[Two diagnostic assays for serum procalcitonin measurement in clinical practice]

Procalcitonin (PCT) is a novel acute phase reactant useful in the diagnosis and monitoring of systemic bacterial infections. The aim of the study was to compare in clinical settings validity of two diagnostic methods for PCT determination. Serum PCT concentrations were measured by semiquantitative immunochromatographic test (PCT-Q) and immunoluminometric assay (ILMA)--LUMItest PCT in 192 serum samples. Results obtained by PCT-Q test were categorized into 4 groups: < 0.5 ng/ml (n = 118); 0.5-1.9 ng/ml (n = 35); 2.0-9.9 ng/ml (n = 16); IV > or = 10 ng/ml (n = 23); and compared with values measured by ILMA. In 130 cases (67.7%) measurements were identically categorized by both methods, in 56 samples (29.2%) results measured by ILMA were categorized within the next higher or lower category of the PCT-Q test and in 6 cases (3.1%) results were more aberrant.

Immunochromatographic PCT-Q test is useful for the rapid, semi-quantitative measurement of serum PCT concentration and can be used as a screening method in patients suspected of systemic bacterial infection. However the results of semi-quantitative test in comparison to ILMA method are not always identical. In doubtful cases, to get more accurate results and for the monitoring of treatment the ILMA method should be recommended.