White blood cell counts in a geriatric hospitalized population: A poor diagnostic marker of infection

Introduction: Older people suffer more often and from more severe infections than do younger people. Several studies have shown a correlation between higher white blood cell count (WBCC) and the presence of infection. The usefulness of increased WBCC to assess the presence of infection in geriatric patients is debated. To answer this question, we investigated the correlation between the total and differential WBCC and documented infection in hospitalized geriatric individuals. Population and methods: Clinical data (medical history, comorbidities, treatments, geriatric syndromes) and biological parameters were collected from 166 hospitalized geriatric patients (67–106 yrs) presenting with acute inflammation (C-reactive protein (CRP) > 10 mg/l) and were compared according to the presence/absence of infection. Results: The mean WBCC was not significantly different (p = 0.71) according to the presence of infection or not, although the mean CRP level was higher in the infected group compared to the non-infected group (p = 0.0019). In regression analyses, the presence of infection was not associated with an increase in total and differential WBCC. Additionally, we found a positive correlation between cardiovascular risk factor and diseases (CVRF & diseases) and WBCC. Conclusion: In geriatric patients, WBCC is not a reliable biomarker for infection; however, combined with CRP, it represents a marker of cardiovascular disorders.