WBC and mortality

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Clin Nephrol. 2005 Jan;63(1):22-34.

A low lymphocyte percentage is a predictor of mortality and hospitalization in hemodialysis patients.Kuwae N, Kopple JD, Kalantar-Zadeh K.Division of Nephrology and Hypertension, Research and Education Institute, Harbor-UCLA Medical Center, Torrance, CA 90509-2910, USA.OBJECTIVES: Lymphocyte percentage (LYM%), an independently measured value to reflect peripheral lymphocyte count and a possible nutritional marker, may be related to clinical outcome in maintenance dialysis (MHD) patients. STUDY DESIGN AND SETTING: We examined the associations of the baseline white blood cell count (WBC) and LYM% with 12-month mortality and three measures of hospitalization in a cohort of 1,283 MHD patients from 10 outpatient DaVita dialysis clinics in Los Angeles County, as well as in a subcohort of 372 MHD patients with additional measures of inflammation, nutrition and comorbidity. Multi-variate and Poisson models that included 13 co-variates including case-mix features, dialysis dose, blood hemoglobin and serum albumin were explored. RESULTS: Patients, aged 57.8 +/- 15.2 years, included 49% men and 49% diabetics. Baseline WBC was 7,353 +/- 2.427 per microl, and LYM% was 21.2 +/- 7.3%. LYM% had significant correlations with "malnutrition-inflammation score" and inverse correlations with serum interleukin-6. The WBC and LYM% had significant but opposite predicting values for mortality and hospitalization, indicating that a high WBC and a low LYM% were each independently associated with increased mortality. After dividing each variable into four quartiles, only the highest WBC quartile (> or = 8,500) but not the other middle two quartiles, predicted increased mortality. However, all three lower quartiles of LYM% vs. the highest quartile (based on quartile cutoffs of 16%, 20.3% and 25.5%) were significantly and progressively associated with greater risks of mortality and hospitalizations. The absolute lymphocyte count (LYM% times WBC/100) exhibited somewhat similar trends but its outcome predictability was not as strong as LYM%. CONCLUSIONS: A high WBC and a low LYM% are associated with significant increase in mortality and hospitalization in MHD patients. Lymphocyte percentage, compared to absolute lymphocyte count, appears to be a better nutritional and anti-inflammatory marker and a more sensitive predictor of mortality and hospitalization in MHD patients.PMID: 15678693