONCLUSIONS: SARS-CoV-2 nucleic acid is detectable long after the resolution of symptoms in a significant percentage of previously diagnosed individuals, which is important to consider when interpreting PCR swab results. Persistence of PCR positivity does not correlate with antibody strength or symptoms of COVID-19. If anti-spike antibody is used to assess CP potency, individuals who suffered severe COVID-19 disease symptoms may represent better donors.

Expansion of hospital-based blood collections in the face of COVID-19 associated national blood shortage.

BACKGROUND: When the coronavirus pandemic caused widespread school and business closures in March 2020, blood drives were canceled and the supply of blood decreased suddenly in the United States (US). In response, hospital-based transfusion medicine physicians instituted policies to conserve blood and decrease blood product usage. These efforts were aided by the US Surgeon General recommendation to cancel all elective procedures. Nevertheless, the duration, severity, and impact of the pandemic on the national blood supply was uncertain. Hospitals with in-house donor programs had the opportunity not only to control demand, but also increase supply. STUDY DESIGN AND METHODS: A hospital-based blood donor center was rapidly mobilized to increase the supply of in-house collected blood, in order to counteract a sudden but potentially long-term depletion of the national blood supply during a pandemic. RESULTS: Collections increased approximately five-fold above baseline for whole blood units, while apheresis platelet units were maintained at the historical average for the blood donor center. Cancellation of elective procedures showed a modest, but not yet statistically significant decrease in average blood product usage per day, nevertheless the in-house collection rate was sufficient to meet demand. CONCLUSION: A hospital-based blood donor center can quickly increase collection volumes and capacity in the face of a national emergency or pandemic. The desire to collect units should be balanced with safety concerns, need for sustainability, and blood product demand.

Current advances in transfusion medicine: a 2019 review of selected topics from the AABB Clinical Transfusion Medicine Committee.

BACKGROUND: The AABB Clinical Transfusion Medicine Committee (CTMC) compiles an annual synopsis of the published literature covering important developments in the field of transfusion medicine (TM) for the board of director's review. This synopsis is now made available as a manuscript published in TRANSFUSION. STUDY DESIGN AND METHODS: CTMC committee members review original manuscripts including TM-related topics published in different journals between late 2018 and 2019. The selection of topics and manuscripts are discussed at committee meetings and are chosen based on relevance and originality. After the topics and manuscripts are selected, committee members work in pairs to create a synopsis of the topics, which is then reviewed by two committee members. The first and senior authors of this manuscript assembled the final manuscript. Although this synopsis is comprehensive, it is not exhaustive, and some papers may have been excluded or missed. RESULTS: The following topics are included: infectious risks to the blood supply, iron donor studies, pre-transfusion testing interference and genotyping, cold agglutinin disease (CAD), HLA alloimmunization in platelet transfusions, patient blood management, updates to TACO and TRALI definitions, pediatric TM, and advances in apheresis medicine. CONCLUSION: This synopsis provides easy access to relevant topics and may be useful as an educational tool.

The effect of serum pretreatment regimens for the detection of HLA class I antibodies in platelet-refractory patients.

BACKGROUND: Single antigen bead (SAB) assays are used to identify human leukocyte antigen (HLA) antibodies in patients with platelet refractoriness due to HLA Class I alloimmunization. Some laboratories use serum pretreatment regimens to eliminate interference from immunoglobulin M antibodies and complement. These modifications may contribute to interlaboratory variability, which is a recognized problem with the SAB assay. STUDY DESIGN AND METHODS: Five patients' sera were overnight shipped to 12 laboratories in the United States and internationally. Recipients used their lab's SAB procedure to identify HLA Class I antibodies. The resultant mean fluorescence intensity (MFI) data were compared by instrumentation, bead lot, and pretreatment regimens. Laboratory-specific cutoffs for positive antibodies were applied to the results. RESULTS: Interlaboratory variability for MFI values appears to be associated with different pretreatment regimens. The coefficient of variation (CV) of MFI from samples pretreated with ethylenediaminetetraacetic acid, dithiothreitol, or heat inactivation (EDHI) were similar, ranging from 14% to 56% (mean, 22%). For samples with no pretreatment, the CVs were significantly higher than EDHI-treated samples, ranging from 25% to 74% (mean, 39%; 95% confidence interval, 12.10-21.90; p < 0.0001). An intralaboratory comparison of pretreatment regimens confirmed these findings. Some positive antibody specificities present in EDHI-treated samples were negative in corresponding samples with no pretreatment when laboratory-specific cutoffs for positive antibodies were applied. CONCLUSION: Our results show that greater interlaboratory precision can be achieved when samples are pretreated with EDHI as opposed to no pretreatment, likely because these pretreatments eliminate interference from inhibitors. Inhibitors may mask antibodies, leading to missed (or uncalled) specificities when no pretreatment is used.

Optimal Storage Conditions for Apheresis Research (OSCAR): a Biomedical Excellence for Safer Transfusion (BEST) Collaborative study.

BACKGROUND: Cell therapy products are often stored and transported between sites. The aim of this study was to determine the effect of storage temperature, solution, and cell concentration on nonmobilized, peripheral blood-derived mononuclear cells (MNCs). STUDY DESIGN AND METHODS: This was a multicenter prospective study involving healthy volunteers who underwent nonmobilized MNC collection by apheresis. Products were processed at local laboratories and concentrated to either 100 × 106 or 300 × 106 nucleated cells/mL in 5% human serum albumin (HSA) or HypoThermosol FRS (HT; BioLife Solutions). Products were stored at room temperature (RT; 20-25°C) or refrigerated temperatures (2-8°C) with assessment at 0, 24, 48, and 72 hours. NC and MNC concentration, viability, and flow cytometric analysis for CD3, CD4, CD8, CD14, CD19, CD25, and CD56 were measured. RESULTS: Viability decreased over time for all conditions tested. Refrigerated storage preserved viability greater than RT storage, especially for products with a higher cell concentration. RT maintenance with a high cell concentration was associated with a relative loss of CD14- and CD4-positive cells, whereas the concentration of cells positive for other markers tested did not vary. Finally, there was delayed decrease in pH when using HT compared with HSA; however, there was no difference in viability between the two solutions. CONCLUSION: Low cell concentrations (approx. 100 × 106 cells/mL), refrigerated temperatures, and HT storage solution appear to be the optimal conditions for storing nonmobilized, peripheral blood-derived MNC products.

Drug-induced immune hemolytic anemia associated with anti-vancomycin complicated by a paraben antibody.

BACKGROUND: Drug-induced immune hemolytic anemia (DIIHA) is rare, but potentially life-threatening. A high index of clinical suspicion is required for diagnosis, since the number of medications known to induce DIIHA continues to expand. Additionally, in vitro antibody reactivity against reagent additives has been reported, which may complicate test interpretation. CASE REPORT: A 61-year-old group A, D+ woman with a history of negative antibody detection tests developed hemolytic anemia on Postoperative Day 7 after repeat incision and drainage of a chronically infected right knee prosthesis. She was treated with multiple antibiotics in the postoperative period, including three cephalosporins and vancomycin intravenously as well as vancomycin and gentamicin-containing intraarticular cement spacers. STUDY DESIGN AND METHODS: A workup for possible DIIHA was performed. Testing was performed using vancomycin and cephalosporin antibiotics. Initially, gentamicin injection solution was used for testing, followed by testing with its component ingredients. RESULTS: A vancomycin antibody was detected and anemia resolved after vancomycin was discontinued. Reactivity was seen when gentamicin injection solution was used for testing, raising the possibility of a gentamicin antibody as well. However, testing with purified gentamicin as well as methylparaben and propylparaben demonstrated a paraben antibody that reacted with the paraben-containing gentamicin solution. The patient also demonstrated an anti-N. Neither the paraben antibody nor the anti-N appeared to cause in vivo hemolysis. CONCLUSION: This is the second reported case of DIIHA associated with anti-vancomycin. It is the fourth report describing a paraben antibody.

Mechanical hemolysis in pediatric patients associated with rapid transfusion and one-way valve.

BACKGROUND: Four similar transfusion reactions involving infants were reported in less than 1 year. After transfusion of red blood cells (RBCs) via syringe in the operating room, each patient experienced discolored urine, laboratory evidence of hemolysis, and acute kidney injury. Clerical and serologic investigations were unremarkable. Mechanical hemolysis was considered. STUDY DESIGN AND METHODS: Simulated syringe transfusions were performed. Measurements included hematocrit (Hct), free hemoglobin, and visual hemolysis index. Washed and unwashed RBCs were tested with or without a recently introduced one-way valve, using a 24- or 16-gauge intravenous catheter. Constant manual pressure (1.43 ± 0.49 mL/sec) or syringe pump (2 mL/min) was used and a subset was timed. RESULTS: The valve increased hemolysis during manual transfusion using both catheters with washed and unwashed RBCs. With the 24-gauge catheter, the change in Hct was -3.53 ± 0.69% with the valve and 0.22 ± 0.13% without (p < 0.00001). Comparing the individual valves tested, differences in hemolysis were observed (change in Hct, p < 0.0001). During manual transfusion with 24-gauge catheter and unwashed RBCs, the degree of hemolysis was greater when it took longer to transfuse with a valve (change in Hct versus time, r = -0.75, p < 0.0001) compared to a slight increase in hemolysis for samples that took less time to transfuse without a valve (change in Hct versus time, r = 0.58, p = 0.23). CONCLUSIONS: Mechanical hemolysis should be considered when investigating possible hemolytic transfusion reactions, especially with high rates of transfusion and use of a valve. During rapid manual transfusion with the valve, greater resistance was associated with increased hemolysis.

Heterogeneous expression of PD-L1 in pulmonary squamous cell carcinoma and adenocarcinoma: implications for assessment by small biopsy.

Predicting response to checkpoint blockade therapy for lung cancer has largely focused on measuring programmed death-ligand 1 (PD-L1) expression on tumor cells. PD-L1 expression is geographically heterogeneous within many tumors, however, and we questioned whether small tissue samples, such as biopsies, might be sufficiently representative of PD-L1 expression for evaluating this marker in lung cancer tumors. To evaluate the extent of variability of PD-L1 expression in small tissue samples, and how that variability affects accuracy of overall assessment of PD-L1 in lung cancer, we scored immunohistochemical staining for PD-L1 in tissue microarray cores from a series of 79 squamous cell lung cancers and 71 pulmonary adenocarcinomas. Our study found substantial inconsistencies for the percentages of cells staining positive for PD-L1 among different tissue microarray cores in many cases of both adenocarcinoma and squamous cell carcinoma. This variable scoring was seen at both high levels and low levels of PD-L1 expression, and by further evaluation of cases with discordant results on full-face sections to assess geographic distribution of staining, we found that discordant results among different tissue microarray cores reflected geographic variation of PD-L1 expression in those tumors. Moreover, we found that as a result of heterogeneous expression, the sensitivity of a single small tissue sample can be as low as 85% for detecting PD-L1 expression at scoring thresholds commonly used in clinical practice. Based on these studies, we conclude that many cases of lung cancer could be inaccurately or variably scored for PD-L1 expression with a single biopsy sample. Accordingly, lung cancer patients can be inconsistently classified for PD-L1 expression status, particularly when a threshold for the percentage of positive cells is used to determine eligibility for checkpoint blockade therapy.

A rare, potentially life-threatening presentation of passenger lymphocyte syndrome.

BACKGROUND: Passenger lymphocyte syndrome occurs when donor lymphocytes are transplanted with a solid organ and produce alloantibodies that react with antigens on the recipient's red blood cells (RBCs). Typically, passenger lymphocyte syndrome presents as immunoglobulin G antibody-mediated, extravascular hemolytic anemia with reticulocytosis. Often, the donor was alloimmunized before transplantation. CASE REPORT: A 34-year-old Group O, D+ man with a negative antibody screen received a liver transplant from a Group O, D- donor. Twenty Group O, D+ RBC units were transfused on Postoperative Days (PODs) 0 through 2. On POD 7, the patient developed anemia, a weakly positive antibody screen, and a positive direct antiglobulin test with anti-D in the eluate. After POD 8, a D- transfusion protocol was initiated. Despite laboratory evidence of hemolysis, two initial peripheral blood smears showed no increase in schistocytes or spherocytes, the reticulocyte count was depressed, and a marrow biopsy revealed erythroid hyperplasia. Eventually, anemia resolved after a period of medication non-compliance; however, a positive direct antiglobulin test persisted to the last follow-up date (POD 233). RESULTS: Other potential causes of aplastic anemia were investigated, but no alternative cause was found. History excluded passive anti-D. D+, LW- cells were reactive, excluding anti-LW. Genotyping showed no evidence of a partial D genotype. Chart review revealed that the liver donor had a history of anti-D. A diagnosis of passenger lymphocyte syndrome was reached. CONCLUSION: Although antibody-mediated hemolytic anemia has been reported to cause reticulocytopenia in the presence of marrow erythroid hyperplasia, this report of passenger lymphocyte syndrome causing a similar post-transplant anemia in association with reticulocytopenia is noteworthy.

Blood Product Utilization Among Trauma and Nontrauma Massive Transfusion Protocols at an Urban Academic Medical Center.

BACKGROUND: Hospital-wide massive transfusion protocols (MTPs) primarily designed for trauma patients may lead to excess blood products being prepared for nontrauma patients. This study characterized blood product utilization among distinct trauma and nontrauma MTPs at a large, urban academic medical center. METHODS: A retrospective study of blood product utilization was conducted in patients who required an MTP activation between January 2011 and December 2015 at an urban academic medical center. Trauma MTP containers included 6 red blood cell (RBC) units, 5 plasma units, and 1 unit of apheresis platelets. Nontrauma MTP containers included 6 RBC and 3 plasma units. RESULTS: There were 334 trauma MTP activations, 233 nontrauma MTP activations, and 77 nontrauma MTP activations that subsequently switched to a trauma MTP ("switched activations"). All nontrauma MTP activations were among bleeding patients who did not have a traumatic injury (100% [233/233]). Few patients with a nontrauma activation required ad hoc transfusion of RBC units (1.3% [95% confidence interval {CI}, 0.3%-3.7%]) or plasma (3.4% [95% CI, 1.5%-6.7%]), and only 45.5% (95% CI, 39.0%-52.1%) required ad hoc transfusion of apheresis platelets. Compared to trauma and switched activations, nontrauma activations transfused a lower median number of RBC, plasma, and apheresis platelet units (P < .001 for all comparisons). There was also a lower median number of prepared but unused plasma units for nontrauma activations (3; [interquartile range {IQR}, 3-5]) compared to trauma (7; [IQR, 5-10]; P < .001) and switched activations (8; [IQR, 5-11]; P < .001). The median number of unused apheresis platelet units was 1 (IQR, 1-2) for trauma activations and 0 (IQR, 0-1) for switched activations. There was a high proportion of trauma and switched activations in which all of the prepared apheresis platelet units were unused (28.1% [95% CI, 23.4%-33.3%] and 9.1% [95% CI, 3.7%-17.8%], respectively). CONCLUSIONS: The majority of initial nontrauma MTP activations did not require a switch to a trauma MTP. Patients remaining under a nontrauma MTP activation were associated with a lower number of transfused and unused plasma and apheresis platelet units. Future studies evaluating the use of hospital-wide nontrauma MTPs are warranted since an MTP designed for nontrauma patient populations may yield a key strategy to optimize blood product utilization in comparison to a universal MTP for both trauma and nontrauma patients.