N Latex IgM; In-vitro diagnostic reagent for the quantitative determination of IgM in human cerebrospinal fluid (CSF) and in paired CSF/serum samples by means of particle-enhanced immunonephelometry using the BN II and BN ProSpec Systems. The determination of IgM aids in the evaluation of the patient's immune system.

Complaints have been confirmed on failed proficiency testing due to serum samples recovering too low when using some N Latex IgM reagent kit lots 44018, 44019 and 44042.

The firm, Siemens, sent an "Urgent Medical Device Recall" letter dated January 2015 to its customers on January 13, 2015. The letter described the product, problem and actions to be taken. The customers were instructed to do the following: Discontinue use of the affected lots and discard any remaining material; Identify if IgM quotient was overestimated due to falsely low IgM results with serum sample; Reconsider patient diagnosis taking other patient data into consideration.; When other patient data does not support the result for an intrathecal IgM synthesis or inflammation, re-measurement of samples may be considered using and alternative lot. In addition, Siemens requested customers to review this letter with their Medical Director; to complete and return the attached Effectiveness Check/Product Replacement form via fax to Customer Care Center at (312) 275-7795; retain this letter with your laboratory records, and forward this letter to those who may have received this product. If you have any questions, please contact your Siemens Customer Care Center 800-441-9250 or email: [email protected] or your local Siemens technical support representative.