N ANTISERUM TO HUMAN-IG/L-CHAIN, K TYPE

Additional Manufacturer Narrative

THE SIEMENS HEALTHCARE DIAGNOSTICS INC. (SIEMENS) HEADQUARTERS SUPPORT CENTER (HSC) ANALYZED DATA FILES TO DETERMINE THE CAUSE OF THE DISCORDANT LOW KAPU RESULT ON THE BN PROSPEC SYSTEM AND FOUND NO ISSUES. THE INITIAL PATIENT SAMPLE WAS RE-RUN ON THE BN PROSPEC SYSTEM AND A RESULT THAT MATCHED THE PATIENT'S CLINICAL PICTURE WAS OBTAINED. THE CAUSE OF THE EVENT IS UNKNOWN. IT IS POSSIBLE THAT THE DISCORDANT RESULT WAS CAUSED BY ANTIGEN EXCESS IN THE PATIENT SAMPLE. THE INSTRUCTIONS FOR USE (IFU) STATES THAT "URINE SPECIMENS WITH HIGHLY ELEVATED IMMUNOGLOBULIN/L-CHAIN CONCENTRATIONS MAY YIELD FALSE LOW RESULTS. IN SUCH SUSPECTED CASES, E.G. DUE TO THE CLINICAL FINDINGS OR OTHER LABORATORY DATA, IT IS RECOMMENDED THAT THE SAMPLE SHOULD BE RETESTED USING A HIGHER SAMPLE DILUTION." THE INSTRUMENT IS PERFORMING ACCORDING TO SPECIFICATIONS. NO FURTHER EVALUATION OF THIS DEVICE IS REQUIRED. THE REAGENT THAT IS MARKETED IN THE US IS A BULK IDENTICAL TO THE REAGENT DESCRIBED. THE REAGENT MARKETED IN THE US IS SMN: (B)(4) AND GTIN: (B)(4).

Description of Event or Problem

A DISCORDANT, FALSELY DEPRESSED N ANTISERUM TO HUMAN IG/L-CHAIN, K TYPE (KAPU) RESULT WAS OBTAINED ON A PATIENT SAMPLE ON THE BN PROSPEC SYSTEM. THE DISCORDANT RESULT WAS OBTAINED USING A 1:1 DILUTION AND RESULTED IN 38.6 MG/DL. THIS RESULT WAS REPORTED TO THE PHYSICIAN, WHO QUESTIONED THE RESULT. THE SAME PATIENT SAMPLE WAS RE-RUN AT A HIGHER DILUTION OF 1:5 AND THE RESULT RECOVERED >2,200 MG/L . THE BN PROSPEC SYSTEM INITIATED A THIRD MEASUREMENT WITH AN AUTO-DILUTION FACTOR OF 1:1 AND A RESULT OF 11,100 MG/L WAS OBTAINED. THE REPEATED RESULT OF 11,100 MG/L WAS REPORTED TO THE PHYSICIAN. QUALITY CONTROL WAS WITHIN THE NORMAL RANGES AND NO INSTRUMENT ERRORS WERE FOUND WITH THE BN PROSPEC SYSTEM DURING THE EVENT. THERE ARE NO KNOWN REPORTS OF PATIENT INTERVENTION OR ADVERSE HEALTH CONSEQUENCES DUE TO THE DISCORDANT, FALSELY DEPRESSED KAPU RESULT.