Dimension Vista(R) Systems Vista(R) Theophylline THEO Flex(R) Regent Cartridge (K4071) The THEO method is an in vitro diagnostic test for the quantitative measurement of Theophylline in human serum and plasma on the Dimension Vista(R) system.

Firm has received complaints from customers of "Abnormal Reaction" errors occurring on calibrations, QC and patient samples. The Abnormal Reaction flag is being triggered by an internal check in the method for atypical particle reagent aggregation.

Siemens Healthcare Diagnostic sent a Urgent Field Safety notice dated July, 20. 2012, to all affected customers. The letter identified the product the problem and the action needed to be taken by the customer. Please immediately discontinue use and discard any remaining inventory of Dimension Vista Theophylline Flex reagent cartridge (THEO, Catalog # K4071) lot 12135AE and/or 12171BB. Please complete the attached form and fax it to (302)631-8467 to indicate that you have received this information and to facilitate your additional no charge replacement. We ask that you forward this notification to anyone to whom you may have distributed this lot. If you have technical questions or concerns, please contact the Siemens Technical Solutions Center at 800-441-9250 for further assistance. For questions concerning the status of your no charge replacement order please contact your Siemens Customer Service Center at 888-588-3916. We apologize for the inconvenience that this situation has caused. Thank you for your patience and continued support.