Biosensors for IgG Identification in the Absence of Infection to Isolate Autoimmune Activity

People living with chronic autoimmune conditions could run the risk of misdiagnosis. This study involved a systematic review of literature examining how elevated autoimmune-prevalent immunoglobulin G (IgG) coincides with average or low procalcitonin (PCT) levels and normal lymphocyte and neutrophil levels, which can indicate autoimmunity versus bacterial infection or viral infection, respectively. The study results showed a trend in cases where high IgG levels, despite normal PCT and lymphocytes/neutrophils, were concurrent in people with autoimmune disease, alongside a gap in research surrounding how wearable devices could be used to measure IgG against the presence or absence of indicators of acute infection. These findings helped inform the need for a rudimentary algorithm for a wearable biosensor to identify excess IgG in the presence of baseline or low levels of PCT and normal levels of lymphocytes and neutrophils in the blood serum. This device would theoretically aid in differentiating autoimmune conditions from active infection. Received: 7 December 2025 | Revised: 23 January 2026 | Accepted: 6 February 2026 Conflicts of Interest The author declares that she has no conflicts of interest to this work. Data Availability Statement Data sharing is not applicable to this article as no new data were created or analyzed in this study. Author Contribution Statement Sarah Katz: Conceptualization, Methodology, Software, Validation, Formal analysis, Investigation, Resources, Data curation, Writing – original draft, Writing – review & editing, Visualization, Supervision, Project administration.