RESUMO
A low count of CD4+ and CD8+ lymphocytes is a hallmark laboratory finding in the coronavirus disease 2019 (COVID-19). Using flow cytometry, we observed significantly higher CD95 (Fas) and PD-1 expression on both CD4+ T and CD8+ T cells in 42 COVID-19 patients when compared to controls. Higher CD95 expression in CD4+ cells correlated with lower CD4+ counts. A higher expression of CD95 in CD4+ and CD8+ lymphocytes correlated with a lower percentage of naive events. Our results might suggest a shift to antigen-activated T cells, expressing molecules increasing their propensity to apoptosis and exhaustion during COVID-19 infection.
Assuntos
Linfócitos T CD4-Positivos/química , Linfócitos T CD8-Positivos/química , COVID-19/imunologia , Subpopulações de Linfócitos/química , Linfopenia/etiologia , Receptor de Morte Celular Programada 1/sangue , Receptor fas/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/sangue , Envelhecimento/imunologia , Apoptose , COVID-19/sangue , COVID-19/complicações , Feminino , Humanos , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Prognóstico , SARS-CoV-2RESUMO
Image-guided core needle biopsies (IG-CNB) represent a minimally invasive approach for obtaining tissue in patients with lymphadenopathy and suspected lymphoma. Despite their utility, diagnostic challenges persist, with lower efficacy compared with excisional biopsies. Our study aimed to evaluate the potential utility of incorporation of flow cytometry (FC) alongside immunohistochemistry (IHC) when performing IG-CNB for suspected lymphoproliferative diseases. Analyzing 170 consecutive cases, guided by ultrasound (n = 94) or computer tomography (n = 76), we employed a diagnostic algorithm, already established in our laboratory practice, utilizing three antibody cocktail-equipped tubes tailored for defining lymphomas, particularly those of B-cell origin. FC expedited the diagnostic process, yielding presumptive results in 87.6% of cases within 48 h, with a positive predictive value of 98%. Addition of FC to routine IHC enhanced the diagnostic rate from 91.2% to 95.3%, reducing IG-CNB failure rate by 45%, from 8.8% to 4.7%. This enhancement was particularly notable for deep-seated sites and in the setting of suspected disease recurrences. Consequently, FC emerges as a valuable adjunctive tool, allowing for the improvement of diagnostic performance, with a particular focus on the ability to quantify the expression of surface markers for targeted therapies, and holding the potential to diminish the necessity for repeat excisional biopsies subsequent to IG-CNB procedures.