Citations

Abstract Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (“Mass-Fix”) has replaced serum immunofixation at our institution for detection of monoclonal immunoglobulins. One advantage of Mass-Fix is the ability to differentiate pathogenic endogenous monoclonal antibodies from therapeutic monoclonal antibodies (t-mabs), which are often the first-line treatment for multiple myeloma, by reviewing the light chain signature mass. The objective of this study was to describe the distribution of t-mabs and other key characteristics of clinical serum samples analyzed by Mass-Fix in 2022. Comprehensive results for each sample were extracted retrospectively from the laboratory information system. Of 66,710 total analyzed, 30,701 (46%) samples were reported as “positive” (i.e., contains a monoclonal protein), given the tertiary nature of our institution and reference laboratory services. The positive samples were further subdivided by t-mab (detected by Mass-Fix), with a total of 7,769 (25.3%) t-mabs reported. The top five IgG kappa t-mabs reported include daratumumab (n=6,537), elotuzumab or REGN5458/5459 (n=499), isatuximab (n=348), and rituximab (n=102). Rare observations included monoclonal proteins consistent with tixagevimab/ cilgavimab, for COVID-19 infection (n=7), obinutuzumab, an anti-CD20 t-mab for multiple sclerosis (n=1) and evolocumab, an IgG lambda anti-PCSK9 inhibitor (n=6). Of the 7,769 samples, the t-mab was the only reported clone in 47.7% of cases and was found along with the original disease-associated clone in remaining cases. When the original disease clone was present, it was an IgG kappa isotype 31% of the time and could have confounded the definition of complete therapy response for patients. 69% were non-IgG kappa original clones. Mass-Fix test orders have a multiple-choice prompt to provide any current therapy to aid in the patient’s result interpretation. For those samples where a t-mab was reported, the answer to this question regarding administered therapy was often discrepant from the report: only 38.5% of daratumumab-positive samples had an affirmation of daratumumab administration. The remaining 61.5% of daratumumab-positive samples reported an assortment of therapies, including bone marrow transplant, other t-mabs, no active therapy, or the field was left blank, highlighting poor compliance. Additionally, 154/36,009 samples where the provider affirmed daratumumab administration were reported as negative (i.e., no monoclonal protein observed on Mass-Fix). Often, the send-out laboratory does not have medical record access where treatment information is detailed. In conclusion, we reported the presence of a t-mab in 11.6% of all samples tested with Mass-Fix, suggesting that t-mabs have entered the clinical practice to stay, and accurately determining their presence in the challenging environment of poor compliance to prompt questions and evolving treatment regimens is something that cannot be ignored by clinical laboratories. Mass-Fix allows detection of a t-mab in the same routine run as other testing, without need of a second immunofixation to rule out the IgG kappa finding is not a t-mab.

Abstract Introduction/Objective Anaplastic thyroid carcinoma (ATC) is a fatal malignancy. We report an unusual case of a patient with ATC whose chief complaint and clinical history were listed as “jaundice and liver mass” without mention of disease in the neck. Methods/Case Report A 66-year-old female presented to the emergency department with worsening “yellow-green skin discoloration” for a few weeks. She also reported worsening dyspnea and recent dysphagia with solid foods, fatigue, abdominal pain and recent hemoptysis. Physical examination revealed conjunctival icterus, jaundice, a tender neck mass, right upper chest wall tenderness and palpable lymphadenopathy in the lower neck. Assessment notes indicated inability to carry out self-care and being bedridden, even though she reported having been active, swimming and cycling, up to one month before her presentation. Computed tomography studies confirmed findings compatible with widespread malignancy with mass lesions in her liver, lungs, adrenals, kidneys, neck, pancreas, gallbladder, and brain. Mild anemia, hemoglobin 10.5g/dL, mild leukocytosis, leukocytes 17,000/mm3, were confirmed. Bilirubin was 15µmol/L, and hepatic enzymes were elevated. An ultrasound-guided liver biopsy was performed and evaluated for cytologic features, histologic features and pattern of immunoreactivity. The combined cytomorphologic and histologic features were those of a pleomorphic sarcomatoid high-grade malignancy with variably spindled to epithelioid morphology and associated necrosis. Immunohistochemical studies performed on sections from the accompanying core biopsy confirmed the malignant cells to be positive with CK-AE1/AE3, CK 7, TTF-1, GATA3, PAX8, SATB2, and BRAF V600E. The malignant cells were nonreactive with CK 20, thyroglobulin, calcitonin, napsin, CDX2, PCEA, and ER. The combined clinical setting, imaging findings, cytomorphology, histomorphology and ancillary testing results together allowed for a specific diagnosis of metastatic anaplastic thyroid carcinoma. The patient was referred for palliative care services and died within a few days of diagnosis. Results (if a Case Study enter NA) NA Conclusion Metastatic disease from a sarcomatoid ATC, as diagnosed in this case, is an important differential diagnosis to keep in mind when an elderly patient presents with multisite metastases from an undefined primary source. Clinical, radiological and laboratory correlations are of paramount importance in correlating with cytomorphology/histomorphology and in helping to determine the best panel of IHC studies to consider.

Abstract Monoclonal gammopathy of undetermined significance (MGUS) is the most common plasma cell dyscrasia, present in ~3% of the population over 50yo. MGUS carries a 1% per year risk of malignant transformation for the rest of the affected individual’s life; long-term followup is recommended for all patients with MGUS. Different risk stratification models exist to evaluate potential for progression to malignancy. The Mayo risk model, published in 2005, uses the presence of 3 risk factors (abnormal free light chain (FLC) kappa/lambda ratio (KLr), M-spike ≥1.5 g/dL, non-IgG isotype) to confer a 3% per year risk of progression instead of the average 1%. For many years, the only FDA-approved measurement of FLC was the FreeLite assay (Binding Site), which uses polyclonal sheep antibodies. Recently, other FLC assays have become available in the US, including the Sebia FLC ELISA, which employs rabbit polyclonal antibodies. The assays have similar reference intervals (RI), however differences in analytical performance between the FreeLite and Sebia were previously reported. The objective of this study was to determine the performance of the Sebia FLC assay in the Mayo risk stratification model of MGUS patients for progression in comparison to FreeLite. Cryopreserved serum samples from a cohort of 923 MGUS patients with available long-term clinical followup (median follow-up time: 7.7years, range: 0.0 to 46.9) was used to measure FLC using Sebia ELISA on a DS2 automated platform (Dynex) and FreeLite on a Siemens BNII nephelometer. Passing-Bablok (P-B) regression and Spearman correlation were used to compare the KLr between assays. Cox proportional hazards models for progression to multiple myeloma or a related plasma cell malignancy were used to estimate the prognostic effect and ability to discriminate low and high risk of abnormal KLr for each assay. Analyses were carried out in R software. Correlation between Sebia and FreeLite KLr had a Spearman r = 0.796; P-B fit: Sebia KLr = 0.825*(FreeLite KLr) – 0.048, 95% CI of slope: 0.810-0.839). With FreeLite, 32.9% of patients had a KLr outside RI for the method. For Sebia, 48.0% of patients had a KLr outside the method specific RI. Despite the individual samples analytical disagreement, both assays showed similar clinical performance for risk stratification: Sebia abnormal KLr was associated with a hazard ratio (HR) of 2.77 (95%CI: 1.79-4.28 c-statistic=0.6505) for progression, while FreeLite abnormal KLr was associated with a HR of 3.31 (95%CI: 2.20-5.00, c-statistic=0.6529), and the difference in c-statistics was not statistically significant (p=0.93). The risk assessment is performed only once per patient, at the initial diagnosis of MGUS. The similarity in clinical performance between FreeLite and Sebia assays support the use of either method as a predictor for risk of progression for MGUS patients.

Abstract Introduction/Objective Nodal PTCL with EBV positivity can occasionally contain Reed Sternberg-like cells, and EBV- LPD can mimic Hodgkin lymphoma. Coexistence of these two unusual lymphomas in the same lymph node is very rare. We present a case of a 56-year-old male with Composite EBV+ PTCL NOS and EBV LPD, with positive B-cell gene rearrangement and negative T-cell gene rearrangement presenting a significant diagnostic challenge. Methods/Case Report A 56-year-old male with a history of abdominal tuberculosis presented with lethargy, fatigue, and poor appetite. Physical examination revealed generalized lymphadenopathy. CT scan confirmed lymphadenopathy in bilateral axilla, supraclavicular lymph nodes along with lytic lesions on illiac crest. Ill defined splenic lesions raised concerns for metastasis. Cervical lymph node and bone marrow biopsies were performed. Flow cytometry on the lymph node was not done due to tuberculosis history. Flow cytometry on the bone marrow showed an inverted CD4:CD8 ratio. H&E sections of the lymph node revealed a polymorphic lymphoid infiltrate with prominent Reed Sternberg-like cells. Immunohistochemical staining showed CD30-positive and CD45-negative large cells. T-cell and B-cell gene rearrangements were performed. Initially, B-cell gene rearrangements were positive, while T-gamma was negative. Further testing by IHC and morphological evaluation revealed two distinct cell populations, one with CD3, CD5, and CD7 positivity with partial weak positivity for PD1, CD43, and CD8 and the other consisting of B-cells expressing CD30, EBV, MUM1, and partial expression of BCL6 rare CD79a, and partial weak Pax5. Outside molecular testing showed positive T-cell gene rearrangements. The diagnosis of Composite EBV+ Peripheral T Cell Lymphoma, not otherwise specified, with cytotoxic profile along with EBV driven LPD was made. Bone marrow studies confirmed involvement by the same lymphoma. Results (if a Case Study enter NA) NA Conclusion Identifying EBV-positive Reed Sternberg-like cells in both EBV LPD and PTCL-NOS in a composite lymphoma can be challenging. In the absence of flow cytometry, a composite lymphoma can potentially be misdiagnosed, leading to under-treatment. Repeat testing can be helpful in case of any doubt. Although EBV-positive PTCL with cytotoxic profile and EBV-positive LPD has been reported, the combination of these two lymphomas together is exceedingly rare.

Abstract Introduction/Objective Ki-67, a nuclear protein present during the active phases of the cell cycle, is an important prognostic and predictive marker for many tumor types, including breast cancer. This study compared the results of breast cancer specimens immunohistochemically (IHC) stained with the FDA-approved vs. Mayo Clinic’s (MC) validated Ki-67 protocol using AI-based image analysis algorithms for quantitative examination at an individual cell level. Methods/Case Report Sixty-two breast cancer specimens were selected with a rough equal representation of Ki-67 percentage in low (<10%), intermediate (10-20%) and high (>20%) categories. Two adjacent sections of each specimen were stained with the FDA and MC protocols, respectively, and scanned to obtain whole slide digital images. Two AI algorithms, one with tumor cell identification and the other without, were used to quantify positive and negative cells and calculate Ki-67 percentages. Results (if a Case Study enter NA) Both algorithms show high concordance between the two staining protocols, with r-squared scores of 0.989 and 0.992, respectively, analyzing with or without tumor identification. AI identified tumor better on MC stained slides vs. FDA stained slides. The results demonstrate a high-performance concordance between the MC and the FDA IHC staining protocols. Conclusion The data also illustrates the accuracy of using AI image analysis algorithms to compare different IHC protocols at an individual cell level. The AI tumor identification difference in slides stained with two IHC protocols reflects the importance of training an algorithm with a specific staining protocol to achieve optimal tumor recognition.

Abstract Background Interleukin 6 (IL-6) plays important roles in both innate and adaptive immunity, while dysregulated persistent production of IL-6 is involved in pathological development of various diseases associated with inflammation. Targeting the IL-6 pathway has led to many innovative treatment approaches. Siltuximab and Tocilizumab are monoclonal antibodies targeting IL-6 and IL-6 receptors respectively and have been FDA-approved for treatment of Castleman disease (Siltuximab), a rare lymphoproliferative disorder characterized by hyperproduction of IL-6 with an unknown prevalence, autoimmune diseases such as rheumatoid arthritis (Tocilizumab), and both shown potential as treatment for cytokine release syndrome in hospitalized COVID-19 patients. However, the presence of siltuximab can interfere with IL-6 assays, leading to the use of C-reactive protein (CRP) as a surrogate marker to monitor its efficacy. Aim To evaluate potential Siltuximab and Tocilizumab antibody interference on IL-6 measurements in three different IL-6 protein immunoassays. Method: Serum or EDTA plasma sample pools with different IL-6 concentrations ranging from low (2.3 – 11.1 pg/mL, around the reference interval cut-off for each assay) to high (18.5 – 1142 pg/mL), above reference interval cut-off for each assay) were utilized. Various concentrations of Siltuximab or Tocilizumab were spiked into the sample pools (at 10% of total volume) to achieve final concentrations up to 600 µg/mL and up to 300 µg/mL, respectively. Sample spiked with 10% saline were used as no-drug control. Three assays were used to measure IL-6 concentration: Beckman Access IL-6 assay on UniCel DxI 800 (Beckman Coulter), V-PLEX Plus human IL-6 assay on QuickPlex SQ120 (Meso Scale Diagnostics), and a Luminex cytokine panel assay developed in house (R&D systems) with upper reference interval limits of 6.4,1.8 and 5 pg/mL respectively. Results Siltuximab interfered with the measurement of IL-6 for all three assays. A significant interference (> 20% reduction) was observed at even a very low siltuximab concentrations in all three assays (0.05 µg/mL). In the presence of 5 µg/mL or greater Siltuximab, a maximum reduction of 93%, 83%, and 40% was observed for Beckman Access, R&D Luminex assay, and V-PLEX Plus Mesoscale assay, respectively. Tocilizumab did not interfere with the measurement of IL-6 in the three assays when serum was spiked with up to 300 µg/mL of the drug. Conclusion Siltuximab falsely reduce the measured IL-6 concentration on all three immunoassays tested in this study to differing degrees, whereas Tocilizumab does not. Consider the therapeutic range of Siltuximab (84 to 332 µg/mL) for treatment of Castleman disease, and a half-life of 20.6 days, measurement of IL-6 may not be useful in Siltuximab treated patients for an extended time-period.

Abstract Introduction/Objective Our laboratory implemented a full COPAN WASPLab microbiology automation line in March of 2023. Prior to this implementation, our laboratory routinely observed potential bacterial contamination of sterile specimens, as well as culture plates in which the specimens were not struck out, due to a large number of new staff members and heavy workloads. Both of these quality issues directly impact patient care due to potential misleading or delayed results. We hypothesized that automation of the plating and incubation steps would reduce both of these quality issues significantly. Methods/Case Report Potential contamination and plates not struck were self-reported by technologists during pre- implementation (July 2022-Feb 2023) and post-implementation (Mar-Apr 2023) periods. Potential contamination was defined as one or two colonies of bacteria on a single agar plate, consistent with skin fora, from a normally sterile source specimen and reviewed by the Director for potential clinical correlation. Plates unstruck in the post- implementation period continued to include those manually set up. A 2 two proportion z-test was performed to compare pre and post implementation data. Results (if a Case Study enter NA) A total of 3,055 and 1,750 sterile source cultures were analyzed in the pre- and post-implementation periods, respectively. Of these, 109 versus 8 were designated as potential contamination, respectively, resulting in a significant reduction (Z stat 6.7, p<0.0001). For the plate streaking portion, 22,814 and 7,211 cultures were analyzed in the pre- and post-implementation periods, respectively. Of these, 21 versus 3 plates were not struck, respectively, resulting in a greater than 2-fold reduction per culture, but did not meet significance. Conclusion Implementation of microbiology automation significantly reduced skin flora contamination of sterile source cultures. Proportions of unstruck plates were also reduced, although these did not meet significance, likely due to the low numbers.

Abstract Introduction/Objective In January of 2021 our laboratory experienced the occupational exposure of 3 technologists to the select agent Burkholderia pseudomallei due to improper recognition and manipulation outside a biosafety cabinet. Subsequently, an interactive computer module was created to train technologists on timely recognition, followed by a “fake” patient test to evaluate comprehension. In that initial period, 100% compliance and successful recognition was demonstrated. To evaluate sustained compliance and recognition, another wave of evaluation was performed Jan- Dec 2022. Methods/Case Report During the study period several new staff members were hired and demonstrated compliance with completing the computer module. Clinical isolates suspicious for a select agent were reported to the Medical Director on rounds daily and reviewed for potential exposure, which was defined as manipulation of the suspicious isolate outside of the biosafety cabinet. Additional challenge “fake” patients were circulated. Results (if a Case Study enter NA) During the study period, 16 isolates were deemed suspicious for select agents based on macroscopic and microscopic morphology and biochemical reactions. Of these, 0 resulted in laboratory exposures. Of the challenge isolates, 1 resulted in a near-miss potential for exposure due to the lack of recognition of macroscopic characteristics. Conclusion The use of an interactive computer module focused around timely recognition and safe handling of potential select agents resulted in sustained laboratory safety and avoidance of potential occupational exposures.

Abstract Uncontrolled hemorrhage accounts for up to 40% of trauma related mortality, and approximately 30% of trauma related deaths occur in the hospital within the first 1-4 hours of injury. The Advanced Trauma Life Support (ATLS) guidelines still recommend initial resuscitation with crystalloid fluid as an integral part of maintaining or restoring hemodynamic stability, but are starting to recognize the role of early resuscitation with blood products in patients with evidence of Class III and IV hemorrhage, in line with recent clinical trial and observational data. Although there is a growing body of evidence that early transfusion with blood products may be associated with improved survival compared with crystalloid infusion, the optimal transfusion strategy still remains unclear and is being actively investigated in clinical trials. In silico models of resuscitation offer a means to evaluate the effectiveness and safety of resuscitation protocols, including effects on body fluid compartment volumes, tissue oxygenation, and hemostatic factors. Here we describe our work extending earlier deterministic models of trauma resuscitation to incorporate hemodynamic, hemostatic, resuscitation, biomarker, and tissue-oxygenation domains into a single comprehensive model. Additionally, this model expands upon previous deterministic models to create a stochastic computational model of hemostatic resuscitation that accounts for variations in blood component composition and temporal features of transfusion therapy. Using this stochastic model, an in silico trial was piloted to compare conventional component therapy, i.e. red cell, platelet and plasma components, to cold-stored whole blood using the following starting assumptions: patient weight of 81.3±21.8 kg, hematocrit of 41.8±4.3%, initial bleeding rate between 50 and 150 mL/min, systolic blood pressure of 125±18 mmHg, fibrinogen of 293±88 mg/dL, international normalized ratio of 1.0±0.1 and platelet count of 239±62x109/L, with blood component and whole blood constituent distributions based on laboratory quality control data. This in silico trial demonstrated that resuscitation with whole blood was associated with a 28-minute reduction in the time spent in the critical window defined by platelet count <50x109/L, INR≥2, hemoglobin <9 g/dL and fibrinogen <150 mg/dL compared with conventional component resuscitation over the course of a 4 hour simulation (p<0.001 based on median regression). We demonstrate how stochastic models of hemostatic resuscitation can be used to perform in silico trials of resuscitation strategies. Our work can guide inclusion and exclusion criteria for future clinical trials and facilitate identification of patient subgroups most likely to benefit from certain resuscitation strategies. This work was partially funded by the AABB Foundation (formerly the National Blood Foundation).