Complete blood count reference intervals and age- and sex-related trends of North China Han population

Defining common reference intervals (RIs) are encouraging. The aim of this study is to establish RIs for complete blood count (CBC) in a Chinese Han population and probe their age- and sex-related CBC trends. Additionally, we will compare the CBC RIs of Han with those of other races.

In total 1259 Han individuals (584 male and 675 female) were recruited in North China. CBC was processed on Sysmex XE-2100, Coulter LH750 and Mindray BC5800 whose traceability was well verified. The non-parametric 2.5th-97.5th percentiles RIs were calculated.

The RIs for CBC parameters did not show apparent analyzer-specificity, apart from mean cellular volume (MCV), mean platelet volume (MPV), plateletcrit (PCT) and platelet distribution width (PDW). Red blood cell (RBC), hemoglobin (HBG), hematocrit (HCT), mean cellular hemoglobin (MCH), and mean cellular hemoglobin concentration (MGHC) are higher in males; and their male mean values tend to drop after 40 years; conversely, the female mean values tend to rise. Platelet (PLT) is higher in females and tends to drop after 40 years in both sexes. White blood cell (WBC) and absolute count of neutrophils (NE) and monocytes (MO) are higher in males, but there is no apparent change with age. Lymphocytes (LY) absolute count declines with age in males, but the same change in females is not obvious. RIs for HBG and HCT are similar among Han, Nordic, US European and US Mexican populations and are lower in US Africans. WBC RIs for Han and US African populations are lower than that for US Europeans and US Mexicans.

RIs for major blood cell parameters are not method-dependent; variations obviously exist in age, sex and race. Consequently, common RIs for most CBC parameters appear inapplicable.