FLOW-CYTOMETRY PROVIDES RAPID AND HIGHLY ACCURATE DETECTION OF ANTISPERM ANTIBODIES

Objective: Immunobead testing (IBT), the current standard for antisper m antibody detection, is time consuming and somewhat subjective. To ov ercome these limitations and maintain accuracy, we studied an immunofl uorescent assay using flow cytometry. Design: A validation study compa ring flow cytometry to IBT in the detection of serum antisperm antibod ies. Setting: Flow cytometry laboratory. Patients: Sera from 37 men af ter vasectomy (test) and sera from 35 fertile men (control). Main Outc ome Measure: Test serum with and without immunoglobulin (Ig)G, IgA, an d IgM antisperm antibodies as defined by IBT were analyzed by flow cyt ometry. Sensitivity and specificity of flow cytometry was calculated b y defining the IBT as the true result. Results: Flow cytometry identif ied 22 of 22 sera that were IgG positive (100% sensitivity), 12 of 14 sera that were IgA positive (86% sensitivity), and 4 of 4 sera that we re IgM positive (100% sensitivity). Overall, 22 of 37 men were positiv e for antisperm antibodies. The flow cytometry correctly identified 71 of 71 negative sera (100% specificity). Fluorescence intensity values from the 37 study patients significantly correlated with immunobead b inding to the head region and to the entire (more than one) region. Co nclusions: Detection of IgG, IgA, and IgM antisperm antibodies by flow cytometry is highly sensitive and specific. In addition, flow cytomet ry is able to assess thousands of sperm rapidly and accurately, reduci ng sampling error and technical time.