Dataset Information

An Analytical Comparison of Dako 28-8 PharmDx Assay and an E1L3N Laboratory-Developed Test in the Immunohistochemical Detection of Programmed Death-Ligand 1.

ABSTRACT:

Aim

Nivolumab, a fully human immunoglobulin G4 programmed death-1 (PD-1) immune checkpoint inhibitor antibody, has activity in melanoma, non-small-cell lung cancer (NSCLC), renal cell carcinoma (RCC), and Hodgkin lymphoma. Nivolumab is approved in the USA and EU for advanced melanoma, NSCLC, and RCC, and relapsed Hodgkin lymphoma in the USA. Programmed death-ligand 1 (PD-L1), a PD-1 ligand, is expressed on mononuclear leukocytes, myeloid cells, and tumor cells. PD-L1 is being investigated as a potential biomarker to predict the association of tumor PD-L1 expression with nivolumab efficacy.

Methods

Bristol-Myers Squibb and Dako previously reported on an automated PD-L1 immunohistochemical (IHC) assay that detects cell surface PD-L1 in formalin-fixed, paraffin-embedded, human tumor tissue specimens using Dako's Autostainer Link 48. The primary antibody for this assay is a rabbit monoclonal antihuman PD-L1 antibody, clone 28-8. Another rabbit monoclonal antihuman PD-L1 antibody, clone E1L3N, was compared with 28-8 for specificity and sensitivity using an identical detection method followed by vendor-recommended detection methods.

Results

Using PD-L1 null clones of L2987 and ES-2 tumor cell lines, both antibodies were specific for detection of PD-L1 on the plasma membrane, although E1L3N also stained cytoplasm in ES-2 knockout cells. Using the identical method, E1L3N was slightly more sensitive than 28-8 based on staining intensities. Using manufacturer-recommended detection methods and predefined scoring criteria for plasma membrane staining of tumor and immune cells, 28-8 demonstrated significantly improved detection compared with E1L3N.

Conclusions

Epitope retrieval and highly sensitive detection reagents are key determinants in IHC detection of PD-L1.

SUBMITTER: Cogswell J

PROVIDER: S-EPMC5250639 | biostudies-literature | 2017 Feb

REPOSITORIES: biostudies-literature

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Publications

An Analytical Comparison of Dako 28-8 PharmDx Assay and an E1L3N Laboratory-Developed Test in the Immunohistochemical Detection of Programmed Death-Ligand 1.

Cogswell John J Inzunza H David HD Wu Qiuyan Q Feder John N JN Mintier Gabe G Novotny James J Cardona Diana M DM

Molecular diagnosis & therapy 20170201 1

<h4>Aim</h4>Nivolumab, a fully human immunoglobulin G4 programmed death-1 (PD-1) immune checkpoint inhibitor antibody, has activity in melanoma, non-small-cell lung cancer (NSCLC), renal cell carcinoma (RCC), and Hodgkin lymphoma. Nivolumab is approved in the USA and EU for advanced melanoma, NSCLC, and RCC, and relapsed Hodgkin lymphoma in the USA. Programmed death-ligand 1 (PD-L1), a PD-1 ligand, is expressed on mononuclear leukocytes, myeloid cells, and tumor cells. PD-L1 is being investigate ...[more]

PMID: 27667773

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Project description:Management of Human Immunodeficiency Virus Type 2 (HIV-2) infections present unique challenges due to low viral titers, slow disease progression, and poor response to standard antiviral therapies. The need for a nucleic acid assay to detect and quantify HIV-2 virus has led to the development of a number of molecular-based assays for detection and/or quantification of HIV-2 viral RNA in plasma in order to provide laboratory evidence of HIV-2 infection and viral loads for use in treatment decisions. As HIV-2 is less pathogenic and transmissible than HIV-1 and has resistance to several of the antiretroviral drugs, delay of treatment is common. Cross sero-reactivity between HIV-1 and HIV-2 makes it difficult to distinguish between the two viruses based upon serological tests. As such we developed a quantitative reverse transcription PCR (qRT-PCR) assay targeting the 5' long terminal repeat of HIV-2 for detection and quantification of HIV-2 viral RNA in plasma to identify HIV-2 infection and for use in viral load monitoring. Serial dilutions of cultured HIV-2 virus demonstrated a wide dynamic range (10 to 100,000 copies/ml) with excellent reproducibility (standard deviation from 0.12-0.19), linearity (R2 = 0.9994), and a lower limit of detection at 79 copies/ml (NIH-Z). The assay is highly specific for HIV-2 Groups A and B and exhibits no cross reactivity to HIV-1, HBV or HCV. Precision of the assay was demonstrated for the High (Mean = 6.41; SD = 0.12) and Medium (Mean = 4.46; SD = 0.13) HIV-2 positive controls. Replicate testing of clinical specimens showed good reproducibility above 1,000 copies/ml, with higher variability under 1,000 copies/ml. Analysis of 220 plasma samples from HIV-2 infected West African individuals demonstrated significantly lower viral loads than those observed in HIV-1 infections, consistent with results of previous studies. Slightly more than seven percent of clinical samples (7.3%) demonstrated viral loads above 100,000 copies/ml, while 37.3% of samples were undetectable. The high sensitivity, specificity, precision, and linearity of the WRAIR qRT-PCR assay makes it well suited for detection and monitoring of HIV-2 RNA levels in plasma of infected individuals.

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Dataset Information

An Analytical Comparison of Dako 28-8 PharmDx Assay and an E1L3N Laboratory-Developed Test in the Immunohistochemical Detection of Programmed Death-Ligand 1.

Aim

Methods

Results

Conclusions

Publications

An Analytical Comparison of Dako 28-8 PharmDx Assay and an E1L3N Laboratory-Developed Test in the Immunohistochemical Detection of Programmed Death-Ligand 1.

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