Validation of the cerebrospinal fluid module of the Siemens ADVIA® 2120i for automated cell counts of cerebrospinal fluid

Abstract

Background: Most haematology analysers routinely used for whole blood specimens are now equipped with cerebrospinal fluid (CSF) and/or body fluid modules. These automated cell counters are steadily replacing manual microscopy for CSF cell counts. This change in methodology is attributed to the automated counters’ higher throughput, improved turnaround times, superior precision and higher accuracy. This study aimed to evaluate the CSF module of the Siemens ADVIA® 2120i for CSF cell counts by comparing the results to manual microscopy counts. The ADVIA^® 2120i was also assessed for precision, linearity, accuracy and carryover.
Methods: In total, 46 routine CSF samples were analysed using the ADVIA® 2120i CSF module to obtain a red cell count (RCC), white cell count (WCC) and a four-part WCC differential. Results were compared with the mean of two CSF cell counts performed by manual microscopy using the Neubauer Improved Haemocytometer Counting Chamber. A quantitative method comparison was performed using EP Evaluator^® Release 8.0.0 and Microsoft Excel^®.
Results: The ADVIA^® 2120i met all the manufacturer’s claims in terms of precision and demonstrated acceptable accuracy for RCC, lymphocytes and polymorphonuclear (PMN) cell counts compared to the reference method. Linearity results indicated that the ADVIA^® 2120i produced results that were proportional after serial dilutions. All the parameters demonstrated acceptable carryover.
Conclusion: The ADVIA^® 2120i offers rapid, precise and accurate RCCs and WCCs for both normal and abnormal cell counts. Our results show that the ADVIA^® 2120i is a suitable alternative to manual microscopy for CSF cell counts and is regarded fit for purpose.