A flow cytometric assay for D8/17 B cell marker in patients with Tourette's syndrome and obsessive compulsive disorder.

D8/17 is proving to be an important diagnostic and treatment tool in patients with Tourette's syndrome (TS) and obsessive compulsive disorder (OCD). The present study represents a direct comparison of immunofluorescence microscopy and flow cytometry in terms of their relative efficiency in the detection of the DB/17 B cell marker. Analysis of 41 patients with OCD or TS and 31 control subjects by immunofluorescence microscopy and flow cytometer demonstrated an average of 6.5% of D8/17-positive B cells in controls with an average of 19.6% in OCD patients. Using the flow cytometer, values of 6.2% for controls and 22.4% for OCD patients were obtained. The flow cytometer test was able to count many more cells, induce less operator error and offer faster analysis while correlating strongly with the microscopic technique. Overall in our sample, the FACS assay test has a sensitivity of 77% and a specificity of 87%. The ease of use and close correlation to disease activity makes this an ideal test for clinical laboratories.