Performance of High Throughput SARS-CoV-2 Antigen Testing Compared to Nucleic Acid Testing.

OBJECTIVE: Independent assessment of SARS-CoV-2 antigen (COV2Ag) tests remains important as varying performance between assays is common. We assessed the performance of a new high-throughput COV2Ag test compared to SARS-CoV-2 nucleic acid amplification tests (NAAT). METHODS: A total of 347 nasopharyngeal samples collected from January to October 2021 were assessed by NAAT as part of standard-of-care testing (CDC LDT or GeneXpert System, Cepheid) and COV2Ag using the ADVIA Centaur CoV2Ag assay (Siemens Healthineers). RESULTS: Among NAAT positive specimens we found 82.4% agreement and in NAAT negative specimens we found 97.3% agreement (overall agreement 85.6%). In symptomatic persons, COV2Ag agreed with NAAT 90.0% (n = 291), and in asymptomatic persons, 62.5% (n = 56). Agreement between positive NAAT and COV2Ag increased at lower cycle threshold (Ct) values. CONCLUSION: The COV2Ag assay exceeded the World Health Organization minimum performance requirements of ≥ 80% sensitivity and ≥ 97% specificity. The COV2Ag assay is helpful for large scale screening efforts due to high-throughput and reduced wait times.

Pediatric SARS-CoV-2 seroprevalence during mitigation procedures in Southwestern Pennsylvania.

Background: Children infected with SARS-CoV-2 are often asymptomatic or have only mild symptoms, leading to underestimation of disease prevalence in symptom-based testing strategies. Objectives: This study sought to determine pediatric SARS-CoV-2 disease burden during local mitigation efforts by using antibody testing to compare seroprevalence estimates to cumulative PCR prevalence estimates. Study design: In this cross-sectional study, we collected 1142 strict phase and 1196 relaxed phase remnant blood specimens from patients less than 19-years-old in southwestern Pennsylvania (SWPA). Patients were excluded if their residential zip code was outside the region of interest, if they were under 6-months-old, or they had recently received antibody-modifying treatments. Demographic, encounter, and laboratory electronic medical record information was extracted. Samples were tested for SARS-CoV-2 spike protein IgG using an EUA ELISA, and PCR results were recorded from county health department data. Seroprevalence and Clopper-Pearson exact 95% confidence intervals were calculated. Results: The observed seroprevalence of SARS-CoV-2 spike protein antibodies in children during strictest mitigation was 0.53% (95% CI 0.19, 1.14) and 0.92% (95% CI 0.46,1.64) during moderately relaxed. Strict and relaxed phase PCR-based prevalence were significantly higher, 2.87% (95% CI 1.95, 4.08) and 3.64 (95% CI 3.01, 4.38), respectively. Conclusions: Estimates of pediatric seroprevalence were significantly lower than cumulative PCR prevalence estimates, and less than adult seroprevalence estimates, potentially due to biological, population, or sampling differences. Biological differences in pediatric immune responses to SARS-CoV-2 may make serosurvey interpretation challenging and these differences warrant further study.

Recognizing Laboratory Medicine's Collaborative Role in Identifying and Eliminating Health Disparities.

BACKGROUND: A health disparity is a health outcome that presents in a lesser or greater extent between populations. Health disparities in diseases are products of complex interactions between social, economic, and to a lesser extent, biological factors and can be mediated by structural racism and discriminatory policies. The objective of this review is to understand how both laboratorians and nonlaboratorians think about the relationship between laboratory medicine and health disparities and to highlight ways in which laboratory medicine can play a role in eliminating health disparities. CONTENT: We developed an electronic survey from which we selected the top responses reported by the 215 participants to frame a discussion around why laboratorians perceive health disparities exists, and how they can reduce health disparities. SUMMARY: We found that both laboratorians and nonlaboratorians feel that laboratory medicine can and should play a role in reducing health disparities using many tools already in use in the clinical laboratory. The skills of laboratory workers in data generation, the establishment of reference ranges, control over the presentation of laboratory results, generation of test menus, and the development of novel diagnostics may impact health disparities. Laboratorians' responses in our survey indicated that they felt that they could reduce health disparities by using laboratory data to proactively track in cooperation with healthcare providers individuals with chronic conditions to prevent acute events, ensuring gender and ethnic diversity in new clinical trials, including appropriate curriculum in laboratory medicine training, using equations and reference intervals based on physiological differences and participating in unconscious bias training.

SOX10 ablation arrests cell cycle, induces senescence, and suppresses melanomagenesis.

The transcription factor SOX10 is essential for survival and proper differentiation of neural crest cell lineages, where it plays an important role in the generation and maintenance of melanocytes. SOX10 is also highly expressed in melanoma tumors, but a role in disease progression has not been established. Here, we report that melanoma tumor cell lines require wild-type SOX10 expression for proliferation and SOX10 haploinsufficiency reduces melanoma initiation in the metabotropic glutamate receptor 1 (Grm1(Tg)) transgenic mouse model. Stable SOX10 knockdown in human melanoma cells arrested cell growth, altered cellular morphology, and induced senescence. Melanoma cells with stable loss of SOX10 were arrested in the G1 phase of the cell cycle, with reduced expression of the melanocyte determining factor microphthalmia-associated transcription factor, elevated expression of p21WAF1 and p27KIP2, hypophosphorylated RB, and reduced levels of its binding partner E2F1. As cell-cycle dysregulation is a core event in neoplastic transformation, the role for SOX10 in maintaining cell-cycle control in melanocytes suggests a rational new direction for targeted treatment or prevention of melanoma.

Biology of human cutaneous melanoma.

A review of the natural behavior of cutaneous melanoma, clinical and pathological factors, prognostic indicators, some basic research and the present and possible futuristic strategies in the management of this disease are presented. While surgery remains to be the most effective therapeutic approach in the management of early primary lesions, there is no standard adjuvant therapy after surgical resection, or for metastatic disease.

Cytokines and growth factors expressed by human cutaneous melanoma.

Cytokines and growth factors have biologic effects that could stimulate tumor growth, invasion and angiogenesis. The incidence of 24 factors was investigated in 25 cultured human melanoma cell lines and in 62 fixed tissues at different stages of the disease. Over 80% of the human melanoma cell lines expressed TGF-ß, IL-8, IL-6, VEGF, PDGF-AA and OPN. Significantly higher TGF-ß, IGF-1 and IL-15 were determined in primary lesions compared to distant metastases by immunohistochemistry. Illustrating the complexity of the milieu of the tumor microenvironment, some of these factors may have to be considered in targeted therapy.

Wnt5A activates the calpain-mediated cleavage of filamin A.

We have previously shown that Wnt5A and ROR2, an orphan tyrosine kinase receptor, interact to mediate melanoma cell motility. In other cell types, this can occur through the interaction of ROR2 with the cytoskeletal protein filamin A. Here, we found that filamin A protein levels correlated with Wnt5A levels in melanoma cells. Small interfering RNA (siRNA) knockdown of WNT5A decreased filamin A expression. Knockdown of filamin A also corresponded to a decrease in melanoma cell motility. In metastatic cells, filamin A expression was predominant in the cytoplasm, which western analysis indicated was due to the cleavage of filamin A in these cells. Treatment of nonmetastatic melanoma cells with recombinant Wnt5A increased filamin A cleavage, and this could be prevented by the knockdown of ROR2 expression. Further, BAPTA-AM chelation of intracellular calcium also inhibited filamin A cleavage, leading to the hypothesis that Wnt5A/ROR2 signaling could cleave filamin A through activation of calcium-activated proteases, such as calpains. Indeed, WNT5A knockdown decreased calpain 1 expression, and by inhibiting calpain 1 either pharmacologically or using siRNA, it decreased cell motility. Our results indicate that Wnt5A activates calpain-1, leading to the cleavage of filamin A, which results in a remodeling of the cytoskeleton and an increase in melanoma cell motility.

Sequential administration of GM-CSF (Sargramostim) and IL-2 +/- autologous vaccine as adjuvant therapy in cutaneous melanoma: an interim report of a phase II clinical trial.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-2 (IL-2) are 2 cytokines with distinct mechanisms of action that complement one another in the adjuvant management of melanoma. Forty-five patients with high-risk melanoma were enrolled in an open-label, single-arm, phase II clinical trial to examine the safety, tolerability, and effectiveness of this combination. After potentially curative surgery, each patient received 12 months of GM-CSF 125 microg/m2/d subcutaneously (SC) for 14 days followed by IL-2, 9 million IU/m2/d SC for 4 days (given every other cycle from months 7-12), followed by 10 days of no treatment. In addition, patients who had tumors yielding an adequate number of live cells received autologous melanoma vaccines. For months 13-24, patients received only GM-CSF 250 microg/m2 twice weekly. This is an interim analysis based on the 45 enrolled patients with a median of 15.9 months follow-up (range, 1-50 months). Thirty-two patients are alive: 9 of 13 with stage IV resected melanoma, 16 of 25 with stage III disease, and 7 of 7 with stage II disease. Twelve died of the disease, and one due to stroke. Adjuvant use of sequential GM-CSF and IL-2 +/- autologous vaccine was well tolerated with good patient compliance and seemed to benefit high-risk patients with surgically resected melanoma.

In vivo effects of sequential granulocyte-macrophage colony stimulating factor (GM-CSF) and interleukin-2 (IL-2) on circulating dendritic cells (DC) in patients with surgically resected high risk cutaneous melanoma.

Dendritic cells were assayed repeatedly in the peripheral blood of consenting melanoma patients receiving adjuvant biotherapy for high risk (stages IIb-IV) melanoma. Postoperatively, adjuvant biotherapy consisted of granulocyte-macrophage colony-stimulating factor [125 microg/m2/day] for 14 consecutive days, followed by interleukin-2 [9 million IU/m2/day] for the next 4 days, and then no treatment for 10-12 days. This was repeated monthly for six cycles. Although white blood cell counts increased, there was no significant elevation in dendritic cell counts during therapy of eleven patients. Within the first cycle during granulocyte-macrophage colony-stimulating factor treatment of seven patients, the absolute DC count decreased (p < 0.04), the percentage of myeloid BDCA-1+ BDCA-2- dendritic cells was significantly lower than baseline (p < 0.003) and the percentage of plasmacytoid BDCA-1- BDCA-2+ dendritic cells was significantly higher than baseline (p < 0.009). Our data suggest mechanisms of potential anti-tumor responses in patients receiving systemic sequential granulocyte-macrophage colony-stimulating factor and interleukin-2 do not include a cumulative gain in peripheral dendritic cell counts or an increase in myeloid BDCA-1+ BDCA-2- dendritic cell subset in the peripheral blood.