ELECSYS ACTH

Additional Manufacturer Narrative

THE E411 ANALYZER SERIAL NUMBER WAS (B)(6). THE COMPETITOR METHOD WAS SIEMENS. THE SAMPLES WERE REQUESTED FOR INVESTIGATION.

Description of Event or Problem

THERE WAS AN ALLEGATION OF QUESTIONABLE LOW RESULTS FOR 2 PATIENT SAMPLES TESTED FOR ELECSYS ACTH (ACTH) ON A COBAS E 411 ANALYZER (DISK SYSTEM). PATIENT 2 INITIAL RESULT WAS <1.5 PG/ML. THE SAMPLE WAS REPEATED AND THE RESULT WAS "THE SAME." A NEW SAMPLE WAS OBTAINED AND THE RESULT WAS 80 PG/ML. PATIENT 3 INITIAL RESULT WAS <1.5 PG/ML ON THE E411 ANALYZER. A NEW SAMPLE WAS OBTAINED AND THE RESULT WAS 50 PG/ML ON THE E411 ANALYZER. THE NEW SAMPLE WAS REPEATED BY A COMPETITOR METHOD AND THE RESULT WAS 50 PG/ML. THE HIGHER RESULTS FOR EACH PATIENT WERE BELIEVED TO BE CORRECT.

Additional Manufacturer Narrative

CALIBRATION AND QC WERE ACCEPTABLE. THE PLASMA SAMPLES WERE PIPETTED IN A FALSE BOTTOM SECONDARY TUBE. THE SAMPLES WERE CENTRIFUGED FOR 5 MINUTES AT 3500 REVOLUTIONS PER MINUTE (RPM). NO FURTHER PREANALYTICAL DETAILS WERE PROVIDED. PRODUCT LABELING STATES: "K2- AND K3-EDTA PLASMA, COLLECTED USING SILICONIZED GLASS TUBES OR PLASTIC TUBES AS ACTH ADSORBS TO NON-SILICONIZED GLASS TUBES AND THEREBY REDUCES SAMPLE ACTH VALUES. DO NOT USE OTHER TYPES OF PLASMA SAMPLES. CRITERION FOR K2-EDTA PLASMA: SLOPE 0.85-1.15 FOR METHOD COMPARISON VS K3-EDTA PLASMA. ONLY USE PRE-COOLED SAMPLING VIALS. AFTER DRAWING THE BLOOD, PUT THE VIALS IMMEDIATELY ON ICE. USE A COOLED CENTRIFUGE TO SEPARATE THE PLASMA. MEASURE SAMPLES IMMEDIATELY OR FREEZE THEM AT -20 °C (± 5 °C). STABLE FOR 3 HOURS AT 2-8 °C FOLLOWED BY 2 HOURS AT 20-25 °C, 10 WEEKS AT -20 °C (± 5 °C). FREEZE ONLY ONCE.". THE SAMPLES IN QUESTION FOR BOTH PATIENTS WERE RECEIVED FOR INVESTIGATION. FOR PATIENT 2: THE CUSTOMER'S RESULT WAS REPRODUCED ON AN E411 ANALYZER AT THE INVESTIGATION SITE (<TEST). THE SAMPLE WAS SENT TO AN EXTERNAL LABORATORY USING THE SIEMENS METHOD AND THE RESULT WAS 168 PG/ML. FOR PATIENT 3: THE SAMPLE WAS NOT TESTED ON THE E411 ANALYZER AT THE INVESTIGATION SITE DUE TO LOW SAMPLE VOLUME. THE SAMPLE WAS SENT TO AN EXTERNAL LABORATORY USING THE SIEMENS METHOD AND THE RESULT WAS 201 PG/ML. AS THE SAMPLE MATERIAL FOR BOTH PATIENT SAMPLES WAS USED UP, NO FURTHER TESTING WAS POSSIBLE. BASED ON THE INVESTIGATION RESULTS AND THE LIMITED INFORMATION AVAILABLE, THE SPECIFIC ROOT CAUSE COULD NOT BE DETERMINED. THE CUSTOMER'S CALIBRATION AND QC DATA DO NOT SUGGEST A REAGENT ISSUE. THE INVESTIGATION DID NOT IDENTIFY A PRODUCT PROBLEM.