Sysmex Journal International

2005Vol.15 No.2


Automated Counting of White Blood Cells in Synovial Fluid


Robert de JONGE

Department of Clinical Chemistry, Erasmus MC, University Medical Centre Rotterdam


This presentation will describe the automated analysis of white blood cells in synovial fluid, research that was initiated by the Clinical Chemistry and Rheumatology Departments in the Erasmus University Medical Centre in Rotterdam, The Netherlands. The picture shows the routine blood counting section of the laboratory with an analytical line consisting of two SYSMEX XE-2100 fully automated blood cell analysers linked to an SP-100 slide preparation unit.

Synovial fluid analysis forms part of the routine work of the laboratory as an important step in the diagnosis and management of arthritis. The discrimination between noninflammatory and inflammatory forms of joint swelling is important and many parameters exist, which may differentiate between non-inflammatory and inflammatory joint effusions.

Schmerling and colleagues studied these parameters by means of Receiver Operator Characteristic ( ROC ) analysis to determine which tests were most useful.

ROC analysis characteristics show that the total leukocyte count and the percentage neutrophil count were the best discriminators between inflammatory and noninflammatory effusions. Chemistry analyses proved to be quite poor discriminators with the exception of lactic dehydrogenase which lay somewhere in the middle. Thus it is clearly demonstrated that synovial fluid cytology forms a vital step in the evaluation of a painful and swollen joint.


Synovial Fluid, Automated Haematology Analyser, XE-2100, Arthritis, Body Fluids


This article is re-printed from the “Proceedings of the Sysmex European Symposium 2003” pp.68-79.