Mouse anti-CD4 Monoclonal antibody [clone SQB-U5], FITC-Conjugated

Purpose Peripheral blood T lymphocytosis (PBTL) is a rare, yet poorly understood manifestations of thymoma, which is postulated to be linked with autoimmune/paraneoplastic manifestations such as myasthenia gravis (MG), pure red cell aplasia (PRCA), etc.; more commonly encountered in this neoplasm. Method We aim to describe the flowcytometric immunophenotypic data of PBTL in a 43-year-old male; 6 months after successful completion of chemoradiotherapy (CT/RT) for a large, invasive, and metastatic type B1 thymoma; and present a comprehensive review of all such cases reported over last 42 years (N = 21) (1977-2019). Result A larger size of the tumors (>= 10 cm), presence of local invasion and/or distant metastasis, and type B (cortical or lymphocyte rich) histology were more likely to be associated with PBTL. Tumors associated with MG/PRCA (N = 9/21) tend to have lower PBTL compared to those without such manifestations; and PBTL subsided following thymectomy with or without CT/RT. Immunophenotypic analysis of PB revealed a CD8 + > CD4 + mature (naive) polyclonal T cells resembling late cortical thymocytes. Conclusion Thymic intratumoral microenvironment might influence occurrence PBTL that may have a pathophysiologic link to development of autoimmune manifestations. Immunophenotypic characteristics of peripheral blood lymphoid cells should be the clue for accurate characterization and to avoid a misdiagnosis of a lymphoproliferative neoplasm.

Background: The world is facing the global spread of the severe acute respiratory syndrome coronavirus 2 (SARSCoV-2). T cell-induced immune responses during acute SARS-CoV-2 infection have rarely been reported. Methods: We use cell counting chips and PCR arrays to offer the first insights into the T cell involved in the course of acute SARS-CoV-2 infection. All consecutive patients with suspected SARS-CoV-2 infection treated at the designated hospital between January 2020 and February 2020 were recruited for the study, and cases were confirmed by real-time RT-PCR. Baseline characteristics for inpatients were prospectively collected and analyzed. Results: 96 patients with suspected SARS-CoV-2 infection in our center were screened for inclusion in the study. The median age of the patients was 39.0 years, and 47 (49.0%) were female. Multivariate logistic regression analysis showed that only the CD4+ cell counts were significantly lower in the infection group and slightly higher in the control group. Receiver operating characteristic curve analysis showed good discrimination power between subjects with and subjects without infection. Limitations: This is a single-center study of patients with a specific ethnic background and lacks a mechanism. Conclusions: These findings imply the importance of CD4+ T cells (but not CD8+ and CD3+ T cells) in SARSCoV-2 infection associated pneumonia and indicate that CD4+ T cells might be important for the control of SARS-CoV-2.