Establishment of reference intervals for hematological parameters of adult population in the western region of Saudi Arabia

Abstract

Background Most of hematology laboratories in Saudi Arabia utilize the reference intervals (RIs) provided by instrument manufacturers. This study aimed to define RIs of hematological parameters for adult population in the western region of Saudi Arabia and to explore their specific features from an international perspective. Method This study was conducted according to the harmonized protocol of IFCC Committee on RIs and Decision Limits. Blood samples collected from 409 healthy Saudi males and females adults were analyzed for complete blood count (CBC) by using Cell-Dyn Sapphire analyzer and for iron profile by using Architect analyzers. The needs for RIs partitioned by sex and age was based on standard deviation ratio (SDR) and/or bias ratio (BR). RIs were derived parametrically with/without application of the latent abnormal values exclusion method (LAVE). Results Based on thresholds of SDR≥0.4 and/or BR≥0.57, RIs were partitioned by sex for red-blood cell count, hemoglobin, hematocrit, red cell distribution width, erythrocyte sedimentation rate, iron, transferrin, ferritin, eosinophil, platelet, plateletcrit, etc. Partitioning by age was not necessary for any of the analytes. LAVE procedure caused appreciable changes in RI limits for most erythrocyte and iron parameters but not for leukocyte parameters. Comparable to other non-IFCC studies on CBC RIs, the RBC and hematocrit (Ht) ranges have shifted to a higher side in both genders. After applying the LAVE method, the male and female RIs for Hb were 4.56 to 6.22 ×106/μL and 3.94 to 5.25 ×106/μL respectively while RIs for Ht were 40.2 to 52.0% and 33.6 to 44.5% respectively. Conclusion LAVE method contributed to reducing the influence of latent anemia in deriving RIs for erythrocyte related parameters. Using the up-to-date methods, the RIs of CBC determined specifically for Saudis will help to improve the interpretation of test results in medical decision making.

Establishment of reference interval for hemoglobin A1C and other hemoglobin subfractions for healthy Saudi adults

“…By the application of both approaches on A1C, the 90% CI of the RI limits became narrower in comparison to nonparametric method (NP) but the differences in the UL and LL were almost negligible ( S3 Table ) . The effect of both parametric and LAVE methods on clinical biochemistry [ 48 ], immunoassays [ 49 ], and hematological parameters [ 50 ]. were more effective in our previous studies.…”

“…The questionnaire includes information about lifestyle, recent infection, clinical history, genetic diseases, medication and/or supplements. Inclusion and exclusion criteria of the modified C-RIDL protocol were applied as previously described [ 50 ]. Twenty-eight subjects were specifically excluded: three for abnormal hemoglobin subfractions, two for sickle cell carrier, and 1 for leukemia.…”

“…For complete blood count (CBC) analysis, Cell-Dyn Sapphire Hematology automated analyzer from Abbott Diagnostic, USA was used. All data related to CBC analysis and outcomes were reported in our recently published article [ 50 ]. For uncovering subjects with latent diseases, uric acid (UA), low density lipoprotein- cholesterol (LDL-C), high density lipoprotein- cholesterol (HDL-C), triglycerides (TG), gamma-glutamyl transferase (GGT), alanine aminotransferase (ALT), glucose (GLU), insulin (INSUL) and insulin C-peptide (C-PEP) were measured in the aliquot of sera by chemistry and immunoassay auto-analyzers of Abbott Architect 16000c and 2000i as described in our previous studies [ 48 , 49 ].…”

“…Multiple regression analysis (MRA) was performed separately for each sex by setting the RVs of each analyte as an objective variable. As explanatory variables, the following four factors were set: age, BMI, Smoking, and Allergy, which were chosen as relevant in the previous RI study for hematological parameters [ 50 ]. The association between the objective and each of explanatory variables was expressed using partial correlation coefficient (rp) that gives values between −1.0 and 1.0.…”

“…The Committee on Reference Intervals and Decision Limits (C-RIDL) of the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) has initiated an international multicenter project to establish appropriate reference intervals (RIs) for each laboratory based on local healthy subjects [ 46 , 47 ]. Within the scope of this initiative, since 2014, we have started to derive Saudi-based RIs for clinical biochemistry [ 48 ], immunoassays [ 49 ], hematological parameters [ 50 ], and recently free light chains [ 51 ].…”