ABSTRACT
CONTEXT.: We implemented multiple nucleic acid amplification test platforms because of the limited availability of test kits for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the early stages of the pandemic. Interpretation of results generated by different platforms and prioritization for testing algorithms required cross-comparison. OBJECTIVE.: To compare the analytical sensitivity of 3 commercial SARS-CoV-2 molecular assays, selected samples were studied in parallel with Cobas SARS-CoV-2 test, NxTAG CoV Extended Panel, and ID NOW COVID-19 assays. DESIGN.: A total of 8043 SARS-CoV-2 tests performed from March 22 to April 19, 2020, were included in this study. For all 1794 positive specimens detected by the cobas SARS-CoV-2 assay, the cycle threshold (Ct) values were manually tracked and plotted to demonstrate the distribution of sample viral levels. Additionally, 50 and 63 low-positive specimens (Ct values >32) as well as 50 and 61 consecutive positive specimens by the cobas assay were tested with NxTAG and ID NOW, respectively, to estimate their relative sensitivities. RESULTS.: The Ct values of cobas SARS-CoV-2-positive samples were evenly distributed throughout ranges of 13.32 to 39.50 (mean, 25.06) and 13.60 to 42.49 (mean, 26.45) for ORF1 and E gene targets, respectively. NxTAG reliably detected only specimens with E gene Ct values lower than 33, and is estimated to detect 89.4% of positive specimens detected by cobas assay. ID NOW had performance variation independent of Ct value and is estimated to detect 83.5% of cobas positives. CONCLUSIONS.: Clinical specimens exhibit a wide range of viral burden, with a significant portion at low levels. Analytical sensitivity of testing platforms is critical for reliable detection of SARS-CoV-2 and uniform care to patients.
Subject(s)
Betacoronavirus/genetics , Coronavirus Infections/diagnosis , Molecular Diagnostic Techniques/methods , Nucleic Acid Amplification Techniques/methods , Pneumonia, Viral/diagnosis , Severe Acute Respiratory Syndrome/diagnosis , Severe acute respiratory syndrome-related coronavirus/genetics , Adult , Betacoronavirus/isolation & purification , Betacoronavirus/physiology , COVID-19 , Clinical Laboratory Techniques/methods , Coronavirus Infections/virology , Diagnosis, Differential , Early Diagnosis , Female , Humans , Male , Middle Aged , Nasopharynx/pathology , Nasopharynx/virology , Pandemics , Pneumonia, Viral/virology , Severe acute respiratory syndrome-related coronavirus/isolation & purification , Severe acute respiratory syndrome-related coronavirus/physiology , SARS-CoV-2 , Sensitivity and Specificity , Severe Acute Respiratory Syndrome/virology , Specimen Handling/instrumentation , Specimen Handling/methodsABSTRACT
Thrombocytopenia is a hematological finding commonly encountered in daily clinical practice from asymptomatic clinic patients to critically ill intensive care unit patients. A broad spectrum of etiologies and variation in clinical presentation often present a diagnostic challenge. Furthermore, concomitant presence of thrombosis and thrombocytopenia, as in cases of thrombotic thrombocytopenia, complicates the management. In hospitalized patients, new-onset thrombocytopenia is an important reason for hematology consultation. Therefore, it is of utmost importance that the etiology is diagnosed accurately. In addition, a basic understanding of the pathophysiology and the differential diagnosis avoids delay in the diagnosis and leads to rapid initiation of treatment. This review will address causes of thrombocytopenia that arises in hospitalized patients with an emphasis on the pathophysiological basis of each disorder.
ABSTRACT
Multiple myeloma (MM) is a neoplastic lymphoproliferative disorder characterized by uncontrolled monoclonal plasma cell proliferation. Among different isotypes of MM, immunoglobulin D (IgD) MM is very rare, representing only 1 to 2% of all isotypes. Chronic myelogenous leukemia (CML) is a neoplastic myeloproliferative disorder of pluripotent hematopoietic stem cell, which is characterized by the uncontrolled proliferation of myeloid cells. An 88-year-old male was diagnosed simultaneously with IgD kappa MM and CML. A distinctive feature in this patient was the progression to plasma cell leukemia without any symptomatic myeloma stage. He was treated simultaneously with lenalidomide, bortezomib and imatinib. Synchronous occurrence of these rare hematological malignancies in a single patient is an exceedingly rare event. Multiple hypotheses to explain co-occurrence of CML and MM have been proposed; however, the exact etiological molecular pathophysiology remains elusive.
