[Exploratory analysis of elevated C-reactive protein without leukocytosis from the clinical laboratory database]

We studied the characteristics of admitted patients who showed discrepancy between C-reactive protein(CRP) and white blood cell count(WBC). We extracted those patients from our laboratory information system by two criteria: WBC is less than 9500/microliter and either(1) CRP is more than 5.0 mg/dl, or(2) the pair of CRP and WBC is out of 95% confidence ellipse. We found 346 and 90 cases by the two criteria, respectively. They consisted of a variety of diseases, prevalent were such as pneumonia, rheumatoid arthritis, malignant lymphoma, post-operative state and so on by either criterion. There was predominance of elderly patients as a whole. The analysis of individual time courses revealed that WBC did not change in parallel with CRP in patients with rheumatoid arthritis and malignant lymphoma, while they paralleled in those with infectious diseases and post-operation states. The elevation of WBC in some patients might have been overlooked since WBC was not always to be ordered together with CRP. We need a prospective study to closely analyze serial relationship between CRP and WBC for factors leading to the discovery.