CSL Behring GmbH

Negative bias for the carbohydrate-deficient transferrin (CDT) measurement in comparison to the HPLC method, observed to occur after 15 months based on shelf life monitoring

Siemens Healthcare Diagnostics has observed a negative bias for the carbohydrate-deficient transferrin (CDT) measurement when using the affected N Latex CDT lots in comparison to the HPLC method. CDT results in absolute concentrations may be influenced by patients transferrin levels and, therefore, results are reported as ratio of CDT to total transferrin, called %CDT. As the transferrin determination with N Antiserum to Human Transferrin is not affected, the observed effect leads to calculated %CDT values that show a negative bias of approximately 15% compared to the HPLC method. This could result in a shift of weak positive patient samples into the reference range of 1.19  2.47 %CDT which was derived from a study population of healthy adults. There are no control or calibrator materials that would catch this bias.

Siemens Healthcare Diagnostics has confirmed a negative bias of approximately -20% for results obtained with N Antiserum to Human Ceruloplasmin when calibrating Ceruloplasmin with various lots of N Protein Standard SL. N/T Protein Controls SL for Ceruloplasmin are similarly biased. --- The affected standards and controls for the affected lots were incorrectly value assigned, which led to a lower result compared to correctly assigned standards. Note: N Antiserum to Human Ceruloplasmin (REF OUIE) works as intended. --- Siemens investigation indicated that N Protein Standard SL and corresponding N/T Protein Control SL (Levels Low, Mid and High) are inaccurately assigned for Ceruloplasmin.

Siemens Healthcare Diagnostics has confirmed a negative bias of approximately -20% for results obtained with N Antiserum to Human Ceruloplasmin when calibrating Ceruloplasmin with various lots of N Protein Standard SL. N/T Protein Controls SL for Ceruloplasmin are similarly biased. --- The affected standards and controls for the affected lots were incorrectly value assigned, which led to a lower result compared to correctly assigned standards. Note: N Antiserum to Human Ceruloplasmin (REF OUIE) works as intended. --- Siemens investigation indicated that N Protein Standard SL and corresponding N/T Protein Control SL (Levels Low, Mid and High) are inaccurately assigned for Ceruloplasmin.

Reagent lots # 15243MA and 15243MB shows a reduced stability once opened that does not meet the Instructions For Use claim of seven (7) days. A maximum bias of -37% was observed.