The ID NOW COVID-19, a high-speed high-performance assay.

The ID NOW COVID-19 assay is a promising tool for the rapid identification of COVID-19 patients. However, its performances were questioned. We evaluate the ID NOW COVID-19 in comparison to a reference RT-PCR using a collection of 48 fresh nasopharyngeal swabs sampled on universal transport media (UTM). Only 2 false negatives of the ID NOW COVID-19 were identified. They display PCR cycle threshold values of 37.5 and 39.2. The positive percent agreement and the negative percent agreement were 94.9% and 100%, respectively. The Kappa value was 0.88. The ID NOW COVID-19 combines high-speed and accurate processing. Using UTM, the ID NOW COVID-19 could be repeated in the case of invalid result. Further analyses, such as screening of genetic variants or genome sequencing, could also be performed with the same sample. As for all tests, the results should be interpreted according to clinical and epidemiological context.

Relationship between IkappaBalpha constitutive expression, TNFalpha synthesis, and apoptosis in EBV-infected lymphoblastoid cells.

In order to understand the role of NF-kappaB in EBV transformation we have established stably transfected IkappaBalpha into lymphoblastoid cells. Two clones were obtained in which the loss of NF-kappaB binding activity correlated with the constitutive expression of the transgenic IkappaBalpha. Protein latency expression was determined by immunocytochemistry. Expression of surface markers, intracytoplasmic content of cytokines cell cycle analysis after BrdU incorporation and DNA staining with propidium iodide were studied by flow cytometry. Percentage of apoptotic cells was determined by in-situ labelling of DNA strand breaks. No significative changes in EBV latency nor in cell surface marker expression was found. In contrast, intracytoplasmic TNFalpha levels were strongly reduced in transfected clones. Furthermore, 30% of IkappaBalpha transfected cells were apoptotic after 8 h of TNFalpha treatment. This correlated with a strong reduction of BrdU incorporation after 24 h of TNFalpha treatment. No effect was seen with non transfected cells or with cells transfected with a control plasmid. Our results suggest that the TNFalpha gene could be one of the targets of NF-kappaB in EBV infected cells and that NF-kappaB protects EBV-infected cells from apoptosis induced by TNFalpha, which may favour the proliferative effect of this cytokine.

Nasal natural killer lymphoma associated with Epstein-Barr virus in a patient infected with human immunodeficiency virus.

Nasal natural killer (NK) lymphoma associated with Epstein-Barr virus (EBV) is a rare lymphoma that has not yet been reported in patients with human immunodeficiency virus (HIV). This report describes the first case, to our knowledge, of nasal NK cell lymphoma in an HIV-positive patient. A 50-year-old African man presented with an obstructive nasopharyngeal tumor, leading to the diagnosis of HIV infection. Nasal biopsy specimens showed NK cell lymphoma, confirmed on nasal tissues by morphologic, immunohistochemical, and polymerase chain reaction studies using a denaturing gradient gel electrophoresis technique that showed no T-cell receptor gamma rearrangement. The EBV was detected by in situ hybridization. The patient received chemotherapy but died from infection. To our knowledge, this is the first reported case of nasal NK cell lymphoma associated with EBV in an HIV patient. Involvement of EBV in HIV non-B-cell lymphomas may represent a further manifestation of opportunistic EBV infection arising in these patients.

Inducible loss of NF-kappaB activity is associated with apoptosis and Bcl-2 down-regulation in Epstein-Barr virus-transformed B lymphocytes.

The Epstein-Barr virus (EBV)-encoded latent membrane protein-1 induces NF-kappaB activity by targeting IkappaBalpha. To understand the role of NF-kappaB activation in EBV-related oncogenesis, we have subcloned mutated IkappaBalpha(32/36A) cDNA into a pHEBo vector containing doxycycline regulatory sequences and stably transfected this construct into a lymphoblastoid cell line. Two tightly regulated clones were obtained in which IkappaBalpha(32/36A) was inducible in a doxycycline dose-dependent manner. Levels of inducible IkappaBalpha(32/36A) peaked at day 2. Inhibition of NF-kappaB activity was closely correlated with levels of inducible IkappaBalpha(32/36A). Levels of 3 well-known NF-kappaB-dependent genes, CD54, p105, and endogenous IkappaBalpha, were decreased when IkappaBalpha(32/36A) was induced, and the growth of IkappaBalpha(32/36A)-induced EBV-infected cells was slightly reduced. Loss of NF-kappaB activity was associated with decreased Bcl-2 protein levels. Finally, the induction of apoptosis was strongly increased in IkappaBalpha(32/36A)-overexpressing cells. Together these results show that it is possible to control IkappaBalpha(32/36A) levels, ie, NF-kappaB activity, in EBV-infected B-lymphocytes using a doxycycline-inducible vector. Moreover, our results indicate that NF-kappaB can protect EBV-infected cells from apoptosis by Bcl-2. Finally, our results suggest that a cellular model with doxycycline-inducible IkappaBalpha(32/36A) may be useful in the identification of genuine NF-kappaB target genes in EBV-infected B cells. (Blood. 2000;95:2068-2075)

Diagnostic value of dominant T-cell clones in peripheral blood in 363 patients presenting consecutively with a clinical suspicion of cutaneous lymphoma.

It is now widely accepted that polymerase chain reaction (PCR) analysis of cutaneous T-cell clonality is of diagnostic value in cutaneous T-cell lymphomas (CTCLs) and most helpful in the diagnosis of mycosis fungoides (MF). However, the diagnostic and prognostic value of circulating clonal T cells remains unclear. We studied T-cell clonality in the peripheral blood (PB) and the cutaneous lesion, sampled at the same time, in 363 consecutively seen patients with a clinical suspicion of cutaneous lymphoma. Using a PCR technique providing a specific imprint of T-cell clones (PCRgamma-denaturing gradient gel electrophoresis), we found that detection of identical circulating and cutaneous T-cell clones was associated with the diagnosis of CTCL (P <.001). Detection of circulating tumor cells in patients with MF was infrequent (12.5%), except in those with erythrodermic MF (42%; P =.003). Moreover, among the 46 patients who had identical circulating and cutaneous T-cell clones, 25 (56%) had erythroderma. The finding of a dominant clone in the PB but not in the skin was frequent, regardless of the clinicohistologic classification; it occurred in 30% of patients with CTCL, 41% with non-CTCL malignant infiltrates, and 34% with benign infiltrates. This pattern was significantly more frequent in patients over 60 years of age (P <.002), even in the CTCL group (P <. 01). In conclusion, dominant T-cell clones detected in the PB of patients with MF by using a routine PCR technique are rarely tumoral and are more often related to age. A multicenter prospective study is under way to establish the prognostic value of circulating tumor cells.