Systematic Comparison of Temperature Effects on Antibody Performance via Automated Image Analysis: A Key for Primary Ciliary Dyskinesia Diagnostic

Immunofluorescence (IF) microscopy of ciliated epithelium is gaining increased popularity as a pre-genetic diagnostic method in primary ciliary dyskinesia (PCD). Ensuring reliable IF-based diagnostics in PCD requires robust standardization of staining methods and antibody performance. We applied whole slide scanning and automated image analysis to systematically evaluate the influence of various sample storage conditions on the specificity of IF staining. We tested eight polyclonal antibodies targeting diverse axonemal protein epitopes, routinely used for PCD diagnostics, under seven different temperature and time combinations. The storage conditions simulated handling of epithelial brushing on glass slides: after material collection at the clinic, during transport, or after reception at the diagnostic laboratory. Our study revealed that proper slide storage conditions are essential for the reliable PCD diagnosis via IF staining. We suggest continuous storage at -80 °C or -20 °C for slides prepared at the diagnostic laboratory, and storage at -20 °C or 4 °C for slides prepared remotely and shipped. Moreover, the IF sensitivity to slide storage conditions differs among antibodies targeting various ciliary elements, with molecular ruler proteins being particularly sensitive to prolonged storage at room temperature. We emphasize the inclusion of additional control slides to mitigate the inter-individual differences and the crucial correlation of IF results with comprehensive patient clinical history for enhanced diagnostic reliability.