Implementation and Evaluation of Virtual Laboratory Tours for Laboratory Diagnosis of Hematologic Disease.

OBJECTIVES: There is often limited time allocated to teaching laboratory medicine to medical students. Without adequate time and context, it can be difficult for students to learn appropriate uses and limitations of laboratory tests. Introducing students to the laboratories and test methods may help them learn these concepts, but physical laboratory tours are difficult to organize for large groups, especially during the coronavirus disease 2019 pandemic. METHODS: We created virtual laboratory tours consisting of short video clips and voiceover PowerPoint slides to teach students about the laboratory tests used to diagnose hematologic malignancies. We assessed the impact on student performance on laboratory medicine-themed quiz questions and surveyed the students to determine their attitudes about the activity. RESULTS: In total, 129 first-year medical students participated in the study. The average score on the preactivity quiz was 59.8%, and the average score on the postactivity quiz was 92.2%. Students were more confident in their ability to answer quiz questions after completing the activity. Postactivity survey data indicated that the students enjoyed the activity and felt it was an effective way to learn the material. CONCLUSIONS: Virtual laboratory tours show promise as a method of incorporating more laboratory medicine content into medical school curricula.

Evidence of Alternative Modes of B Cell Activation Involving Acquired Fab Regions of N-Glycosylation in Antibody-Secreting Cells Infiltrating the Labial Salivary Glands of Patients With Sjögren's Syndrome.

OBJECTIVE: To better understand the role of B cells, the potential mechanisms responsible for their aberrant activation, and the production of autoantibodies in the pathogenesis of Sjögren's syndrome (SS), this study explored patterns of selection pressure and sites of N-glycosylation acquired by somatic mutation (acN-glyc) in the IgG variable (V) regions of antibody-secreting cells (ASCs) isolated from the minor salivary glands of patients with SS and non-SS control patients with sicca symptoms. METHODS: A novel method to produce and characterize recombinant monoclonal antibodies (mAb) from single cell-sorted ASC infiltrates was applied to concurrently probe expressed genes (all heavy- and light-chain isotypes as well as any other gene of interest not related to immunoglobulin) in the labial salivary glands of patients with SS and non-SS controls. V regions were amplified by reverse transcription-polymerase chain reaction, sequenced, and analyzed for the incidence of N-glycosylation and selection pressure. For specificity testing, the amplified regions were expressed as either the native mAb or mutant mAb lacking the acN-glyc motif. Protein modeling was used to demonstrate how even an acN-glyc site outside of the complementarity-determining region could participate in, or inhibit, antigen binding. RESULTS: V-region sequence analyses revealed clonal expansions and evidence of secondary light-chain editing and allelic inclusion, of which neither of the latter two have previously been reported in patients with SS. Increased frequencies of acN-glyc were found in the sequences from patients with SS, and these acN-glyc regions were associated with an increased number of replacement mutations and lowered selection pressure. A clonal set of polyreactive mAb with differential framework region 1 acN-glyc motifs was also identified, and removal of the acN-glyc could nearly abolish binding to autoantigens. CONCLUSION: These findings support the notion of an alternative mechanism for the selection and proliferation of some autoreactive B cells, involving V-region N-glycosylation, in patients with SS.