TABLE 1.

Main issues encountered in mucosal analyses and potential solutions

IssuePotential solution(s)
Contamination of secretions with blood or systemic cellsApply stringent and adapted sampling procedures, quantify serum proteins or hemoglobin in secretions, phenotype cells (mucosal vs systemic integrins)
Unknown dilution of secretionsQuantify total Ig or other nonspecific protein of known concentration, quantify internal standard present in lavage buffers
Too high dilution of secretionsConcentrate samples, use appropriate devices (e.g., wicks instead of lavages), perform cellular rather than humoral analyses
Unknown site of secretion (in particular in the case of gastrointestinal secretions)Perform cellular analyses on biopsies rather than humoral analyses on secretions
Limited amount of material or limited amount of the factors or cells of interestUse sensitive detection methods, expand cells in vitro, perform analysis at the single-cell level
Limited availability of mucosal secretions or biopsiesTry to identify correlates in periphery