Clinical relevance and contemporary methods for counting blood cells in body fluids suspected of inflammatory disease

Abstract

Abstract:In many inflammatory diseases, the cellular components in body fluids [cerebrospinal fluid (CSF), serous fluids] are increased, rendering essential diagnostic information. The diagnostic value of the total white blood cell count (WBC) and differential count has been evaluated extensively over the years, and a remarkable amount of knowledge has been gained; yet, there is a great deal of clinical uncertainty whether the diagnosis should be based solely on these variables. In some diseases, such as peritonitis, the total WBC and differential count has high sensitivity; whereas, in differentiating pleural effusions, it lacks the sensitivity required to be clinically useful. Nevertheless, many guidelines consider these tests as cornerstone parameters, and in combination with clinical variables, they can successfully guide clinical decision making in initiating or postponing a treatment course for infection and/or inflammatory diseases while awaiting culture results. Although other methods are available for detecting and differentiating WBCs in body fluids, manual microscopy is still considered the gold standard despite its many limitations. During the last decade, automated analyzers have become a popular method for first line screening. Continued progress in their design has led to major improvements including their speed, improved accuracy and lower variability compared with microscopy. Disadvantages of this method include high imprecision in low ranges (depending on the method) and interfering factors.In a time where automation is at the front line in clinical laboratories, it is essential the results obtained are precise, accurate and reproducible. This review provides an overview of the relevance for cell counting in a variety of diagnostic body fluids, and highlights the current technologies used.

Evaluation of Mindray BC-6800 body fluid mode for automated cerebrospinal fluid cell counting

“…Total and differential cellular counts in cerebrospinal fluid (CSF) provide important diagnostic information in different pathological conditions of the central nervous system (CNS) [1][2][3][4][5][6][7].…”

Higher positive identification of malignant CSF cells using the cytocentrifuge than the Suta chamber

“…However, the percentage of positively identified malignant cells was higher by the cytocentrifuge method when the WBC count was normal and when it was greater than 200 cells/mm 3 . The majority of samples in this series had a CSF WBC count within the normal range (WBC < 5 cells mm 3 …”

“…There was no statistical difference between the two methods when analyzing CSF samples with a normal number of CSF WBCs (p = 0.17 or =1.5, 95%CI = 0.82-2.9; Table 2). The number of malignant CSF cells that were positively identified was higher in the samples with either a normal range of WBCs (< 5 cells/mm 3 ) or WBC count greater than 200 cells/mm 3 , with a statistical trend observed in the normal range ( Figure 2, Table 2). If the WBC count was greater than 200 cells/mm 3 , then the percentage of CSF neoplastic cells identified by the cytocentrifuge was 78% (7/9), whereas 50% (3/6) were identified by the Suta chamber.…”

“…The number of malignant CSF cells that were positively identified was higher in the samples with either a normal range of WBCs (< 5 cells/mm 3 ) or WBC count greater than 200 cells/mm 3 , with a statistical trend observed in the normal range ( Figure 2, Table 2). If the WBC count was greater than 200 cells/mm 3 , then the percentage of CSF neoplastic cells identified by the cytocentrifuge was 78% (7/9), whereas 50% (3/6) were identified by the Suta chamber. Thus, the probability of a clinical diagnosis of malignant CSF cells was 3.5-fold higher using the cytocentrifuge than that using the Suta chamber, although this difference was not significant ( Table 2).…”

“…Automated cell analyzers have been able to generate automated counts of cells present in CSF samples in recent years, although most cannot provide reliable counts of the low cell levels usually present in the CSF, including the normal WBC counts that are frequent in CNS malignant infiltration 8,25 . The disadvantages of this method include high imprecision in low ranges (depending on the method) and interfering factors, which reinforces the importance of traditional methods and the necessity of establishing the best concentration method 3 . Flow cytometry used in combination with conventional cytology can lead to a significant increase in the detection rate of leptomeningeal infiltration of malignant cells and is therefore of value in detecting these diseases 4,7,26,27 .…”